75 terms Terms Definitions Which of the following is FALSE regarding the condition pictured above? A. Female to male preponderance 2:1 B. It is the most common cause of progressive conductive hearing loss in adults C. It is transmitted Autosomal Dominant with variable penetrance D. Hearing loss associated with this disease is bilateral 30% of the time Answer: D Otosclerosis is the most common cause of progressive conductive hearing loss in adults. • The prevalence of otosclerosis is greater in women, with a 2 : 1 female-to- male distribution. • The typical age of onset of noticeable hearing loss is in the third decade of life, and hearing loss is bilateral in 70% of cases. • Otosclerosis is transmitted in an autosomal-dominant fashion, with variable penetrance. • The pathologic changes of otosclerosis begin as spongification of the bone of the otic capsule. • Assessment of hearing with tuning forks provides important information on which to base clinical decisions. • Management options include stapes surgery or hearing aids; rarely, cochlear implantation may be indicated. • Stapes surgery options include total stapedectomy,
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75 terms
Terms DefinitionsWhich of the following is FALSE regarding the condition pictured above?A. Female to male preponderance 2:1B. It is the most common cause of progressive conductive hearing loss in adultsC. It is transmitted Autosomal Dominant with variable penetranceD. Hearing loss associated with this disease is bilateral 30% of the time
Answer: DOtosclerosis is the most common cause of progressive conductive hearing loss in adults.• The prevalence of otosclerosis is greater in women, with a 2 : 1 female-to-male distribution.• The typical age of onset of noticeable hearing loss is in the third decade of life, and hearing loss is bilateral in 70% of cases.• Otosclerosis is transmitted in an autosomal-dominant fashion, with variable penetrance.• The pathologic changes of otosclerosis begin as spongification of the bone of the otic capsule.• Assessment of hearing with tuning forks provides important information on which to base clinical decisions.• Management options include stapes surgery or hearing aids; rarely, cochlear implantation may be indicated.• Stapes surgery options include total stapedectomy, partial stapedectomy, or small fenestra stapedotomy. Footplate fenestration may be accomplished with a laser or microdrill.• Prosthesis options include pistons, wires, or clips (MRI compatible); prosthesis measurement is taken from the incus to the footplate.• Complications of stapes surgery include sensorineural hearing loss, vertigo, fistula, infection, and tympanic membrane perforation.• The surgeon performing stapes procedures should be aware of the possibility of a fixed malleus accounting for a conductive hearing loss.
• Cochlear otosclerosis manifests with sensorineural hearing loss and may be amenable to stabilization with fluoride therapy.
What is the most common area for stapedial fixation in otosclerosis?A. FootplateB. HeadC. Fissula ante finestrumD. Anterior Crus
Answer: C. Fissula ante finestrumRick's Bits : This area is just anterior to the oval window (note in this photo the focus anterior to the footplate between the footplate and the cochlea)
True or False:Small fenestra stapedotomy results in a better long term post-operative improvement of pure tone averages than complete stapedectomy.
False. Stapedectomy Versus Stapedotomy: Comparison of Results With Long-Term Follow-up. House ,Hansen et al. Laryngoscope Nov. 2002."There were no significant differences in hearing results between the two groups at any of the three test intervals for PTA, PTA air-bone gap, or speech discrimination score (SDS). Further, the amount of improvement in the PTA air-bone gap from preoperative to either the early or late postoperative follow-up was not different between the two groups. The stapedotomy group did show significantly better hearing at 4 kHz and better closure of the 4-kHz air-bone gap in the early postoperative follow-up. However, this difference was not significant by the latest follow-up or when only cases with at least 5 years of follow-up were included"
1. What of the following current standard criteria for implantation is INCORRECT?a. PTA>85 both earsb. 12 months of agec. <30% on open set word ID with appropriate HA for kidsd. <40% HINT sentence score
Answer: A- only need PTA for 500, 1k, 2k to be >70 dB both ears, rest are true. Also need <60% HINT sentence in contralateral ear hint sentence, and if trial can be <50% for implanted ear.
2. What is the best predictor of performance in kids w/ CI?a. Genetic deafnessb. Age of implantationc. Support of familyd. Normal anatomy
B. Goal is to screen all children for hearing loss by age 3 months, with intervention (HA or otherwise) by 6 months. CI's approved for use officially at 12 mos or before if due to meningitis . While it's true some genetic causes of deafness seem to do better with CIs,
family support is crucial, and cochlear abnormalities can predispose to decreased efficacy of implanted device the greatest predictor of success is early age at implantation. Mondini's NOT absolute contradincation, but Michel's deformity is. Other predictors of success include: shorter length of deafness, postlingual deafness, increased use of implant (has to wear it). Connor CM Ear Hear. 2006 Dec;27(6):628-44. With all of that said, benefits of early implantation on speech perception and language differences disappear by age 12. Dunn CC Ear Hear. 2008 Jun;29(3):352-9.
3. What are the benefits of bilateral cochlear implantation (compared to unilateral CI)?a. Speech perception in quietb. Speech perception in noisec. Sound localizationd. All of the above
Answer: D. better signal to noise ratio (13dB) compared to monoaural implant benefits yield 19% higher scores for sentences and 24% higher for words, but most impressive gain is in localization, error of which sound localization is around 20 degrees for CI/CI vs. 45 degrees CI/noCI. Dunn CC Ear Hear. 2008 Jun;29(3):352-9.
Patient was determined to have severe congenital sensorineural hearing loss by audiologic evaluation and had tunnel vision progressing to blindness by the time they reached adulthood secondary to retinitis pigmentosa as determined by ophthlamologic evaluation. They deny any problems with dizziness or balance. Patient has which type of Usher Syndrome?a) type Ib) type IIc) type IIId) type IV
Answer: B. Type I: profound SNHL, no vestibular response, legally blind by early adulthood (most common type). Type II: moderate to severe SNHL, legally blind by mid adulthood, normal vestibular function. Type III: progressive SNHL, varied progression in blindness, progressive vestibular function. There is no type IV. Source: Pasha
Which of the following disorders is not caused by the following form of inheritance?a) Pendred Syndromeb) Jervell and Lane-Nielsen Syndromec) Waardenburg Syndromed) Goldenhar Syndrome
Answer: C. Waardenburg syndrome is caused by autosomal dominant inheritance, all the rest are autosomal recessive which is shown in the figure.Pendred syndrome: severe to profound SNHL, also associated with multinodular goiter at young age, positive perchlorate test, due to defect in tyrosine iodination.Jervell and Lange-Nielsen Syndrome: severe bilateral SNHL, cardiac abnormalities with recurrent syncope and sudden death, uncertain
etiology.Goldenhar Syndrome: preauricular appendages, EAC atresia, ossicular malformation or absence, abnormal facial nerve, abnormal SCC and oval window, unknown origin of abnormal first and second arch derivatives.Waardenburg Syndrome: unilateral or bilateral SNHL with possible vestibular dysfunction, pigmentary abnormalities, craniofacial abnormalities, may be due to abnormal tyrosine metabolism.Source: Pasha
What is the frequency of autosomal recessive nonsyndromic hearing loss accounted for by a mutation in GJB2?a) 20%b) 50%c) 70%d) 90%
Answer: B. Mutations in the GJB2 gene which encodes the connexin 26 protein is found in up to 50% of patients with autosomal recessive nonsyndromic hearing loss.Source: Snoeckx et al. GJB2 mutations and degree of hearing loss: a multicenter study. Am J Hum Genet 2005;77:945-957.
A 4 year old child with congenital bilateral SNHL presents with a suppurative otitis media. Within hours, patient develops a high fever, lethargy and neck stiffness. What is a likely finding in this child that you should suspect?a. Mondini's malformationb. Goiterc. Dilated vestibular aquaductd. Superior semicircular canal dehiscience
Answer: A Mondini's malformationIn a child with rapid onset of meningitis within hours of an acute suppurative otitis media in which the offending organism is S. pneumonia or H. influenza and in which the child has a unilateral or bilateral congenital sensorineural deafness and possible vestibular deficit, a Mondini Dysplasia should be suspected. The malformation allows an abnormal communication from the middle ear to CSF through the stapes footplate or round window to the vestibule or cochlea, respectively, and ultimately the internal auditory meatus.Bailey's Chapter 138: Intratemporal and Intracranial Complications of Otitis Media
A 67 yo diabetic patient presents with persistent right sided otagia, otorrhea, and new onset of mild right facial weakness. Clinical exam demonstrates granulation tissue at the bony-cartilaginous junction. What imaging is best to follow progression of this disease?a. CTb. MRI c. Gallium-67 bone scan
Answe: C gallium-67 bone scanCT of the temporal bone with contrast is the initial imaging of choice in a patient with suspected necrotizing external otitis. Technetium-99m bone scanning, gallium-67 bone scanning , and Indium-111 labeled leukocyte (In-WBC) planar scintigraphy have been advocated in the evaluation of NOE. Tc-99m gives excellent information about the bone function but poor information about
d. No follow up imaging is necessary as long as proper antibiotics are initiated and clinical symptoms improve
bone structure. A positive scan is secondary to osteoblastic activity as little as 10% above normal. A scan can be positive with acute or chronic osteomyelitis and in areas of active bone repair without infection. Increased uptake between 4-24 hours Is thought to the sensitive for temporal bone osteomyelitis. Ga-67 is incorporated into proteins and polymorphonucleocytes at sites of active infection as a Ga-67 lactoferrin complex. It highlights an acute infective focus but not the full extent of an osteomyelitic process. As treatment progresses, the scan returns to normal, however Tc-99m will lag behind for many months. Baseline studies of both are recommended. In addition, Indium-111 labeled leukocyte (In-WBC) planar scintigraphy has been demonstrated to have better results for detection complared to Ga-67 or Tc-99m and can also be used.
In patients with meningitis secondary to otitis media, what treatment is thought to help reduce post recovery neurologic sequelaea. Extended IV antibiotic treatment (6 months)b. Physical therapyc. Weekly lumbar puncturesd. Dexamethasone during initial treatment
Answer D. Dexamethasone during initial treatmentDespite effective antibiotics treatment, about one third of meningitis survivors suffer neurologic sequelae such as behavioral disorders, mental retardation, and deafness which is thought to be secondary to inflammatory mediators such as cytokines. Dexamethasone (DXM) interferes with the production of tumor necrosis factor-α (TNF-α) and interleukin-1 (IL-1) and can diminish this secondary inflammatory response. A beneficial effect on the outcome of Haemophilus meningitis in children has been proven, but until recently the effect of DXM therapy in pneumococcal meningitis was uncertain. In a 2003 study, Lutsar et al evaluated the modulatory effect of DXM on the antibiotic-induced inflammatory response in a rabbit model of pneumococcal meningitis. In those animals, DXM therapy prevented significant elevations in CSF TNF-α versus controls, P = 0.02 and lactate concentrations versus controls (no DXM), P = 0.01. These effects were independent of the timing of DXM administration.
1. Which of the following is NOT true of Wegener's Granulomatosis?A. c-ANCA is greater then 95% specificB. c-ANCA titers often parallels the activity of diseaseC. The inner ear is the most common site of temporal bone involvementD. May cause obstruction of the eustachian tube
C. The inner ear is not the most common site.Middle ear and mastoid are the most common sites within the temporal boneMay cause obstruction of the eustachian tube with resultant serous otitis media and conductive hearing loss. Some patients also have purulent otitis media, and others may have frank granulomatous involvement of the middle ear and mastoid. The process can extend to involve the facial nerve and the inner ear, which is usually manifested as rapidly progressive SNHL and loss of vestibular function. Otologic disease may be the sole and initial presenting feature in some patients with WG.
Specificity of positive c-ANCA testing in WG is greater than 95%; Sensitivity is variable and depends on the phase and type of WG. c-ANCA is positive in more than 90% of patients with systemic and active WG, whereas in limited WG (e.g., ear or head and neck only or inactive disease), the sensitivity of c-ANCA is only 65% to 70Antibody titer parallels the activity of the disease, but controversial as a guide for immunosuppressive therapyCummings.
