7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 137
Classification for cochleovestibular
malformations
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 237
bull The CT results were reviewed for malformations
of bony otic capsule under the following
subgroups
bull Cochlear malformations
bull Vestibular malformations
bull Semicircular canal malformations
bull Internal auditory canal (IAC) malformations
bull Vestibular and cochlear aqueduct malformations
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 337
Cochlear malformations were classified as
bull Michel deformity
bull Common cavity deformity
bull Cochlear aplasia
bull Hypoplastic cochlea
bull Incomplete partition types I (IP-I)
bull Incomplete partition types II (IP-II) (Mondinideformity)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 437
Incomplete partition
bull type I (cystic cochleovestibular malformation)is defined as a malformation in which the
cochlea lacks the entire modiolus andcribriform area resulting in a cysticappearance and there is an accompanyinglarge cystic vestibule
bull has an empty cystic cochlea and vestibulewithout an enlarged vestibular aqueduct
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 537
In IP-II
bull (the Mondini deformity) there is a cochlea
consisting of 15 turns (in which the middle
and apical turns coalesce to form a cystic
apex) accompanied by a dilated vestibule and
enlarged vestibular aqueduct
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 637
bull for clinical purposes to classify thesemalformations (in descending order of severity)as follows
1 Michel deformity2 cochlear aplasia
3 common cavity
4 IP-I (cystic cochleovestibular malformation)5 cochlear hypoplasia
6 IP-II (Mondini deformity)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 737
bull Failure of otic placode formation during the
third gestational week results in complete
labyrinthine aplasia (Michel anomaly Fig 1)
bull whereas insults occurring later (during the
seventh week) would only cause mild
abnormalities (IP-II or Mondini dysplasia)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 837
bull In 2002 Sennaroglu and Saatci roposed aclassification for cochleovestibular malformationsthat included in order of decreasing severity
bullLabyrinthine aplasia
bull Cochlear aplasia
bull Common cavity deformities
bull
Cystic cochleovestibular malformations (IP-I)bull cochleovestibular hypoplasia
bull IP-II
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 937
bull 3rd week complete labyrinthine aplasia (orMichel deformity)
bull 4th week common cavity to the cochlea and
vestibule bull 5th week cochlear aplasia
bull 6th week cochlear hypoplasia
bull 7th week incomplete partition anddilatational defects (including Mondinidysplasia)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1037
bull Michel deformity 6
bull Cochlear aplasia 5
bull Common cavity 8bull Cochlear hypoplasia 12
bull Incomplete Partition 41
bull IP-I (Cystic cochleovestibular malformation) 20
bull IP-II (Mondini deformity) 19bull IP-III (X-linked Deafness) 2
bull LVAS 15
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1137
Complete labyrinthine aplasia
bull Complete labyrinthine aplasia (CLA) also
referred to as Michel aplasia is a severe
congenital anomaly of the inner ear
bull Defined by the complete absence of inner ear
structures
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1237
bull
6 of the cochlear malformationsbull The most severe malformation
bull Either there is no response or profound
hearing loss at 125 250 and 500 Hz atmaximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1337
bull
CI contraindicatedbull Auditory Brainstem Implant (ABI) can be done
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1437
A Axial CT scan of the temporal bones of patient 1 shows bilateral absence of total inner ear
structures with aplasia of the otic capsules bilaterally
copy
B CT scan of patient 4 reveals unilateral CLA on the left with a type 1 incomplete cochlear
partition on the right The petrous bone and the otic capsule are hypoplastic on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1537
A Flattening of the cochlear promontory (arrow) in CLA B Normal appearance of the
cochlear promontory (arrow) and inner ear in a healthy patient
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1637
Coronal reformatted image of a patient with unilateral (left-sided) CLA reveals severe
narrowing of the IAC on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1737
Case 1
bull 9-year-old girl with profound bilateral
congenital sensorineural hearing loss
bull A Axial CT scan shows right petrous bone
aplasia with absence of inner ear structures
The medial wall of the middle ear is flattened
(arrow) being in close contact with theinfratentorial nervous structures Note normal
differentiation of the malleus
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1837
bull Coronal CT scan shows a normallydeveloped external and middle right earThe long process of the incus (arrow)
leans against the medial middle ear wallThe oval window the stapes and thesecond portion of the facial nerve areabsent A small dehiscence of the medial
wall of the middle ear (arrowhead) locatedat the IAM probably corresponds to theentrance of the facial nerve
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1937
Case 1 9-year-old girl with profound bilateral congenital sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 237
bull The CT results were reviewed for malformations
of bony otic capsule under the following
subgroups
bull Cochlear malformations
bull Vestibular malformations
bull Semicircular canal malformations
bull Internal auditory canal (IAC) malformations
bull Vestibular and cochlear aqueduct malformations
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 337
Cochlear malformations were classified as
bull Michel deformity
bull Common cavity deformity
bull Cochlear aplasia
bull Hypoplastic cochlea
bull Incomplete partition types I (IP-I)
bull Incomplete partition types II (IP-II) (Mondinideformity)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 437
Incomplete partition
bull type I (cystic cochleovestibular malformation)is defined as a malformation in which the
cochlea lacks the entire modiolus andcribriform area resulting in a cysticappearance and there is an accompanyinglarge cystic vestibule
bull has an empty cystic cochlea and vestibulewithout an enlarged vestibular aqueduct
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 537
In IP-II
bull (the Mondini deformity) there is a cochlea
consisting of 15 turns (in which the middle
and apical turns coalesce to form a cystic
apex) accompanied by a dilated vestibule and
enlarged vestibular aqueduct
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 637
bull for clinical purposes to classify thesemalformations (in descending order of severity)as follows
1 Michel deformity2 cochlear aplasia
3 common cavity
4 IP-I (cystic cochleovestibular malformation)5 cochlear hypoplasia
