Purpose: This study investigates alteration of regional cerebral blood flow (rCBF) and identification of epileptic foci in interictal frontal lobe epilepsy (FLE) using statistical parametric mapping (SPM).
Methods: Noninvasive rCBF measurements using 99mTc-ECD SPECT were performed on 23 patients with frontal lobe epilepsy and 49 age-matched normal subjects. The FLE patients were divided into three groups, 3 patients with dorsolateral and frontocentral seizures, 2 patients with supplementary motor seizures, and 18 patients with frontobasal-cingulate seizures by Mihara' s classification determined by clinical and EEG findings.
Results: The SPM analysis revealed rCBF abnormality in frontal lobes in 12 patients when compared rCBF data　for each patient with those for normal subjects in accordance with Mihara's classification in 8. On the contrary, rCBF abnormality in frontal lobes was detected in 4 patients by visual inspection in accordance with the classification in only one. The rCBF significantly decreased in orbitofrontal regions, frontopolar regions, and anterior cingulate gyrus in the group with frontobasal-cingulate seizures as compared with age-matched normal subjects with confounding covariates of plasma concentrations of antiepileptic drugs.
Conclusions: These results suggest that SPM analysis of brain perfusion SPECT gives us useful information about frontal lobe epilepsy even in the interictal phase.