The following is a CXR of a 56yo African-American female with fatigue, weight loss, and arthritis: Which of the following is NOT true regarding the patient's disease process?A. The facial nerve is the most commonly affected cranial nerveB. SNHL and vestibular dysfunction is more common than middle ear diseaseC. Parotitis, uveitis, and facial nerve paralysis can occur in combinationD. Skin lesions occur in more then half of patients
D. Skin lesions (erythema nodosum) occurs in about 25% of patientsCXR shows bilateral hilar adenopathy commonly seen in sarcoidosis. More common in African americans and women. Steroids and methotrexate, cyclophosphamide, azathioprine, chlorambucil, cyclosporine, chloroquine, pentoxifylline are often used in treatment.
Otologic manifestations of sarcoidosis include SNHL, vestibular dysfunction, and facial nerve paralysis, and occasionally granulomatous disease of the external or middle ear and mastoid.The facial nerve is the most commonly affected cranial nerve and is usually involved as part of the triad of uveoparotid fever (Heerfordt's syndrome) that is characterized by parotitis, uveitis, facial nerve paralysis, and mild pyrexia. The facial paralysis may be sudden in onset, it is often bilateral, and it may resolve spontaneously. Histopathology of the temporal bone in sarcoidosis has been reported in only one case; the main findings were perivascular lymphocytic infiltration and granulomatous inflammation involving the cochlear, vestibular, and facial nerves within the internal auditory canal
Which of the following is true regarding secondary (metastatic) malignant tumors involving the temporal bone?A. Usually spreads through lymphatics B. Vestibular dysfunction is the most common symptom attributed to temporal bone involvementC. Breast cancer is the most common tumor to spread to the temporal boneD. The petrous apex is the second common site of temporal bone metastasis
Of Temporal bone metastasis most common primaries: Breast cancer (21%), Lung (12%), Prostate (10%)76% demonstrated hematogenous spreadMost common symptoms: Hearing loss (40%), No symptoms (36%), Vertigo/Dizziness (15%) The petrous apex is the most common site of temporal bone metastasis, 83%.Next most common: mastoid, IAC
you are asked to evaluate a patient with a suspected right t-bone fx. During the history the report not being able to hear out of the right ear. On exam you note nystagmus when the patient is looking forward. When you ask the patient to look laterally, which direction of gaze would you expect to have the largest amplitude in nystagmus?
A. LeftB. RightC. EqualD. No nystagmus on lateral gaze
Answer. A.
Right temporal bone fracture with severe spontaneous nystagmus manifesting immediately after trauma. The fast component beats away from the fracture site (to the left) in all directions of the gaze. According to Alexander's law, the nystagmus increases when the eyes are turned in the direction of the quick component and decreases when the eyes are turned in the direction of the slow component. 1st degree: present with gaze in direction of fast phase. 2nd degree: present on straight ahead gaze. 3rd degree: present in all directions of gaze, but greatest in the direction of the fast phase.
What is the most common site of ossicular chain abnormlities following t-bone trauma?A. Incudostapedial joint separationB. Incus dislocation C. Fracture of the stapes crura D. Incudomalleolar joint separation
Answer A:• Incudostapedial joint separation: The incudostapedial joint is the most common site of traumatic separation. (82%)• Incus dislocation (57%)• Fracture of the stapes crura (30%)• Fixation of the ossicles in the attic (25%)• Incudomalleolar joint separation
Which is the most accurate statement with respect to this patient's condition? a. the condition is associated with a defect in the SLC26A4 gene b. the condition is the result of de novo mutations in ~90% of cases c. the condition is associated with a defect of chromosome 22 d. the condition is associated with premature macular degeneration
Correct answer: C This patient has bilateral vestibular schwannomas, the hallmark of NF-2. This condition exhibits autosomal dominant transmission in its inherited form; however, approximately 50% of cases are the result of de novo mutations. In the familial form, the culprit is a defect in the long arm of chromosome 22 (22q12). The defect results in absence of a tumor suppressor gene that is important in regulating press proliferation of Schwann cells. The gene product is called Merlin which appears to control cadherin-mediated cell to cell contact. In its absence, cells lose the ability for contact dependent growth arrest.
The SLC26A4 gene encodes for pendrin, the defective gene product associated with Pendred syndrome
NF2 is associated with juvenile cataractsAn elderly male presents for evaluation of newly diagnosed vestibular schwannoma found incidentally. He is apprehensive about pursuing surgery and would like to observe the tumor. Which of the following statements would be an inaccurate statement in your counseling of this
Correct answer: B Small, asymptomatic tumors can be reasonably observed in elderly patients. The average reported growth rate is 1-2 mm per yr. ~14-24% of pts who are initially observed with eventually go on to need some form of treatment. A surveillance MRI should be
patient?a. the reported average growth rate of vestibular schwannomas is 1-2 mm annually b. ~50% of patients who are initially observed will eventually need some form of treatment c. a repeat MRI should be obtained in 6 months and then yearly if stable d. all of the above are accurate statements
obtained in 6 months and then yearly if stable. If left untreated, gradual enlargement can lead to indentation of the brainstem, increased intracranial pressure, and death during a course of 5 to 15 years.
Which statement is true with respect to recurrent vestibular schwannomas following gamma knife radiosurgery (GKR) vs. traditional microsurgery?a. recurrent tumors following GKR demonstrate lower proliferation potential than recurrent tumors following traditional microsurgeryb. recurrent tumors following GKR demonstrate higher proliferation potential than recurrent tumors following traditional microsurgeryc. there is no difference in proliferation potential of recurrent tumors for these two groups d. the proliferation potential of the recurrent tumor is based upon pre-treatment potential
Correct answer: A
Lee et al. performed a retrospective study that looked at the proliferation potential of recurrent VS following gamma knife radiosurgery (GKR) versus microsurgery. They reviewed 23 pts with unilateral recurrences of VS; 8 pts had undergone initial GKR, 15 pts had initial microsurgery. Immunohistochemical studies were performed to evaluate the expression of proliferating cell nuclear antigen (PCNA). PCNA has been demonstrated to be a valid means of assessing proliferate potential of VS as it is a nucleoprotein that is a good marker for DNA replication and repair. Basically, they found lower proliferation potential in the GKR group. This observation helps explain why tumor doubling time in recurrent tumors following GKR is typically longer than in non-radiated, microsurgical recurrent tumors. Radiation-induced apoptosis thought to contribute to the low-dose effects of gamma knife radiosurgery. Such that tumor cells that have the highest proliferation potential underwent apoptosis and those cells that were dividing more slowly survived.
A forty year old female presents with left pulsatile tinnitus and aural fullness. Audio demonstrates left sided conductive loss. On examination it appears as if there is a mass in the middle ear, and there is blanching of the TM with positive pressure. An MRI is obtained and a mass is seen in the middle ear that has an intermediate signal intensity of T1-
Answer: B• Paragangilomas: Typically occur in fourth or fifth decades of life. Slow-growing tumors, rare metastasis. Grow along the path of least resistance. 1% display functionally significant catecholamine secretion similar to a pheochromocytoma. Pathologically, the chief cell is the cell of origin of the tumor and contains acetylcholine, catecholamines and
weighted images and a high intensity on T2-wieghted images. Both demonstrate a "salt and pepper" pattern. What is the characteristic histopathologic finding of this tumor?
A) Antoni Type AB) ZellballenC) Antoni Type BD) Physaliphorous cells
serotonin. Classic findings are clusters of chief cells arranged in cell balls, termed Zellballen, with a rich vascular plexus throughout the entire tumor. Blanching of the TM with positive pressure is called Brown's sign. Aquino sign is the blanching of the mass with manual compression of the ipsilateral carotid artery.• Acoustic neuromas: Antoni Type A: histologically parallel nuclei, uniform spindle cells, tightly packed cells. Antoni Type B: histologically less uniform, may have fatty or hyalin degeneration, less cellular.• Physaliphorous cells are characteristic of chordomas.
A patient presents it unilateral SNHL. An MRI is obtained with an IAC lesion which is hyperintense on T1 weighted imaging, shows no enhancement with gadolinium, and is hypointense on T2 weighted imaging and with fat suppression. What is this lesion?
A) Acoustic neuromaB) ParagangliomaC) Cholesterol granulomaD) LipomaE) Meningioma
Answer: D
Patient presents with profound SNHL in right ear. On MRI there is a globular 1.6 cm CPA lesion that is centered over the right IAC, extending into the lateral IAC. It is hypointense on T1 and T2, with strong enhancement. Which approach would be best to remove this tumor?
A) RetrosigmoidB) Fisch AC) TranslabyrinthineD) Fisch BE) Extended middle fossa
Answer: CThe translabyrinthine approach is a good choice for nonservicable hearing. The retrosigmoid does not offer access to the lateral IAC. The MCF is a hearing preservation approach, used for small intracanalicular lesions. The Fisch A and Fisch B approaches are used for paragangliomas.
1) A 65-year old female with a history of presbycusis presents for hearing aid evaluation. You perform audiologic testing which reveals a sloping bilateral , moderate to severe high frequency hearing
Answer: COne complaint of most patients with cochlear loss is a decrease in dynamic range, also called cochlear recruitment. This is because the loudest sounds are still perceived with the
loss with limited dynamic range. Based on this, which of the following is the most appropriate recommendation for hearing rehabilitation?
a) Bilateral BTE aids with standard gainb) Bilateral CIC aids with limited ventingc) Bilateral BTE aids with compression circuitryd) Bilateral BTE aids with large venting
same intensity, whereas patients with cochlear loss are unable to hear quiet sounds. Therefore the range between comfortable listening and uncomfortable loudness is much smaller than in normal subjects. Aids must then be able to supply adequate gain to the user without creating sounds which are too loud. Most aids sold today use linear amplifiers, which increase the signal amplitude by a constant amount, regardless of input level. These aids then require some kind of output limiting - such as peak clipping or compression amplification - to differentially amplify soft sounds more than loud sounds.
2) A 67 year old male with a history of bilateral temporal bone fractures presents for evaluation. An audiogram in performed showing moderate sensorineural hearing loss with speech discrimination scores of 80% in the left ear. The right ear has profound sensorineural hearing loss with speech discrimation score of 35%. Which of the following is the most appropriate form of aural rehabilitation to offer this patient?a. Cochlear implant for the right earb. Digital hearing aid for the right earc. CROS aidd. BiCROS aid
Answer: DExplanation:CROS stands for contralateral routing of signal and is a special configuration used for profound unilateral hearing loss that is unaidable with conventional amplification. It involves the microphone being placed on the side with the profound loss and delivering the sound to the better hearing ear. This is done either by hard wiring or radio frequency. Hearing must be reasonably good in the better hearing ear or a Bi CROS (Bilateral CROS) is necessary which is CROS with the addition of conventional amplification to the better hearing ear. Reference: Cummings 4th edition
3. What is the most common reason for feedback in a hearing aid?a. Too large a ventb. Too small a ventc. Poor fitd. Too much gain
Feedback occurs when the amplified sound leaks from the receiver back to the microphone causing a high pitched squeal. Acoustic waves from the hearing aid speaker leak through the air space between the hearing aid body and the external auditory canal wall back to the microphone, where (for a subset of frequencies) they add to existing microphone input and are amplified further. The resulting positive feedback loop causes the familiar squealing and hum that signify a poorly fitting or overamplified aid. Potential for feedback is worst for CIC aids, in which the microphone is closest to the speaker, and for ears with mastoid bowls, in which an air seal is difficult to obtain. At very high amplification, it is a problem even for BTE aids. Fitting aids
tightly into the external auditory canal can decrease feedback, but at the cost of increased discomfort, and the risk of otitis externa, autophony, and blockage of natural sound input.
A pt undergoes VEMP testing with the results seen below: Which of the following conditions did the tested patient suffer from? Unilateral Menieres DiseaseUnilateral Acoustic NeuromaUnilateral Semicircular canal dehiscencePendred Syndrome
Ans: C Unilateral Semicircular Canal Dehiscence; Streubel SO, Cremer PD, Carey JP, et al: Vestibular-evoked myogenic potentials in the diagnosis of superior canal dehiscence syndrome. Acta Otolaryngol Suppl 2001; 545:41-49.
Although rarely seen during residency, this is a VEMP tracing. In patients with unilateral SCCD, the VEMP response appears to occur at lower thresholds and with increased amplitude. Patients with Meniere's disease may have higher thresholds for responses to VEMPs. AN and PS are generally not worked up with VEMP.
Vestibular Evoked Myogenic Potentials, aka VEMPS are due to :A. Selective activation of vestibular nerve afferents innervating the sacculus.B. Selective activation of vestibular nerve afferents innervating the utricle.C. Selective activation of vestibular nerve afferents innervating the inferior collicus.D. Selective activation of vestibular nerve afferents innervating the cerebellum.E. Some process the resident author of the question has never heard of before.