6 IP-II (Mondini deformity)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 737
bull Failure of otic placode formation during the
third gestational week results in complete
labyrinthine aplasia (Michel anomaly Fig 1)
bull whereas insults occurring later (during the
seventh week) would only cause mild
abnormalities (IP-II or Mondini dysplasia)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 837
bull In 2002 Sennaroglu and Saatci roposed aclassification for cochleovestibular malformationsthat included in order of decreasing severity
bullLabyrinthine aplasia
bull Cochlear aplasia
bull Common cavity deformities
bull
Cystic cochleovestibular malformations (IP-I)bull cochleovestibular hypoplasia
bull IP-II
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 937
bull 3rd week complete labyrinthine aplasia (orMichel deformity)
bull 4th week common cavity to the cochlea and
vestibule bull 5th week cochlear aplasia
bull 6th week cochlear hypoplasia
bull 7th week incomplete partition anddilatational defects (including Mondinidysplasia)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1037
bull Michel deformity 6
bull Cochlear aplasia 5
bull Common cavity 8bull Cochlear hypoplasia 12
bull Incomplete Partition 41
bull IP-I (Cystic cochleovestibular malformation) 20
bull IP-II (Mondini deformity) 19bull IP-III (X-linked Deafness) 2
bull LVAS 15
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1137
Complete labyrinthine aplasia
bull Complete labyrinthine aplasia (CLA) also
referred to as Michel aplasia is a severe
congenital anomaly of the inner ear
bull Defined by the complete absence of inner ear
structures
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1237
bull
6 of the cochlear malformationsbull The most severe malformation
bull Either there is no response or profound
hearing loss at 125 250 and 500 Hz atmaximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1337
bull
CI contraindicatedbull Auditory Brainstem Implant (ABI) can be done
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1437
A Axial CT scan of the temporal bones of patient 1 shows bilateral absence of total inner ear
structures with aplasia of the otic capsules bilaterally
copy
B CT scan of patient 4 reveals unilateral CLA on the left with a type 1 incomplete cochlear
partition on the right The petrous bone and the otic capsule are hypoplastic on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1537
A Flattening of the cochlear promontory (arrow) in CLA B Normal appearance of the
cochlear promontory (arrow) and inner ear in a healthy patient
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1637
Coronal reformatted image of a patient with unilateral (left-sided) CLA reveals severe
narrowing of the IAC on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1737
Case 1
bull 9-year-old girl with profound bilateral
congenital sensorineural hearing loss
bull A Axial CT scan shows right petrous bone
aplasia with absence of inner ear structures
The medial wall of the middle ear is flattened
(arrow) being in close contact with theinfratentorial nervous structures Note normal
differentiation of the malleus
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1837
bull Coronal CT scan shows a normallydeveloped external and middle right earThe long process of the incus (arrow)
leans against the medial middle ear wallThe oval window the stapes and thesecond portion of the facial nerve areabsent A small dehiscence of the medial
wall of the middle ear (arrowhead) locatedat the IAM probably corresponds to theentrance of the facial nerve
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1937
Case 1 9-year-old girl with profound bilateral congenital sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 337
Cochlear malformations were classified as
bull Michel deformity
bull Common cavity deformity
bull Cochlear aplasia
bull Hypoplastic cochlea
bull Incomplete partition types I (IP-I)
bull Incomplete partition types II (IP-II) (Mondinideformity)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 437
Incomplete partition
bull type I (cystic cochleovestibular malformation)is defined as a malformation in which the
cochlea lacks the entire modiolus andcribriform area resulting in a cysticappearance and there is an accompanyinglarge cystic vestibule
bull has an empty cystic cochlea and vestibulewithout an enlarged vestibular aqueduct
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 537
In IP-II
bull (the Mondini deformity) there is a cochlea
consisting of 15 turns (in which the middle
and apical turns coalesce to form a cystic
apex) accompanied by a dilated vestibule and
enlarged vestibular aqueduct
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 637
bull for clinical purposes to classify thesemalformations (in descending order of severity)as follows
1 Michel deformity2 cochlear aplasia
3 common cavity
4 IP-I (cystic cochleovestibular malformation)5 cochlear hypoplasia
6 IP-II (Mondini deformity)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 737
bull Failure of otic placode formation during the
third gestational week results in complete
labyrinthine aplasia (Michel anomaly Fig 1)
bull whereas insults occurring later (during the
seventh week) would only cause mild
abnormalities (IP-II or Mondini dysplasia)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 837
bull In 2002 Sennaroglu and Saatci roposed aclassification for cochleovestibular malformationsthat included in order of decreasing severity
bullLabyrinthine aplasia
bull Cochlear aplasia
bull Common cavity deformities
bull
Cystic cochleovestibular malformations (IP-I)bull cochleovestibular hypoplasia
bull IP-II
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 937
bull 3rd week complete labyrinthine aplasia (orMichel deformity)
bull 4th week common cavity to the cochlea and
vestibule bull 5th week cochlear aplasia
bull 6th week cochlear hypoplasia
bull 7th week incomplete partition anddilatational defects (including Mondinidysplasia)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1037
bull Michel deformity 6
bull Cochlear aplasia 5
bull Common cavity 8bull Cochlear hypoplasia 12
bull Incomplete Partition 41
bull IP-I (Cystic cochleovestibular malformation) 20
bull IP-II (Mondini deformity) 19bull IP-III (X-linked Deafness) 2
bull LVAS 15
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1137
Complete labyrinthine aplasia
bull Complete labyrinthine aplasia (CLA) also
referred to as Michel aplasia is a severe
congenital anomaly of the inner ear
bull Defined by the complete absence of inner ear
structures
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1237
bull
6 of the cochlear malformationsbull The most severe malformation
bull Either there is no response or profound
hearing loss at 125 250 and 500 Hz atmaximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1337
bull
CI contraindicatedbull Auditory Brainstem Implant (ABI) can be done
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1437
A Axial CT scan of the temporal bones of patient 1 shows bilateral absence of total inner ear
