CENTRAL VESTIBULAR DISORDERS Dr. ANITA BHANDARI
VERTIGO PERIPHERAL CENTRALThe sensation of balance is the result ofappropriate information detected byvestibular , ocular and proprioceptive sensoryreceptors that is then properly integratedwithin the cerebellum and brainstem.
Disruption of central integrators – brainstem and cerebellumSensory information mismatch – cortexLesion of vestibular N. or root entry – CPA lesions – affect primaryvestibular sensory info
1.Spontaneous nystagmus – not suppressed by fixation ,may change direction with gaze2.Nystagmus is purely vertical , horizontal or torsional3.Saccade dysmetria4.Nystagmus is paroxysmal but not fatiguable on Dix-Hallpike test, with no latency, > 60 sec., may changedirection with diff. head positions
CEREBELLAR TUMORS Primary in children, sec. in adults S/S depend on tumor location size Growth rate Positional vertigo Headaches Gait disturbances Neurosurgical intervention
TEMPORAL LOBE TUMORS Recurrent attacks of vertigo , followed by transient disorientation,amnesia,dysphagia MRI enhanced Neurosurgical intervention
BRAINSTEM LESIONSCaused by neoplastic, traumatic orvascular lesionsVertigo may be mild or severePositional vertigo but no nystagmus
CPA TUMORS• Vestibular schwanoma• Meningioma• Lipoma• Cholesteatoma• Metastatic Features: Unilateral hearing loss Nystagmus inhibited by visual fixation Disequilibrium rather than vertigo unless sudden increase in tumor size
GENESIS OF THE MIGRAINE SYNDROME OLDER HYPOTHESIS : VASCULAR REACTIVITY Reduced regional blood flow through cortex AURA Dilatation of scalp arteries HEADACHE
Migraine Pathophysiology• Baseline sensory hyperexcitability(thicker sensitive brains)•Environmental events push past a threshold leading to:•Electrical changes (cortical spreading depression -- CSD) occurs in brain.•Causes aura (aura is no longer a
Theory of cortical spreading depression ( Cutrer and Baloh) Spreads in all directions from Ion fluxes site of origin Suppresses central neuronal activity Transient wave formStimulus(chemical/Mechanical)
Release of Decreased neuropeptides sub Cerebral blood P, neurokinin CGRP Decreased flow in areas of (calcitonin gene Extracellular spreading related peptide) Calcium depression Increased Extracellular PotassiumIon fluxes
Neuropeptide release causes excitation ofDizziness occurs baseline firingwith release of rate of sensoryneuropeptides epithelium of inner ear & vest. nuclei in pons
Asymmetric peptide release causes vertigo Symmetrical peptide release leads toincrease sensitivity to motion due to increased vestibular firing rate
MRV Vasospasm of internal auditory artery Ischemia of labyrinthPeripheral cochleovestibular dysfunction
Classification by IHS BenignMigraine without Migraine with Migraine with Migraine paroxysmal aura aura prolonged aura infarction vertigo of childhood
1. Migraine without auraHeadache attacks : 4 to 72 hoursIn children less than 15years age : 2 to 48 hoursFormerly called COMMON MIGRAINE80%
Headache has at least two of the following characteristics: Unilateral Pulsating Severe intensity prevents or inhibits daily activities Aggravation by walking up stairs or similar routine physical activity
During headache at least one of the following prevails: Nausea and/or vomiting Photo and phonophobia
2. Migraine with auraFormerly called CLASSIC Migraine15%
Aura with at least 2 of the following: • Reversible aura symptoms with focal CNS1. dysfunction • Aura that develops over > 4 minutes2. • No aura symptoms which lasts for > 1 hour3
BASILAR MIGRAINE• VARIANT OF CLASSICAL MIGRAINE• FEATURES OF BASILAR ART. INV. • VERTIGO • TINNITUS • DYSARTHRIA • ATAXIA • VISUAL SYMPTOMS • TINGLING , NUMBNESS, WEAKNESS OF LIMBS
3. Migraine with prolonged aura Aura for > 60 minutes but < 7 days4. Migrainous infarction Complicated migraine Neurological Deficits not completely reversed within 7 days
5. Benign paroxysmal vertigo of childhood Brief episodes of disequilibrium, anxiety, nystagmus or vomiting Normal neurological findings Normal EEG
CLINICAL PRESENTATION• AGE – ANY AGE – OFTEN STARTS EARLY IN LIFE – BENIGN PAROXYSMAL VERTIGO OF CHILDHOOD IS AN EARLY MANIFESTATION OF MV 30 25 20 15 10 5 0 0-10 11-20 20-30 31-40 41-50 51-60 > 61
MALE : FEMALE• FEMALE PREPONDERANCE FEMALE MALE
CLINICAL PRESENTATION • Headache – only 50% pts. presented with H/o headache along with or after vertigo . • Several patients had headaches earlier in life but now vertigo was the predominant symptom • Duration – usually few hrs.
