Problems of differentiation between epilepsy and non-epileptic paroxysmal events in the first year of life.

Twenty two babies under 1 year old were referred for evaluation of suspected epileptic seizures. Nine were found to have epilepsy. In the other 13--all developing normally, aged up to 10 months--the spells were non-epileptic paroxysmal events (NEPE). They consisted of five patterns of movement: (1) eye blinking; (2) 'no' movements; (3) body posturing with head and arm jerks; (4) masturbation-like movements; and (5) myoclonic head flexion. The NEPE were present for a period of two weeks to seven months. Although some NEPE cannot be clinically differentiated from true epilepsy, in these infants at least four interictal EEGs were normal, the spells completely resolved after a relatively short period without antiepileptic treatment, and the infants continued to develop normally with no evidence of epilepsy during a follow up period of 28 to 38 months. This sample indicates that the frequency of NEPE in the first year of life may be high. Cautious clinical consideration, repeat EEGs and, when appropriate, a few weeks' observation are recommended. Awareness of these benign behavioural spells in this young age group is important, and parents can be reassured. Nevertheless, the spells may illustrate a 'foggy frontier' between NEPE and epilepsy. The lack of evidence for any other disease process in affected infants, as well as the disappearance of the NEPE without any intervention, indicates that a maturational process may be involved.