Figure 1

Whole-brain MRS analysis. Each spectral was analysed to extract concentrations of five major metabolites (Cr, Cho, Glx, NAA and mI), which were then converted into 3D maps in subjects’ native space. A modified SPM procedure was applied to remove non-brain areas from the metabolism maps and normalise to the standard MNI space using high-resolution T1-weighted MRI data. The ratio between other metabolites and the internal reference Cr was computed before the maps were smoothed for statistical analysis. 3D, 3 dimensional; Cho, choline; Cr, creatine; Glx, glutamate and glutamine; GM, grey matter; mI, myo-inositol; MRI, magnetic resonance imaging; MRS, magnetic resonance spectroscopy; NAA, N-acetylaspartate; WM, white matter.