Brain 1H magnetic resonance spectroscopic differences in myotonic dystrophy type 2 and type 1.

To evaluate cerebral metabolism and intergroup differences in closely matched patients with myotonic dystrophy type 2 (DM2, n = 15) and type 1 (DM1, n = 14), we performed (1)H magnetic resonance spectroscopic (MRS) analyses of the occipital and temporoparietal cortical regions as well as of subcortical frontal white matter. Relative to healthy subjects, the concentration of N-acetylaspartate was significantly reduced in all tested brain regions in both disease groups. In the DM1 patients we also observed a concomitant depletion of creatine and choline levels, particularly in the frontal white matter. A discriminant analysis based on the (1)H-MRS data distinguished between the DM2, DM1, and control groups with an overall accuracy of 88%. (1)H-MRS indicates that neurochemical alterations involving gray and white matter occur in patients with DM2 and DM1. Although structural abnormalities (cerebral atrophy, white matter lesions) are similar in DM2 and DM1, changes in cerebral metabolites can differentiate these disease groups, suggesting that the diseases differ in their neurocellular pathology.