Vertical and horizontal epileptic gaze deviation and nystagmus.

Periods of epileptic nystagmus consisting of rightward eye deviation and right-beating nystagmus, alternating with upward eye deviation and upbeating nystagmus, occurred in a comatose patient with a left hemisphere subdural hematoma and seizures. The periods of upbeating nystagmus were associated with symmetric, low-voltage 3 to 4 Hz bifrontal spikes. Rightward eye deviation and right-beating nystagmus occurred with diffuse, predominantly left hemispheric 4 to 6 Hz sharp waves. No eye movements occurred in the absence of spike and wave activity. These correlations agree with current concepts of the cortical control of saccadic eye movements in monkeys studied by electrical stimulation.