Seizures and myoclonus in patients with Alzheimer's disease.

We reviewed 81 patients with dementia and autopsy findings of Alzheimer's disease (AD) to identify patients with seizures or myoclonus after onset of dementia. Eight (10%) had seizures, and eight others (10%) had myoclonus. The incidence of seizures was 10 times more than expected in a reference population. Seizures occurred in any stage of AD, but myoclonus was often a late manifestation. Both seizures and myoclonus, individually or together, are manifestations of AD and may be seen at any time in the course of the illness.