Supranuclear paralysis preventing lid closure in amyotrophic lateral sclerosis.

We report a case of amyotrophic lateral sclerosis (ALS) in which the ability to close the eyes on command or voluntarily, was lost in spite of retention of reflex activity. A electrophysiological study of the blink reflex revealed a prominent R1 component with normal latency, which confirmed that the blink reflex was exactly preserved and also suggested a hemispherical lesion. Postmortem examination disclosed prominent cortical and subcortical lesions of the precentral areas on both sides. These lesions seem to be very closely related to the inability to initiate lid closing.