Motor neuron disease presenting with slow saccades and dementia.

A 46-year-old man with a 2-year history of dementia presented with very slow saccades and tongue fasciculations. The diagnosis of amyotrophic lateral sclerosis (ALS) was established by electrophysiologic studies and ultimately on autopsy. Rarely, slowed saccades may be present in ALS, and slow saccades in a relatively young demented patient should prompt consideration of ALS.