Prognosis of single unprovoked seizure

201 patients (131 males and 70 females) with mean age of 18 years (range 5-55 years) who presented at median of 6 days after the onset of first unprovoked seizure were studied. They were followed for a mean period of 60 months (range 12-84 months). One hundred and fifty four (76%) patients were treated with anticonvulsant medication (group A) on a non-randomized basis and the remaining 47 patients (24%) were not treated (group B). Both the groups were comparable for age, sex, type of seizure and interval between onset of seizure and consultation. The cumulative risk of recurrence for entire study group was 24% at 1 month, 32% at 6 months, 34% at 12 months, 35% at 24 months and 36% at 36 months. The cumulative risk of recurrence in group A was 23%, 30%, 32%, 33% and 33% as compared to 28%, 36%, 40%, 43% and 45% at 1, 6, 12, 24 and 36 months respectively (p > 0.05). Maximum number of recurrences (67%) occurred within 1 month. No recurrence occurred after 36 months after the onset of first seizure. Age at onset, sex, seizure type, family history of seizure, EEG abnormalities and nature of antiepileptic drugs did not influence the risk of recurrence.