Neurophysiologic and clinical correlations of epileptic nystagmus.

Epileptic nystagmus (EN) is a rare sign of seizure activity. We describe eight patients with horizontal EN and hypothesize that the frequency of ictal discharge, anatomic localization of ictal activity, and level of consciousness determine its occurrence and mechanism. We believe that EN is due to epileptic activation of a cortical saccade region; in each case, quick phases were generated away from the side of the focus, and both quick and slow phases were totally confined to the field contraversive to the seizure focus.