Abstract 155: Risk of Seizures after Malignant MCA Stroke and Decompressive Hemicraniectomy

Background Post-stroke seizures (PSS) have a devastating effect on morale and may further impair an already compromised quality of life. The reported incidence of PSS is 5-12%, but may be higher in patients with malignant MCA stroke requiring decompressive hemicraniectomy. Seizure prophylaxis for stroke survivors is not recommended, and little guidance exists about the use of prophylactic antiepileptic drugs (AEDs) after neurosurgical procedures. We aimed to determine the incidence of seizures after hemicraniectomy in stroke survivors and to identify risk factors for development of seizures after stroke. Via telephone interview, we explored patients own experience after their stroke. Methods We reviewed charts of patients aged 18-99 with malignant MCA infarction who underwent decompressive hemicraniectomy from Jan 1, 2002 to Dec 31, 2008. We looked for seizures that occurred after their stroke and for clinical and imaging factors related to those. All patients who consented to a telephone interview were contacted to inquire about seizure history. Seizure-free survival analysis was used, with log rank testing for associations. Results We identified 38 patients, mean follow-up time was 504 days (IQR 140-857). Nearly half of patients suffered a seizure (18/38) and the seizures were difficult to control in 9/18. Four patients suffered their first seizure during initial hospitalization. For 14/18, the first seizure occurred after or around cranioplasty and mostly at home. Perioperative seizure prophylaxis was variable and did not influence seizure occurrence. Older age showed a trend towards increased seizure risk (log rank p=.09). Neither gender, race, severity, location or hemorrhagic transformation were associated with development of post-stroke seizures. Modified Rankin Scale score (mRS) at discharge was 4 or above in all patients. By last follow-up, 17/38 patients had a mRS of 3 or better. Patients who suffered a seizure did not feel well prepared for the possibility of PSS, and for some the seizures were considered a major setback. Among those who responded to the questionnaire (n=14, 12 had seizures), all would have wanted to know whether or not they were at high risk for developing PSS, and would have opted to take anti-epileptic medications for seizure prophylaxis. Conclusions The frequency of seizures after malignant MCA stroke requiring decompressive hemicraniectomy is higher than expected, and the seizures often difficult to control.