22. Vestibular System Flashcards
what causes vestibular symptoms?
a mismatch of firing of the canal functional pairs
what is the most common peripheral vestibular dysfunction
which canal does this happen the most?
BPPV
PSCC
what is BPPV
otoconia become dislodged from utricle or saccule and are displacced in the SCC
BPPV:
the displaced _______ affect the flow of the _________ within the canal. leads to the defection of the ________, leading to a nerve signal and vertigo
the displaced otoconia affect the flow of the endolymph within the canal. leads to the defection of the cupula, leading to a nerve signal and vertigo
causes of BPPV
idiopathic, head trauma, inflammation, ischemia, pressure changes
risk factors for BPPV
age, female, VitD def, HTN, migraine, hyperlipidema
symptoms of BPPV
brief spells of vertigo with changes in head position against gravity
clear sign of BPPV
nystagmus is upbeat for PSCC
- named by torsion or rotary component which indicates if it is R or L PSCC
which is more commom: cupulolithiasis or canalithiasis
canalithiasis
Cupulolithiasis:
otoconia fall off and adhere to _______, making cupula denser than surrounding
__________ onset of vertigo
__________ vertigo/nystagmus at provoking position
otoconia fall off and adhere to cupula, making it denser than surrounding
immediate onset of vertigo
persistent vertigo/nystagmus at provoking position
canalithiasis:
otoconia fall off otolith and are free floating in _____________ of PSCC
_______ onset of vertigo/nystagmus
___________ intensity of nystagmus/vertigo, diminishes after 1 minute of provocation
otoconia fall off otolith and are free floating in long arm of PSCC
latent onset of vertigo/nystagmus
fluctuating intensity of nystagmus/vertigo, diminishes after 1 minute of provocation
both nystagmus for cupulolithiasis and canalithiasis are
upbeat and rotary R/L for PSCC
inflammation of the inner ear
vestibular labyrinthitis
inflammation of the vestibular nerve
neuritis
which inflammatory vestibular issue has hearing loss?
labyrinthitis, and it has tinnitus
main cause of neuritis and labyrinthitis
viral infection (98%), also head trauma
symptoms of neuritis and labyrinthitis
sudden onset of vertigo/vomiting
how long does symptoms of neuritis and labyrinthitis last
3-7 days with residual balance and dizziness lasting 1-2 wks
what is the hallmark of neuritis and labyrinthitis?
direction fixed of nystagmus and if it occurs in 1st, 2nd. 3rd degrees of gaze
damage to inner ear or vestibular nerve that results in diminished or weaker neurological signal
peripheral vestibular hypofunction
causes of peripheral vestibular hypofunction
neuritis, labyrinthitis, meniere’s disease, acoustic neuroma, some medications
symptoms of peripheral vestibular hypofunction
affects VOR and VSR
postural and gait instability
movement dizziness, motion sensitivity, foggy headedness
what is tinnitus
ringing in the ear
before diagnosis of vestibular neuritis/labyrinthitis, what should you do first?
rule out central causes!
types of central vestibular dysfunction
stroke
tumor
MS lesions
degenerative neuro conditions
vestibular migraine
persistent postural positional dizziness
mal de debarquement
anything affecting central vestibular connection in brain or brainstem!
signs of vestibular dysfunction
nystagmus and oscillopsia
non voluntary rhythmic oscillations of eyes with clearly defined fast and slow components beating in opposite directions
nystagmus
physiologic nystagmus
induced by a normal stimuli
pathologic nystagmus
abnormal, appears with or without stimulation; 4 types
4 types of pathologic nystagmus
spontaneous
positional
gaze evoked
congenital
T or F: peripheral vestibular hypofunction is unilateral
F: can be unilateral or bilateral
spontaneous nystagmus
due to central or peripheral vestibular problempo