ANS: A; Colebatch JG, Halmagyi GM, Skuse NF: Myogenic potentials generated by a click-evoked vestibulocollic reflex. J Neurol Neurosurg Psychiatry 1994; 57:190-197.VEMPS are a relaxation of the ipsilateral sternocleidomastoid (SCM) muscle in response to auditory stimulation (100- to 200-msec rarefaction clicks, 95-dB sound pressure level [SPL] or tone bursts) exhibited in healthy subjects. VEMP responses are a result of selective activation of vestibular nerve afferents innervating the sacculus. These responses are recorded with electromyelography (EMG) and occur at a short latency (12 msec) relative to onset of the click stimulus. The responses are abolished on the side of surgery after unilateral vestibular neurectomy. For those picking E, a very thorough yet less than stimulating for most grand rounds was given during the middle years of the last decade. It was one of many that lead to the changes in grand round being required to be more engaging and "ground breaking" topics. The question did not ask whether said resident understood the VEMP, just whether he had ever heard of it before.
An adult patient suffers a stroke and now has isolated unilateral vestibular hypofunction. They are thus assigned to ROD clinic as a new patient who bit their tongue 2 years ago swallowed a marble at age 6. On questioning, they in fact complain of unsteadiness. Due to this unilateral vestibular hypofunction, what would you expect to see on eye exam? A. A purely torsional nystagmusB. A jerk nystagmus that is present when the head is still, reduced by visual fixation, and is increased during use of Frenzel lenses.C. Downbeating nystagmusD. Horizontal component beats toward the hypofunctioning ear with torsional component involving superior poles beating toward the hypofunctioning ear.
Answer: B-Purely torsional nystagmus is associated with intrinsic brainstem involvement within the vestibular nuclei; suggestive of syringomyelia- Vestibular Hypofunction: Nystagmus may be more pronounced with Frenzel glasses, but the nystagmus is usually a jerk type nystagmus that can be suppressed with fixation. -Downbeating nystagmus is associated with cerebellar lesions/injury and Arnold-Chiari malformations-In acute unilateral vestibular LOSS, A horizontal-torsional nystagmus typically is observed acutely. The horizontal component beats toward the "stronger" (intact) ear, and the torsional component involves beating of the superior poles of the eyes toward the intact ear.
A patient presents with unilateral Meniere's disease and has elected to have intratympanic aminoglycoside treatment. Which of the following has the aminoglycosides orders from most cochleotoxic to vestibulotoxic.a. Neomycin, gentamycin, amikacin, streptomycinb. Streptomycin, gentamycin, neomycin, amikacinc. Gentamycin, neomycin, streptomycin, amikacind. All are equally oto and vestibulotoxic.
Answer: AKanamycin, amikacin, neomycin, and dihydrostreptomycin are preferentially cochleotoxic. Gentamicin affects both cochlear and vestibular systems and is considered more ototoxic than amikacin. Streptomycin, tobramycin, and netilmicin are primarily vestibulotoxic.
A patient with Meniere's disease has failed medical management and is deciding between intratympanic gentamicin treatment versus endolymphatic shunt surgery. The ideal outcome is vertigo control with hearing preservation. What percentage of patients in the gentamicin treated group versus the endolymphatic shunt group achieved vertigo control and hearing preservation?a. 47% versus 82%b. 23% versus 76%c. 56% versus 62%d. 78% versus 63%
Answer: CAccording to a review from the House institute of their ELS results compared with published IT gentamicin 62% of ELS patients achieved good vertigo control and preserved hearing versus 56% for IT gentamicin.Outcomes of Endolymphatic Shunt Surgery for Ménière's Disease: Comparison With Intratympanic Gentamicin on Vertigo Control and Hearing Loss
A patient presents to your office with a diagnosis of Meniere's disease which you confirm. You elect to give intratympanic gentamicin. The patient returns complaining of severe hearing loss. Where is the location of damage.a. Inner hair cellsb. Stria vascularisc. Outer hair cellsd. Cochlear nerve
Answer: CCochlear toxicity that results in hearing loss usually begins in the high frequencies and is secondary to irreversible destruction of outer hair cells in the organ of Corti, predominantly at the basal turn of the cochlea.
A 54 yo F comes to your clinic 2 months after an episode of facial weakness on one side for which she received no treatment. She complains today of incomplete recovery in terms of continued weakness and inability to make discrete movements of individual facial regions without involuntary movement of other parts of the face. Histologically at the time of injury you could see what?a. intact endoneurium with injured axonb. injured axon, endoneuriumc. injured axon, endoneurium, perineuriumd. both and b and c
d.
Patient has synkinesis which results from Sunderland III to V injuries termed neurotmesis injuries in which the endoneurium at a minimum is disrupted resulting in regenerating axons potentially entering the wrong endoneurial tubes or that may fail to enter an endoneurial tube at all resulting in aberrant regeneration and possibly incomplete recovery. In class V in which epineurium is disrupted secondary to complete nerve transection, without approximation, spanning or repair there is no chance of meaningful recovery.Sunderland classificationClass I: Pressure on a nerve trunk, causes conduction block, termed neurapraxia No physical disruption of axonal continuity occurs, and supportive connective tissue elements remain intact.Class II: axonal disruption without injury to supporting structures. Wallerian degeneration occurs and propagates distally from the site of injury to the motor end plate and proximally to the first adjacent node of Ranvier. In a class II injury, the connective tissue elements remain viable, so regenerating axons may return precisely to their original destinations - no synkinesis. Termed axonotmesis. Regrowth 1 mm/day.Class III: disrupts the endoneurium, see aboveClass IV: Perineurial disruption implies an even more severe injury, in which the potential for incomplete and aberrant regeneration is greater. Intraneural scarring
may prevent most axons from reaching the muscle, resulting in not only greater synkinesis but incomplete motor function recovery. The perineurium binds the axons into fascicles.Class V: A complete transection of a nerve, including its epineurial sheath, carries almost no hope for useful regeneration, unless the ends are approximated or spanned and repaired. The epineurium binds fascicles into the common nerve.Class VI: Insults to the facial nerve trunk, whether compressive, inflammatory, or traumatic in origin, can be heterogeneous in nature, with differing degrees of injury from fascicle to fascicle. Such mixed injury involving both neurapraxia and a variable degree of neurodegeneration has been advocated as an additional class of injury.
The same patient wants to know whether there is a quantitative way in which to test her level of impairment. You offer her the following electrodiagnostic test:a. Maximal Stimulation Testb. Electromyographyc. Electroneuronographyd. Nerve Excitability test
Electroneuronography, or ENoG, that should better be known by the more descriptive term, evoked electromyography is the only objective means of measuring facial function from the above. The facial nerve is stimulated transcutaneously at the stylomastoid foramen, as in the NET, although a bipolar stimulating electrode is used. Responses to maximal electrical stimulation of the two sides are compared, as in the MST, but they are recorded in a more objective fashion by measuring the evoked compound muscle action potential (CMAP) with a second bipolar electrode pair placed (usually) in the nasolabial groove. A supramaximal stimulus often is used, and peak-to-peak amplitude is measured in millivolts (mV). The average difference in response amplitude between the two sides in healthy patients has been said to be only 3%. Testing with any of the above really does not affect management at this point as she is well past the 14 days used as cut-off for surgical decompression. But EMG can help determine remaining neural activity to help determine appropriateness of reanimation. Criteria to Consider Facial Nerve
DecompressionNerve excitability test (NET): >3.5-mA threshold difference between sidesMaximal stimulation test (MST): No response on injured side at maximal stimulationElectroneurography (EnoG): >90% degeneration within 14 days
A patient with Mobius Syndrome undergoes gracilis microneurovascular free tissue transfer. With no facial nerve available for grafting on either side of the face what other nerve can be used to provide motor input?a. abducensb. suralc. great auriculard. nerve to masseter
Meltzer, Noah E; Alam, Daniel S Facial paralysis rehabilitation: state of the art. Current Opinion in Otolaryngology & Head and Neck SurgeryIssue: Volume 18(4), August 2010, p 232-237
In Mobius syndrome CN VI and VII are congenitally absent. In this review, they had excellent results using the motor nerve to the masseter for neuronal input.
How do you calculate mean arterial pressure (MAP)?
MAP is often calculated by the following equation:
What can you say about the cerebral blood flow (CBF) in a patient with a MAP = 70 compared to another patient with a MAP = 140?
a) The CBF will be twice as much in the patient with a MAP = 140
b) The CBF will be 4 times as much in the patient with a MAP = 140
c) The CBF will be the same in both patients
c) the CBF will be the same
The cerebral autoregulation keeps cerebral blood flow the same when MAP is between 60 and 150. Outside of these ranges, the autoregulation is overwhelmed
Ref: Bailey's 4th Ed; Chapter 126
What is the primary method of minimizing cerebral edema caused by vascular engorgement intraopertively during cranial-base surgery?
Maintaining the intraoperative pCO2 between 20-30 mm Hg is the primary method of minimizing cerebral edema.
Ref: Bailey's 4th Ed; Chapter 126
What do you worry about if the vein of Labbe is occluded?
The vein of Labbe drains the temporal lobe and enters the transverse sinus (figure).
Occlusion of the vein of Labbe can lead to temporal lobe edema
What is the rate of cerebellopontine angle (CPA) tumor in patients that present with Sudden SensoriNeural Hearing Loss (SSNHL)?
The rate of CPA tumor in SSNHL is 2.7-10.2% depending on the study.
However, 10-20% of patients with CPA tumor with report a sudden decrease in hearing at some point in their history.
Otolaryngol Head Neck Surg. 2012 Mar;146(3 Suppl):S1-S35
A patient presents with left sided SSNHL and you treat them with prednisone. Their hearing comes back to baseline 1 week later. What can you say about the likelihood of hearing recovery on ruling out CPA tumors.
Hearing recovery has not been shown to predict whether a patient's SSNHL is the result of a tumor
Otolaryngol Head Neck Surg. 2012 Mar;146(3 Suppl):S1-S35
What is the most common MRI finding in patients with SSNHL?
a) CPA tumor
b) enhancement of CN8 in the IAC
c) incidental findings unrelated to the hearing loss
c) incidental findings unrelated to the hearing loss
About 47% of MRI studies obtained for SSNHL had an "abnormality" and only about 1/4 of those where related to the hearing loss
Otolaryngol Head Neck Surg. 2012 Mar;146(3 Suppl):S1-S35
What is the equivalent dose of dexamethasone for 60 mg Prednisone?
60 mg of prednisone is equivalent to 10 mg dexamethasone.
Otolaryngol Head Neck Surg. 2012 Mar;146(3 Suppl):S1-S35
You see a patient with a 1 day history of right-sided SSNHL. There are not focal neurologic defects and an MRI is negative. The patient completes 14 days of 60 mg
Intratympanic steroids for salvage therapy (after failed oral steroid treatment) have shown improvement in most studies (26-83% improvement).
oral prednisone. The audiogram is unchanged with residual right sided SNHL. What should you discuss with this patient?
The patient should be offered IT steroids therapy for salvage (Clinical practice guidelines)
Otolaryngol Head Neck Surg. 2012 Mar;146(3 Suppl):S1-S35
A patient presents with this lesion AD seen on CT (Images). What diagnosis do you suspect and what would the pathology show?
Glomus Jugulare
This is a contrast enhanced CT showing a lesion in the hypotympanum near the junction of the jugular bulb and carotid artery
Pathology would show clusters of chief cells, surrounded by vascular structures, referred to as a Zellballen pattern
What percentage of patients with glomus tumors present with symptomatic catecholamine secretion?
~4% of patients present with symptomatic secretion of catecholamines.
What serum testing do you order pre-operatively in patient about to undergo glomus tumor surgery? Do you order somatostatin?
Order metanephrine, normetanephrine, vanillylmandelic acid (breakdown products of catecholamines)
Glomus tumors are APUD tumors; Catecholamines are produced by chief cells.
These tumor can posses the enzyme phenylethanolamine-N-methyltransferase, that converts norEpi to Epi (Figure).
