Epilepsy surgery has been demonstrated to be an effective alternative treatment for intractable partial or localization related epilepsy. Primary intracranial neoplasms and other structural lesions of the brain are important etiological factors in patients with partial seizure disorders. A neuroimaging identified lesion in patients with seizures, not necessarily medically refractory, may also be an indication for surgery in selected patients. Twelve patients operated on under local or general anesthesia for resection surgery underwent intraoperative recording(electrocorticogram) and/or functional mapping by electrical stimulation or somatosensory evoked potentials-(SSEPs) for identification of the secondary epileptogenic area and/or functional area; 2 meningiomas, 5 astrocytomas, 1 gangliocytoma, 1 abscess, 1 small AVM, 1 cysticercosis and one gliosis by previous intracerebral hemorrhage with middle cerebral artery(MCA) aneurysm. Among these, additional corticectomy or anterior temporal lobectomy was performed in eleven patients. All the patients did well after surgery with good outcomes as seizure free in nine(75%) out of 12 patients with 11.9 months of follow-up period, without any neurological deficits. Intraoperative recording and functional mapping of adjacent areas of the structural lesions of the brain are useful in surgery and can guide the extent of further resection.
Adolescent ; Adult ; *Brain Mapping ; Brain Neoplasms/physiopathology/*surgery ; Electroencephalography ; Evoked Potentials, Somatosensory ; Female ; Human ; Intraoperative Period ; Male ; Middle Age ; Seizures/physiopathology/*surgery ; Support, Non-U.S. Gov't

OBJECTIVETo explore the ability of interictal diffusion-weighted imaging (DWI) to localize the temporal lobe of seizure origin and to predict postoperative seizure control in patients with temporal lobe epilepsy (TLE).

METHODSTwenty-seven patients with intractable TLE considered for surgery and 19 healthy volunteers were studied with conventional magnetic resonance imaging (MRI) and DWI. Apparent diffusion coefficients (ADCs) of bilateral hippocampi in both TLE patients and control subjects were obtained. Lateralization to either temporal lobe with hippocampal ADC was based on the threshold values derived from +/- SD of right/left ratios in normal subjects. And the postoperative pathology was reviewed.

RESULTSHippocampal ADCs were higher on the side of surgery compared with those on the contralateral side as well as the ipsilateral side in control subjects [resected side (109.8 +/- 7.3) x 10(-5) cm2/s, contralateral side (91.7 +/- 4.7) x 10(-5) cm2/s, control subjects (81.6 +/- 5.2) x 10(-5) cm2/s, all P < 0.01]. Right/left hippocampal ADC ratio and conventional MRI lateralized to the operated temporal lobe in 21 of 27 (77.8%) and in 18 of 27 (66.7%) patients. Lateralization to the surgical side was not associated with postoperative seizure control with right/left hippocampal ADC ratio (P > 0.05).

CONCLUSIONSConventional MRI is a sensitive method to detect hippocampal sclerosis. Accuracy of the right/left hippocampal ADC ratio for lateralizing to the side of surgery is very high, but it isn't a better predictor of surgical outcome.

Adolescent ; Adult ; Brain ; anatomy & histology ; metabolism ; Child ; Diffusion Magnetic Resonance Imaging ; methods ; Epilepsy, Temporal Lobe ; diagnosis ; physiopathology ; surgery ; Female ; Humans ; Magnetic Resonance Imaging ; methods ; Male ; Middle Aged ; Prognosis ; Seizures ; physiopathology ; Treatment Outcome ; Young Adult