PHOSPHORUS MAGNETIC-RESONANCE SPECTROSCOPIC IMAGING IN PATIENTS WITH FRONTAL-LOBE EPILEPSY

Phosphorus magnetic resonance spectroscopic imaging has previously dem onstrated localized metabolic abnormalities within the epileptogenic r egion in patients with temporal lobe epilepsy, including alkalosis, in creased inorganic phosphate level, and decreased phosphomonoester leve ls. We studied 8 patients with frontal lobe epilepsy, finding interict al alkalosis in the epileptogenic region compared to the contralateral frontal lobe in all patients (7.10 +/- 0.05 vs 7.00 +/- 0.06, P < 0.0 01). Seven patients exhibited decreased phosphomonoester levels in the epileptogenic frontal lobe compared to the contralateral frontal lobe (16.0 +/- 6.0 vs 23.0 +/- 4.0, P < 0.01). In contrast to findings in temporal lobe epilepsy, inorganic phosphate level was not increased in the epileptogenic region. Based on values derived from normal control subjects, 5 patients had elevated pH in the seizure focus and 2 patie nts had decreased phosphomonoesters while none had abnormalities in th e contralateral frontal lobe. These data suggest that magnetic resonan ce spectroscopy will be useful in the presurgical evaluation of patien ts with frontal lobe epilepsy.