Changes and migration of EEG foci with age in 208 patients with childhood partial epilepsy followed for more than 3 years are reported from the Department of Pediatrics, Toyama Medical and Pharmaceutical University, Toyama City, Japan. Frontal and central foci were frequent before school age and after adolescence. Temporal foci peaked around adolescence, and occipital foci between 3 to 7 years. Parietal foci were rare at all ages. Migration of EEG foci in 39% of patients was frequent at early school age (anterior to posterior) and preadolescence (posterior to anterior). The migration of EEG foci was not accompanied by changes in seizure patterns or frequency. [1]

COMMENT. Migration of EEG foci in this study occurred with symptomatic partial epilepsies as well as idiopathic seizures. This phenomenon is not necessarily indicative of a benign epilepsy but reflects maturational changes in the brain, similar to those that characterize the changing patterns of seizures and EEG with infantile spasms and other epileptic syndromes. The authors suggest that this migration is an epiphenomenon on the scalp EEG since changes in clinical seizures were not observed.