Neuropsychological effects of seizures.

The neuropsychological effects of seizures, including an accumulation of single attacks, on mental abilities are explored through a selective review of the world's literature. Each paper included in this review was longitudinal in nature, and in each case, formal psychological testing was accomplished both at the beginning and at the end of the study. Of the 22 investigations meeting all requirements for inclusion, 9 focused on children and 13 on adolescents and adults. Some difficulties were encountered in that the types and numbers of seizures occurring during the studies were rarely included. Except in three studies where there were very few seizures of any kind, it appears justifiable to assume that the patients in all other studies had active seizure disorders. Assuming this to be true, in 12 of the remaining 20 papers, a relationship was found between seizures and changes in mental abilities, in 5 cases the results were mixed or uncertain, and in 3 cases the available evidence was against such a relationship. Mild but definite relationships between seizures and mental decline are supported by this literature review, but these relationships require much more study, particularly with a clearer understanding of the types and frequencies of seizures experienced. Suggestions for future research are offered.