Study of factors responsible for recurrence of seizures in controlled epileptics for more than 1 years after withdrawal of antiepileptic drugs.

531 epileptic patients, who had achieved remission mostly for 2 years or more were studied. The mean follow up period was 5 years. Recurrence was noted in 103 patients (19%) after gradual withdrawal of AED, over a period of 3-4 months. 424 patients (81%) did not have recurrence. The recurrence rate was influenced adversely by factors like adolescent age and later onset seizures, pre-treatment duration of symptoms more than 3 years, pre-treatment precipitating factors like emotional stress, lack of sleep and meals (however, number in each group is small), positive family history of epilepsy, focal neurodeficit, absence and myoclonic plus grandmal type of clinical seizures, paroxysmal generalized spike and wave discharges and generalized short polyspike and wave discharges in the pretreatment EEG, atrophic changes on CT brain scan (in small numbers), head trauma at birth or later and hereditary factors as etiology of epilepsy, and more than 30 number of seizures before achieving the remission. Factors like, sex, frequency of seizures, period of remission i.e. two years or more and number of drugs used to achieve remission, did not have any significant adverse effect. However, in the last parameter 95% remission was achieved by one or a combination of two drugs (72% and 23% respectively).