PROTON SPECTROSCOPIC IMAGING AT 4.1 TESLA IN PATIENTS WITH MALFORMATIONS OF CORTICAL DEVELOPMENT AND EPILEPSY

We used proton magnetic resonance spectroscopic imaging (MRSI) at 4.1 tesla in patients with malformations of cortical development (MCDs) an d epilepsy. We compared the spectroscopic results with normative data using 2 SDs (95% confidence) above normal values for detection of sign ificant abnormalities for creatine-N-acetylated compounds (Cr/NA) rati o and choline-N-acetylate compounds (Cho/NA), The results were correla ted with clinical, EEG, and histologic findings. Patients with focal c ortical dysplasia showed significant metabolic abnormalities in corres pondence with the structural lesions, whereas patients with heterotopi a and polymicrogyria demonstrated no subcortical MRSI abnormalities. S ignificant correlations were found between the metabolic abnormalities and the frequency of seizures but not with the degree of interictal E EG discharges. Quantitative neuronal and glial cell counts revealed no statistically significant correlation between cell loss and the abnor mal metabolic ratios in those who underwent surgery. These preliminary findings suggest that MRSI-based metabolic abnormalities in patients with MCDs are variable and are likely to be associated with complex ce llular mechanisms involving the regulation of NA, total Cr content, an d Cho.