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Medical Management of Vestibular Disorders

Discover the latest advancements in managing vestibular disorders, including central causes and pharmacotherapy. Learn about pathophysiology, treatment goals, and specific drug classes targeting symptoms. Improve patient outcomes with expert insights.

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Medical Management of Vestibular Disorders

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  1. Medical Management of Vestibular Disorders Dr. W. WATAD

  2. Introduction • Basic inputs – • Vision - ocular stability • Proprioception - gait control • Vestibular system - balance • Disorders of vestibular system are major disruptors causing spatial disorientation • Vestibular DD has remained stable over the past several decades, but the management strategies continue to improve

  3. The Goal • To review and discuss the medical management of vestibular disorders

  4. Pathophysiology • Vestibular labyrinth - detects linear and angular head movements • Semicircular canals - angular • Hair cells - cupula • Otolithic organs (utricle, sacule) - linear • Hair cells - macula

  5. Vestibular nerve - superior, inferior • Afferent nerve fibers are bipolar • cell bodies lie within Scarpa’s ganglion

  6. pathophysiology

  7. Pathophysiology • Balance requires – • Normal functioning vestibular system • Input from visual system (vestibulo-ocular) • Input from proprioceptive system (vestibulo-spinal) • Disruption of balance between inputs results in : • vertigo (acute) • disequilibrium (chronic)

  8. Pathophysiology

  9. Central causes of vestibular dysfunction compromise central circuits that mediate vestibular influences on posture, gaze control, and autonomic function : • nausea, vomiting • Pallor • Respiratory/circulatory changes • Goal of treatment: restore balance between different inputs

  10. Medical Treatment • Symptomatic : • Relieve acute symptoms , autonomic complaints • Specific therapy : • Targeting the underlying cause of vertigo

  11. Symptomatic Pharmacotherapy • Predominant targeted vestibular neurotransmitters: • Cholinergic • Histaminergic • GABA neurotransmitters - negative inhibition • Vomiting center transmitters: • Dopaminergic (D2) • Histaminergic (H1) • Serotonergic (5-HT3) • Multiple classes of drugs effective

  12. Symptomatic Pharmacotherapy • Main classes : • Antihistaminergic - dimenhydrinate • Anticholinergics - scopolamine, meclizine • Anti-dopaminergic - droperidol • (gamma)-aminobutyric acid enhancing (GABA-ergic) agents - lorazepam, valium • Reduce the severity of vestibular symptoms

  13. Symptomatic Pharmacotherapy

  14. Suppressant agents : • Anticholinergics • Antihistamines • Benzodiazepines • Anti-emetic drugs

  15. anticholinergics • Inhibit stimulation ( exessive impulses ) from peripheral organs – vestibular n. • Inhibit transmission in LVN ( lat. Vestibular Nucleus ) • Non-specific muscarine receptor antagonist • Reversible overcompensation

  16. Agents not cross BBB are ineffective • Ineffective after symptoms have appeared • Scopalamine / atropine • SE : • Dry mouth dilated pupils • Urinary retention sedation • Constipation confusion • C/I : BPH , closed angle glaucoma

  17. antihistamines • Uncertain mechanism • Central effect ( block H1-R) • Inhibiton synaptic transmission on MVN ( medial vestibular nucleus ) • Anticholinergic and sedative effects • Effective also after symptomes have appeared • Cinnarazine • promethazine / diphenhydramine - sedative • prochlorperazine / miclizine - antiemetic

  18. benzodiazepines • GABA modulators • Central suppression of vestibular response • Sedative , hypnotic, muscle relaxant , reduce anxiety • Clonazepam / lorazepam / alprazolam • SE : • Impaired vestibular compensation • Impaired memory • addiction

  19. Anti emetics • Dopamine block activity • Not ideal for emesis from vestibular imbalance • Antihistamine effect – promethazine ( H1-R block) • Metoclopramide – potent central antiemetic, speed gastric emptying is not effective antivertigo drug

  20. Sulpiride : • Selective dopamine (D2) antagonist • Low incidence of extrapyramidal • Antiemetic action • Improve blood flow, mucosal secretion in GI • Antivertigo , anti-migraine headache • Antidepressant activity ( low doses ) • Antipsychotic activity ( high doses )

  21. New antiemetic – 5-HT3 antagonist serotonin ( 5 hydroxytryptamine subtype 3 receptor ) antagonist • Ondensetron / granisetron • Nausea and vomiting associated with chemotherapy , post. Operation • Less effective for vestibular emesis • High cost

  22. Other options • Ca channel blockers : • Vestibular suppression on Ca channel in hair cells • Flurnarazine / cinnarazine • Antihistamines and anticholinergic activity • Effective in menier’s and migrane • SE : sedation , weight gain , parkinsonism

  23. Na channel blocker : • Affect GABA NT , glutamate antagonist • Phenytoin / nerontin / tegretol • Central nystagmus • Anticonvulsants are promising agents for treatment vertigo ( uncertain mechanism )

  24. Histamine agonist : • Betahistine – H1/H3 – R agonist • Increase circulation to inner ear • Suppress veastibular function • Facilitation of compensation • SE : nausea , headache • Caution ; peptic dis , pheochromocytoma

  25. Steroids • Reduce duration of vertigo episodes • Effective in meniere’s , vestibular neuritis • Sypmpathomimetics • Counterbalance sedative effect of vestibular suppressant - increase compensation • Ephedrine / amphetamine – limitted use

  26. Acetyl- leucine • Vestibular suppresant • Rapid antivertigo effect ( IV) • Ginkgo-Biloba • Vestibular suppresant • Effective in tinnitus , improve memory

