Studies on Prenatal Factors in Childhood Epilepsy

Part 2. Electroencephalographic Aspects

Abstract

To investigate the characteristics of childhood epilepsy, an electroencephalographic study was performed on 187 epileptic children with prenatal causative factors.
Subjects consisted of the cases with 1) family history of convulsions, without any other exogenous or endogenous factors, 2) known disease entities with hereditary or chromosomal abnormalities, 3) apparent intra-uterine abnormalities, or 4) congenital brain dysgenesis and/or multiple anomalies.
Electroencephalographic characteristics were analyzed on the following five groups; 96 cases with familial convulsive predisposition (A), 39 cases with phacomatoses (B), 10 cases with chromosomal abnormalities (C), 32 cases with cerebral dysgenesis (D), and 10 other cases (E).
Persistent asymmetry of the background activity was noted in 6 cases (6.3%) of group A, and 31 (44.9%) of 69 cases excluding 22 cases without visible basic activity due to marked seizure activity in groups B, C, D and E.
Focal cortical epileptic discharges were noted in 55 cases (57.2%) of group A, and 45 cases (49.5%) of groups B, C, D and E.
Regarding the localization of focal cortical discharges, 18 cases (32.7%) among 55 cases of group A showed the central focus, while 21 cases (46.8%) among 45 cases of groups B, C, D and E showed multifocal discharges.
Subcortical epileptic discharges were noted in 37 cases (38.6%) of group A. On the other hand, in groups B, C, D and E, diffuse cortico-reticular discharges were noted in 38 cases (41.7%). Twenty-one cases (55.3%) showed hypsarhythmia, mainly atypical pattern such as modified or periodic hypsarhythmia.