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• Patient position
Video head impulse test (vHIT)
This test records the movements of the eyes and head. The clinician’s hands must be
well away from the goggles and the goggle-strap to minimize the chance of any
artifact camera movement. The patient should keep staring at target point on the
screen , and the clinician gives the patient brief, abrupt, horizontal head rotations
through a small angle (about 10-20 degrees) unpredictably turning to the left or right
on each trial.
In a full test usually around 20 impulses are delivered randomly in each direction. In a
full test
Usually around 20 impulses are delivered randomly in each direction and it may take
4 or 5 minutes to do that.
This test plots the eyes velocity and head velocity.
Warnings
• Patient position
Supine
The examiner places the patient in each position and evaluates for a minimum of 20-
30 seconds. Mental tasking is used to keep the patient from suppressing Nystagmus.
Visual suppression must also be avoided by the use of infrared goggles.
Somestandard positions usedincludethefollowing:
Supine Head 20-30º
1. Supine, head right 60º
2. Supine, head left 60º
3. Supine Head 20-30º (Primary position)
Warnings
• Patient position
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