The tumors do NOT secrete somatastatin;
However, they express somatostatin receptors; Thus, octreotide (Somatostatin analog) scans can be used to look for residual/recurrent tumor
You are about to operate on a patient with a catecholamine-secreting glomus tumor. BP is 180/100. What do you tell the anesthesiologist about treatment of the HTN?
In patients with confirmed hypersecreting tumors (catecholamine levels 4 times higher than normal) require preparation with an ALPHA and BETA catecholamine blocker (i.e. Labetalol) before surgery. Beta-blockers should NOT be used. Unopposed alpha agonist can lead to severe hypertension
The CT below depicts the most common middle ear neoplasm. What is the most common middle ear neoplasm? A. Squamous cell carcinomaB. AdenocarcinomaC. Paraganglioma (glomus tumor)D. Middle ear adenoma Answer C.
Glomus tumors of the head and neck are associated with 4 primary locations, the jugular bulb, middle ear cavity, vagus nerve, and carotid body. This image depicts a glomus tympanicum.
Glomus tumors originate in the paraganglia, which exist throughout the temporal bone, including on the jugular dome, the promontory of the middle ear, and along the Jacobson (IX) and Arnold nerves (XI).
In a large series of 80 patients, presenting symptoms, in order of decreasing frequency, were pulsatile tinnitus (73%), hearing loss (conductive 49%, mixed 11%,sensorineural 6%), aural pressure/fullness (39%), vertigo/dizziness (16%), otalgia (16%), and bloody otorrhea (6%).The Brown sign, which consists of a purple-red middle ear mass that blanches with positive pneumatic otoscopy, was seen in less than 10% of patients.Middle ear adenoma= MEAs are thought to arise from pluripotent cells in the middle ear mucosa and may have mixed patterns of differentiation, ranging from purely epithelial (adenoma) to purely neuroendocrine
(carcinoid). They are nonencapsulated and demonstrate solid, glandular, or trabecular architecture. They are benign tumors.
The Jugular bulb is situated where in the jugular foramen?A. PosteriomedialB. PosteriolateralC. AnteriomedialD. Anteriolateral
B. PosteriorlateralAn imaging based subclassification exist, using the jugular spine, which is a bony ridge partially separating the jugular foramen, into two parts.The smaller, anteromedial, "pars nervosa" compartment contains CN IX, Jacobson nerve, and receives the venous return from inferior petrosal sinus.The larger, posterolateral, "pars vascularis" compartment contains CN X, CN XI, Arnold's nerve, jugular bulb, posterior meningeal artery (branch of vertebral artery), and meningeal branch of ascending pharyngeal artery.
Jugular foramen
Which of the following represents a contraindication to use of the expanded endonasal approach (EEA) for resection of skull base tumors? 1. Large JNA with extension lateral to the optic canal2. An olfactory groove meningioma in a 5 year old male3. A cholesterol granuloma of the temporal bone with extension lateral to the petrous carotid artery
1. . Large JNA with extension lateral to the optic canalExplanation: The limits of the EEA continue to be defined. Currently, the boundaries of the expanded endoscopic endonasal approach for the anterior cranial base are defined as anteriorly, the frontal sinus and cribriform plate, and laterally, the medial orbital walls anteriorly, the cavernous sinus and carotid arteries in the sellar region, and the dorsum sella and posterior clinoids posteriorly.
4. A 3 cm esthesioneuroblastoma which cannot be removed en bloc5. none of the above
Any significant optic canal extension, especially laterally, is a contraindication for the endoscopic approach if the objective of surgery is total removal. This technique has been deemed safe for patients older than the age of 4, based on suitable anatomy for endoscopic instrumentation at this age. Tumors of the petrous apex with extension medial to the petrous carotid have been resected with this technique. The carotid can be retracted laterally in most cases to afford additional exposure.En bloc resection is generally not achieved with endoscopic technique. Piecemeal resection is typically used during endoscopic removal of esthesioneuroblastoma. Studies have shown no adverse oncologic outcomes when piecemeal rather than en bloc resection is used.
Which of the following best describes the "inverted bottle" theory for the development of pneumocephalus?1. positive pressure events (e.g. Valsalva maneuvers) force air through a cranial defect with subsequent trapping 2. the size of the cranial defect is inversely proportional to the ability of iatrogenically introduced air to escape 3. leakage of CSF creates a negative pressure gradient in the intracranial cavity with a resultant influx of air 4. all of the above are versions of this theory
There are 2 proposed mechanisms for the development of pneumocephalus. The "inverted bottle" theory (choice 3) suggests that in the presence of a skull base defect and leakage of CSF, a negative pressure gradient is created and there is a resultant influx of air. The "ball-valve" theory (choice 1) suggests that positive pressure events (sneezing, coughing, vomiting etc.) forces are through a cranial defect that becomes trapped in the intracranial cavity
A 45 y/o female presents with complaints of headache and clear rhinorrhea on postoperative day 6 following skull base surgery. She has a clear sensorium with no focal deficits on exam though she complains that the headaches are worsening. A CT scan demonstrates pneumocephalus with a 3 mm skull base defect. Which treatment modality do you opt for next? A. decompression of intracranial air
Answer D. Pneumocephalus occurring after skull base surgery is very rare, thus no standard treatment algorithm exists. DelGaudio et al. published a retrospective review of 10 cases of pneumocephalus following either ESS or microscopic skull base surgery. 7/10 pts had small defects (3 mm or less) and 5/7 had spontaneous resolution with conservative measures alone. 3/3 pts with larger defects failed conservative measures, including lumbar drainage and
B. placement of a lumbar drain C. repair of the skull base defectD. conservative measures including HOB elevation, pain control and avoidance of positive pressure maneuvers
placement of an LD seemed to worsen the amount of intracranial air in the skull base surgery pts with larger defects (likely by way of the "inverted bottle effect described previously). A trach was performed on one pt to divert air away from the nose which helped improve pneumocephalus prior to definitive repair. Take home point: smaller defects with no acute signs/sx can be managed conservatively and most will resolve on spontaneously, however, it is recommended that the defect is explored and repaired at a later date. Larger defects are more likely to fail conservative measures and may require surgical intervention early on.
You are reviewing the CT scan of a trauma patient and note an injury to the area identified below by the arrow. Which of the following nerves would potentially NOT be injured? a) CN IIIb) CN V1c) CN V2 d) CN VI
c) CN V2. The image is showing the superior orbital fissure which is bounded by the greater and lesser wings of the sphenoid. It contains the superior and inferior divisions of CN III (oculomotor), CN IV (trochlear), CN V1 (lacrimal, frontal and nasociliary branches), CN VI (abducens), superior and inferior division of ophthalmic vein (inferior division also through inferior orbital fissure), sympathetic fibers from cavernous plexus. The inferior orbital fissure contains CN V2 (maxillary division, zygomatic nerve), infraorbital vessels, ascending branches from sphenopalatine ganglion.
A patient presents to the ER with the following appearance and evidence of a fracture of the sphenoid on CT scan. Which of the following findings should NOT be present on exam? a) Exophthalmosb) Ptosisc) Loss of EOM
d) BlindnessThe patient has superior orbital fissure
d) Blindnesse) You would expect all to be present
syndrome which results from injury to the superior orbital fissure. This results in diplopia, paralysis of extraocular movements, exophthalmos, and ptosis. If the patient has blindness there is involvmenet of the orbital apex, which is known as orbital apex syndrome and requires urgent surgical intervention.
What makes up the posterior aspect of the floor of the middle cranial fossa? a. clivusb. anterior aspect of the petrous temporal bonec. greater wing of the sphenoidd. pterion
b. anterior aspect of the petrous temporal boneAnterior Cranial fossa boundaries1. Anterior: posterior wall of the frontal sinus.
2. Posterior: The anterior clinoid processes and the planum sphenoidale, which forms the roof of the sphenoid sinus3. Lateral: frontal bone
Middle cranial fossa boundaries: 1. IntracraniallyAnterior: The greater wing of the sphenoidPosterior: clivus (sphenoid and occipital bones). Central: body of sphenoidLateral wall, anterior floor: Greater wing of the sphenoid posterior floor: anterior aspect of the petrous temporal bone Pterion : H -shaped suture ( frontal bone, the greater wing of the sphenoid bone, the squamous temporal bone, and the parietal bone); 3.5 cm behind the zygomaticofrontal suture and 4 cm above the zygomatic arch; thin bone, easily fractured during traumainjury to the anterior branches of the middle meningeal artery, with eventual formation of an epidural hematoma.
2. extracranially- anterior: posterolateral wall of the maxillary sinuses-Posterior: the petro-occipital sutures Lateral: squamous and petrous portions of the temporal bone.
Posterior cranial fossa boundariesAnterior: basal portion of the occipital bone
(the basiocciput) and the basisphenoid combine to form the midclivusLateral: posterior surface of the petrous temporal bone and the lateral aspect of the occipital bonePosterior: occipital bone
What is an important landmark within the middle cranial fossa will help to identify the IAC during an middle crania fossa approach to an acoustic neuroma? a. pterionb. tegmenc. arcuate eminenced. greater petrosal nerve
C. arcuate eminenceThe arcuate eminence (#19 in the image below) is the superior extent of the superior semicircular canal. It can be appreciated on the superior aspect of the midpetrous ridge, important landmark during the middle fossa approach for localization of the internal auditory canal (IAC). Lateral to the arcuate eminencetegmen tympani and tegmen mastoideum
What are the AAO-HNS diagnostic criteria for definite Meniere's Disease?
1995 AAO-HNS criteria for definite Meniere's Disease:----2 or more definitive spontaneous episodes of vertigo lasting >20 minutes----Audiometrically documented hearing loss (SNHL) on at least 1 occasion----Tinnitus or aural fullness----Other causes excluded
What is the histologic marker of Meniere's Disease?
Endolymphatic hydrops is the histologic marker of Meniere's Disease. In this study all 28 symptomatic patients had hydropsHOWEVER, there are some asymptomatic patient temporal bones with hydrops.Otol Neurotol. 2005 Jan;26(1):74-81
What is the role of dexamethasone in treatment of Meniere's disease?
Intratympanic (IT) dexamethasone in the treatment of MD has limited data. One randomized trial of 5 consecutive days of IT 4mg/ml dexamethasone showed 82% complete control of vertigo compared to placebo rate of 57%.Otolaryngol Head Neck Surg. 2005 Aug;133(2):285-94.
What is the best study to determine absence of cochlear nerve?a) ABRb) OAEsc) MRId) CT
c) MRIOAEs test outer hair cell functionABR performance could be abnormal for many reasons, as it tests the pathway from the haircells to the brainstem.CT scan can assess IAC diameter; However, it would miss all cases of absent cochlear nerve
when the IAC is normal sizeThus, MRI should be the primary modality for imaging children with severe to profound SNHL.Otol Neurotol. 2007 Aug;28(5):597-604.
A 1 year old has congenital deafness. Prior to cochlear implantation, an MRI is obtained. What are the structure at the arrow? What is the structure at the arrowhead?
Arrow = facial nerve; Arrowhead = cochlear nerveThis is an oblique sagittal MRI of the distal IAC. This is a right ear; note the cerebellum is posterior for orientation; The facial nerve is superior and anterior in the IAC; The cochlear nerve is anterior/inferior in the IACThe superior and inferior vestibular nerves are posterior in the IAC and often run as a complex
In the midportion of the IAC, what should be the normal size relationship between the facial nerve and the cochlear nerve?
At the midportion of the IAC, the cochlear nerve should be the same size or larger than the facial nerve. If the cochlear nerve is smaller than the facial nerve, it is considered "deficient". If the cochlear nerve cannot be identified, it is considered "absent".Otol Neurotol. 2011 Aug;32(6):956-61
The superior vestibular nerve carries information from which of the following?a) Superior semicircular canalb) Sacculec) Horizontal semicircular canald) Utriclee) Posterior semicircular canal
Superior vestibular nerve carries information from:a) Superior SCC c) Horizontal SCCd) Utricle (I remember that U = Up and Utricle = UP)The Inferior vestibular nerve carries information from:b) Sacculee) Posterior SCCREMEMBER: VEMPs stimulate the saccule and inferior vestibular nerve
Name the otolithic organs of the vestibular system and what do they detect?
The otolithic organs (or macular organs) are the Utricle and SacculeThe utricle and saccule detect linear accelerationThe image shows how the type I (flask shaped) and type II (cylinder shaped) hair cells sense motionThe kinocilium is the longest stereocilia and this is surrounded in a gelatinous matrix covered with otoconia.Stimulation is through shear force and activation of ther stereocilia
What is the structure labeled with the black arrow?
