Fig. 1.

Regional loss of GM volume in placebo and B-vitamin groups. Placebo- and B-vitamin–treated groups showed significant reduction of GM volume over the 2-y period in similar regions (in yellow, P < 0.001 FWE-corrected for multiple comparisons, overlaid onto the average of all 156 GM volume images; Montreal Neurological Institute (MNI) coordinates in mm: x = −12, y = 4, z = −18). The extent and significance of volume loss appeared markedly greater in the placebo group compared with the B-vitamin group and is confirmed by direct statistical comparison (text and Fig. 2.