Common Medical and Audiologic Tests in Vestibular Disorders

Question 1

Why do you perform vestibular function tests?

Answer 1

-determine if the dysfunction is peripheral or central origin
-location an extent of lesion

-informs prognosis
-helps to educate patient on findings and how they relate to chosen interventions

Question 2

ENG

Answer 2

electronystagmography

-electrodes placed around eye mm.
-patient has to wear a head set
-track eye movements

1.) oculomotor function - test smooth pursuit and saccades

2.) positional tests

3.) caloric testing - cold or warm water is placed in the inner ear and stimulates or inhibits semicircular canals—> stimulate the horizontal canal, elicit nystagmus, and graphically measure the response

Question 3

VNG

Answer 3

videonystagnmography

1. Oculomotor exam
2. Optokinetic nystagmus
3. Positional nystagmus
4. Caloric testing

-assess the integrity of the vestibular nerve

Question 4

Frenzel lenses/goggles function

Answer 4

helps to identify the direction of nystagmus

significant magnification of the eyes

Question 5

Rotary Chair testing

Answer 5

good for bilateral vestibular hypofunction due to stimulation of both ears at the same time

DETERMINE if dizziness is due to:
-disorder of inner ear vs brain
-unilateral vs bilateral impairment

THREE PARTS
1. chair test - chair turned slowly in motorized chair, wearing goggles
2. optokinetic test - patient asked to view moving stripes
3. fixation test- chair is rotating and the person is looking at a dot of light that is rotating with them

Question 6

VEMPs

Answer 6

vestibular-evoked myogenic potential (VEMP)
-test of otolith function

-electrodes placed on SCM
-tone is played in the ear–> excites saccule (otolith organ) –> looks at activation of the SCM based on excitation of otolith

-to test ocular function–> oVEMP–> uses bone vibration and looks at EMG of the eye

DX: Can help diagnose
superior canal
dehiscence,
Meniere’s

Question 7

Types of audiologic testing

Answer 7

audiogram - An audiogram is a graph that shows the softest sounds a person can hear at different pitches or frequencies.

AEP- Auditory evoked potential (AEP) is a type of EEG signal emanated from the brain scalp by an acoustical stimulus.

ECOG - ECoG tests measure electrical potentials generated in the cochlea, a part of the inner ear, in response to audio stimulation.