Figure 4. Atrophy of the basal forebrain cholinergic system in AD compared to healthy elderly controls.

Upper row: Overview of the basal forebrain cholinergic system region of interest (BFCS-ROI) (purple) projected onto coronal slices of the elderly-AD template in MNI space (MNI-coordinates y = 9 to y = −7 in intervals of 2mm). Lower rows: Results of the voxel-wise analysis restricted to the BFCS-ROI projected onto the same coronal slices and magnified to better represent the basal forebrain (running from y = 9 in upper left corner to y = −7 in lower right corner). Results of the voxel-wise analysis restricted to the BFCS-ROI are corrected for total intracranial volume, age and gender and thresholded at p<0.01, FDR-corrected. A minimum cluster extension threshold of 5 contiguous voxels was applied. Statistical significance (in terms of T-values, 189 degrees of freedom) is coded by a color-scale from black-blue to red. Voxel-wise effects of reduced grey matter volumes in AD compared to age-matched controls are more widespread than in the vmAD group and are seen throughout the whole BFCS-ROI, including the rostral nuclei of the diagonal band of Broca (Ch2, Ch3) and the whole extend of the nucleus basalis (NBM, Ch4). Similar to the vmAD group, effects are statistically most robust over posterior parts of the NBM.