structures with aplasia of the otic capsules bilaterally
copy
B CT scan of patient 4 reveals unilateral CLA on the left with a type 1 incomplete cochlear
partition on the right The petrous bone and the otic capsule are hypoplastic on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1537
A Flattening of the cochlear promontory (arrow) in CLA B Normal appearance of the
cochlear promontory (arrow) and inner ear in a healthy patient
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1637
Coronal reformatted image of a patient with unilateral (left-sided) CLA reveals severe
narrowing of the IAC on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1737
Case 1
bull 9-year-old girl with profound bilateral
congenital sensorineural hearing loss
bull A Axial CT scan shows right petrous bone
aplasia with absence of inner ear structures
The medial wall of the middle ear is flattened
(arrow) being in close contact with theinfratentorial nervous structures Note normal
differentiation of the malleus
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1837
bull Coronal CT scan shows a normallydeveloped external and middle right earThe long process of the incus (arrow)
leans against the medial middle ear wallThe oval window the stapes and thesecond portion of the facial nerve areabsent A small dehiscence of the medial
wall of the middle ear (arrowhead) locatedat the IAM probably corresponds to theentrance of the facial nerve
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1937
Case 1 9-year-old girl with profound bilateral congenital sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 437
Incomplete partition
bull type I (cystic cochleovestibular malformation)is defined as a malformation in which the
cochlea lacks the entire modiolus andcribriform area resulting in a cysticappearance and there is an accompanyinglarge cystic vestibule
bull has an empty cystic cochlea and vestibulewithout an enlarged vestibular aqueduct
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 537
In IP-II
bull (the Mondini deformity) there is a cochlea
consisting of 15 turns (in which the middle
and apical turns coalesce to form a cystic
apex) accompanied by a dilated vestibule and
enlarged vestibular aqueduct
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 637
bull for clinical purposes to classify thesemalformations (in descending order of severity)as follows
1 Michel deformity2 cochlear aplasia
3 common cavity
4 IP-I (cystic cochleovestibular malformation)5 cochlear hypoplasia
6 IP-II (Mondini deformity)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 737
bull Failure of otic placode formation during the
third gestational week results in complete
labyrinthine aplasia (Michel anomaly Fig 1)
bull whereas insults occurring later (during the
seventh week) would only cause mild
abnormalities (IP-II or Mondini dysplasia)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 837
bull In 2002 Sennaroglu and Saatci roposed aclassification for cochleovestibular malformationsthat included in order of decreasing severity
bullLabyrinthine aplasia
bull Cochlear aplasia
bull Common cavity deformities
bull
Cystic cochleovestibular malformations (IP-I)bull cochleovestibular hypoplasia
bull IP-II
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 937
bull 3rd week complete labyrinthine aplasia (orMichel deformity)
bull 4th week common cavity to the cochlea and
vestibule bull 5th week cochlear aplasia
bull 6th week cochlear hypoplasia
bull 7th week incomplete partition anddilatational defects (including Mondinidysplasia)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1037
bull Michel deformity 6
bull Cochlear aplasia 5
bull Common cavity 8bull Cochlear hypoplasia 12
bull Incomplete Partition 41
bull IP-I (Cystic cochleovestibular malformation) 20
bull IP-II (Mondini deformity) 19bull IP-III (X-linked Deafness) 2
bull LVAS 15
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1137
Complete labyrinthine aplasia
bull Complete labyrinthine aplasia (CLA) also
referred to as Michel aplasia is a severe
congenital anomaly of the inner ear
bull Defined by the complete absence of inner ear
structures
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1237
bull
6 of the cochlear malformationsbull The most severe malformation
bull Either there is no response or profound
hearing loss at 125 250 and 500 Hz atmaximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1337
bull
CI contraindicatedbull Auditory Brainstem Implant (ABI) can be done
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1437
A Axial CT scan of the temporal bones of patient 1 shows bilateral absence of total inner ear
structures with aplasia of the otic capsules bilaterally
copy
B CT scan of patient 4 reveals unilateral CLA on the left with a type 1 incomplete cochlear
partition on the right The petrous bone and the otic capsule are hypoplastic on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1537
A Flattening of the cochlear promontory (arrow) in CLA B Normal appearance of the
cochlear promontory (arrow) and inner ear in a healthy patient
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1637
Coronal reformatted image of a patient with unilateral (left-sided) CLA reveals severe
narrowing of the IAC on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1737
Case 1
bull 9-year-old girl with profound bilateral
congenital sensorineural hearing loss
bull A Axial CT scan shows right petrous bone
aplasia with absence of inner ear structures
The medial wall of the middle ear is flattened
(arrow) being in close contact with theinfratentorial nervous structures Note normal
differentiation of the malleus
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1837
bull Coronal CT scan shows a normallydeveloped external and middle right earThe long process of the incus (arrow)
leans against the medial middle ear wallThe oval window the stapes and thesecond portion of the facial nerve areabsent A small dehiscence of the medial
wall of the middle ear (arrowhead) locatedat the IAM probably corresponds to theentrance of the facial nerve
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1937
Case 1 9-year-old girl with profound bilateral congenital sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 537
In IP-II
bull (the Mondini deformity) there is a cochlea
consisting of 15 turns (in which the middle
and apical turns coalesce to form a cystic
apex) accompanied by a dilated vestibule and
enlarged vestibular aqueduct
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 637
bull for clinical purposes to classify thesemalformations (in descending order of severity)as follows
1 Michel deformity2 cochlear aplasia
3 common cavity
4 IP-I (cystic cochleovestibular malformation)5 cochlear hypoplasia
6 IP-II (Mondini deformity)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 737
bull Failure of otic placode formation during the
third gestational week results in complete
labyrinthine aplasia (Michel anomaly Fig 1)
bull whereas insults occurring later (during the
seventh week) would only cause mild