Prior to headacheVertigo may During headache occur In headache free interval (most common)
Photophobia & phonophobia were common symptoms.
AUDIOLOGICAL PRESENTATIONMost had normal hearingAny SNHL was not related to MV
MOTION SICKNESS• Has been reported to occur commonly in MV due to a optokinetic stimulation
BPPV AND MVBPPV is a well documented sequelae toischemic damage of the inner earpresumably d/t release of otoconia fromthe macular membrane.The vasospasm associated with classicalvisual aura is secondary to a primaryneuronal metabolic defect
MANAGEMENT HistoryNo diagnostic testNeurotological Exam NormalTherapeutic trial If history unclear
MANAGEMENTLifestyle changes • Explaining to the pt. what is going on • Avoidance of irregular lifestyle and stress. Migrainous and nonmigrainous brains are wired differently. Migraine pts. are more susceptable to the effects of overexertion – mental & physical , irregular eating and sleeping habits.
AVOIDANCE OF TRIGGER FACTORS• A personal vertigo and diet diary• Common triggers – bright and blinking lights – monosodium glutamate – caffeine – cheese – chocolates – alcohol – pills – strong smells
PROPHYLACTIC TREATMENTBeta blockers Propanolol – 40 -240 mg / day Metoprolol – 50 -120 mg / day Side effects –fatigue , hypotension , impotence , depression , nightmares , bronchial constrictionCalcium channel blockers Flunerizine – 5-10 mg / day Verapamil -120 -240 mg / dayTricyclic antidepressants Nortryptiline – 10 mg initially , upto 25 mg / day Second line of drugs include Valproic acid and methysergide.
PROPHYLAXIS TREATMENT• Botulinum toxoid [Botox] injections into the scalp or neck – Mechanism – inhibition of acetylcholine in brain – Efficacy after pericranial injection can last for 3 or more months – Used in case studies and trials , not yet approved
CEREBROVASCULAR DISEASES The blood supply of the brainstem, cerebellum and inner ear is obtained from the vertebrobasilar system or posterior circulatory system of the brain. The blood supply of this system may be impaired by atherosclerosis,emboli/thrombi and hemorrhage.
