Abstracts

Rationale: Cure from epilepsy due to a cerebral cavernoma may be surgically achieved depending on both, the complete removal of the cavernoma, as well as the hemosiderotic rim around the lesion. Intraoperative MR imaging and neuronavigation may play a crucial role to achieve both goals. Thus, we retrospectively investigated the impact of neuronavigation combined with intraoperative MR imaging on the seizure outcome of such patients. Methods: Altogether, 34 patients (17 female, 17 male, mean age 40.8 yrs, range: 17 to 65 yrs) suffering from epilepsy due to a cerebral cerebral cavernoma (25 temporal, 9 extra- temporal), were operated on at the Epilepsy Center, University Erlangen Nuremberg between 2002 and 2012. Mean duration of epilepsy was 9.3 years (range: 1 month to 38 years). Three patients suffered from multiple cavernomas and 3 from dual pathologies. Twenty-nine selective lesionectomies and 5 lesionectomies combined with partial temporal lobe resections were performed. Results: The use of neuronavigation and intraoperative MR lead to complete cavernoma removal in all patients as documented by delayed postoperative imaging. In 5 patients (14.7%), an intraoperative second look procedure according to intraoperative MRI findings was necessary to complete resection. The removal of the hemosiderotic rim was confirmed in 31/34 (91%) patients by intraoperative MRI imaging. Futher resection of hemosiderin in 3/34 (9%) patients was abandoned, due to intended preservation of the optic radiation. No severe complications occured. In 3 patients mild visual field defects occurred (upper quadrantanopsia). Excellent seizure outcome (Engel Classification Grade I) was achieved in 79.3% of the patients (mean FU 26.6 month, range 2-83). No correlation between the duration of epilepsy and seizure control was found. Conclusions: In a retrospective analysis of surgically treated patients suffering from temporal lobe epilepsy due to temporal cavernomas, resection of the lesion and the hemosiderotic rim was performed safely and sufficiently using neuronavigation and intraoperative MR imaging, leading to an excellent seizure outcome.