StriolaThe macular organs (saccule and utricle) detect linear acceleration and are oriented perpendicular to each other.The striola divides the macular organs and the kinocilium of the hair cells are oriented in opposite directions on either side of the striola; The kinocilium is pointed toward the striola in the utricle; The kinocilium is pointed away from the striola in the sacculeStimulation always increases with deflection toward the kinocilium; Thus, vertical acceleration increases firing in the pars externa (pe) in the saccule and decreased firing in the pars interna (pi).ALSO NOTE: this diagram has the saccule above the utricle, which is only for diagram purposes (the utricle is superior to the saccule)
What is the structure labeled with the black arrow?
StriolaThe macular organs (saccule and utricle) detect linear acceleration and are oriented perpendicular to each other.The striola divides the macular organs and the kinocilium of the hair cells are oriented in opposite directions on either side of the striola; The kinocilium is pointed toward the striola in the utricle; The kinocilium is pointed away from the striola in the sacculeStimulation always increases with deflection toward the kinocilium; Thus, vertical acceleration increases firing in the pars externa (pe) in the saccule and decreased firing in the pars interna (pi).ALSO NOTE: this diagram has the saccule above the utricle, which is only for diagram purposes (the utricle is superior to the saccule)
What is the most common presenting symptom/sign patients with the condition shown in the axial CT?
89% of patients present with facial paresis or paralysis (Table); many have facial twitchingDX: GENICULATE GANGLION HEMANGIOMAThe CT shows a mass in the geniculate ganglion/labyrinthine segment often with "calcium stippling" and poorly marginated lesionContrast this to facial nerve schwannomas show smooth margins and no intratumoral calcium
What is the most common presenting symptom/sign patients with the condition shown in the axial CT?
89% of patients present with facial paresis or paralysis (Table); many have facial twitchingDX: GENICULATE GANGLION HEMANGIOMAThe CT shows a mass in the geniculate ganglion/labyrinthine segment often with "calcium stippling" and poorly marginated lesionContrast this to facial nerve schwannomas show smooth margins and no intratumoral calcium
A patient presents with a geniculate ganglion hemangioma. If the patient has hearing loss, what type of hearing loss will this patient most likely have?
Hearing loss can occur in patients with geniculate ganglion hemangioma (about 20%). All patients present with SNHL.Cochlear fistula from otic capsule erosion can occur and may be seen on pre-op CT scan; Attempting to remove the hemangioma will most likely deafen the ear.
A patient presents with progressive facial paralysis and MRI enhancement of the geniculate ganglion consistent with geniculate ganglion hemangioma. The lesion histologically will demonstrate:a) endothelial cells with mitosisb) fat cellsc) Absence of glucose transporter protein isoform 1 (GLUT-1) stainingd) Spindle cells
c) Absence of glucose transporter protein isoform 1 (GLUT-1) stainingGeniculate ganglion hemangiomas are NOT actually hemangiomas. Instead they are venous vascular malformationsThey do not stain for GLUT-1 as other hemangiomas doAlso negative for podoplanin (stain for lymphatic endothelial cells)
What do otoacoustic emissions (OAEs) test?
OAEs test outer hair cell function.OHCs are capable of changing shape (contracting and elongating) when stimulated and function as the cochlear amplifierTransient evoked OAEs (TEOAEs) are record after a broad-band auditory stimulusThe presence of TEOAEs in ears with normal middle ear function suggests normal OHC function and is considered to be indicative of normal audiometric sensitivity. TEOAEs are used for newborn hearing screen (NBHS); REMEMBER: the presence of an evoked OAE does not tell anything about the integrity
of the auditory nerve or central auditory systemRef: CUMMINGS
A child presents with delayed speech production who passed their newborn hearing screen (NBHS). Now ABR is absent. Diagnosis?
Auditory NeuropathyCharacterized by absent or impaired ABR with intact outer hair cell function (OAEs) and/or cochlear microphonicsDefect would localize to the inner hair cells, the synapse between the inner hair cells and the auditory nerve, or the auditory nerve itself.
True OR False: Patients with auditory neuropathy benefit from cochlear implantation.
True: Patients with auditory neuropathy achieve average to above-average performance with cochlear implants.Ann Otol Rhinol Laryngol Suppl. 2002 May;189:29-31
Terms Definitions
Contraindications to cochlear implantMichel's inner ear aplasiaSmall IAC syndrome
Most common primary malignant tumor of the temporal bone in adults
SCCA
Hearing findings in Paget's disease50% of patients with the disease have hearing loss. Mixed SNHL and CHL seen.
Histologic patterns in acoustic neuroma
Antoni A: densely packed cells with small spindle shaped nuclei (compact, cellular)
Antoni B: loosely arranged vacuolated, pleomorphic cells
Terms Definitions
Audiometric criteria for BAHAPTA thresholds lower than 60 dB and speech discrim scores greater than 60%.
How far back from the auricle should the screw for a BAHA be placed?
50 to 55 mm posterior to the EAC.
How do osteomas and exostoses differ on exam?
Ostoeomas are solitary pedunculated lesions that are smooth and round and originate on the tympanosquamous or tympanomastoid suture lines. Exostoses are broad-based and occur
around the circumference of the medial aspect of the EAC, more often bilateral.
What are two surgical procedures for BPPV that fails to respond to noninvasive treatment?
Singular nerve sectioning and PSCC occlusion.
What are spondee words?Two syllable words with equal stress on each syllable such as: hot dog, baseball, eardrum
What is the speech reception threshold?
Softest intesity at which a patient can correcty repeat spondee words 50% of the time. Should have good agreement with the PTA (as the PTA measures speech frequencies).
How is speech discrimination measured?
A list of 25-30 phonetically balanced single-syllable words are presented at a fixed intensity. The percentage of words correctly repeated is recorded.
What is believed to be stimulated by a cochlear implant?
Spiral ganglion cells
Where is the cochleostomy made for a cochlear implant?
Just anterior and inferior to the round window.
Adult candidacy criteria for cochlear implantation
1) Bilateral severe to profound hearing loss2) Minimal benefit from conventional hearing aids (<40% to 50% sentence recognition scores in the best aided condition)3) No medical contraindications"
Describe the histology of osteomas and exostoses.
Osteomas consist of lamellar bone around trabeculated cancellous bone that contains marrow spaces or fibrovascular tissue. The bone is lined with periosteum and keratinizing stratified squamous epithelium.
Exostoses consist of parallel layers of subperiosteal bone containing no or only poorly developed trabeculated fibrovascular channels.
Pediatric candidacy criteria for cochlear implantation
1. >12 months of age2. Bilateral severe to profound SNHL (PTA 90 dB or greater in better ear)3. No appreciable benefit with hearing aids (parental survey if <5 years, 30% sentence
recognition if >5)4. Tolerate wearing hearing aids (or device)5. Enrolled in education program with aural/oral component6. Motivated parents
8 terms
Terms Definitions
Describe Michel's deformityComplete aplasia of the inner ear. AD. Arrested development at 3rd week (otic placode). Very rare. Profound hearing loss.
Describe the common cavity deformity
Common cavity for cochlea and vestibule. Common form of congenital HL. Arrested growth at 4th week (otocyst). SCC may be normal. Severe to profound SNHL.
Describe cochlear aplasia.
Infrequent cause of congenital HL. Arrested development at 5th week (cochlear bud). Cochlea fails to form. Remnants of vestibule and canals are appreciated. Profound hearing loss.
What syndrome is cochlear hypoplasia associated with? When in embryogenesis does the defect occur?
Branchio-Oto-Renal. 6th week (cochlear duct).
How does Mondini malformation present?
Progressive dor fluctuating unilateral or bilateral hearing loss. Autosomal dominant. Increased risk of perilymphatic gushers and meningitis.
Describe the Mondini malformation.
Incomplete cochlear partition. Basilar turn present, common cavity for middle/apical turns. Arrest of maturation at 7th week. Most common congenital cochlear defect. SCC may be absent or wide, wide vestibular aqueduct. Unilateral or bilateral SNHL.AD
What's the syndrome: profound hearing loss and prolonged QT interval
Jervell-Lange-Nielsen. Profound SNHL due to auditory snese organ agenesis. May have syncopal attacks in early childhood. Risk of sudden death due to arrythmia. Treat with beta blocker.
Findings in Jervel-Lange-Nielsen syndrome
Profound SNHL and prolonged QT
What type of hearing loss is associated with Treacher-Collins syndrome?
Conductive
Difference between Treacher Collins and Goldenhar syndrome
UPPER lid coloboma in Goldenhar, lower lid in Treacher Collins
Describe the embryology of the stapedial artery
Derivative of 2nd branchial arch. Courses from ICA to fallopian canal and geniculate ganglion. Terminates in the middle meningeal artery. Usually regresses by 10th week.
How many hours can you be exposed to 110 dB in the workplace per OSHA?
30 min
How many hours can you be exposed to 115 dB in the workplace per OSHA?
15 min
How does gent ototox present initially.ataxia in dark, low freq SNHL, Dysequilibrium only on exertion"
Ataxia in the dark. Gent is vestibulotoxic more than ototoxic.
Incidence of dehiscent fallopian canal
up to 57%
Most likely dx for chronic otorrhea, TM perf, new onset of facial paralysis, with no e/o cholesteatoma?
Dehiscent fallopian canal.
What part of the cochlea is a cochlear implant inserted in to? What is stimulated?
through the round window into the scala tympani. the spiral ganglion is stimulated.
What part of CN VII is most likely to be injured in a canaloplasty?
distal segment of the mastoid portion
What condition results in a maximal conductive hearing loss?
Intact TM with ossicular discontinuity (55-65 dB). TM perf allows more sound through so CHL is 30-50 dB.
Cause of preauricular pit? Failure of fusion of 1st and 2nd hillocksPt s/p stapes L ear, now with 3-4days vertigo after surgery. What test to do next?
Fistula test. Likely a PLF. Reparative granuloma usually at 8-10 days.
Type of hearing loss in Wegener's granulomatosis
CHL. Usually a SOM due to ET obstruction.
Pt with blue sclera and hearing loss, short stature. When doing surgery, what do you have to watch out for?
Osteogenesis imperfecta. Ossicles are fragile.
Findings in Usher's.SNHL and retinitis pigmentosa (abnormal electroretinogram)
s/p T-mastoid for cholesteatoma extending into epitympanum, what is the best way to confirm the absence of residual disease?
2nd look surgery
Patient with cochleootosclerosis at increased risk for what with
stimulation of facial nerve
cochlear implant.a) Placement of electrode into IACb) Stimulation of facial nerveMost common site of facial nerve injury
Tympanic segment
Working between basal turn and jugular bulb. Break a membrane and get pulsing clear fluid. What did you get into?
Cochlear aqueduct
Where's a congenital cholesteatoma most often seen? What's the best surgical approach?
Anterior superior quadrant. Transcanal with superior based tympanomeatal flap.
What is the appropriate treatment for traumatic perilymph fistula
Conserative for 2-3 days with bed rest. If symptoms persists, then explore.
Best type of audiogram for a child <5 months
behavioral observation
best type of audiogram for a child 5m to 2 yers
visual reinforcement
best type of audiometry for a child 2 to 5 yrs
conditioned play audiometry
what age group are each types of audiometry best for: behavioral observation, visual reinforcement, conditioned play
behavioral observation: <5mvisual reinforcement: 5m to 2 yrsconditioned play audiometry: 2 to 5 yrs
What is the earliest recommended age for surgical treatment of atresia?
5-6 years (need to wait for mastoid to pneumatize). until then, use bone conduction aid.
What are classic findings of glomus jugulare extension into the middle cranial fossa, posterior cranial fossa, or middle ear?
MCF: VII palsyPCF: ataxia and imbalanceMiddle ear: CHL and pulsatile tinnitus
Where do olivocochlear nerve fibers go?
To the outer hair cells and their afferents
Terms DefinitionsWhat are some things that can happen during birth than can be risk factors for acquired hearing loss?
Perinatal hypoxia, bradiacardia during delivery, perinatal cyanosis, poor muscle tone after delivery, admission to the NICU
8 week old failed infant hearing screening. Prenatal history questions to ask? HPI? Family history/social history questions to ask?
