Recurrence of afebrile status epilepticus in a population-based study in Rochester, Minnesota

Abstract

Objective: To determine the risk of recurrence of status epilepticus (SE) in a population-based sample and to identify risk factors for recurrence.

Methods: We ascertained all first episodes of afebrile SE in residents of Rochester, MN, through the Rochester Epidemiology Project's records-linkage system between January 1, 1965, and December 31, 1984. Information was collected on age, gender, duration, seizure type, etiology, therapeutic response to initial antiepileptic drug medication, and subsequent episodes of SE.

Results: Among the 183 episodes of first afebrile SE, the risk of recurrent SE was 31.7% over a 10-year follow-up period. The risk of recurrence was about 25% for those with acute symptomatic SE, remote symptomatic SE, and idiopathic cryptogenic SE. Recurrence was 100% for those with progressive symptomatic SE. Female gender (rate ratio [RR] = 2.3, 95% CI = 1.1 to 5.0) and progressive symptomatic etiology (RR = 2.4, 95% CI = 0.6 to 8.9) increased the risk for recurrent SE. Both partial SE (RR = 0.5, 95% CI = 0.2 to 1.1) and good therapeutic response to the initial antiepileptic drug therapy (RR = 0.3, 95% CI = 0.1 to 0.7) were associated with a decreased risk of recurrent SE.

Conclusions: Status epilepticus (SE) recurs in about one-third of individuals with a first episode of SE. Except for SE occurring in the setting a progressive brain disorder, the risk of recurrence is about 25%, regardless of the underlying etiology. Female gender and lack of response to the first antiepileptic drug medication after the initial episode of SE identify those individuals at greatest risk for recurrence.