Two of the most common neurological conditions encountered during early childhood are epilepsy and mental deficiency. They are both very complex and of heterogenous origin, hence constituting syndromes and not disease entities. The whole problem becomes further complicated by the fact that in a considerable proportion of the affected patients mental deficiency and epileptic attacks coexist. In such instances, the most frequent denominator of these two disorders is brain damage, malformation, or metabolic disturbance.
Cerebral seizures of idiopathic type commencing in older children are not usually associated with serious mental retardation. However, observations have been made suggesting that frequent daily attacks occurring under one year of age can be in themselves the cause of severe retardation of development. This view is not shared by all investigators in the field. Illingworth (1955), Livingston (1958, p. 131), and Low et al. (1958) expressed the belief that in all of such patients there