Senile myoclonic epilepsy of Genton: two cases in Down syndrome with dementia and late onset epilepsy.

Senile myoclonic epilepsy of Genton is a newer epileptic syndrome of the older patients with Down syndrome associated with an Alzheimer-type dementia. We report two observations in whom the clinical and electroencephalographic features are consistent with the description of this syndrome. Both experienced a progressive deterioration of cognitive functions few years before the onset of the epilepsy. The EEG was characteristic with generalized fast spike-waves or polyspikes or polyspike-waves with or without bilateral myoclonic jerks especially at awakenings. One patient had a photoparoxysmal response (11-21Hz) with bilateral myoclonic jerks. Hence, the senile myoclonic epilepsy of Genton is an easily recognizable newer epileptic syndrome of the older Down syndrome patient.