Vestibular Pathology

Question 1

Describe the mechanism behind Meniere’s

Answer 1

abnormally large amount of endolymph> inner ear swelling> increased pressure and membranous labyrinth>hair cell death and mechanical change in otolith

Question 2

Describe Meniere’s presentation

Answer 2

-vertigo sometimes w/ aura(may or not be symptomatic between attacks)
-sudden and spontaneous
-minutes-24 hrs episodes variable in frequency
-ear fullness/fluctuating tinnitus /hearing loss
-drop attacks
-sympathetic NS symptoms

Question 3

What are the 3 stages of Meniere’s Progression

Answer 3

1. unpredictable vertigo attack
2. vertigo>tinnitus>hearing loss
3. Hearing loss>balance difficulties>tinnitus

Question 4

Describe the mechanism behind neuritis

Answer 4

viral infection of the vestibular branch of vestibulocochlear nerve ganglion
-preceding upper respiratory or GI infection in 50% of cases

Question 5

Describe the mechanism behind labyrinthitis

Answer 5

viral or bacterial inflammation within entire labyrinth; viral is most common and usually post-upper respiratory tract

Question 6

Describe Neuritis and Labyrinthitis presentation

Answer 6

-severe acute vertigo that gradually reduces in severity
-spontaneous and sudden onset
-acute (days-week) vs chronic (weeks to months)
-labyrinthitis (hearing loss) vx neuritis
-imbalance and disorientation + oscillopsia

Question 7

What are examination findings for ACUTE labyrinthitis and neuritis?

Answer 7

dx of exclusion, +vHIT with symptoms more than a few days

Question 8

What are examination findings for CHRONIC labyrinthitis and neuritis?

Answer 8

rotary chair test, audiogram, VEMP, MRI, blood work

Question 9

Describe the mechanism behind acoustic neuroma/Schwannoma

Answer 9

slow growing tumor from schwann cells of CN 8 or internal auditory canal

Question 10

Describe acoustic neuroma presentation

Answer 10

usually vertigo is secondary and onset is gradual
constant w/ auditory involvement
tumor can hit CN 5 & 7 as well

Question 11

How are acoustic neuromas diagnosed?

Answer 11

MRI w/ contrast is gold standard but there is also audiograms for hearing dom dx

Question 12

Describe the mechanism behind perilymph fistulas.

Answer 12

opening between middle and inner ear mostly assoc w/ head trauma or rapid increases in ICP> dysfn to labyrinth and cochlea+leaking perilymph

Question 13

Describe perilymph fistula presentation.

Answer 13

vertigo worsens with activity and pressure changes, traumatic onset, fluctuating hearing symptoms, imbalance, commonly HA and motion intolerance

Question 14

How are perilymph fistulas diagnosed?

Answer 14

fistula test, valsalva test, audiogram, ENG/VNG, MRI (CNS rule out)

Question 15

Describe the mechanism behind semicircular canal dehiscence (superior/anterior most common)

Answer 15

can result from premorbid trauma or congenital structure> a fistula due to lack of temporal bone covering semicircular canal

Question 16

Describe semicircular canal dehiscence (superior/anterior most common) presentation

Answer 16

vertigo triggered by pressure changes, spontaneous onset, activity dependent duration and frequency, fluctuating auditory involvement, imbalance w/ sound sensitivity

Question 17

How are SCDs diagnosed?

Answer 17

Bone conduction sensitivity test (tuning fork on lat malleoli)
Tulio’s Phenomenon
Valsalva Test
Radiograph+ Audiogram

Question 18

Describe the mechanisms behind bilateral vestibular hypofunction

Answer 18

can be idiopathic or secondary to ototoxic agents (often antibacterial)

Question 19

Describe bilateral vestibular hypofunction presentation.

Answer 19

vertigo is sequential and onset depends on cause, constant symptoms that worsen with head movement, imbalance and hearing issues if ototoxic, severe oscillopsia

Question 20

How is bilateral vestibular hypofunction

Answer 20

rotary chair test is gold standard

clinical exam: HIT bilaterally, Dynamic visual acuity, bilateral caloric testing