Neuro – Vestibular Disorders

Vestibular Disorders
Host: Jimmy McKay, PT, DPT
Featured Guest; Alicia Flach, PT, DPT, NCS
Notes by Alexis Lancaster
Vestibular Disorders
 
What is it?

Disruption that can occur from vestibular apparatus (inner ear) through the cranial nerve to the CNS where the information is processed
Any disruption along this path will cause a vestibular disorder

 
Anatomy

Peripheral vestibular system

BPPV: problems within the vestibular apparatus, specifically semicircular canal

Creates sensation of moving, pt feels dizzy


Problem with cranial nerve 8 (before synapse in brain stem)
Problem here= peripheral problem


Central vestibular system

After cranial nerve 8 synapses in brainstem
Travels different pathways to locations within the brain
Problem here= central problem



 
Differential diagnosis

Dizziness can be due to different things

Vertigo: room spinning, could be peripheral or central vestibular problem
Feeling of imbalance or disequilibrium, pt doesnt feel steady on their feet. Could be peripheral or central vestibular problem


Unrelated to vestibular system

Polypharmacy
Orthostatic hypotension (pt complains of feeling light-headed, passing out, fainting)
Low blood sugar (hypoglycemia)
Migraines


Get to the root of how the patient describes their dizziness

 
Special Tests

Subjective interview: try to understand when it happens, how long it has been going on, how long it lasts when it happens, does it come and go or is it constant, is it related to positional changes?
Rule out/in peripheral condition, BPPV: Dix Hallpike, head thrust test, dynamic visual acuity test
Look for central signs throughout exam

Hypermetria with saccades
Abnormal changes in the ability to perform


Vestibulo-occular reflex cancellation: being able to follow a moving object with your eyes and head moving in the same direction
Rule in the vestibular system overall, rule in/out peripheral vs. central

 
Treatment

Common encounter: BPPV

Managed through canalith repositioning maneuvers (otoconia getting stuck in canal): Epley and BBQ Roll


Dysfunction of peripheral nerve/hypofunction

Gaze stabilization Tx


Movement sensitivity/central component

Habituation
Exercise
Graded exposure



 
Sample Question
A physical therapist evaluates a patient who reports dizziness when getting out of bed. The physical therapist suspects the pt is experiencing symptoms related to BPPV. Which of the following would be the most appropriate assessment to confirm the presence of BPPV

Head thrust test
Dynamic visual acuity testing
Dix Hallpike maneuver
Clock drawing test

 

Answer: C. Dix Hallpike: it is an assessment in which an individual is moved into a position and is intended to elicit a response from the presence of otoconia in the semicircular canal. Position the patient and look for the presence of nystagmus to rule in BPPV.

 
Why the others are wrong:
A: Head thrust test looks at the ability of a patient to perform VOR (vestibulo-ocular reflex)--> specifically looks for hypofunction

B: Dynamic visual acuity testing tests for peripheral hypofunction. Perform eye chart and look at visual acuity in static position and then pt will move head side to side to see visual acuity dynamically.