3.HEAD SHAKING TEST
3.HEAD SHAKING TEST
The patient’s head is turned horizontally for 20 seconds with their eyes closed. Afterwards, in normal patients, nystagmus is not triggered. With patients suffering from a condition affecting the inner ear, nystagmus is observed and indicates a lesion of the inner ear on one side.
Video Head Impulse Test (VHIT)
Our inner ear balance organs stabilise the visible world upon the retina as we move our heads during walking and running. This is achieved by the vestibulocular reflex, by means of powerful connections between the balance organs and the extraocular muscles which move the eye. The VHIT tests your ability to match rapid head movements with equal and opposite eye movements.
Method
You will be asked to sit upright and wear a pair of lightweight video-glasses. You will focus upon a fixed target. The examiner (an audiologist or doctor) will deliver 20 head turns in the direction of each semicircular canal. The speed of eye movement is measured and expressed as a fraction of the speed of head movement. This test is a valuable screening test of semicircular canal function.
Preparation
Do not wear mascara or eye-liner since these interfere with pupil tracking.
Time taken: 10 minutes