Recurrence after a first untreated seizure in the Hong Kong Chinese population

There is wide variation in the reported prognosis after a first unprovoked generalized tonic-clonic convulsion and in the risk factors that are associated with recurrence. Estimates for the risk of recurrence range from 26 to 71%. We investigated the likelihood of a second attack in Hong Kong Chinese patients.

One hundred thirty-two patients with a first convulsion that was unexplained by acute neurological or medical causes were retrospectively ascertained. Patients' demographic details, potential risk factors for recurrence, and current seizure status were recorded. Survival analysis was performed using the Kaplan-Meier procedure.

The cumulative probability of a second attack at 1, 2, 3, and 4 years was 30, 37, 42, and 47%, respectively. Seizures in patients with abnormal computer tomography scans of the brain were associated with an increased risk of recurrence on multivariate analysis.

Thirty percent of the sample population experienced a second seizure after 1 year. An additional 17% continue to be at risk of a second convulsion during the next 3 years.