Lesionectomy versus electrophysiologically guided resection for temporal lobe tumors manifesting with complex partial seizures

Complex partial seizures associated with tumors and other mass lesions are readily diagnosed by modern imaging techniques but their optimum surgical treatment remains unresolved. Lesionectomy has been reported to produce seizure outcomes equal to outcomes after resection that ablates the epileptogenic cortex with the lesion. However, some evidence suggests that when the lesion is in the temporal lobe, simple excision of the tumor or lesion more often fails to control seizures. After retrospectively reviewing the records of 30 patients with complex partial seizures and temporal lobe tumors who underwent surgical treatment at the University of Cincinnati hospitals (1985-1992), the authors divided them into two groups: Group A (16 patients) underwent lesionectomy only and Group B (14 patients) received surgical treatment for seizures with electroencephalographic delineation of the epileptogenic zone and resection of the lesion. Seizure control was best achieved in Group B patients with 13 (92.8%) seizure free at follow up (mean 52 months). Only three (18.8%) of the Group A patients became seizure free after lesionectomy at follow up (mean 33 months). In eight Group A patients, who underwent temporal lobectomy as a second procedure after lesionectomy failed to control seizures, five (62.5%) became seizure free. Group B patients had a longer duration of seizures and were more likely to have lesions smaller than 2.5 cm compared with Group A. Analysis of covariance demonstrated that the differences in outcome between the groups remained significant even with adjustment for the variation in duration of seizures (p = 0.0006) and size of tumor (p = 0.0001). Based on this study, the authors found that the probable relief from seizures caused by a temporal lobe lesion is greater if the region of epileptogenicity, usually the amygdalohippocampal complex, is resected along with the tumor in a temporal lobectomy.