abnormalities (IP-II or Mondini dysplasia)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 837
bull In 2002 Sennaroglu and Saatci roposed aclassification for cochleovestibular malformationsthat included in order of decreasing severity
bullLabyrinthine aplasia
bull Cochlear aplasia
bull Common cavity deformities
bull
Cystic cochleovestibular malformations (IP-I)bull cochleovestibular hypoplasia
bull IP-II
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 937
bull 3rd week complete labyrinthine aplasia (orMichel deformity)
bull 4th week common cavity to the cochlea and
vestibule bull 5th week cochlear aplasia
bull 6th week cochlear hypoplasia
bull 7th week incomplete partition anddilatational defects (including Mondinidysplasia)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1037
bull Michel deformity 6
bull Cochlear aplasia 5
bull Common cavity 8bull Cochlear hypoplasia 12
bull Incomplete Partition 41
bull IP-I (Cystic cochleovestibular malformation) 20
bull IP-II (Mondini deformity) 19bull IP-III (X-linked Deafness) 2
bull LVAS 15
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1137
Complete labyrinthine aplasia
bull Complete labyrinthine aplasia (CLA) also
referred to as Michel aplasia is a severe
congenital anomaly of the inner ear
bull Defined by the complete absence of inner ear
structures
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1237
bull
6 of the cochlear malformationsbull The most severe malformation
bull Either there is no response or profound
hearing loss at 125 250 and 500 Hz atmaximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1337
bull
CI contraindicatedbull Auditory Brainstem Implant (ABI) can be done
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1437
A Axial CT scan of the temporal bones of patient 1 shows bilateral absence of total inner ear
structures with aplasia of the otic capsules bilaterally
copy
B CT scan of patient 4 reveals unilateral CLA on the left with a type 1 incomplete cochlear
partition on the right The petrous bone and the otic capsule are hypoplastic on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1537
A Flattening of the cochlear promontory (arrow) in CLA B Normal appearance of the
cochlear promontory (arrow) and inner ear in a healthy patient
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1637
Coronal reformatted image of a patient with unilateral (left-sided) CLA reveals severe
narrowing of the IAC on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1737
Case 1
bull 9-year-old girl with profound bilateral
congenital sensorineural hearing loss
bull A Axial CT scan shows right petrous bone
aplasia with absence of inner ear structures
The medial wall of the middle ear is flattened
(arrow) being in close contact with theinfratentorial nervous structures Note normal
differentiation of the malleus
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1837
bull Coronal CT scan shows a normallydeveloped external and middle right earThe long process of the incus (arrow)
leans against the medial middle ear wallThe oval window the stapes and thesecond portion of the facial nerve areabsent A small dehiscence of the medial
wall of the middle ear (arrowhead) locatedat the IAM probably corresponds to theentrance of the facial nerve
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1937
Case 1 9-year-old girl with profound bilateral congenital sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 637
bull for clinical purposes to classify thesemalformations (in descending order of severity)as follows
1 Michel deformity2 cochlear aplasia
3 common cavity
4 IP-I (cystic cochleovestibular malformation)5 cochlear hypoplasia
6 IP-II (Mondini deformity)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 737
bull Failure of otic placode formation during the
third gestational week results in complete
labyrinthine aplasia (Michel anomaly Fig 1)
bull whereas insults occurring later (during the
seventh week) would only cause mild
abnormalities (IP-II or Mondini dysplasia)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 837
bull In 2002 Sennaroglu and Saatci roposed aclassification for cochleovestibular malformationsthat included in order of decreasing severity
bullLabyrinthine aplasia
bull Cochlear aplasia
bull Common cavity deformities
bull
Cystic cochleovestibular malformations (IP-I)bull cochleovestibular hypoplasia
bull IP-II
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 937
bull 3rd week complete labyrinthine aplasia (orMichel deformity)
bull 4th week common cavity to the cochlea and
vestibule bull 5th week cochlear aplasia
bull 6th week cochlear hypoplasia
bull 7th week incomplete partition anddilatational defects (including Mondinidysplasia)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1037
bull Michel deformity 6
bull Cochlear aplasia 5
bull Common cavity 8bull Cochlear hypoplasia 12
bull Incomplete Partition 41
bull IP-I (Cystic cochleovestibular malformation) 20
bull IP-II (Mondini deformity) 19bull IP-III (X-linked Deafness) 2
bull LVAS 15
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1137
Complete labyrinthine aplasia
bull Complete labyrinthine aplasia (CLA) also
referred to as Michel aplasia is a severe
congenital anomaly of the inner ear
bull Defined by the complete absence of inner ear
structures
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1237
bull
6 of the cochlear malformationsbull The most severe malformation
bull Either there is no response or profound
hearing loss at 125 250 and 500 Hz atmaximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1337
bull
CI contraindicatedbull Auditory Brainstem Implant (ABI) can be done
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1437
A Axial CT scan of the temporal bones of patient 1 shows bilateral absence of total inner ear
structures with aplasia of the otic capsules bilaterally
copy
B CT scan of patient 4 reveals unilateral CLA on the left with a type 1 incomplete cochlear
partition on the right The petrous bone and the otic capsule are hypoplastic on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1537
A Flattening of the cochlear promontory (arrow) in CLA B Normal appearance of the
cochlear promontory (arrow) and inner ear in a healthy patient
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1637
Coronal reformatted image of a patient with unilateral (left-sided) CLA reveals severe
narrowing of the IAC on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1737
Case 1
bull 9-year-old girl with profound bilateral
congenital sensorineural hearing loss
bull A Axial CT scan shows right petrous bone
aplasia with absence of inner ear structures
The medial wall of the middle ear is flattened
(arrow) being in close contact with theinfratentorial nervous structures Note normal
differentiation of the malleus
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1837
bull Coronal CT scan shows a normallydeveloped external and middle right earThe long process of the incus (arrow)
leans against the medial middle ear wallThe oval window the stapes and thesecond portion of the facial nerve areabsent A small dehiscence of the medial
