Extended resection of hemosiderin fringe is better for seizure outcome: A study in patients with cavernous malformation associated with refractory epilepsy

Background: Cerebral cavernous malformation (CCM) is frequently associated with intractable focal epilepsy. Epileptogenicity is usually attributed to the hemosiderin deposits. Extent of resection is a crucial issue for achieving good seizure outcome. Aim: To assess whether seizure outcome is related to the extended resection (ER) of surrounding hemosiderin fringe brain tissue. Materials and Methods: Between April 2000 and April 2008, 132 patients with CCM and refractory epilepsy were scheduled for surgery based on the high-resolution magnetic resonance imaging (MRI) findings and intensive video-electroencephalogram (EEG) monitoring. All patients underwent pre- and post-operative MRI. Based on MRI findings patients were grouped into: ER group (ER, hemosiderin completely removed) and lesionectomy group (LE, hemosiderin not/partially removed). Post-operative seizure outcome was compared between the two groups based on Engel and the International League Against Epilepsy outcome scales. Results: At 1-year follow-up of the 86 patients in the ER group, 54 (74.4%) achieved seizure free outcome and in the LE group of the 46 patients, 20 (59.5%) achieved seizure-free outcome. At 5-year follow-up, 59.5% (25/42) of patients in ER group and 27.8% (5/18) of patients in LE group achieved seizure-free outcome. ER was not associated with increased neurological morbidity. Conclusions: Our study suggests that complete removal of hemosiderin fringe brain tissue surrounding CCMs may improve short-term and long-term seizure outcome.