Temporal lobe epilepsy: Correlation of proton magnetic resonance spectroscopy and F-18-fluorodeoxyglucose positron emission tomography

Proton magnetic resonance spectroscopy (MRS) has demonstrated reduction of N-acetylaspartate (NAA) in the epileptogenic temporal robe. However, the correlation of NAA reduction with cerebral metabolic abnormalities is unknown in temporal robe epilepsy (TLE). Proton MRS and F-18-fluorodeoxyglucose positron emission tomography (FDG/PET) were used to study 12 unilateral TLE patients with medically intractable seizures and 26 age-matched healthy volunteers. The epileptogenic temporal lobe of each patient was determined by both electroencephalography and FDG/PET. The NAA/choline-plus-creatine (NAA/(Cho + Cr)) ratio correlated significantly with the interictal glucose metabolism (r = 0.54, P < 0.01) in 12 TLE patients. The mean NAA/(Cho + Cr) ratio in the epileptogenic temporal robe was significantly less than that in the contralateral side (P < 0.01), and less than that in normal control temporal robes (P < 0.0001). These results suggest that quantitative MRS abnormalities reflect underlying metabolic pathology in TLE.