C erebrovascular disease is the most commonly identified cause of acute symptomatic seizures and secondary epilepsy in adults, underlying approximately 11% of epilepsy diagnoses. 1 The incidence and associations of poststroke epilepsy (PSE) are not well-established; many previous studies have investigated seizure episodes, rather than epilepsy diagnoses, with uncertainty frequently arising from varying definitions of seizure timing, selective recruitment, and short follow-up. [2][3][4][5] Hemorrhagic strokes, cortical lesions, and large lesions are most consistently associated with poststroke seizures, 6 defined as early or late, based on timing and differing pathophysiology.7-10 A wide range (2% to 67%) of patients has been reported for the risk of early or late seizures after ischemic stroke, 11 whereas intracerebral and subarachnoid hemorrhages have been associated with a range of between 8% and 15% over varying durations of follow-up. 6 There is insufficient evidence to reliably predict those who will have development of PSE and would benefit from prophylactic antiepileptic treatment. Of those with a single seizure, approximately half were observed to have progression to epilepsy in a well-designed study with a maximum follow-up of 6.5 years.3 Associations have been suggested with deep infarctions extending to subcortical structures and late onset of first seizure after ischemic stroke.2,12 PSE impairs self-reported vitality and physical and social functioning. 13 We used a population-based register in a multiethnic area of London, including hospital and community diagnoses of first stroke, to investigate the epidemiology and associations of PSE over 12 years, focusing on long-term rates and predictors of epilepsy.
Methods
Study PopulationStroke subjects were recruited from the South London Stroke Register, an ongoing longitudinal register of first-ever strokes in subjects of all ages in a multiethnic inner-city population of 271 817.14 Background and Purpose-To describe the epidemiology and associations of poststroke epilepsy (PSE) because there is limited evidence to inform clinicians and guide future research. Methods-Data were collected from the population-based South London Stroke Register of first strokes in a multiethnic innercity population with a maximum follow-up of 12 years. Self-completed forms and interviews notified study organizers of epilepsy diagnosis. Kaplan-Meier methods and Cox models were used to assess associations with sociodemographic factors, clinical features, stroke subtype, and severity markers. Results-Three thousand three-hundred ten patients with no history of epilepsy presented with first stroke between 1995 and 2007, with a mean follow-up of 3.8 years. Two-hundred thirteen subjects (6.4%) had development of PSE. PSE incidence at 3 months and 1, 5, and 10 years were estimated at 1.5%, 3.5%, 9.0%, and 12.4%, respectively. Sex, ethnicity, and socioeconomic status were not associations, but markers of cortical location, including dysphasia, visual neglect, and field defect, ...