Short-term mortality after a first epileptic seizure: a population-based study

To determine the short-term mortality in a prospective incidence cohort of patients included after any kind of first afebrile epileptic seizure (i.e., provoked and unprovoked).

Information on death occurring within the first year of follow-up was collected in a cohort of 804 patients with a first seizure between March 1, 1984, and February 28, 1985, in southwest France. The variables analyzed were the etiology of seizure, cause of death, interval between seizure and death, and age of patients.

By the end of the 1-year follow-up, there were 149 deaths among these patients as compared with 16 expected deaths [standardized mortality ratio (SMR), 9.3; 95% confidence interval (CI), 7.9-10.9]. There were no deaths in patients with idiopathic seizures. Patients with cryptogenic seizures had slightly increased mortality (SMR, 1.6; 95% CI, 0.4-4.1). Mortality was increased for patients with remote symptomatic seizures (SMR, 6.5; 95% CI, 3.8-10.5), provoked seizures (SMR, 10.1; 95% CI, 8.1-12.4), and seizures due to a progressive neurologic condition (SMR, 19.8; 95% CI, 14.0-27.3). Causes of death were underlying pathology (64%), unrelated condition (20%), unknown cause (9%), seizure-related death (6%), and one suicide.

Early mortality clearly differed according to the etiology of the first seizure. The highest mortality was associated with provoked seizures and with seizures caused by progressive central nervous system disorders. Patients died far more often from underlying or unrelated conditions than from seizures.