Labyrinths and Vestibular: Meniere's, BPPV, acoustic neuroma, viral labyrinthitis, vestibular neuritis

Question 1

Anatomy of vestibular apparatus

Answer 1

In inner ear, petrous part of temporal for protection

Bony labyrinth
-3 semicircular canals
-vestibule
-cochlea

Membranous labyrinth in bony
-semicircular duct opens up into utricle and saccule
-surrounded by perilymph (low Na, high K)
-endolymphatic duct allows fluid circulation
-voltage difference across membranous labyrinth aids with vestibular function

Question 2

Ménière’s disease vs BPPV
-epidemiology, etiology
-pathophysiology
-symptoms, signs

Answer 2

Meniere’s - excess endolymph
-middle age, M+F
-episodes last mins-hours
-symptoms generally unilateral but may become bilateral with time
-recurrent attacks of vertigo, tinnitus, sensorineural hearing loss, ear pressure
-nystagmus, +ve Romberg test

BPPV - otoliths move into semicircular ducts, cause vertigo when displaced
-most common cause of vertigo
-55s
-episodes last seconds
-nausea, +ve Dix Hallpike manoueuvre

Question 3

Meniere’s Disease vs BPPV
-diagnosis
-management (practical, attacks, prevention)
-prognosis

Answer 3

ENT assessment confirms diagnosis for both

Meniere’s
-inform DVLA, stop driving until symptoms controlled

Acute - prochlorperazine (typical antipsychotic with antiemetic properties)
Prevention - betahistine (anti-vertigo) and vestibular rehab
Self-limiting- 5-10years but with hearing loss and psychological distress

BPPV
-Epley, vestibular rehab
-Betahistine given but not always effective
Self-limiting but can recur

Question 4

Acoustic neuroma
-epidemiology, etiology
-pathophysiology
-symptoms, signs

Answer 4

No obvious cause but linked to neurofibromatosis T2

Benign tumour that may compress CN5, 7, 8

Triad of vertigo, hearing loss, tinnitus (CN8), no corneal reflex (CN5), facial palsy (CN7)

Question 5

Acoustic neuroma
-diagnosis
-management

Answer 5

If suspected => URGENT REFERRAL TO ENT

Gold standard - MRI of CPA
-audiometry

Management
-observe/surgery/radiotherapy

Question 6

Viral labyrinthitis vs vestibular neuritis
-epidemiology, etiology
-pathophysiology
-symptoms and signs

Answer 6

Viral labyrinthitis - inflammed membranous labyrinth
-40-70, recent URTI
-vertigo exacerbated by mv but not a trigger => N+V
-sensorineural hearing loss, tinnitus
-nystagmus

Vestibular neuritis - inflammation of vestibular nerve
-recent URTI
-vertigo attack lasts hours-days => N+V
-no hearing loss
-nystagmus

Question 7

Viral labyrinthitis vs vestibular neuritis
-diagnosis
-management (practical, attacks, prevention)
-prognosis

Answer 7

Clinical diagnosis

Self limiting
-prochlorperazine or betahistine can help

Question 8

Sudden onset sensorineural hearing loss
-key investigations
-causes
-management

Answer 8

Rinne and Weber => sensorineural

URGENT REFERRAL TO ENT in 24HRS for MRI

MAJORITY IDIOPATHIC
-want to exclude acoustic neuroma

High dose CS used for all cases
-PO pred