Changes in EEG foci with age in childhood partial epilepsies

The age changes of epileptic foci on EEG were evaluated in 208 patients with childhood partial epilepsies, who were followed for more than 3 years. 1) The incidence of EEG foci in each region apparently differed with age. Frontal and central foci were frequent before school age and after adolescence. Temporal foci showed a peak around adolescence, and occipital foci a peak from 3 to 7 years, respectively. Parietal foci were rare at all ages. 2) The migration of EEG foci was recognized 171 times in 81 of the 208 patients (38.9%) during the clinical course. The migration was frequently seen at early school age and preadolescence, and the direction of migration was predominantly anterior to posterior at early school age, and posterior to anterior at preadolescence. These results suggest that EEG foci show characteristic changes with age during the clinical course, which may be related to maturation of the central nervous system.