gms | German Medical Science

Objective: Lesional temporal lobe epilepsy comprises a heterogeneous group of pathologies, frequently presenting with ill-defined borders or even with multiple lesions. During surgery, intraoperative functional neuronavigation and MR imaging may be of value to optimize the amount of resection and to spare eloquent areas.

Method: To clarify this question, we performed a retrospective clinical study investigating patients operated on between August 2002 and March 2012 in our Department. Altogether, there were 103 patients (57 male, 46 female, mean age 37 yrs, from 12 to 69 yrs). Surgery consisted of lesionectomies (n=63) and lesionectomies combined with extended temporal resections (n=40). Additionally to functional neuronavigation including speech, motor, sensory cortical areas and tracts, eighty-nine patients had intraoperative MR imaging.

Results: Complete resection of the lesion was achieved in 89 of 103 patients (86.4%). Intraoperative MRI scanning revealed total lesionectomy in only 67 of 89 patients (75%), leading to a removal of remnant pathological tissue in 19 more patients. Thus, overall resection rate was improved by 18.4% (19/103) as a direct effect of intraoperative MR imaging. The most common histological diagnoses were: 43 gangliogliomas (41.7%), 26 cavernomas (25.2%), 9 DNTs (8.7%) and 9 FCDs (8.7%). In radically resected tumor patients, no recurrent tumors were detected during the follow-up. Altogether, an Engel Class 1 seizure outcome was found (65% Engel Class 1A) in 73.8% of the re-evaluated patients (76/103) during a mean follow-up of 26 months. Postoperative complications were temporary in 9% and permanent in 12.6% of the patients (mainly superior visual field defects).

Conclusions: By using intraoperative MRI and functional neuronavigation, we were able to increase the rate of complete resections in lesional TLE patients by nearly 20%, which resulted in an excellent outcome in terms of seizure control and a low complication rate.