OUTCOMES OF SURGERY IN PATIENTS WITH PARADOXICAL TEMPORAL LOBE EPILEPSY
Abstract number :
3.228
Submission category :
Year :
2002
Submission ID :
1588
Source :
www.aesnet.org
Presentation date :
12/7/2002 12:00:00 AM
Published date :
Dec 1, 2002, 06:00 AM
Authors :
Richard B. Kim, Arthur C. Grant, Steve S. Chung. Neurological Surgery, University of California, Irvine, Orange, CA; Neurology, University of California, Irvine, Orange, CA
RATIONALE: A paucity of data exists on patients with apparent medial temporal lobe epilepsy (MTLE) but whose MRI scans do not disclose mesial temporal sclerosis. This entity has been termed paradoxical temporal lobe epilepsy (PTLE). In this study, seizure outcomes following intracranial electrode monitoring and resective surgery in these patients is examined.
METHODS: Ten consecutive patients (ages 16-62 yrs.) were included in this study who fulfilled the following criteria: normal brain MRI scan using high-resolution techniques, video-EEG monitoring with scalp and sphenoidal electrodes demonstrating temporal onset, and intracranial electrode monitoring. Bilateral hippocampal depth and temporal subdural strip electrodes were placed when the laterality was in question, in 6 patients. Unilateral temporal recording with a grid array, subdural strips, and a hippocampal depth electrode was performed when the laterality was known but medial vs. lateral localization was unclear, in 4 patients The average time of follow-up is 9.8 months (range 1-23 months).
RESULTS: Unilateral hippocampal seizure onset was observed in 5 of the 6 patients with bitemporal monitoring, with bilateral independent hippocampal seizure onsets in 1 patient. Of the 4 patients with unilateral monitoring, seizure onsets were in hippocampus alone in 1, hippocampus and parahippocampal gyrus in 1, hippocampus, parahippocampal gyrus, and orbitofrontal cortex in 1, and parahippocampal gyrus in 1. Eight patients underwent anteromedial temporal resections (1 with additional orbitofrontal resection) and 2 patients underwent trans-sylvian selective amygdalohippocampectomy. Pathological analysis revealed mild MTS in 5, moderate MTS in 2, severe MTS in 2, and was normal in 1. Overall, 9 patients are seizure-free and 1 patient has moderate improvement.
CONCLUSIONS: Medial temporal resection in patients with PTLE may result in excellent seizure-free outcomes. Intracranial electrode monitoring is recommended because of the possibility of neocortical seizure onset or bilateral temporal onsets. Further study of this patient population is required to elucidate the relationship of this entity to medial temporal lobe epilepsy caused by mesial temporal sclerosis.