Single-voxel proton MR spectroscopy and positron emission tomography for lateralization of refractory temporal lobe epilepsy.
OBJECTIVE
We compared the metabolic information obtained from single-voxel proton MR spectroscopy and positron emission tomography (PET) in patients with temporal lobe epilepsy.


METHODS
Twenty-nine patients with temporal lobe epilepsy were screened for metabolic abnormalities with both proton MR spectroscopy and PET. Lateralization with MR spectroscopy was possible by using NAA/(Cho+Cr) and an asymmetry index. Hypometabolism as determined by PET was classified as typical or complex.


RESULTS
Twenty-four (96%) of 25 patients whose seizure onset could be lateralized to one temporal lobe showed ipsilateral lateralization with either MR spectroscopy or PET, whereas concordant lateralization with both techniques was possible only in 14 (56%) of the 25 patients. MR spectroscopy showed 42 abnormal temporal lobes whereas PET showed only 25 lobes with decreased metabolism. All temporal lobes with hypometabolism at PET also had a low NAA/(Cho+Cr). Five patients (20%) with negative PET studies had seizures lateralized correctly with MR spectroscopy.


CONCLUSIONS
Proton MR spectroscopy is more sensitive in depicting metabolic abnormalities than is PET in patients with temporal lobe epilepsy. Patients with negative PET studies will benefit from MR spectroscopy for the purpose of lateralization.
Achten
E
E
Department of Radiology, University Hospital Ghent, Belgium.
Santens
P
P
Boon
P
P
De Coo
D
D
Van De Kerckhove
T
T
De Reuck
J
J
Caemaert
J
J
Kunnen
M
M
D000293:Adolescent; D000328:Adult; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis* / Q000378:metabolism; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D013702:Temporal Lobe / Q000378:metabolism; D014055:Tomography, Emission-Computed
D019788:Fluorodeoxyglucose F18