2. Anatomy and Physiology

3. Inner ear Consists of: Bony labyrinth Membranous labyrinth
The tubes and chambers within the petrous portion of the temporal bone
Membranous labyrinth
The functional part of the vestibular apparatus. 3 portions
Cochlea – has little input into balance. The main hearing apparatus
2 large chambers, the saccule and the utricle – these are the main balance apparatus
3 semicircular canals – useful for detecting rotation, also vital in maintaining balance

4. Utricle and Saccule Maculae
Chambers containing a small sensory area
known as the macula
Maculae
This consists of thousands of hair cells which, as well as synapsing with the vestibulocochlear nerve at their proximal end, project into a gelatinous layer covering the maculae. The gelatinous layer has many tiny calcium carbonate crystals (otoliths) embedded in it. It is the difference between the specific gravity between these crystals and the surrounding fluid (endolymph) that bends the hair cells to produce signals regarding position.

5. Semicircular canals Function by different mechanism
Do not contain otoliths
Works by the presence of enodolymphatic fluid within the chambers flowing through the canals in response to movement. Hair cells within ampullae of the canals will bend with the flow of liquid, producing signals.

6. Movement is detected by hair cells
2 types of hair cells
Type 1 detects head movement
Type 2 detects linear acceleration
Travels via CN VII to brainstem nuclei
Important reflexes are elicited
Vestibuloocular reflex (VOR).....this stabilizes images on the retina during head movement by producing an eye movement in the direction opposite to the head movement, therefore preserving the image in the centre of the visual field
VST
VCT

7. Causes of pathology Central Peripheral Important to differentiate:
Presence of focal neurology, cerebellar signs, eye problems, LOC, weakness
Peripheral
Ear symptoms, abnormal Rinne or Weber

8. Central disease Cerebrovascular disease Acoustic Neuroma Vasculitis
Cerebellar stroke
Vertebrobasilar insufficiency
Acoustic Neuroma
Vasculitis
Migraine
Demyelination (MS)

9. Peripheral Disease Labyrinthitis Benign paroxysmal positional vertigo
Acute vertigo sometimes associated with nausea, vomiting and ataxia “world shakes up and down when I walk”. Often spontaneously resolves over several days
Benign paroxysmal positional vertigo
Caused by otoliths ending up in the semicircular canals, inappropriately activating the hair cells there. Acute episodes of short lived vertigo
Menieres Disease
Triad of vertigo, sensorineural deafness and tinnitus. Unknown cause, attacks last from a few hours to several days. Usually remits after several years.
Otitis
Ototoxicity
Frusemide, gentamicin, NSAIDS, quinine

10. Treatment
General treatment for vertigo
Disease specific

11. General
Symptomatic
Vestibular rehabilitation

12. Symptomatic treatment
Best for acute episodes, but not for very brief, i.e. BPPV
Antihistamines.....Drug of choice
Meclizine, diphenhydramine
Phenothiazine antiemetics....if severe vomiting. Beware of sedation
Prochlorperazine, domperidone, metoclopramide
Benzodiazepines.....reserved for those with contraindications to anticholinergics, i.e. prostatism and glaucoma
Should be stopped as soon as vomiting ceases

13. Vestibular rehabilitation
Better for peripheral injury
Total recovery comes from central nervous system compensation
Activities promotes adaption, strategic substitution and prevents negative effects such as deconditioning
Evidence more effective if commenced early
Different types
Acute peripheral....focusing on object with blank background
Chronic peripheral......eye and head movements – more aggressive
Bilateral vestibular loss.....saccadic eye exercises and neck exercises
Central....gait and balance activities
Ask your local physio!

14. Disease specific
Peripheral
Central

15. Peripheral Labyrinthitis BPPV Menieres Corticosteroids in acute period
Diagnosed with Hallpike, treated with Epley manoeuvre
Menieres
Patient education
Lifestyle adjustments
Salt restriction, caffeine + nicotine avoidance, stress relief, limit alcohol to one drink per day
Diuretics and betahistine ? Efficacy
Interventional
Intratympanic gent....low dose may not cause deafness
Vestibular neurectomy...craniotomy. Relieves 90% of vertigo, % hearing loss
Labyrinthectomy....results in deafness
Shunting

16. Otitis
Antibiotics, analgesia, antiemetics
Ototoxicity
Abstinence

17. Central CVA (posterior circulation/ vertebrobasilar insufficiency)
Vascular
Acoustic neuroma
ENT referral and removal
Vasculitis
Steroids
Migraine
Analgesia
Demyelination
Steroids, interferon

18. Hallpike manoeuvre
(It should work if you click on it and wait for a couple of seconds!)

19. Epley manoeuvre