Document Type


Publication Date



Alzheimer's disease; Myoclonus


Although anecdotal references commonly presume that seizures eventually occur in patients affected with dementia of the Alzheimer type (DAT), no previous American study has documented the rate of new onset, unprovoked seizures in DAT patients. There are few documented cases of the occurrence of myoclonus in autopsy-proven DAT. In a series of 83 autopsy-proven DAT cases, medical records were scrutinized for the presence of any seizure or myoclonic activity. Final evaluations were made by a neurologist. Of the 83 cases, 8 had experienced one or more unprovoked seizures after the onset of DAT. Based on age-specific incidence rates from a population study of Rochester, Minnesota, the expected number was 0.80 (p<.0l). Eight patients developed myoclonus during the dementing illness. (No appropriate general population study exists that would make comparison of rates of new onset myoclonus possible.) There was no overlap between those who developed myoclonus and those who developed seizures. These data suggest that individuals with DAT have a tenfold greater risk of developing seizures than an age-matched control, but that seizures cannot be considered a universal sign of DAT. Whether this increase in risk is uniform or whether seizures or myoclonus define unique subgroups of DAT types remains to be explored.

First Page


Last Page


Primo Type


Included in

Neurology Commons



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.