VERTIGO Dr NAYANA V G VESTIBULAR SYSTEM TWO

VERTIGO Dr. NAYANA. V G

VESTIBULAR SYSTEM Ø TWO SETS OF END ORGANS IN INNER EAR Ø SEMICIRCULAR CANALS -ANGULAR ACCELERATION Ø UTRICLE & SACCULE -LINEAR ACCELERATION &GRAVITY Ø VESTIBULAR NERVE

SEMICIRCULAR CANALS The two vertical scc are the anterior (superior) and posterior the horizontal scc is also known as the lateral canal. Sensory epithelium of scc localized in the ampulla is the crista ampullaris. Crista ampullaris is made up of sensory hair cells , connective tissue and supporting cells.

OTOLITH ORGANS ØUtricle and Saccule ØThey respond to linear acceleration & gravity ØThe utricular macula is oriented in the horizontal plane and the saccular macula is oriented in the vertical plane. ØMacula comprises sensory hair cells & otolithic membrane

CENTRAL VESTIBULAR CONNECTIONS ØVestibular nuclei -4 ØAfferents – peripheral receptors, cerebellum , reticular formation , spinal cord &c/l vestibular nuclei Ø Efferents – 3, 4, 6 cranial nerve nuclei ANS Cerebral cortex vestibulo spinal tract Vestibulo cerebellar tract C/l vestibular nuclei

DEFINITION Vertigo can be defined as an illusion of either oneself or the environment rotating. It is a symptom were there is feeling of motion when one is stationary often associated with nausea, vomiting, difficulty in standing or walking, This may be a sensation of turning, spinning, falling, rocking etc. Vertigo came from the latin word “verto” a whirling or spinning movement

PERIPHERAL VERTIGO CENTRAL VERTIGO Involves vestibular end organ and vestibular nerve Involves CNS after entrance of VIIIth nerve to brainstem Inner ear or VIIIth nerve Involves vestibule-spinal, vestibuloocular and other CNS pathways 85% of vertigo

PERIPHERAL VESTIBULAR DISORDERS 1. Meniere’s disease – Vertigo, fluctuating hearing loss, tinnitus, and aural fullness. Vertigo lasts for minutes to hours 2. BPPV – vertigo with certain head movements, less than a minute, nausea 3. Vestibular neuronitis – viral infections of 8 th nerve, days to weeks, self limiting, no cochlear symptoms 4. Labyrinthitis– complication of CSOM, both cochlear and vestibular symptoms 5. Vestibulotoxic drugs ( aminoglycosides, anti-malarials, diuretics, antihypertensives.

PERIPHERAL VESTIBULAR DISORDERS 6. Head trauma – Concussion of labyrinth/8 th nerve, perilymph fistula. 7. Perilymph fistula – Through oval or round window, intermittent vertigo, fluctuating SNHL, tinnitus and aural fullness 8. Syphilis – Mimic MD, Hennebert’s sign positive 9. Acoustic neuroma – Arise from 8 th nerve within IAM, unsteadiness/vague sensation of motion

CENTRAL VESTIBULAR DISORDERS 1. Vestibulo basilar insufficiency - > 50 yrs, atherosclerosis, precipitated by hypotension /neck movements , transient vertigo with other neurologic symptoms 2. PICA/WALENBERG SYNDROME – cuts off blood supply to lateral medullary area, violent vertigo with diplopia, dysphagia and hoarseness, horners, sensory loss. 3. Basilar migraine –unilateral, throbbing headache, vertigo lasts 5 -60 mins

CENTRAL VESTIBULAR DISORDERS 4. Cerebellar disease – vertigo, ataxia, incordination etc 5. Multiple sclerosis – Ataxia, cranial nerve inolvement 6. Tumours of brain stem/IVth ventricle 7. Temporal lobe epilepsy

