Seizures and epilepsy following strokes: recurrence factors

Abstract

Background and purpose: Though there have been many reports on poststroke seizures, there is still much we do not know about them. Using a large cohort of stroke patients we analyzed the characteristics of the seizure(s) and the rate and factors involved in seizure recurrence.

Methods: Out of the 3,205 patients admitted for a first-ever stroke to our department between 1984 and 1994, we retrospectively studied the data of all patients with a first-ever seizure and analyzed their evolution. Two types of seizure(s) were defined: 'early-onset' seizures (occurring within the 14 days following the stroke) and 'late-onset' ones (after the 14th day).

Results: 159 patients were included in the study, i.e. 4.96%. There were 116 ischemic strokes and 43 primary hematomas. Cortical involvement was found in 87% of the patients. Early-onset seizures occurred in 57 patients and late-onset ones in 102 patients, 76% of which were observed within 2 years. Follow-up was performed in 135 patients with a mean follow-up period of 47 months; 68 of them presented a seizure recurrence. A 2nd seizure occurred more often in the patients with late-onset seizures (p < 0.01); recurrence was either single (24 patients) or multiple (44 patients). Univariate analysis demonstrated 3 factors for multiple recurrences: hemorrhagic component, low Rankin scale after the initial seizure and occipital involvement. Multivariate analysis determined 2 factors: occipital involvement and late onset of the 1st seizure as a predictive model of multiple recurrences.

Conclusions: This study confirms that poststroke seizures are frequent and must be divided into 2 types: early-onset (</=14 days) and late-onset seizures. It demonstrates that a significantly lower rate of patients with early-onset seizures develop another seizure, i.e. epilepsy, than do patients with late-onset seizures. Other factors are involved in recurrence suggesting that poststroke epilepsy probably occurs in a chronically injured brain. The problem of treatment remain unanswered.