Correlation between the changes in ambulatory electroencephalography findings and epilepsy recurrence after medication withdrawal among the population in southern China.

Patients suffering from epilepsy need long-term medication. However, after the epilepsy is completely under control, the recurrence rate is high once the drug dose is reduced gradually. The present study investigated the possible correlation between the changes shown by ambulatory electroencephalography (EEG) and epilepsy recurrence after medication withdrawal, and assessed the value of ambulatory EEG findings in predicting the recurrence of epilepsy after medication withdrawal, in 265 patients from Southern China followed up for 5 years. Anticonvulsants were withdrawn until onset had been controlled thoroughly for over 3 years and ambulatory EEG detected no abnormalities. Ambulatory EEG was performed at least once per year, and findings at the first visit, during treatment, and before and after medication withdrawal were compared and analyzed. There were 47 patients with recurrent epilepsy in this study. Patients with normal ambulatory EEG findings at the first visit and during treatment had lower recurrence rate (about 8.1%) compared to patients with epileptic waves (25.0%), and patients with focal epileptic waves in the temporal, occipital, frontal, and parietal lobes, or in multiple areas was even higher. Patients with epileptic waves also showed higher clinical recurrence rate during the follow-up period. Abnormal ambulatory EEG findings are an important indicator of epileptic recurrence, and is of great value in predicting the recurrence of epilepsy after medication withdrawal.