PRENATAL:What is the birth history?Were there complications with the pregnancy?Full term?Was there any hypoxia?Was the child admitted to the NICU?
HPI:Any ear infections or fluid in ears?Ototoxic medications?Pacifier use?
FAMILY/SOCIAL:Mother with STDs?Drug use?Daycare?Smokers at home?Family history of hearing loss?Are there siblings? Any medical problems?Any history of sudden death at a young age?Any history of thyroid problems?
Tests to order for failed hearing screening?
1. ABR for thresholds wih AC and BC.2. Transient evoked OAE's.3. MRI with fast spin ECHO.4. UA (look for hematuria for Alport's)5. Consider TFT or EKG depending on history.6. FTA-ABS
Hearing aid trial. Retest hearing every 6 months. Begin CI workup.
What percentage of patients with sudden sensorineural hearing loss have vestibular schwannomas?
1%
What percent of patients with vestibular scwhannomas present with sudden sensorineural hearing loss?
10%
Terms Definitions
1) otoscopyuses1. xm of ext ear, TM, middle ear if perforation2. surgically in myringoplasty, stapedectomy
II) siegle's speculumuses: testing TM mobilityN free mobile limited or absent in : MEE & adhesive otitis media
III) politzer's bag uses:- dx of ET obstr- tx of ET dysfunction bu repeated inflation
cx:- TM perforation- spread of infection (AOM)
- pneumatocele (air in brain)
IV) CN xm
1. trigerminal n 5th - absent corneal reflex- weakness of ms of mastication2. abducent n 6th: diplopia-> lat rectus paralysis (LR6)3. facial n 7th :- frontalis p- orbicularis occuli p- orbicularis oris p
4) glossopharyngeal n (9th)absent gag reflex
5) vagus n 10th VC paralysis
6) accessory n (11th)- weakness of sternomastoid & trapezius ms
7) hypoglossal n (12 th)- deviation of tongue
V) tuning fork tests 1. rinne's test mcqAC compared to BC in same earresults: - AC > BC (+ve) in N ear- BC> AC (-ve) (dec AC, N BC) in CHL- AC> BC but both reduced (reduced rinne's +ve) in SNHL
2. weber's test mcqBC compared btw both earsresults:- no lateralization (equal in both sides) N- lateralize to diseased ear : CHL- lateralize to N ear : SNHL
3. schwabach test- bone conduction (BC) of pt compared to BC of physicianRESULTS:. N, both equal. shortened schwabach test : SNHL. prolonged schwabach test: CHL
4) gille's testtuning firk placed over mastoid while P in EAC
changed by siegel's otoscopeRESULTS:- N ear : BC dec by applying P changes (ossicular fixation)- otosclerosis : no change (ossicle already fixed)
VI) pure tone audiometry (PTA)
uses:1. detect hearing loss2. differentiate type of hearing lossa) N : BC & AC at N (0-25 dB) and no air-bone gapb) CHL: air bone gap, BC N , AC decc) SNHL: BC , AC dec e no air bone gapd) mixed: BC, AC dec e air-bone gap
3.give etiology of SNHL- low frequency SNHL- high freq SNHL- high freq at 4 Khz
1) objective test ti detect hearing level so useful in. child. mentally retarded. malingers2. diff btw sensiry & neural- srnsory: preserved waves- neural : absent or delayed
surgical operations 1. myringotomy in AOM2. myringoplastyI: central TM perforation e intact ossicular chain3. tympanoplasty: I: central TM perforation e ossucular discontinuity
4. mastoidectomyDEF: excentraction of mastoid air cell system
e) intact canal wall mastoidectomy (can up mastoidectomy)
cx:- facial n inj (ant wall of mastoid)- sigmoid sinus inj (pist wall)- CSF otorrhea (sup wall)- labyrinth inj (dead ear / vertigo) med wall
5) stapedectomyDEF: replacement of stapes bone e prosthesisINDICATIONS:- otosclerosis- cong fixationCX:- persistent conductive deafness- SNHL- perilymphfistula- dizziness
Terms Definitions
embryology of hillocks of his
1st branchial arch (Hillocks of his 1-3)1 - tragus2 - helical root3 - helix2nd branchial arch (Hillocks of his 4-6)4 - antihelical crus5 - antihelix6 - antitragus and lobule
small protuberance from posterosuperior helix
Darwin's tubercle
this embryologic structure forms the EAC first branchial cleft/groove
sensory contributions to auricle and EACV3, VII, IX (Jacobsen's), X (Arnold's), greater auricular nerve (cervical), lesser occipital nerve
lymphatic channels connecting lateral cartilaginous EAC with glenoid fossa and parotid region, allows for extension of infection and malignancy
Fissure of Santorini
lymphati channels connecting medial EAC with glenoid fossa and parotid region, allows for extension of infection and malignancy
Foramen of Huschke
Forms EAC and outer epidermal squamous layer of TM
first branchial cleft
Forms middle fibrous layer of TM mesodermforms inner mucosal layer of TM first branchial pouch (endoderm)
shape and boundaries of facial recesstriangular - bound superiorly by short process of incus (fossa incudis), medially by facial nerve, laterally by chorda tympani
4 parts of temporal bone (surface anatomy) petrous, squamous, mastoid, tympanic
muscle attaching to malleus - where it attaches to and CN
tensor tympani - from cochleariform process to malleus neck and manubrium (V3)
muscle attaching to stapes - where it attaches to and CN
stapedial muscle, from pyramidal eminence to posterior neck (CN VII)
how does stapes attach to oval windowfootplate attaches to bony margins of oval window by the annular ligament forming a joint (syndesmosis)
embryologic origin of eustachian tube ventral first branchial pouchwhere ET ends in nasopharynx torus tubarius
muscles associated with ET
tensor veli palatini (V3, includes dilator tubae), levator veli palatini (pharyngeal plexus), tensor tympani (V3), salpingopharyngeus (pharyngeal plexus)
vertical divisions of middle ear spaceepitympanum (above annulus), mesotympanum (betw superior and inferior annulus), hypotympanum (below annulus)
fissula ante fenestrum - location and significance
anterior to oval window, common site of otosclerosis
tympanic branch of CN IX Jacobsen'stympanic branch of CN X Arnold's nervethe mesenchyme (mesoderm) encapsulating the otocyst forms this cartilaginous structure. ossification of this occurs around the 16th week
otic capsule
the cochlear aqueduct contains this structure. it is ends in posterior cranial fossa, inner ear
periotic duct
opening as at base of scala tympanithe vestibular aqueduct contains this structure and veins of vestibular aqueduct. it runs from the vestibule to the posterior surface of the petrous pyramid in the posterior cranial fossa
endolymphatic duct
opening of the endolymphatic duct operculumectodermal thickening on side of head forms this around day 22-23
otic placode
otic placode deepens to form this, which later forms ___, this then forms ___
otic pit, otocyst, membranous labyrinth
the endolymphatic duct connects the endolymphatic compartment to this
endolymphatic sac
labyrinthine fluid similar in composition to extracellular fluid and CSF (Na>K)
perilymph
labyrinthine fluid similar in composition to intracellular fluid (K>Na)
endolymph
type of hair cells and shape in crista ampullaris, what they contain, and what type of movement produces firing
type 1 (flask shaped) (think container for #1)type 2 (cylindrical shaped) (think #2 shape)contain 1 kinocilium and ~60 stereocilia, deflection toward kinocilium -> increased vestibular neuronal firing rate
in horizontal SCC, this type of movement increases vestibular neuronal firing rate
ampullopetal - displacement of stereocilia toward the vestibule (kinocilia are on utricular side). ampullofugal decreases vestibular neuronal firing rate. (think pedestrians walk horizontally, increases rate)
in vertical SCCs, this type of movement increases vestibular neuronal firing rate
ampullofugal - displacement of stereocilia away from the vestibule (kinocilia are on the SCC side). ampullopetal decreases vestibular firing rate (think vertical spinning produces centrifugal force)
this otolith organ detects horizontal acceleration." " " " vertical acceleration
horizontal - Utricle (think U-haul driving horizontally)vertical - Saccule (think sac bouncing up and down)
sensory element of otolith organs, consists of supporting cells and hair cells whose stereocilia/kinocilia are within an overlying gelatinous mass on surface of which lies the otolithic membrane and otoliths (otoconia)
macula
superior vestibular nerve innervates (3 structure)
this structure contains perilymph and begins in vestibule." " " and begins at round window
scala vestibuliscala tympani
this structure contains endolylmph and organ of Corti
scala media
2 cell layer membrane between scala media and scala vestibuli
Reissner's membrane
between scala media and scala tympani, stifffer and thinner at base, supports organ of Corti
basilar membrane
this forms the lateral wall of the scala media, Na/K ATPase keeps potential ~80mV, contains highly metabolically active cellsa nd supports cochlear function
stria vascularis
Supporting cells of organ of cortiDeiter'sHensen'sClaudius's cells
these hair cells are in a single row, rounded (flask shape with nucleus in center), afferent innervation is type I (radial, bipolar, myelinated) 95% of fibers, each is innervated by 10-20 neurons, efferent innervation is sparse
inner hair cells
may amplify motion from basilar membrane (cochlear amplifier), 3 rows, cylindrical shaped, afferent innervation is type II (spiral, pseudomonopolar, unmyelinated) form 5% of fibers of cochlear nerve, efferent innervation from auditory cortex to cochlear nuclei with additional contributions from superior olive
outer hair cells
area advantage (hydraulic) ratio of vibrating portion of TM and stapes footplate
17:1
the lever action of the ossicles affords this advantage ratio
1.3:1
transformer ratioarea advantage + lever advantage = 22:1 or approximately 25-30 dB gain
how the TM protects the round window
allows a phase difference between sound conducting to oval window and sound directly reaching round window (if simultaneous, forces would suppress cochlear fluid wave)
tonotopic organization of cochleahigher frequencies at base, lower frequencies at apex
auditory nerve pathway E COLI
Eighth nerveCochlear nucleusOlive (bilateral innervation from cochlear nucleus)Lateral lemniscusInferior colliculus (then to thalamus->auditory cortex in temporal lobe)
direction of nystagmus determined by this phase
fast phase
the physiologic component of nystagmus slow phasea right sided peripheral disorder results in a ___ beating nystagmus
left
Alexander's law - pathologic peripheral nystagmus will ___ when in direction of fast phase and ___ in direction of slow phase
increase, decrease
Ewald's law - (1) peripheral nystagmus is in the plane of SCC being stimulated and its direction is ___ to direction of endolymphatic flow (2) stimulating/excitatory responses are ___ than inhibitory responses
oppositegreater
formula for Bell, decibel
I = Psquared, P= unit of sound pressure levelBell (B) = log (Iinput/Ireference) = unit of intensity leveldB = 10 log (Ioutput/Ireference)dB = 10 log (Poutput sq/Preference sq) = 20 log (Poutput/Preference)
Speech reception threshold (SRT)lowest dB HL at which patient can repeat a spondee (2 syllable word) 50% of the time
Word recognition score (WRS)
% of phonetically balanced monosyllabic words (phonemes) repeated correctly after being presented at 20-40dB SL above the SRT
interaural attenuation for different devices (headphones, bone conduction)
amount of sound intensity needed before crossover occursinsert headphones - 70 dBover the ear headphones - 40 dBbone conduction - 0 dB
masking dilemmabilateral ABG of 50-70dB cannot be masked
recruitment causes this effect. it suggests this type of hearing loss
increasing sound intensity produces out of proportion perception of loudness. cochlear hearing loss
rollover is this. it suggests this type of disorder
paradoxical decrease in word recognition ability with increasing sound intensity.retrocochlear disorder
tone decay and fatigue is this and suggests this type of disorder
decrease in auditory perception with sustained signal stimulus.retrocochlear disorder
this type of OAE is used in neonatal screening
TEOAE - transiently evoked OAE
OAE for hearing screening, ototoxicity, noise induced hearing screening. able to record higher and more specific freqencies than TEAOE
DPOAE - distortion product OAE. simultaneous application of 2 pure tone frequencies
Stenger's test
2 tones of same freq cannot be heard by both ears if one is louder - alleged poorer ear receives tone at higher intensity. should hear in better ear if truly poor hearing. if report nothing suspect pseudohypoacusis.