EVALUATION OF VERTIGO -HISTORY Is it true vertigo (rotation or spinning sensation) or a feeling of light headedness (syncope - cvs) Onset- sudden/insidous Single attack(vestibular neuronitis)/recurrent(BPPV) or episodic(meniers)/c/c Duration of each episode(Seconds-BPPV, Hours-MD, Days –VN) Spontaneous(MD)/provoked (BPPV) Syndrome of postural imbalance (position change -If associated with turning the head, lying supine, or sitting upright)

EVALUATION OF VERTIGO -HISTORY Associated symptoms (Ear symptoms, headache or visual symptoms). Family history of balance disorders Other medical illnesses H/o head trauma H/o drug intake (Orthostatic hypotension, vestibulotoxic) Previous ear surgery (stapectomy -peri-lymphatic fistula, labyrinthine fistula)

ASSESSMENT OF VESTIBULAR FUNCTION A. CLINICAL TESTS B. LABORATORY TESTS

ROUTINE EXAMS Cardiovascular, : BP (including orthostatic) in both arms, bruits in the neck, pulse. Neurologic & cranial nerves, Ent Examinations Tympanic membrane for retraction, perforation, cholesteatoma. Assess hearing on both sides.

A. CLINICAL TESTS Occulomotor examination Eye movements & spontaneous nystagmus Fistula test Hallpike manoeuvre (positional test) Postural test –romberg test Examination of gait Past pointing and falling Tests of cerebellar dysfunction

B. LABORATORY TESTS OF VESTIBULAR FUNCTION CALORIC TEST MODIFIED KOBRAK TEST FITZGERALD-HALLPIKE TEST (BITHERMAL CALORIC TEST) COLD-AIR CALORIC TEST ELECTRONYSTAGMOGRAPHY OPTOKINETIC TEST ROTATION TEST

LABORATORY TESTS OF VESTIBULAR FUNCTION GALVANIC TEST POSTUROGRAPHY AUDIOMETRY CT MRI

1. OCCULOMOTOR EXAMINATION Spontaneous & gaze evoked nystagmus Convergence Smooth pursuit Saccades VOR Positional tests

SPONTANEOUS NYSTAGMUS Involuntary, rhythmical, oscillatory movement of eyes It may be horizontal, vertical, rotatory Vestibular nystagmus - slow & fast component Direction of nystagmus – indicated by fast component. GAZE EVOKED NYSTAGMUS Visible only on deviation of gaze to the opposite side of lesion – in the direction of the fast phase

DIFFERENCE BETWEEN CENTRAL AND PERIPHERAL NYSTAGMUS Peripheral Central Latency 2 -20 sec No latency Duration Less than 1 min More than 1 min Direction of nystagmus Direction fixed towards the undermost ear Direction changing Fatigability fatigable Non- fatigable Accompanying symptoms Sever vertigo None or slight

2. FISTULA TEST Induce nystagmus by producing pressure changes in EAC which is then transmitted to the labyrinth. By applying intermitted pressure on the tragus or by using Siegel's speculum Normally negative Positive when : ü Erosion of horizontal semi-circular canal ü Abnormal opening in the oval window(post- stepedectomy fistula) ü Abnormal opening round window (rupture)

• False negative fistula test • When cholesteatoma covers the site of fistula • Dead labyrinth • False positive fistula test • Seen in congenital syphilis & meniere’s disease (25%)

3. POSITIONAL TEST (DIX – HALLPIKE) Pt sits upright, turn head 30 -45 degrees to side being tested, Pt keeps eyes open and focused on examiner’s eyes or forehead. Then, supporting head, pt quickly lies supine (<2 s), allowing head to hyperextend 20 -30 degrees past horizontal This position is maintained for at least 30 seconds. The nystagmus characteristic of BPPV begins after a latency of 2 to 10 seconds increases in amplitude over approximately 10 seconds, and decreases in velocity over the next 30 seconds

DIX - HALLPIKE Onset of torsional or horizontal nystagmus denotes positive test. Nystagmus will change direction when returning to upright

DIX HALLPIKE

Posterior canal BPPV –Torsional nystagmus to the affected side & intense vertigo Posterior canal bppv shows presence of latency, adaptation and fatigability. Purely horizontal nystagmus observed in horizontal canal BPPV. Purely vertical nystagmus(up or down beating) indicates central origin. Anterior canal BPPV, a torsional component downbeating nystagmus.

