Fluorodeoxyglucose-positron emission tomographic imaging for the diagnosis of mesial temporal lobe epilepsy.
OBJECTIVE
Fluorodeoxyglucose (FDG)-positron emission tomographic (PET) imaging plays an important role in the evaluation of intractable epilepsy. The metabolic defect has proven utility in the lateralization of temporal lobe epilepsy. However, the role of FDG-PET imaging in the localization of a seizure focus within the temporal lobe is uncertain. We evaluated FDG-PET imaging for the capability to localize a temporal seizure focus within the mesial structures.


METHODS
Twenty-eight patients who underwent selective amygdalohippocampectomy for intractable temporal lobe epilepsy were studied. Patients were divided into 2 groups: those who were free of seizures (FS) and those with persisting seizures postoperatively. FS patients were defined by having mesial temporal lobe epilepsy (MTLE). Preoperative FDG-PET activity was evaluated in temporal lobe structures and contrasted with magnetic resonance imaging (MRI) for usefulness in identifying MTLE in an individual.


RESULTS
Pathology of the hippocampus revealed mesial temporal sclerosis in all but 1 patient. Qualitative visual inspection of the MRI scan was not reliable in the identification of MTLE (P = 0.15). MRI volumetry found smaller mesial temporal structures (P = 0.04) in FS patients. Mesial temporal metabolic activity was reduced in the FS group (hippocampus, P = 0.001). However, a combination of imaging modalities was found to be the best predictor of MTLE. PET imaging plus MRI qualitative inspection identified all patients with and without MTLE correctly and was superior to MRI alone (P = 0.01 and P = 0.02, respectively).


CONCLUSIONS
MRI volumetry and PET imaging were comparable (P = 0.73) and able to identify MTLE in most patients, but a combination of PET imaging and MRI visual inspection was superior in the recognition of MTLE.
Boling
Warren W
WW
Department of Neurosurgery, West Virginia University School of Medicine, Morgantown, West Virginia 26506, USA. wboling@hsc.wvu.edu
Lancaster
Melissa
M
Kraszpulski
Michal
M
Palade
Adriana
A
Marano
Gary
G
Puce
Aina
A
D000293:Adolescent; D000328:Adult; D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18