Subclavian art. 2 Vertebral art. Ant. Spinal A. Post. Spinal A. Join at pontomedullary PICA jtn. To form Basilar art. Pontine art. Common Sup. Cerebellar art. cochlear A. AICA Labyrinthine art. Ant. 2 post. Cerbral A. Vestibular A.ant. Cerebral art. ant. Communicating A.(br. Of ICA) (br. Of ICA) Circle of Willis Communication of ant. & post. circulation
Basilar A Bl. Of inner ear Labryriathine A.Ant. Common cochlear AVestivular A.Supplies Main Vestibulo cochlear A.sup. & cochlear A.horizontalscc &utricle Supplies Cochlear A. Post vestibular A. upper ¾ of cochlea & modiolus Supplies Supplies post. Scc remaining ¼ & saccule of cochlea
NEUROTOLOGICAL MANIFESTATIONS Depends on: 1.Location of stasis or stenosis 2.Size of embolus or thrombus 3.Presence or absence of collateral circulation
CVS DISEASES OF POST. CIRCULATION1.VBI2.SUBCLAVIAN STEAL SYNDROME3.LATERAL MEDULLARY/WALLENBERG’S SYND.4.MEDIAL MEDULLARY SYND.5.LATERAL PONTINE/FOVILLE’S SYND.6.MEDIAL PONTINE/MILLARD-GUBLER SYND.7.CEREBELLAR HEMORRHAGE/INFARCTION
VBI FEATURESFEATURE AREA INVOLVED1. ATAXIA INF. CEREBELLAR PEDUNCLE2. VERTIGO, INSTABILITY(EXACERBATED BY HEADHYPEREXTENSION OR. VEST. NUCLEUSROTATION)3. PERIORAL PARESTHESIA TRIGEMINAL NUCLEUS IN PONS4. VISUAL DISTURBANCES OCULOMOTOR NUCLEUS5 DYSPHAGIA, NUCLEUS AMBIGUSSHOARSENESS
SUBCLAVIAN STEAL SYNDROME Exercise of arms leads to greater req.ment of bl. which is obtained by stealing from VBS. The pt. presents with few sec. of vertigo, ataxia , headache , visual disturbances. More common in 6th-7th decade. More on left side. Systolic BP diff. of 20mm Hg b/w arms. Delayed radial pulse on affected side. Occ systolic murmur in supraclav. fossa on exercise .
Etiology - bl. flow to basilar art. d/t occlusion of subclavian art Decreased BP distal to obstruction Decreased BP in vertebral art. Retrograde flow VBS into subclavian art. & brachial art. of ipsilat. upper limb
LAT. MEDULLARY/WALLENBERG SYNDCause : occlusion of PICA or vertebral art. leading to infarction of lat. aspect of medulla FEATURE AREA INVOLVEDVERTIGO VEST. NUCLEUSVOMITTING DORSAL MOTOR N. OF VAGUSVISUAL DISTURBANCES MLFATAXIA INF. CEREBELLAR BODY & RESTI FORM BODYDYSPHAGIA, HOARSENESS NUCLEUS AMBIGUUSHORNER’S SYND/ DESCENDING SYMP. TRAITLOSS OF PAIN AND & TEMP.SENSATIONA. LIMBS LAT. SPINOTHALMIL TRACTB. FACE SPINAL NUCLEUS OF TRIGEMINALN
MED.MEDULLARY SYNDROMECause : occlusion of ant.spinal art. Combination of lat. & med. Medullary synd.- hemimedullary infarction d/t thrombosis of vertebral art. FEATURE AREA INVOLVED PARESIS OF TONGUE XII NUCLEUS/ NERVE LOSS OF PROPRIOCEPTION MED. LEMNISCUS HEMIPLEGIA- CONTRALAT PYRAMIDAL TRACT WITH SPARING OF FACE BEFORE DECUSSATION
CEREBELLAR HEM./INFARCTION Each cerebellar hemisphere controls movement of same side of body as opposed to cerebral cortex which controls movements of opp. side. Cl. picture acc. to site involved
2.InvasiveA]AngiographyB]CT AngiographyCardiac profile –lipid profile,ECG CT angiogram showing a hypoplastic right vertebral, in a person with symptoms of vertebrobasilar insufficiency. Left vertebral (left lower) is large and dominant. Right vertebral (right lower) is small and hypoplastic. This is the same case as shown in the selective vertebral angiogram below.
VBI : CLINICAL TESTS1.George’s test – measure B/L BP , pulse,auscultate subclavian & carotid art.2.Maigne’s test –rotate head Rt.& Lt., then lat.lybend and extend head in seated position. Look fornystagmus,nausea,vertigo,tinnitus. May indicatevascular compromise.
