Unit 4 - Vestibular Clinical Correlation

peripheral vestibular system consists of

vestibular nerve, vestibular apparatus with semicircular canals, and utricles with crystals

central vestibular system consists of

cerebral cortex, thalamus, cerebellum, vestibular nuclei

peripheral causes of dizziness

neuronitis, labyrinthitis, BPPV, perilymphatic fistula, meniere's disease, TBI, vestibular schwannoma

perilymphatic fistula is a

hole in the perilymph causing whoosing sounds and dizziness

meniere's disease

inflammation in bony labyrinth

vestibular schwannoma

benign tumor that can grow on cranial nerve, decreases firing rate unilateral to the side where the tumor was (poor balance and stability)

central vestibular disorders

CVA, MS, cerebellar atrophy, TBI and mTBI, motion sensitivity, migraine, tumor

CVA in what blood supply of the brain would cause dizziness

posterior blood supply to brain

brainstem injury can effect

eye movements

nystagmus

rapid, involuntary eye movements (can be physiological or pathological)

nystagmus types

vertical, horizontal and torsional

nystagmus is named by

the fast phase of movement

vertcial nystagmus occurs in

anterior semicircular canal

horiztonal nystagmus occurs in

horizontal semicircular canal

torsional nystagmus occurs in

posterior semicircular canal

vestibular ocular reflex

communication between vesitbular pathway and extraocular muscles, maintains stable vision during FAST head motion

VOR ratio

1:1 ratio for eye to head movement in the equal and opposite direction

VOR reflex interacts with what nerves

CN 3, 4, 6

oculomotor exam includes

observation, smooth pursuits, saccades, near point convergence, gaze holding nystagmus, rebound nystagmus

vestibular exam includes

head impulse test, head shaking nystagmus, dynamic visual acuity, positional testing

BPPV

crystals free floating in semicircular canal causes nystagmus - test via dix hallpike

what tracts are responsible

lateral vestibulospinal tract and vestibulocerebellar pathway

epley maneuver helps treat

BPPV in the posterior canal

BBQ maneuver helps treat

BPPV in the horizontal canal