  27. Selective Ach antagonist • M2-R antagonist • Vestibular suppressant without SE • Little reaserch

  28. Alternative medicine agents • Ambra grisea D6 • Anamirta cocculus D4 • Conium maculatum D3 • Petroleum rectificatum D8

  29. Specific Pharmacotherapy • Vestibular Neuritis * • Meniere’s Disease * • Benign Paroxysmal Positional Vertigo * • Otosyphilis • Vertebrobasilar Insufficiency • Migraine (with vertigo) * more common

  30. Vestibular Neuritis • Sudden onset of peripheral vertigo • Inflammation of vestibular nerve - presumably of viral origin • Spontaneous, complete symptomatic recovery with supportive treatment • Treatment aimed at stopping inflammation

  31. Vestibular Neuritis • Ariyasu et al. (1990) • 20 patients: double-blinded, crossover • Methylprednisolone vs. placebo • 90% decrease in vertigo within 24 hours vs. 30% of placebo group • Placebo switched to steroid after 24 hours with decrease in vertigo over next 24 hours • 16 patients receiving steroid with resolution had normal ENG within one month

  32. Meniere’s Disease • Hallpike and Cairns - 1938 found endolymphatic hydrops by histology • Precise etiology is unknown

  33. Meniere’s Disease • Widely accepted medical treatment • Dietary salt restriction • Diuretics • Thiazide diuretics • Decrease Na absorption is distal tubule • Side effects - hypokalemia, hypotension, hyperuricemia, hyperlipoproteinemia • Combination potassium sparing agents spironolactone , thiazide + amiloride

  34. Meniere’s Disease • At least 3 months of diuretic therapy recommended before discontinuing • Sulfa allergies - can try loop diuretics or alternate therapies

  35. Meniere’s Disease • Carbonic anhydrase inhibitors (acetazolamide) • “inner ear glaucoma” • Decreased Na-H exchange in tubule • Decreased CSF production • Diuretic effect not as long-lasting • Side effects - nephrocalcinosis, mild metabolic acidosis, GI disturbances

  36. Meniere’s Disease • Vasodilators • Based on hypothesis - pathogenesis results from ischemia of stria vascularis • Rationale - improve metabolic function • IV histamine, ISDN, cinnarizine (CA antagonist), betahistine (oral histamine analogue) • Anecdotal success • No demonstrated beneficial effects in studies

  37. Meniere’s Disease • Newer theories • Multifactorial inheritance • Immune-mediated phenomena • Association of allergies • Study by Gottschlich et al. • 50% meeting criteria have antibodies to 70-kD heat-shock protein • 70-kD HSP implicated in AI-SNHL

  38. Meniere’s Disease • Immunosuppressive agents gaining favor • Systemic and intra-tympanic glucocorticoids • Cyclophosphamide • Methotrexate • Shea study - intractable Meniere’s • 48 patients IT dexamethasone • 66.7% elimination of vertigo • 35.4% improvement in hearing (>10dB and/or 15% change in word recognition score)

  39. Meniere’s Disease • Chemical labyrinthectomy • Disabling vertigo • After trial of adequate medical therapy • Intratympanic aminoglycoside (ITAG) • Allows treatment of unilateral disease • Gentamicin • Primarily vestibulotoxic • may impair vestibular dark cells (endolymph) • Inherent hearing loss risk - 30%

  40. ITAG • Stock solution - 40mg/mL gentamicin • 10 to 20 mg injected over round window • Patient supine, ear up for 30 minutes • Instructed not to swallow • Bolus injections - weekly or bi-weekly • End point variable - vestibular hypofunction • Audiometry monitoring between injections • Total vestibular ablation not necessary

  41. ITAG • Minor • 91% control of vertigo • 3% rate of profound SNHL (usually sudden) • 22% recurrence rate • Continuous delivery • Microwick • Round Window Microcatheter • Direct injection (labyrinthotomy) • Significant hearing loss • Out of favor

  42. BPPV • Most common cause • Dysfunction of posterior SCC • Cupulolithiasis vs. Canalithiasis

  43. BPPV • Treatment approaches • Liberatory maneuvers • Particle repositioning • Habituation exercises

  44. BPPV • Epley • Canalithiasis • Canalith repositioning • Move into vestibule • Cure rates • 80% - one treatment • 100% - multiple

  45. Otosyphilis • Penicillin established treatment • IM and IV routes acceptable • IM - 2.4 million units benzathine PCN weekly x 3 consecutive weeks is minimal treatment (some advocate up to 1 year) • IV - 10 million units PCN G qD in divided doses x 10 days, followed by 2.4 million units benzathine PCN x 2 weeks

  46. Vertebrobasilar insufficiency • Vertigo, diplopia, dysarthria, gait ataxia and bilateral sensory & motor disturbance • Transient ischemia - low stroke risk • Antiplatelet therapy - aspirin 325mg qD • Ticlid • Platelet aggregate inhibitor • Risk of life-threatening neutropenia • Only in patients unable to tolerate aspirin

  47. Migraine • Concomitant vertigo and disequilibrium • Headache control improves vertigo • Diagnostic criteria • Personal/family history • Motion intolerance • Vestibular symptoms - do not fit other causes • Theories - vascular origin, abnormal neural activity (brainstem), abnormal voltage-gated calcium channel genes

  48. Migraine • Treatment • Modifying risk factors • Exercise and diet • Avoid nicotine, caffeine, red wine and chocolate • Abortive medical therapy • Ergots • Sumatriptin • Midrin • Prophylactic medical therapy • B blockers, Ca channel blockers, NSAIDs, amitryptiline, and lithium

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