Senile myoclonic epilepsy: Delineation of a common condition associated with Alzheimer's disease in Down syndrome

In Down syndrome (DS), epilepsy is frequent in all age classes and is recognized as a significant cause of additional handicap and morbidity. Longer life expectancy has led to the recognition of the high incidence of both Alzheimer's disease and seizures in elderly persons with DS. Neuropathological markers of AD are found in all DS brains and clinical symptoms of AD become apparent by the age of 60 years and above in over 50% of DS subjects. Following preliminary description of myoclonic seizures and/or myoclonic epilepsy in isolated cases or small series, we wish to report the diagnostic criteria, treatment and prognosis of a specific and recognizable form of epilepsy associated with AD in a larger group of middle-aged to elderly DS patients. This markedly under-recognized entity may indeed concern an already large and steadily increasing number of patients. We reviewed all medical records of patients with DS referred to our centers (Centre Saint Paul-Gastaut, Marseille; Epilepsy Unit, Montpellier University Hospital; Department of Neurology, Hospital General de Asturias, Oviedo) since 1995. DS had been diagnosed in all at birth, and all presented with the typical morphological changes associated with DS. We selected all cases (18) referred as adults with new onset of myoclonic jerks (MJ) and/or behavioral or cognitive deterioration (CD).