Sudden unexpected death in epilepsy in adults with mental retardation.

The medical records of residents of a facility for persons with mental retardation from January 1, 1978, through December 31, 1997, were analyzed to identify incidence of sudden unexpected death for groups of 180 individuals with and 125 without comorbid epilepsy. Eighty deaths were identified, with 55 occurring in the epilepsy group and 25 in the nonepilepsy group. The rate of sudden unexpected death was 1.3 deaths per 1,000 patient years in the nonepilepsy group and 3.6 deaths per 1,000 patient years in the epilepsy group. The risk factors for sudden unexpected death in the epilepsy group were nonambulatory status and poorly controlled seizure disorder (increased seizure rate and increased number of antiepileptic drugs).