Date post: | 18-Dec-2014 |
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VERTIGO
-- Prashiddha Dhakal MBBS,KUSMS
Vertigo
• “Illusion” or “Hallucination” of movement.
Abnormal sense of motion
between patient & surrounding
PLUS
Loss of balance
• Patient often complain of DIZZINESS/GIDDINESS which is a vague term & mayn’t always mean vertigo.
• Most dizzy patients can be placed in to one of four categories:
1. True Vertigo (50%)2. Pre- syncope3. Dysequillibrium4. Vague lightheadedness
True Vertigo
•Loss of balance
PLUS
Abnormal sense of motion between patient & surrounding
Pre-syncope
• Transient sensation that a faint in about to occur.
• May present as nausea ,weakness, SOB or change in vision.
Dysequilibrium
• Loss of balance
• No sense of faintness.
• No abnormal sense of motion.
Vague lightheadedness• Head discomfort due to:
1.Psychiatric disorders
2.Hyperventilation syndrome
3.Encephalopathies
How do we maintain equilibrium?
Visual input
Proprioceptiual
input
Vestibular input
labyrinths.
equilibrium
Sensory cortex
Causes of Vertigo
Central Peripheral
Evaluation of a patient with vertigo
1. Clinical tests
2. Laboratory tests
Clinical tests of vestibular function
1. Spontaneous Nystagmus
• Nystagmus- Involuntary,
rhythmic, oscillatory
movements of eyes.• Procedure--• May be horizontal,
vertical or rotatory• Direction of nystagmus—
direction of fast component
• Nystagmus of peripheral origin:
Suppressed by- Looking at a fixed pointEnhanced by- Darkness or Frenzel glasses (+20 D), both of which abolish optic
fixation
Frenzel Glasses
2. Fistula Test
• Normally, the test is NEGATIVE• POSITIVE--- Erosion of horizontal semicircular
canal(Cholesteatoma), Abnormal opening in oval window(Poststapedectomy fistula) or round window (Rupture of round window membrane)
• FALSE NEGATIVE--- When cholesteatoma covers the fistula
• FALSE POSITIVE--- Congenital Syphilis & Meniere’s disease (25% cases)
3. Romberg Test
• Peripheral lesion- Patient sways to the side of lesion
• Central lesion- Patient doesn’t sway
• Sharpened Rhomberg test If the Rhomberg test is
normal, this test is performed.Inability to perform this test
indicates vestibular impairment.
4. Past-Pointing
Past pointing, Falling and the Slow component of nystagmus are all in the same direction
5. Hallpike Manoeuvre (Positional Test)
6. GaitPeripheral lesion- Patient deviates to affected
side.
7. Test of cerebellar function
LAB TESTS OF VESTIBULAR FUNCTION
• A. caloric test• 1. modified kobrak test• 2. fitzgerald-hallpike test• 3. cold air caloric test• B. Electronystagmograph• C. optokinetic test• D. rotation test• E. galvinic test• F. posturography
Caloric test
• Test of lateral semicircular canal• Induce nystagmus by thermal stimulation• Each labyrinth can be tested separately
Modified kobrak test
• Ear is irrigated with icewater for 60 s• First with 5 ml then with 10,20 and 40• If no response to 40 ml ,it indicates dead
labyrinth
Fitzgerald-hallpike test
• ears are irrigated for 40 s alternately with water at 30 and 44 degree celcious
• Time taken is recorded in calorigram• If no nystagmus, repeated at 20 degree
celcious for 4 min• Depending on response of caloric test • a.canal paresis• b.directional preponderance
• A.canal paresis• indicates response illicted from particular
canal is less than that of opposite side• depressed function of ipslateral
labyrinth,vestibular nerve or vestibular nuclei
b. Directional perponderance
• Duration of nystagmus irrispective to rt or left is considered.
• Right beating nystagmus is caused by LC and RW
• Left beating nystagmus is caused by RC and LW
• TOTAL RESPONSE = RW+RC+LW+LC
FORMULA FOR RB AND LB NYSTAGMUS
• Right beating nystagmus=(LC+RW)/TR X100%
• Left beating nystagmus=(RC+LW)/TR X100%
• IF nystagmus >25 to 30% in one ear than other ,then it is called directional perponderance
• DP=RT BEATING – LEFT BEATING/TR
• RVR(relative vestibular reduction)=(RC+RW-LC-LW)/TR
• RVR normally is <25%• RVR > 40 % seen in vestibular neuritis
• 3. cold air caloric test• Done when there is perforation of tympanic
membrane• Dundas grant tube • Ethyl chloride is used to cool air
Electronystagmography
• Recoding of nystagmus by caloric,positional,rotational or optokinetic stimulus
• Corneoretinal potential recorded
C. OPTOKINETIC TEST
• EYE movement ellicted by tracking of moving field
• POSITIVE IN brainstem and cerebral lesion
E. Rotational test
• Patient seated in Brany’s revolving chair• Rotated 10 turns in 20 second• Normally nystagmus is for 25 to 40 second• Used for pt with congenital anomalies where
calorie test is not possible•
F. GALVANIC TEST
• VESTIBULAR TEST• Differentiate from end organ lession from
vestibular nerve• 1 mA current passed in one ear• Normally person sways towards anodal
current
G. POSTUROGRAPHY
-- evaluate vestebular function by measuring postural stability
VESTIBULAR NEURITIS
• A type of peripheral vestibular disorder • A common cause of spontaneous vertigo• Definition
– disorder in which there is sudden,– spontaneous, isolated, total or subtotal loss of
afferent vestibular input from one labyrinth
• Etiology– Viral infection of vestibular nerve
• Selective neuron loss in vestibular ganglia
– Virus• Herpes Simplex virus type 1 (latent infection)
• Clinical manisfeststions– Acute spontaneous vertigo– Nausea, Vomitting– Postural imbalance– SYMPTOMS ARE TYPICALLY AGGRAVATED BY HEAD
MOVEMENT AND MINIMIZED BY KEEPING HEAD STILL AND EYES CLOSED
– Symptoms gradually subside over the following days
• In acute phase– Spontaneous horizontal torsional nystagmus
• Unidirectional• Quick phase towards unaffected side• Suppressed by visual fixation
• Patients charcteristically rotate towards the affected side when attempting to march on the spot with their eyes closed – POSITIVE FUKUDA / UNTENBERGER TEST
• Diagnosis– Clinical diagnosis– Investigations
• Subjective visual Horizontal (SVH) test• Electronystagmography• Caloric test• Contrast MRI
• Differential Diagnosis– Cerebellar infarction
-labyrinthine infarction -autoimmune inner ear disease -minner’s disease
Outcome and complication
• Symptoms gradually subsides• Often patient complains of• -oscillopsia• -postural imbalance
Management
theraputic -corticosteroids(methylprednisolone) -antiviral(valacyclovir)Vestibular rehabilation therapy
Early mobilization
Thank You