Risk of epilepsy in long-term survivors of surgery for aneurysmal subarachnoid hemorrhage: a population-based study in Iceland.
OBJECTIVE
Epilepsy is known to result from aneurysmal subarachnoid hemorrhage (SAH). There are no population-based estimates of the absolute risk or the duration for which this risk is elevated. We have conducted a population-based study in Iceland of the risk of epilepsy after a ruptured cerebral aneurysm to address these questions.


METHODS
The index patients are all of the patients who presented with SAH caused by ruptured cerebral aneurysm in Iceland during an 11-year period (1958 to 1968) and survived more than 6 months. We determined the number of index patients who developed epilepsy. The observed number of cases of epilepsy was compared with that expected based on the incidence of epilepsy in Iceland.


RESULTS
There were 44 index patients; 11 (25%) developed epilepsy, all within 4 years of the insult. Seven (70%) of 10 patients with acute symptomatic seizures (defined as seizures during the first 2 weeks after the hemorrhage) developed epilepsy (relative risk, 7.0; 95% confidence interval, 2.3-21.6). Epilepsy was more frequent in patients with severe neurological residua (48%) compared with patients without (20%) (relative risk, 2.5; 95% confidence interval, 0.9-6.3).


CONCLUSIONS
The risk for epilepsy among survivors of SAH caused by ruptured cerebral aneurysm is substantially increased. Both acute symptomatic seizure and persistent neurological impairment are associated with a further increase in the risk of epilepsy.
Olafsson
E
E
Department of Neurology, National University Hospital Landspitalinn, Reykjavik, Iceland. eliasol@rsp.is
Gudmundsson
G
G
Hauser
W A
WA
D004827:Epilepsy / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D002532:Intracranial Aneurysm / Q000601:surgery; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology; D012421:Rupture; D013345:Subarachnoid Hemorrhage / Q000601:surgery*