POSTSURGICAL OUTCOME OF PATIENTS WITH UNCONTROLLED COMPLEX PARTIAL SEIZURES AND TEMPORAL-LOBE HYPOMETABOLISM ON (18)FDG-POSITRON EMISSION TOMOGRAPHY

RATIONALE AND OBJECTIVES. The purpose of this study is to evaluate the relation between a focus of temporal lobe hypometabolism, including c omparison between mesial and lateral asymmetry on fluorine-18-labeled- deoxyglucose-positron emission tomography ((18)FDG-PET) and surgical o utcome in patients with uncontrolled partial seizures. METHODS. Case h istories, electroencephalogram (EEG) findings, radiographic findings, and surgical outcome (36 +/- 11 months of follow-up) were reviewed in 38 consecutive patients who had an interictal (18)FDG-PET scan and sub sequent temporal resection. RESULTS. Among the 36 patients who had a t emporal lobe focus of hypometabolism (more than 15% asymmetry to contr alateral side), 61% (22 of 36) became seizure-free, 33% (12 of 36) mar kedly improved, and 6% (2 of 36) did not improve. The focus of hypomet abolism on PET was in agreement with the epileptic focus on the noninv asive EEG in 30 of 36 patients and in 19 of the 22 patients who underw ent an invasive EEG. The asymmetry index for the mesial temporal lobe was significantly higher in the group of patients who became seizure-f ree compared with the other patients. CONCLUSION. This study confirms that a focus of interictal temporal hypometabolism on PET is associate d with marked improvement of seizure control after surgery in 94% (34 of 36) of the patients, Hypometabolism in the mesial temporal lobe app ears to be associated with a seizure-free outcome.