3.Dizziness test – to diff. dizziness d/t scc andvertebral art. compromise. Rotate neck side to side,then stabilize neck & rotate shoulders side to side.If pt. experiences dizziness in both – VBI If + onlyon head rotation, vestibular cause
MULTIPLE SCLEROSIS Demyelinating disease of brainstem region More common in Caucasians, less in Asians Pathology – localized destruction of myelin sheath followed by scarring. Leads to hampered neural transmission.
MULTIPLE SCLEROSISCharacteristics:Age of onset : 20-40 yrsMore in femalesPositive family history in 10-20%
MULTIPLE SCLEROSISSymptoms depend on area of involvementNeurotological symptoms are due todemyelination of:1. cerebellum & its pathways2. region of vest. nuclei3. vestibulospinal pathway4. vestibulo-ocular pathway Vertigo is presenting symptom in 5% pts- Ass. with poor prognosis Instability is more common
MULTIPLE SCLEROSIS:VESTIBULAR MANIFESTATIONS ABNORMALITIES ON VEST. FUNCTION TESTS 1.Abnormalities on saccades , pendular tracking, optokinetic tests 2.Gaze nystagmus - Cerebellar lesionAtaxic nystagmus -MLF lesion 3.Hyperactive caloric response – loss of cerebellar inhibitory effect on vest. Nuclei 4.Failure of nystagmus suppression on visual fixation
5.Dysrhythmic caloric induced nystagmus onENG6.Bilateral spontaneous nystagmus – horizontalor vertical – upbeating7.Monocular nystagmus- when present is highlysuggestive of MS8.Abnormal Romberg’s test9.Abnormal Unterburger’s test
MULTIPLE SCLEROSIS:AUDITORY MANIFESTATIONS• Retrocochlear SNHL• Unilateral HL indicates plaques in VIII N.- between spiral ganglion & cochlear nucleus• Abnormal BERA – III & IV interpeak latency• Acoustic reflexes – present on ipsilateral stimulation but absent on contralat. stim, increased AR threshold
MULTIPLE SCLEROSIS:OPHTHALMOLOGICAL FEATURES INTERNUCLEAR OPHTHALMOPLEGIA • Weakness on lateral gaze • Normal adduction • Dissociated nystagmus OPTIC NEURITIS
MULTIPLE SCLEROSIS: TREATMENT • ? Etiology – no curative or preventive T/T • Symptomatic T/T Steroids ACTH IM Interferon Cyclophosphamide
ARNOLD CHIARI MALFORMATION Protrusion of cerebellar tonsils thru the foramen magnumInterferes with CSF flow to & from the brain Accumulation of CSF in empty spaces of brain & spinal cord Hydrocephalus
Vertigo- rotatory, lasting few hours,with nausea & vomitingHeadaches- recurrent , lastingseveral hours, often accompanyingvertigo ,no sensory amplificationDecreased hearing & tinnitus – 2months , non-fluctuantParaesthesia – on face
CLINICAL EXAMINATION• No spontaneous nystagmus• Gaze evoked down beating nystagmus• Tandem walking – unsteady,• Unterburger test– ataxic• Caloric testing – hyperactive response
Differential Diagnosis• Migraine related vertigo• Cerebellar disorder• Multiple sclerosis• Drug intoxication• Vitamin B12 deficiency
VESTIBULAR EPILEPSYPathophysiology– focal epileptic discharges in temporal lobe or parietalassociation cortexClinical picturerotational or linear vertigo – few sec, ”quick spin”N/VtinnitusparaesthesiaDirection of nystagmus & body fall SAME [as this is a epileptic posturalresponse; not vestibulospinal compensation]
VESTIBULAR EPILEPSY Rare variant- Volvular/Rotatory Epilepsy paroxysmal repititive walking in small circles without impairment of consciousness Investigations EEG- focal slowing or sharp waves over temporoparietal regions Normal EEG does not exclude diagnosis MRI
VESTIBULAR EPILEPSY • D/D • Other epilepsies • Multiple sclerosis • Migraine, BPV of childhood • Drop attacks • Treatment • 1st line - carbamezepine , pheytoin • 2nd line – gabapentine, Na valproate