wall of the middle ear (arrowhead) locatedat the IAM probably corresponds to theentrance of the facial nerve
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1937
Case 1 9-year-old girl with profound bilateral congenital sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 737
bull Failure of otic placode formation during the
third gestational week results in complete
labyrinthine aplasia (Michel anomaly Fig 1)
bull whereas insults occurring later (during the
seventh week) would only cause mild
abnormalities (IP-II or Mondini dysplasia)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 837
bull In 2002 Sennaroglu and Saatci roposed aclassification for cochleovestibular malformationsthat included in order of decreasing severity
bullLabyrinthine aplasia
bull Cochlear aplasia
bull Common cavity deformities
bull
Cystic cochleovestibular malformations (IP-I)bull cochleovestibular hypoplasia
bull IP-II
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 937
bull 3rd week complete labyrinthine aplasia (orMichel deformity)
bull 4th week common cavity to the cochlea and
vestibule bull 5th week cochlear aplasia
bull 6th week cochlear hypoplasia
bull 7th week incomplete partition anddilatational defects (including Mondinidysplasia)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1037
bull Michel deformity 6
bull Cochlear aplasia 5
bull Common cavity 8bull Cochlear hypoplasia 12
bull Incomplete Partition 41
bull IP-I (Cystic cochleovestibular malformation) 20
bull IP-II (Mondini deformity) 19bull IP-III (X-linked Deafness) 2
bull LVAS 15
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1137
Complete labyrinthine aplasia
bull Complete labyrinthine aplasia (CLA) also
referred to as Michel aplasia is a severe
congenital anomaly of the inner ear
bull Defined by the complete absence of inner ear
structures
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1237
bull
6 of the cochlear malformationsbull The most severe malformation
bull Either there is no response or profound
hearing loss at 125 250 and 500 Hz atmaximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1337
bull
CI contraindicatedbull Auditory Brainstem Implant (ABI) can be done
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1437
A Axial CT scan of the temporal bones of patient 1 shows bilateral absence of total inner ear
structures with aplasia of the otic capsules bilaterally
copy
B CT scan of patient 4 reveals unilateral CLA on the left with a type 1 incomplete cochlear
partition on the right The petrous bone and the otic capsule are hypoplastic on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1537
A Flattening of the cochlear promontory (arrow) in CLA B Normal appearance of the
cochlear promontory (arrow) and inner ear in a healthy patient
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1637
Coronal reformatted image of a patient with unilateral (left-sided) CLA reveals severe
narrowing of the IAC on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1737
Case 1
bull 9-year-old girl with profound bilateral
congenital sensorineural hearing loss
bull A Axial CT scan shows right petrous bone
aplasia with absence of inner ear structures
The medial wall of the middle ear is flattened
(arrow) being in close contact with theinfratentorial nervous structures Note normal
differentiation of the malleus
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1837
bull Coronal CT scan shows a normallydeveloped external and middle right earThe long process of the incus (arrow)
leans against the medial middle ear wallThe oval window the stapes and thesecond portion of the facial nerve areabsent A small dehiscence of the medial
wall of the middle ear (arrowhead) locatedat the IAM probably corresponds to theentrance of the facial nerve
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1937
Case 1 9-year-old girl with profound bilateral congenital sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 837
bull In 2002 Sennaroglu and Saatci roposed aclassification for cochleovestibular malformationsthat included in order of decreasing severity
bullLabyrinthine aplasia
bull Cochlear aplasia
bull Common cavity deformities
bull
Cystic cochleovestibular malformations (IP-I)bull cochleovestibular hypoplasia
bull IP-II
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 937
bull 3rd week complete labyrinthine aplasia (orMichel deformity)
bull 4th week common cavity to the cochlea and
vestibule bull 5th week cochlear aplasia
bull 6th week cochlear hypoplasia
bull 7th week incomplete partition anddilatational defects (including Mondinidysplasia)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1037
bull Michel deformity 6
bull Cochlear aplasia 5
bull Common cavity 8bull Cochlear hypoplasia 12
bull Incomplete Partition 41
bull IP-I (Cystic cochleovestibular malformation) 20
bull IP-II (Mondini deformity) 19bull IP-III (X-linked Deafness) 2
bull LVAS 15
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1137
Complete labyrinthine aplasia
bull Complete labyrinthine aplasia (CLA) also
referred to as Michel aplasia is a severe
congenital anomaly of the inner ear
bull Defined by the complete absence of inner ear
structures
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1237
bull
6 of the cochlear malformationsbull The most severe malformation
bull Either there is no response or profound
hearing loss at 125 250 and 500 Hz atmaximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1337
bull
CI contraindicatedbull Auditory Brainstem Implant (ABI) can be done
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1437
A Axial CT scan of the temporal bones of patient 1 shows bilateral absence of total inner ear
structures with aplasia of the otic capsules bilaterally
copy
B CT scan of patient 4 reveals unilateral CLA on the left with a type 1 incomplete cochlear
partition on the right The petrous bone and the otic capsule are hypoplastic on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1537
A Flattening of the cochlear promontory (arrow) in CLA B Normal appearance of the
cochlear promontory (arrow) and inner ear in a healthy patient
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1637
Coronal reformatted image of a patient with unilateral (left-sided) CLA reveals severe
narrowing of the IAC on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1737
Case 1
bull 9-year-old girl with profound bilateral
congenital sensorineural hearing loss
bull A Axial CT scan shows right petrous bone
aplasia with absence of inner ear structures
The medial wall of the middle ear is flattened
(arrow) being in close contact with theinfratentorial nervous structures Note normal
differentiation of the malleus
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1837
bull Coronal CT scan shows a normallydeveloped external and middle right earThe long process of the incus (arrow)
leans against the medial middle ear wallThe oval window the stapes and thesecond portion of the facial nerve areabsent A small dehiscence of the medial
