[Severe myoclonic epilepsy in childhood. Epidemiologic analytical study]

Severe myoclonic epilepsy in infancy (SMEI) is a relatively rare disorder which etiology is unknown. The descriptive epidemiologic study tries to find the exposure agents or other circumstances present in affected children. Were have studied this agents and circumstances in 28 children with SMEI.

The study included 28 children, 17 girls and 11 boys, diagnosed of SMEI. Patients were selected according to the criteria established by Dravet et al in 1984. For each patient, the following features were studied: sex, parents age, prenatal antecedents, perinatal antecedents, new born stage, psychomotor development until the first convulsion, country/urban social class, family history of epilepsy and for febrile seizures, and cause of the first seizure.

All parents are young adults, between 25 and 40 years at the birth of the child. The number of the fratry is between the first and the fourth. There is no pre and perinatal antecedents. The birth's weight is between 1,800 g and 4,600 g (X: 3,580 g). In 16 children (57.15%), the first seizure appeared after any dose DTP vaccination, frequently the second. Familial antecedents existed for epilepsy in nine cases and for febrile convulsions in six cases.

The more interesting findings are the high percentage of cases that have the first convulsions after any dose of vaccination DTP and the high percentage of cases with family history of epilepsy and/or febrile seizures. It suggests that in pathogenesis of the SMEI there is a constitutional factor or predisposition genetically conditioned in relation to immunological disorders or to a multifocal cortical microdysgenesis, possibly triggered by toxic-allergic factors.