Microsaccadic flutter.

Microsaccadic flutter is a rare symptomatic saccadic oscillation that has been reported only twice previously. Here we describe 5 patients with this disorder. The oscillation is horizontal, has a frequency of 15-30 Hz, an amplitude of 0.1-0.5 degrees, and cannot be seen with the unaided eye. It is usually not associated with any underlying neurological disorder. We hypothesize that microsaccadic flutter is due to malfunction of the brainstem omnipause neurons.