wall of the middle ear (arrowhead) locatedat the IAM probably corresponds to theentrance of the facial nerve
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1937
Case 1 9-year-old girl with profound bilateral congenital sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 937
bull 3rd week complete labyrinthine aplasia (orMichel deformity)
bull 4th week common cavity to the cochlea and
vestibule bull 5th week cochlear aplasia
bull 6th week cochlear hypoplasia
bull 7th week incomplete partition anddilatational defects (including Mondinidysplasia)
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1037
bull Michel deformity 6
bull Cochlear aplasia 5
bull Common cavity 8bull Cochlear hypoplasia 12
bull Incomplete Partition 41
bull IP-I (Cystic cochleovestibular malformation) 20
bull IP-II (Mondini deformity) 19bull IP-III (X-linked Deafness) 2
bull LVAS 15
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1137
Complete labyrinthine aplasia
bull Complete labyrinthine aplasia (CLA) also
referred to as Michel aplasia is a severe
congenital anomaly of the inner ear
bull Defined by the complete absence of inner ear
structures
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1237
bull
6 of the cochlear malformationsbull The most severe malformation
bull Either there is no response or profound
hearing loss at 125 250 and 500 Hz atmaximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1337
bull
CI contraindicatedbull Auditory Brainstem Implant (ABI) can be done
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1437
A Axial CT scan of the temporal bones of patient 1 shows bilateral absence of total inner ear
structures with aplasia of the otic capsules bilaterally
copy
B CT scan of patient 4 reveals unilateral CLA on the left with a type 1 incomplete cochlear
partition on the right The petrous bone and the otic capsule are hypoplastic on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1537
A Flattening of the cochlear promontory (arrow) in CLA B Normal appearance of the
cochlear promontory (arrow) and inner ear in a healthy patient
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1637
Coronal reformatted image of a patient with unilateral (left-sided) CLA reveals severe
narrowing of the IAC on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1737
Case 1
bull 9-year-old girl with profound bilateral
congenital sensorineural hearing loss
bull A Axial CT scan shows right petrous bone
aplasia with absence of inner ear structures
The medial wall of the middle ear is flattened
(arrow) being in close contact with theinfratentorial nervous structures Note normal
differentiation of the malleus
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1837
bull Coronal CT scan shows a normallydeveloped external and middle right earThe long process of the incus (arrow)
leans against the medial middle ear wallThe oval window the stapes and thesecond portion of the facial nerve areabsent A small dehiscence of the medial
wall of the middle ear (arrowhead) locatedat the IAM probably corresponds to theentrance of the facial nerve
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1937
Case 1 9-year-old girl with profound bilateral congenital sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1037
bull Michel deformity 6
bull Cochlear aplasia 5
bull Common cavity 8bull Cochlear hypoplasia 12
bull Incomplete Partition 41
bull IP-I (Cystic cochleovestibular malformation) 20
bull IP-II (Mondini deformity) 19bull IP-III (X-linked Deafness) 2
bull LVAS 15
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1137
Complete labyrinthine aplasia
bull Complete labyrinthine aplasia (CLA) also
referred to as Michel aplasia is a severe
congenital anomaly of the inner ear
bull Defined by the complete absence of inner ear
structures
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1237
bull
6 of the cochlear malformationsbull The most severe malformation
bull Either there is no response or profound
hearing loss at 125 250 and 500 Hz atmaximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1337
bull
CI contraindicatedbull Auditory Brainstem Implant (ABI) can be done
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1437
A Axial CT scan of the temporal bones of patient 1 shows bilateral absence of total inner ear
structures with aplasia of the otic capsules bilaterally
copy
B CT scan of patient 4 reveals unilateral CLA on the left with a type 1 incomplete cochlear
partition on the right The petrous bone and the otic capsule are hypoplastic on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1537
A Flattening of the cochlear promontory (arrow) in CLA B Normal appearance of the
cochlear promontory (arrow) and inner ear in a healthy patient
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1637
Coronal reformatted image of a patient with unilateral (left-sided) CLA reveals severe
narrowing of the IAC on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1737
Case 1
bull 9-year-old girl with profound bilateral
congenital sensorineural hearing loss
bull A Axial CT scan shows right petrous bone
aplasia with absence of inner ear structures
The medial wall of the middle ear is flattened
(arrow) being in close contact with theinfratentorial nervous structures Note normal
differentiation of the malleus
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1837
bull Coronal CT scan shows a normallydeveloped external and middle right earThe long process of the incus (arrow)
leans against the medial middle ear wallThe oval window the stapes and thesecond portion of the facial nerve areabsent A small dehiscence of the medial
wall of the middle ear (arrowhead) locatedat the IAM probably corresponds to theentrance of the facial nerve
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1937
Case 1 9-year-old girl with profound bilateral congenital sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1137
Complete labyrinthine aplasia
bull Complete labyrinthine aplasia (CLA) also
referred to as Michel aplasia is a severe
congenital anomaly of the inner ear
bull Defined by the complete absence of inner ear
structures
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1237
bull
6 of the cochlear malformationsbull The most severe malformation
bull Either there is no response or profound
hearing loss at 125 250 and 500 Hz atmaximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1337
bull
CI contraindicatedbull Auditory Brainstem Implant (ABI) can be done
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1437
A Axial CT scan of the temporal bones of patient 1 shows bilateral absence of total inner ear
structures with aplasia of the otic capsules bilaterally
copy
B CT scan of patient 4 reveals unilateral CLA on the left with a type 1 incomplete cochlear
partition on the right The petrous bone and the otic capsule are hypoplastic on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1537
A Flattening of the cochlear promontory (arrow) in CLA B Normal appearance of the
cochlear promontory (arrow) and inner ear in a healthy patient
