EPILEPSY, DEMENTIA AND ADAPTIVE-BEHAVIOR IN DOWNS-SYNDROME

Widespread enquiry identified 378 adults with Down's syndrome resident in Leicestershire, England. The immediate carer of 351 of these (92.8 %) was interviewed for the purpose of establishing a past history of s eizures, including the age at which the seizures,began. The immediate carer was also invited to provide information to enable the completion of an Adaptive Behaviour Scale (A.B.S.) rating. Individuals with a hi story of seizures were divided into two groups on the basis of whether or not seizures commenced prior to or after age 35 years. Two control groups of individuals with Down's syndrome, but without a history of seizures were selected. Adaptive Behaviour Scale scores for those in w hom seizures commenced at a younger age were similar to those who had no recorded history of seizures. However, in those in whom seizures be gan in later life, scores on all domains of the A.B.S. were significan tly reduced compared to both young epileptic patients and their contro ls. Adaptive Behaviour Scale scores for the older control group held a n intermediate position, suggesting that late-onset epilepsy may be a late manifestation of a dementing process. A clinical diagnosis of dem entia recorded in the case records was significantly associated with t he presence of late-onset epilepsy. This is supportive of the hypothes is that late-onset epilepsy in individuals with Down's syndrome is ass ociated with Alzheimer's disease.