Seizure Rate Higher Following Ischemic Stroke

The rate of unprovoked seizures after a first-ever ischemic stroke is higher than expected, according to a new study.

Researchers at the Mario Negri Institute (Milan, Italy) conducted a multicenter prospective study involving 714 consecutive patients with a first stroke in 32 European centers, looking at both incidence and risk factors. The study population showed a slight preponderance for men, more than 70% of stroke sufferers were 65 years old or older, and 80% of them suffered an ischemic stroke. Of these patients, 38 had an acute seizure, 29 of them in the first day after their stroke, and the remaining nine in days two through seven.

During follow-up, 44 patients suffered an unprovoked seizure; 29 in the first year and 15 in the next year, yielding a cumulative probability of seizure of 5% and 10% at one and two years, respectively. Upon analysis, three risk factors played a significant role in the hazard risk of seizure (HRS). Patients 80 or older had a HRS of 2.01; patients with a cortical—rather than a subcortical—lesion had a HRS of 2.48; and those with moderately severe or severe disability on the modified Rankin scale had a HRS of 3.66. The study was presented at the annual meeting of the American Academy of Neurology (AAN), held during April 2014 in Philadelphia (PA, USA).

“Those risk factors applied only to ischemic stroke. For the minority of patients with hemorrhagic stroke or hemorrhage, the only risk factor that predicted seizure was cardiac embolism,” said lead author and study presenter Ettore Beghi, MD. “If you compare these data with the rest of the literature, you can see that these are among the highest values.”

A seizure is a sudden episode of abnormal or disorganized electric activity in the brain that is usually characterized by spasms or convulsions. Stroke is the most common cause of seizures in the aging population, and approximately 10% of stroke survivors experience a seizure after a stroke. It is difficult to predict which stroke survivors will have a seizure, since research on post-stroke seizures varies widely, reporting 2%–33% percent of ischemic stroke survivors experiencing a seizure.

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Mario Negri Institute