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1637
Coronal reformatted image of a patient with unilateral (left-sided) CLA reveals severe
narrowing of the IAC on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1737
Case 1
bull 9-year-old girl with profound bilateral
congenital sensorineural hearing loss
bull A Axial CT scan shows right petrous bone
aplasia with absence of inner ear structures
The medial wall of the middle ear is flattened
(arrow) being in close contact with theinfratentorial nervous structures Note normal
differentiation of the malleus
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1837
bull Coronal CT scan shows a normallydeveloped external and middle right earThe long process of the incus (arrow)
leans against the medial middle ear wallThe oval window the stapes and thesecond portion of the facial nerve areabsent A small dehiscence of the medial
wall of the middle ear (arrowhead) locatedat the IAM probably corresponds to theentrance of the facial nerve
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1937
Case 1 9-year-old girl with profound bilateral congenital sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1237
bull
6 of the cochlear malformationsbull The most severe malformation
bull Either there is no response or profound
hearing loss at 125 250 and 500 Hz atmaximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1337
bull
CI contraindicatedbull Auditory Brainstem Implant (ABI) can be done
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1437
A Axial CT scan of the temporal bones of patient 1 shows bilateral absence of total inner ear
structures with aplasia of the otic capsules bilaterally
copy
B CT scan of patient 4 reveals unilateral CLA on the left with a type 1 incomplete cochlear
partition on the right The petrous bone and the otic capsule are hypoplastic on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1537
A Flattening of the cochlear promontory (arrow) in CLA B Normal appearance of the
cochlear promontory (arrow) and inner ear in a healthy patient
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1637
Coronal reformatted image of a patient with unilateral (left-sided) CLA reveals severe
narrowing of the IAC on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1737
Case 1
bull 9-year-old girl with profound bilateral
congenital sensorineural hearing loss
bull A Axial CT scan shows right petrous bone
aplasia with absence of inner ear structures
The medial wall of the middle ear is flattened
(arrow) being in close contact with theinfratentorial nervous structures Note normal
differentiation of the malleus
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1837
bull Coronal CT scan shows a normallydeveloped external and middle right earThe long process of the incus (arrow)
leans against the medial middle ear wallThe oval window the stapes and thesecond portion of the facial nerve areabsent A small dehiscence of the medial
wall of the middle ear (arrowhead) locatedat the IAM probably corresponds to theentrance of the facial nerve
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1937
Case 1 9-year-old girl with profound bilateral congenital sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1337
bull
CI contraindicatedbull Auditory Brainstem Implant (ABI) can be done
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1437
A Axial CT scan of the temporal bones of patient 1 shows bilateral absence of total inner ear
structures with aplasia of the otic capsules bilaterally
copy
B CT scan of patient 4 reveals unilateral CLA on the left with a type 1 incomplete cochlear
partition on the right The petrous bone and the otic capsule are hypoplastic on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1537
A Flattening of the cochlear promontory (arrow) in CLA B Normal appearance of the
cochlear promontory (arrow) and inner ear in a healthy patient
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1637
Coronal reformatted image of a patient with unilateral (left-sided) CLA reveals severe
narrowing of the IAC on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1737
Case 1
bull 9-year-old girl with profound bilateral
congenital sensorineural hearing loss
bull A Axial CT scan shows right petrous bone
aplasia with absence of inner ear structures
The medial wall of the middle ear is flattened
(arrow) being in close contact with theinfratentorial nervous structures Note normal
differentiation of the malleus
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1837
bull Coronal CT scan shows a normallydeveloped external and middle right earThe long process of the incus (arrow)
leans against the medial middle ear wallThe oval window the stapes and thesecond portion of the facial nerve areabsent A small dehiscence of the medial
wall of the middle ear (arrowhead) locatedat the IAM probably corresponds to theentrance of the facial nerve
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1937
Case 1 9-year-old girl with profound bilateral congenital sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1437
A Axial CT scan of the temporal bones of patient 1 shows bilateral absence of total inner ear
structures with aplasia of the otic capsules bilaterally
copy
B CT scan of patient 4 reveals unilateral CLA on the left with a type 1 incomplete cochlear
partition on the right The petrous bone and the otic capsule are hypoplastic on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1537
A Flattening of the cochlear promontory (arrow) in CLA B Normal appearance of the
cochlear promontory (arrow) and inner ear in a healthy patient
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1637
Coronal reformatted image of a patient with unilateral (left-sided) CLA reveals severe
narrowing of the IAC on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1737
Case 1
bull 9-year-old girl with profound bilateral
congenital sensorineural hearing loss
bull A Axial CT scan shows right petrous bone
aplasia with absence of inner ear structures
The medial wall of the middle ear is flattened
(arrow) being in close contact with theinfratentorial nervous structures Note normal
differentiation of the malleus
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1837
bull Coronal CT scan shows a normallydeveloped external and middle right earThe long process of the incus (arrow)
leans against the medial middle ear wallThe oval window the stapes and thesecond portion of the facial nerve areabsent A small dehiscence of the medial
wall of the middle ear (arrowhead) locatedat the IAM probably corresponds to theentrance of the facial nerve
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1937
Case 1 9-year-old girl with profound bilateral congenital sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1537
A Flattening of the cochlear promontory (arrow) in CLA B Normal appearance of the
cochlear promontory (arrow) and inner ear in a healthy patient
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1637
Coronal reformatted image of a patient with unilateral (left-sided) CLA reveals severe
