Vestibular Pathology Flashcards
Describe the mechanism behind Meniere’s
abnormally large amount of endolymph> inner ear swelling> increased pressure and membranous labyrinth>hair cell death and mechanical change in otolith
Describe Meniere’s presentation
-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
What are the 3 stages of Meniere’s Progression
- unpredictable vertigo attack
- vertigo>tinnitus>hearing loss
- Hearing loss>balance difficulties>tinnitus
Describe the mechanism behind neuritis
viral infection of the vestibular branch of vestibulocochlear nerve ganglion
-preceding upper respiratory or GI infection in 50% of cases
Describe the mechanism behind labyrinthitis
viral or bacterial inflammation within entire labyrinth; viral is most common and usually post-upper respiratory tract
Describe Neuritis and Labyrinthitis presentation
-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
What are examination findings for ACUTE labyrinthitis and neuritis?
dx of exclusion, +vHIT with symptoms more than a few days
What are examination findings for CHRONIC labyrinthitis and neuritis?
rotary chair test, audiogram, VEMP, MRI, blood work
Describe the mechanism behind acoustic neuroma/Schwannoma
slow growing tumor from schwann cells of CN 8 or internal auditory canal
Describe acoustic neuroma presentation
usually vertigo is secondary and onset is gradual
constant w/ auditory involvement
tumor can hit CN 5 & 7 as well
How are acoustic neuromas diagnosed?
MRI w/ contrast is gold standard but there is also audiograms for hearing dom dx
Describe the mechanism behind perilymph fistulas.
opening between middle and inner ear mostly assoc w/ head trauma or rapid increases in ICP> dysfn to labyrinth and cochlea+leaking perilymph
Describe perilymph fistula presentation.
vertigo worsens with activity and pressure changes, traumatic onset, fluctuating hearing symptoms, imbalance, commonly HA and motion intolerance
How are perilymph fistulas diagnosed?
fistula test, valsalva test, audiogram, ENG/VNG, MRI (CNS rule out)
Describe the mechanism behind semicircular canal dehiscence (superior/anterior most common)
can result from premorbid trauma or congenital structure> a fistula due to lack of temporal bone covering semicircular canal