Fig. 1

Spectral data obtained at intermediate echo-time by single-voxel 1H magnetic resonance spectroscopy of the cerebellar vermis. The amplitude of the resonances is measured on the Y-axis using an arbitrary scale. A low N-acetyl aspartate (NAA) to creatine (Cr) area ratio was found at first assessment with NAA/Cr 0.95, normal values >1.08 (A). MRS findings at 30 months show deterioration of NAA/Cr with a drop from 0.95 to 0.83 (B)