Lombard test
introduce background noise below recorded response threshold as subject asked to read aloud - suspect pseudohypoacusis if voice gets louder
sounds used in ECoGelectrocochleography - uses wide band clicks or frequency specific pips
measurement in ECoG and what is its significance
summation potential and compound action potentialSP amplitude/CAP amplitude - it is elevated in certain disease (>/=0.45 in 66% of Meniere's disease and syphilis), intraoperative monitoring
summation potentialdirect current generated predominantly from stria vascularis or hair cells
whole-nerve (compound) action potential (CAP)
respresents the summation of many individual nerve fibers, "all or none response", N1 is identical to the ABR wave I
mnemonic for indications for ABR
TV DINthreshold testing in those where behavioral testing would be difficult (ie neonates)vestibular schwannoma/retrocochelar pathology concerndiagnosis of brainstem lesion/pathologyintraoperative monitoringneonatal screening
interaural wave V latency difference (normal <-.2ms)abnormal interaural wave I-V and III-V latency differenceprolonged interwave latency between I-V or I-IIIincreased absolute latency measurements
part of cochlea that cochlear implant sits in and where it is placed through
scala tympaniround window
audiogram indications for cochlear implant
minimal benefit from hearing aidsHearing in Noise Test (HINT) <50% in ear to be implanted in best aided conditionsWRS <20% bilaterally
fistula test
Hennenbert's sign - positive pressure causes nystagmus which reverses with negative pressure, may be seen in perilymph fistula and syphilitic labyrinthitis
these antibiotics affect vestibular function more than auditory function
streptomycin and gentamycin
aminoglycosides exert ototoxic effects by damaging these
vestibular and cochlear hair cells
most common ototoxic diuretic agents and where they act
furosemide and ethacrynic acidstria vascularis
postive and negative Rinne tests
positive - AC>BC normal ear or most SNHLnegative - BC>AC CHL or severe to profound SNHL with crossover
weber test findings in SNHL, CHLSNHL - lateralize to better hearing earCHL - lateralize to diseased ear
most common cause of pulsatile tinnitus and treatment
pseudotumor cerebri or benign intracranial hypertension (esp in overweight females, 20-30yo)trx - wt loss and diuretics
common pathogens in acute OMS. pneumoniae (most common)H influenzae, moraxella catarrhalis, gram negative bacilli, group B strep in infants
most common cause of pediatric hearing loss serous OM (OM with effusion)__% of AOM pts have persistent fluid at 1 month__% have fluid at 3 months
50%10%
high risk pathogens in OM type III pneumococcus (intracranial predilection)H. influenzae type B (higher risk
meningitis)presence of coexisting anaerobes
OM can spread intracranially through thisHyrtle's fissure (tympanomeningeal hiatus), embryologic remnant connecting hypotympanum to subarachnoid space
triad seen in petrous apicitis
Gradenigo's triadotorrhearetro-orbital paindiplopia or abducen's palsy (from involvement of Dorello's canal)
pathogens in meningitisH influenzae type Bpneumococcus, hemolytic streptococcus
SSx meningitis
Kernig's (hip in flexion, pain elicited with leg extension)Brudzinski's (with neck flexion there is reflexive leg flexion)HA, lethargy, nuchalr rigidity, irritability, fever, seizures, photophobia
2 physical exam finding of lateral sinus thrombosis
Griesinger's sign - edema and pain over mastoid from occlusion of the mastoid emmisary veinTobey-Ayer or Queckenstedt's test - normally external compression of jugular increases CSF pressure 60-100mmHg, compression on side of lateral sinus thrombosis results in slow or no rise in CSF pressure)
type of patients usually affected by keratosis obturans (compared to canal cholesteatoma), what type of laterality is it usually?
youngerbilateral
canal cholesteatoma usually affects what type of patients (compared to keratosis obturans)? laterality?
olderunilateral
exostoses of canal associated with this and affects this part of the canal
cold water swimmingmedial bony canal
this is usually a single unilateral protrusion at the bony-cartilaginous junction
osteoma
causes of TM perforationsacute/chronic suppurative OM (most common cause),PE tube, trauma, iatrogenic, cholesteatoma
primarily acquired cholesteatomas are most common in these pockets and invade epitympanum through this
pars flaccida pocketsPrussak's space
__% of paragangliomas have a family history__% are multiple<__% malignant degeneration
10%10%<5%
__-__% associated with a paraneoplastic syndrome
1-3%
most common paraganglioma in the head/neck
carotid body (glomus caroticum)
most common paraganglioma in temporal bone
glomus jugulare
2 physical exam signs seen with paragangliomas
Brown's sign - reddish middle ear mass, blanching of TM with positive pressure in glomus tympanicumAquino's sign - pulsation of paraganglioma decreases with carotid artery compression
blood supply to glomus tympanicum ascending pharyngeal
glasscock jackson classification glomus tympanicum
I - promontoryII - fills middle ear spaceIII- extends to mastoidIV - extends to EAC, anterior to carotid
cup ear deformitydeep conchal bowl, anterior protrusion of auricular cartilage
grades of microtia I - auricle slightly smaller but all subunits present (lop, cup ear)
II - auricle half size, all major structures present but absolute deficiency of tissueIII - small piece of cartilage in superior remnant, anteriorly deflected inferior lobule (peanut ear) or anotia
what Frenzel lenses doprevent ocular fixation that may suppress nystagmus
nystagmus due to peripheral lesions usually increase or decrease with fixation
decrease
this is what you call over or undershooting of eye rotation
ocular dysmetria
theoretical normal response in caloric testingCOWScool oppositewarm, same
VEMP tests this nerve, ENG tests this nerveinferior vestibular nervesuperior vestibular nerve
VEMP is useful in evaluation of these disorders
Meniere's diseaseSSC dehiscence (20dB increase in sensitivity)inferior vestibular nerve lesionsaccule function
I - compression of nerve, complete recovery anticipatedII - axon transected endoneurium intactIII - neural tube and endoneurium violated, high risk synkinesisIV - perineurium violatedV - complete transection, epineurium violated
facial paralysis after IMA embolization - petrosal branch off of middle meningeal
why? artery supplies area of geniculate
House Brackmann scale
I - normalII - mild - weakness on close inspectionIII - moderate - more obvious asymmetry with movementIV -moderately severe. scleral show, asymmetry at restV - severe - barely perceptible movementVI - total paralysis
distal branches of facial nerve can be stimulated up to this many days before (after?) transection
3
nerve crossove or transposition graft uses this nerve
hypoglossal
Terms Definitions
What is presbycusis?
bilateral, high-frequency hearing loss with aging that results in1) decreased hearing threshold sensitivity2) decreased ability to understand supra-threshold speech3) impairment of central auditory processing
The outer ear is composed of what structures? Functions?
Pinna: increases dBs arriving at tympanic membrane by as much as 20 dB
Auditory Canal: allows access to the delicate machinery of the middle ear; it produces wax which is extruded via a ciliary action
What is meant by "impedance mismatch" in reference to the function of the middle ear?
natural impedance resulting from air to liquid pressure transfer would decrease the sound pressure arriving at the cochlea by about 30 dB (equivalent of plugging your ear)
How does the middle ear compensate for the impedance mismatch?
Pressure = Force / Area, thus you want to increase the force and decrease the area
Increase F: leverage from the pivot point of the malleous and incus increases F by 1.3x
Decrease A: the tympanic membrane is 20x larger than the oval window connected to the stapes, thus A is decreased by 20x
Increases sound pressure by 28x, thus effectively cancelling the impedance mismatch.
What is conductive hearing loss? Examples?
anything that impedes the mechanical transmission of sound from the air to the cochlea; localized to the external ear, tympanic membrane, and middle ear
What are some examples of conductive hearing loss?
1) Obstruction of the ear canal by wax2) Hereditary atresias of the ear canal3) Acquired atresias of the ear canal (swimmer's ear, cauliflower ear)4) otitis media w/ effusion5) otosclerosis (fusion of incus to stapes)6) perforation of the tympanic membrane
What separates the scala vestibuli from the scala media? Scala media from scala tympani? What connects the scala vestibuli and scala tympani?
membrane of reissner, basilar membrane, helicotrema
What are the properties of the basilar membrane at its base? Apical end?
base: 0.04 mm, narrow, held tight (high frequencies)apex: 0.5 mm, wide, more floppy (low frequencies)
What is perilymph? Where would it be found?
standard ECF (high Na+, low K+), it is in the scala vestibuli and scala tympani
What is endolymph? Where would it be found?
standard ICF (high K+, low Na+), but located extracellularly in the scala media, its high K+ concentration is due to K+ being actively pumped through the stria vascularis (epithelium on the side of the scala media)
What is the electrochemical potential of K+ from apical to basal sides of an auditory hair cell?
-80 mV potential due to apical membrane being exposed to endolymph in scala media and basal membrane being exposed to perilymph of scala tympani; since intracellular environment is maintained at -50 mV, the effective potential is -130 mV
What is the "cochlear amplifier"?
prestin protein present in the outer hair cells extends during depolarization producing more movement of the inner hair cells for smaller vibrations of the basilar membrane
What is sensorineural hearing loss?
impedes the electrical transmission of sound through the ascending auditory system; separated into sensory (presbycusis, noise trauma, ototoxicity) and neural (8th nerve tumors, MS, neural sarcoid) types
What are some ways that outer hair cells can be damaged, leading to sensorineural hearing loss?
a disorder of the inner ear that can affect hearing and balance
characterized by: 1) episodes of vertigo due to endolymphatic hydrops (lasting >20 min w/ more than one episode)2) low-pitched tinnitus3) a fluctuating hearing loss (low frequency) due to dysregulation of fluids in the cochlea producing distention in the "floppy" low frequency portion of the basilar membrane
* time course unpredictable
* treated with low salt diet and diuretics initiallyEach ear contains about _____ nerve fibers comprising. Of these, ____ are Type I (myelinated) nerve fibers and ____ are Type II (unmyelinated) nerve fibers.
30 thousand, 95%, 5%
Type I fibers innervate ___________, while Type II fibers innervate __________.
IHS (inner hair cells), OHS (outer hair cells)
What is meant by the "characteristic frequency" of an auditory nerve fiber? How is this related to "frequency tuning"?
it tells you the location along the basilar membrane that a hair cell innervated specifically by that nerve fiber optimally detects stimuli
With this "frequency tuning" it takes a lower intensity stimulus of a certain frequency to produce a threshold response at a nerve fiber's characteristic frequency
This produces the tonotopic organization of the auditory system.
Neurons encode sound level via _____________. What additional mechanism is responsible?
discharge rate, however this is only functional over a limited dynamic range (20 dB range per neuron for a given frequency)
for high-intensity levels, adjacent auditory hair cells are recruited because they are affected by the significant basilar membrane displacement
thus, both increased rate from individual neurons and increased # of overall firing
neurons contributeLow-frequency sensitive auditory neurons exhibit "phase-locking" to sound waves, however this phenomenon declines in neurons sensitive to frequencies greater than _______. What information is encoded in phase-locking?
1.5 kHz, timing of the stimulus; although each neuron may fire an AP only one out of maybe five times, the collective group will on average fire an AP each time there is a low frequency pressure fluctuation thus keeping track of timing for low-frequency stimuli
Auditory system is very sensitive to hypoxia because there is no direct _____________.
blood supply
The "what" part of sound information is processed as _______________.
spectrograms, which are composed of the spectral (pattern of sound frequencies and their intensities) and temporal (pattern of the relative times of the sound frequencies)
The interaural time difference is very useful for detecting where a sound is localizing on the _____________ axis. It is sensitive to as little as a 10 micro-second difference.
horizontal
The duplex theory of sound localization states that low frequency sounds are localized via _______________, while high frequencies are localized via ______________. Why? What are the corresponding nuclei through which they act?
Interaural Time Differences as phase-locking enables a standard and acoustic shadows are not produced because of the long wavelengths (Medial Superior Olive)
Interaural Level Differences because phase-locking is lost at these high frequencies and the short wave lengths are reflected by the head producing an acoustic shadow (Lateral Superior Olive)
What clinical manifestation would the following lesion locations produce:1) lesion in the left inferior colliculus2) lesion in the left cochlear nucleus
1) hearing would be about normal, however there would be a deficit in localization of sounds on the right side (acoustic space)2) basically complete loss of hearing ability in the left ear
What is the general pathway of the ascending auditory system?
What are the synapses of a medial nucleus of the trapezoid body? medial superior olive? lateral superior olive?
