Pre-stroke seizures: A nationwide register-based investigation

Abstract

PurposeThe relationship between cerebrovascular disease and seizures is clearly illustrated by poststroke epilepsy. Seizures can also be the first manifestation of cerebrovascular disease and case-control studies have demonstrated that seizures carry an increased risk of subsequent stroke. Thus, seizures could serve as a marker for vascular risk that merits intervention, but more data is needed before proper trials can be conducted. The occurrence of pre-stroke seizures has not been assessed on a national scale. We asked what proportion of strokes in middle-aged and elderly patients was preceded by seizures. MethodsAll patients over 60 years of age with first-ever stroke in 2005-2010 (n=92,596) were identified in the Swedish stroke register (Riksstroke) and cross-sectional data on a history of a first seizure or epilepsy diagnosis in the ten years preceding stroke were collected from national patient registers with mandatory reporting. Results1372 patients (1.48%) had a first seizure or epilepsy diagnosis registered less than ten years prior to the index stroke. The mean latency between seizure and stroke was 1474days (SD 1029 days). ConclusionsSeizures or epilepsy preceded 1.48% of strokes in patients >60years of age. Based on recent national incidence figures, 5-20% of incident cases of seizures or epilepsy after 60 years of age could herald stroke, depending on age group. These proportions are of a magnitude that merit further study on how to reduce the risk of stroke in patients with late-onset seizures or epilepsy.