narrowing of the IAC on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1737
Case 1
bull 9-year-old girl with profound bilateral
congenital sensorineural hearing loss
bull A Axial CT scan shows right petrous bone
aplasia with absence of inner ear structures
The medial wall of the middle ear is flattened
(arrow) being in close contact with theinfratentorial nervous structures Note normal
differentiation of the malleus
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1837
bull Coronal CT scan shows a normallydeveloped external and middle right earThe long process of the incus (arrow)
leans against the medial middle ear wallThe oval window the stapes and thesecond portion of the facial nerve areabsent A small dehiscence of the medial
wall of the middle ear (arrowhead) locatedat the IAM probably corresponds to theentrance of the facial nerve
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1937
Case 1 9-year-old girl with profound bilateral congenital sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1637
Coronal reformatted image of a patient with unilateral (left-sided) CLA reveals severe
narrowing of the IAC on the left
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1737
Case 1
bull 9-year-old girl with profound bilateral
congenital sensorineural hearing loss
bull A Axial CT scan shows right petrous bone
aplasia with absence of inner ear structures
The medial wall of the middle ear is flattened
(arrow) being in close contact with theinfratentorial nervous structures Note normal
differentiation of the malleus
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1837
bull Coronal CT scan shows a normallydeveloped external and middle right earThe long process of the incus (arrow)
leans against the medial middle ear wallThe oval window the stapes and thesecond portion of the facial nerve areabsent A small dehiscence of the medial
wall of the middle ear (arrowhead) locatedat the IAM probably corresponds to theentrance of the facial nerve
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1937
Case 1 9-year-old girl with profound bilateral congenital sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1737
Case 1
bull 9-year-old girl with profound bilateral
congenital sensorineural hearing loss
bull A Axial CT scan shows right petrous bone
aplasia with absence of inner ear structures
The medial wall of the middle ear is flattened
(arrow) being in close contact with theinfratentorial nervous structures Note normal
differentiation of the malleus
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1837
bull Coronal CT scan shows a normallydeveloped external and middle right earThe long process of the incus (arrow)
leans against the medial middle ear wallThe oval window the stapes and thesecond portion of the facial nerve areabsent A small dehiscence of the medial
wall of the middle ear (arrowhead) locatedat the IAM probably corresponds to theentrance of the facial nerve
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1937
Case 1 9-year-old girl with profound bilateral congenital sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1837
bull Coronal CT scan shows a normallydeveloped external and middle right earThe long process of the incus (arrow)
leans against the medial middle ear wallThe oval window the stapes and thesecond portion of the facial nerve areabsent A small dehiscence of the medial
wall of the middle ear (arrowhead) locatedat the IAM probably corresponds to theentrance of the facial nerve
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1937
Case 1 9-year-old girl with profound bilateral congenital sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 1937
Case 1 9-year-old girl with profound bilateral congenital sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2037
Cochlear aplasia
[Clinical features absent cochlea with intact
but often deformed vestibular labyrinth
sensorineural hearing loss
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2137
bull
5 of the cochlear malformationsbull Either there is no response or profound
hearing loss at 125 250 and 500 Hz at
maximum audimetric limits
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2237
bull
CI contraindicatedbull ABI is the only option
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2337
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2437
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2537
Cochlear hypoplasia
bull
12 of cochlear malformationsbull Cochlear aperture may be aplastic
bull Cochlear nerve may be absent
bullThree different forms are present
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2637
bull
If they have absent cochlear aperture orabsent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2737
bull Some patients had mild
SNHL who make use of hearing aids with
normal language
development
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2837
bull This is another example
of moderate SNHL whois rehabilitated with
hearing aids
bull They may show air-
bone gaps without
middle ear pathology
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 2937
bull Sometimes cochlear
apex is missing and theyhave only the base of the cochlea
bull They have better
hearing level at highfrequencies than thelow frequencies
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3037
bull Profound hearing loss at
125 250 and 500 Hz at
maximum audimetric
limitsbull They are candidates for
CI or ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3137
bull If they have absent cochlear aperture or
absent cochlear nerve CI is contraindicated
ABI should be done
bull Patients with hypoplastic nerve is very difficult
to decide between CI and ABI
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3237
A Coronal CT reformatted image through the cochlea demonstrates lack of modiolus and a
basal turn of the cochlea
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3337
bull15 of cochleovestibularmalformations
bullMidpoint between the
posterior labyrinth and
operculum gt 15 mm
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3437
bull Hearing is usually not stable and usually
shows progressive loss over time
bull The hearing level also shows fluctuations and
sometimes sudden SNHL
bull The other common form of presentation is
profound SNHL
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3537
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3637
bull Air-bone gap in LVA is not due to disease in
the middle ear
bull LVA introduces a third mobile window into the
inner ear which can produce an air-bone gap
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
7272019 Classification for Cochleovestibular Malformations
httpslidepdfcomreaderfullclassification-for-cochleovestibular-malformations 3737
bull It cause shunting the air-conducted sound away
from the cochlea thus elevating air conductionthresholds
bull It increases the difference in impedance betweenthe scala vestibuli and scala tympani side of the
cochlear partition during bone conductiontesting thus improving thresholds for boneconducted sound