MNTB: only to the ipsilateral LSO (glycinergic)MSO: only to the ipsilateral IC (glutamanergic)LSO: to ipsilateral (glycinergic) + contralateral (glutamanergic) IC
What is associated with a lesion in Wernicke's area?
(BA22) located proximally to the primary and secondary auditory cortices, it has a primary role in comprehension of spoken language
thus, these patients can verbalize language, but cannot understand language spoken to them
* larger in the left hemisphere (speech has a left hemisphere lateralization)
What is associated with a lesion in Broca's area?
(BA44, BA45) located proximally to the primary motor cortex, it has a primary role in the motor function necessary to produce speech
thus, it presents opposite to a lesion in Wernicke's area, patients are not able to verbalize grammatically correct language, but are able to understand language spoken to them
What are areas that, if blocked, can cause disease in the inner ear?
duct from perilymph to CSF, endolymphatic duct and sac within the dura
Perilymph interfaces with atmospheric pressure at the _______ window, while endolymph interfaces at the ______ window.
oval, round
What is benign positional vertigo?
calcium carbonate crystals (otoconia) responsible for gravitational detection in the utricle and saccule loose their ability to stick to each other with age leading to their unwanted presence in other endolymphatic areas (e.g. a spinning sensor)
Hair cells in the _________ face away from the striola, while those in the ________ face towards the striola. What does the utricle sense? saccule?
saccule, utricle
utricle : horizontal orientation, tilt, or rocking; in addition to forward acceleration in a car
saccule: vertical orientation, elevator sensations,
bouncing, falling
* when you lay down, these roles reverse
What is the main motion sensor of the semicircular canal? What is its purpose?
in the ampulla, the crista which is composed of hair cells and gooey cupula
it allows us to sense acceleration and deceleration, but not continuous motion
Why is one able to get rid of a balance sensor on one side, but clinically present pretty well?
it is because of the opposition between semicircular canals; for instance, the left anterior canal is opposed by the right posterior canal, thus if you lost sensation from the left anterior canal the posterior canal would sense the opposite motion and be interpreted by the brain in the same way
Endolymph movement towards the ampulla in the horizontal canal is an ____________ signal.
excitatory, analogous to motion towards the kinocilium
A turn of the head towards the right, results in ___________ signaling from the right vestibular nucleus and ___________ signaling from the left.
increased, decreased
What would happen if you had a lesion in your left vestibular nucleus?
you would constantly experience the sensation of turning right (vertigo)
What portions of the vestibular system does the superior division of the vestibular nerve innervate? inferior division?
superior: anterior and horizontal semicircular canals, utricle, small part of saccule
inferior: posterior semicircular canal, sacculeThe vestibular reflexes run through ______________, to the _____________, and terminate at many motor nuclei producing responses to sensations.
Scarpa's ganglion, vestibular nucleus
What is the shortest reflex in body?
vestibulo-ocular reflex (Doll's eye reflex) which keeps gaze steady by oculomotor nuclei in midbrain; dependent on proper regulation of eye movements by the vestibular system
What is the vestibulo-colic reflex?
a constantly elicited reflex that keeps the head stable and level with bodily movement, it is controlled by motor neurons in the upper spinal cord innervating neck muscles
What is the vestibulo-spinal reflex?
an automatic righting reflex to prevent falls during head and body motion, it effectively keeps an individual stable and upright when sitting and standing; it is controlled by motor neurons in the lower spinal cord
How does the Word Recognition Score add to an audiogram assessment?
it measures the clarity of hearing, many patients can hear pure tones just fine but spoken words sound muddled
What is the primary pathology in sensory hearing loss?
loss of hair cells (DO NOT regenerate); mechanism of injury commonly involves oxidative stress pathways, thus anti-oxidant treatments can be very helpful
What is meant by a temporary threshold shift in response to noise exposure? What are the OSHA regulations for noise exposure?
exposure to excessive noise, especially in the 2-6 kHz range, can lead to a temporary increased shift in the required threshold for those frequencies, leading to a 2-6 kHz specific hearing loss; it does recover after 16 - 48 hours
* 80 dB for 8 hrs, 85 dB for 6 hrs, 90 dB for 4 hrs
What is the most common congenital sensorineural hearing loss?
10-15% of all cases of HL is detected by connexin 26 mutational analysis
* most common non-genetic cause is CMV infection
What characterizes each of these syndromes:1) acute otitis media2) otitis media with effusion3) otitis externa4) chronic suppurative otitis media
1) rapid onset of symptoms and signs of an ear infection in the presence of middle ear effusion2) middle ear fluid in the absence of inflammation/infection3) inflammation of external ear canal4) tympanic membrane perforation or cholesteatoma
What are the signs and symptoms of acute otitis media? How would AOM be treated?
Treatment:- watchful waiting in low-risk patients- systemic antibiotics- surgery in emergency situations
What are the signs and symptoms of otitis media with effusion?
signs: lacks the erythema of AOM
Symptoms: pain/fullness/popping, sleep disturbances, hearing loss, recurrent AOMs, delays in motor, speech, or language development
Treatment:- PE tubes- adenoids removal- no tonsillectomy
What is a cholesteatoma?
a type of skin cyst consisting of keratinizing squamous epithelium in the middle ear usually seen as a small crust on ear exam
- patients present with ear discharge or hearing loss, which can be confused with otitis externa
What characterizes otosclerosis?
it is a localized disorder of bone remodeling that cause stapes fixation (similar pathogenesis to osetgenesis imperfecta)
patients (commonly 30-50 y/o white F) show progressive uni or bilateral conductive hearing loss
etiology: heterogenetic AD, COL1A1/aggrecan mutations, associated with measles virus
What patients would receive cochlear implants?
children: if hearing loss is still profound after 1 year
adult: those with progressive hearing loss in whom hearing aids are not effective
What would be the most common early symptoms of an acoustic neuroma? late symptoms?
asymmetric hearing loss, also unilateral tinnitus and mild vertigo
vestibular schwannoma = acoustic neuroma
benign, slow growing tumors that occur most often on Vestibular nerve >> Auditory > Facial, with sporadic occurrence from mutations in the NF2 gene (also as AD Neurofibromatosis type 2)
late symptoms: facial numbness, ataxia, headache, visual loss, lower CN dysfunction (e.g. difficulty swallowing), death by herniation
Terms Definitionshearing loss type - otosclerosis primarily CHL, also mixed and snHLphysiological etiology of otosclerosis
abnormal deposition/resorption of bone
epidemiology of otosclerosis 1% of caucasian population, 2:1 female ratiogenetic inheritance of otosclerosis autosomal dominant - incomplete penetrance
what is schwartz sign? how often is it seen?
reddish hue seen behind TM - increased vascularity of cochlear promontory in active lesions (otospongiosis). seen in 10% of patients
what is the most common location affected by otosclerosis?
fissula ante fenestram (anterior to oval window) affected in 80-90% of patients. Border of round window, apical medial wall of cochlear, posterior to cochlear aqueduct, adjacent to semicircular canals, stapes footplate itself.
3 phases of otosclerosis
1. otospongiosis (early phase: inc bone resorption and vascularity, formation of new spongy bone --> (blue mantles of Manasse on H&E staining) 2. transitional phase3. otosclerosis (late phase): formation of dense sclerotic bone.
what type of bone does otosclerosis begin in
endochondral bone - as it evolves the endosteal and periosteal layers become involved
obliterative otosclerosis otosclerosis that fills oval window niche
biscuit footplate
otosclerosis involving only the footplate, sparing annular ligament (high risk of postop snHL because of minimal fixation - footplate can become mobilized inadvertently)
how often is the round window involved?
30% of clinical cases of otosclerosis. complete closure is uncommon
mechanism of snHL in patients with otosclerosis
controversial. possible liberation of toxic metabolities into inner ear, vascular compromise, extension of lesions into cochlea. snHL usu associated with significant stapedial otosclerosis.
what is cochlear otosclerosis pure snHL without associated CHL.
shambaugh's 7 criteria for identifying patients suffering from snHL due to otosclerosis.
1. schwartze sign in either ear2. family history of otosclerosis3. unilateral CHL c/w OS and bilat symm snHL4. flat or cookie bite audio with excellent discrims5. progressive pure cochlear loss beginning at usual age of onset for OS6. CT showing demineralization of cochlear typical of OS7. stapedial reflex demonstrating biphasic "on-off effect" before stapedial fixation
percent of OS patients with dizziness
30% - OS lesions in lat semicirc canal. Positive results on ENG. called OS "inner ear syndrome"
absolute contraindication for stapedectomy/stapedotomy
Meniere's disease - enlarged endolymphatic space, saccule may be adherent to underside of stapes footplate, increased risk of profound snHL
clinical signs of OS inner ear no well-defined episodes of rotational vertigo,
syndromenausea, vomiting, or fluctuating snHL. mild/persistent dizziness, low frequency snHL NOT present
Terms Definitions
what is sound
1. vibrations that result in the alternating compression and rarefraction of the surrounding air2. frequence of waves = "pitch" hertz3. amplitude is the max change of the waveform = "loudness" Decibels
hearing
1. earliest sensation to develop2. human hearing ranges from 20-20000Hz3. we only test 250-8000hz4. hearing spans a 10^6 range of sound pressures
decibels
1. Log scale2. SPL = 20Log10(Pt/Pr)3. scale> O db = hearing level (HL) is the SOFTEST SOUND that can be heard ; not the absence of sound = threshold of hearingNORMAL @ 25db or less
basic audiometry
best was of assesing a person's hearing>req. cooperative pt>put them in a sound proof booth, use a pure tone audiometer>sounds are delivered by 1. air, + 2. bone
audiometerdelivers specific pure tones (pitch) at a specific intensity (loudness)>deliver voice at a specific volume
1. a measure of the sound conducting mechanismPinna is 25x bigger than the oval window2. sound conducting components of the ear>pinna, ear canal, eardrum, ossicles (MIS, malleus, incus, stapes)3. sound is delivered to the ear by either headphones or ear canal inserts (archaic!!!)
bone conduction 1. sound is delivered by a bone vibrator 2. stimulates both cochleae simultaneously3. masking must be used to isolate the test ear> masking noise put into nontest ear by AIR conduction>test noise by air or bone conduction4. crossover occurs when the signal is perceived in the opposite or "non-test" ear
>occurs at 40dB in air conduction>occurs at 0 dB in bone conduction
graph
triangles above line = bone conductioncircles below line = air conductionA=B+Cthere is something interfereing > fluid, wax..etc>air bone gap = conductive hearing loss
masking is used whenever there is an
AIR BONE GAP > 10dB
speech audiometryspeech thresholdword discriminationall speech tests are performed by air conduction
mixed hearing losscombo of both conductive & sensorineural hearing loss
speech threshold
1. lowest level at which 50% of spondees are understand>spondees are 2-syllable words. w/ equal stress on each word2. should agree w/ pure tone average w/in 5-10dB
gas compressible yessolid compressible yesliquid compressible no
speech discrimination score
1. the processing of speech begins in the auditory nerve>ppl w/moderate to severe conductive hearing loss > excellent SDS2. indicates the fx of auditory nerve
tympanometryput pressure on ear drum and see what happens>measure compliance of eardrum>by varying the pressure w/in the ear canal
type A vs type B
A = looks like an A = normalB = flat > no movement of TM (otitis media, TM perforation)
CN 8 > CN 7 > 1st branch greater superficial petrosal > lacrimal gland2nd : stapedius (tightens the stapes and oval window)3rd: chorda tympanitest for lesions btw one side to the other and just one side>find the lesion
poor word discrimination w/ good pure tone audiometry indicates
retrocochlear cause of hearing loss>acoustic neuroma
tympanometryacoustic reflex testestimation of ear canal volume
tests of middle ear funtion
sound dampening mechanism of the ear
acoustic reflex>70-90dB elecits a reflexive contraction of the stapedius m. > changes the compliance of TM>processes that disrupt the fx of the middle ear will emilinate this reflexARC: Afferent: 8th n; Efferent: 7th n
bubbles behind TM
= fluid behind TM!! in middle ear>put tube in TM >mastoid probably filled w/fluidso tube lets air in so fluid can move down eustacian tube(mastoid will grow bc stuff in middle ear)
mastoid pressure buffermiddle ear has 2 holes; to eustacian tube and mastoid
serous otitis mediaoften assoc. w/ problem in nasopharynx (hypertrophic adenoids)
