Video head impulse test for follow up of cranial nerve 3, 4, or 6 paresis

Quantification of ocular misalignment is performed using prism-alternative cover technique in neuro-ophthalmology clinics. An objective device-based measurement of ocular misalignment that is not operator dependent would be the next step in improving evaluation of ophthalmoplegia due to cranial nerve palsies or strokes. vestibulo-ocular reflex gain measured by video-oculography is calculated by dividing eye velocity by head velocity during head impulse test. We seek to use the efferent arm of the VOR and measure the gain value of HIT to assess cranial nerve 3, 4, and 6 function.