The Effects of Anticonvulsants on the Epileptiform Discharges-Study by 24-hour Ambulatory Cassette EEG System

Thirty-three epileptic children who had epileptiform discharges in conventional 16 channel EEG study were enrolled in this study. The patients have never been treated with medication at first visit. Then patient were put on ambulatory monitoring EEG with the Oxford Medilog 9-channel cassette LEG system, which included six symmetrical scalp leads, one EOG, one Chin EMG and one channel for time signal. The LEG record was processed under the rule of the international standard method in terms of 10-20 system. The 24 hours EEG cassettes which recorded before and after antiepileptic drugs therapy were reviewed by an experienced electroencephalographer on a video play back unit. The number and duration of spikes or spike wave discharges were calculated. Among those 22 cases who had studied completed, there are 11 cases with generalized spike waves (5 with irregular spike waves, 3 with regular 3 hz spike waves, 1 with multiple spike waves, 1 with slow sharp waves and 1 with abortive spike waves), and 11 cases with focal spike activities (5 with bilateral central or centrotemporal spikes, 4 with temporal spikes and 2 with occipital spike discharges). After anticonvulsants therapy, 9 cases (82%) out of those 11 cases with generalized spike waves, the spike waves were disappeared; 2 cases (18%) revealed no significant change in spike rate and duration. In another 11 cases with focal spike discharges, 3 cases with centrotemporal spikes showed no significant change in spike rate, 2 cases with centrotemporal spikes and 4 cases with temporal spikes revealed significant decrease in spike rate; The occipital paroxysms of the last two cases were totally disappeared after medication. We found that most of generalized spike waves and occipital spike activities could be abolished totally by anticonvulsants, temporal spike discharges revealed marked decrease in spike rate after therapy, whereas, most of central or centrotemporal spike discharges showed no significant change in spike rate after antiepileptic drugs therapy.