ROMBERG TEST • Patient is asked to stand with feet together &arms by the side with eyes opened 1 st then closed • In peripheral vestibular lesion pt. Sways to the side of lesion • In central lesion, pt. Shows instability • Sharpened romberg test – better indicator of vestibular impaiment

GAIT Pt. Is asked to walk along a straight line 1 st eye opened then closed Pt. Deviate to the affected side Utenberger test –patient is asked to walk on the spot with eyes closed.

PAST-POINTING AND FALLING • Past-pointing , falling & slow component of nystagmus are all in the same direction • If there is acute vestibular failure , say on the right side, nystagmus is to the left but the past – pointing & falling will be towards the right i. E. Towards the side of the slow component.

CEREBELLAR TEST Finger-nose test (asynergia) Inability to control range of motion (dysmetria) Inability to perform rapid alternating movement (adiado chokinesia ) Rebound phenomenon Wide base gait , falling in any direction , inability to make sudden turn while walking Truncal ataxia

LAB TESTS ELECTRONYSTAGMOGRAPHY CALORIC TESTS ROTATIONAL TESTS GALVANIC TESTS POSTUROGRAPHY

ELECTRO NYSTAMOGRAPHY This is a method for detecting and recording nystagmus The test depends on the presence of corneoretinal potentials which are recorded by placing electrodes around the eyes Useful to detect nystagmus not seen by naked eye and also keep permanent records

CALORIC TESTS The most useful laboratory investigation for determining the responsiveness of the labyrinth. Allows both labyrinths to be assessed separately 1. Modified kobrak test Head tilted 60 degree backward. Irrigated with cold water for 60 sec. first 5 ml ->if no response 10, 20, 40 ml Normal—nystagmus opposite direction with 5 ml Hypoactive between 5 ml &40 ml. dead – no response with 40 ml

CALORIC TESTS FITZGERALD & HALLPIKE Thermal stimulation of the labyrinth with cold(30 degree) & warm( 44 degree ) water/air induces horizontal nystagmus Lateral scc is tested with the pt lying with head raised 30 degree so that the canal is vertically oriented The procedure follows the order left cold, right cold, left warm, right warm with each irrigation lasting 40 sec. 5 -10 min interval is maintained b/w each irrigation Cold irrigation induces horizontal nystagmus beating in the opposite direction of irrigation, and warm irrigation ipsilaterally cold-opposite-warm-same (COWS)

CALORIC TESTS Thermal change induces convection currents in the horizontal canal (when placed vertically) and thus cupular deflection. Duration of nystagmus is measured B/l absence amino glycoside ototoxicity or postmenigitis Brainstem lesions (associated cns signs) Unilateral canal paresis, a reduced/absent reponse from one ear. U/l vestibular schwannoma / vestibular neuritis/MD

ROTATION TEST Pt. In barany's revolving chair with his head tilted 30 degree & rotated 10 turns in 20 seconds. chair stopped abruptly, watch for nystagmus Normally there is nystagmus 25 -40 sec It is useful in congenital abnormalities of canal wall failure of development and caloric test not possible Disadvantage of the test is , it can’t be tested individually

GALVANIC TEST This test helps to differentiate an end organ lesion from that of vestibular nerve The pt. stands with his feet together , eyes closed and arms out stretched and then a current of 1 ma is passed to one ear normally person sways towards the anodal current Galvanic stimulation excites the viii nerve afferents directly Used to distinguish if a caloric unresponsive ear was due to an VIIIth nerve lesion (absent galvanic response) or a Labyrinthine lesion (present galvanic response)

POSTUROGRAPHY It is a method to evaluate vestibular function by measuring postural stability Posture maintenance depends on 3 sensory inputs- visual , vestibular & somatosensory Using a fixed or moving platform

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