Head Thrust/ Impulse Test
Ask the patient to fixate on a target on the wall in front of the patient while the examiner moves the patient's head rapidly (>2000 deg/sec2) to each side. The examiner looks for any movement of the pupil during the head thrust and a refixation saccade back to the target.
Unilateral - reduced vestibular function to the positive side
Bilateral - ototoxicity or bilateral hypofunction