Fig. 2
Posterior WMH probability is associated with both history of arterial hypertension and Aβ positivity. Analysis: We examined the relationship between WMH segmentation maps (outcome) and arterial hypertension and Aβ positivity (factors) at a voxel level via 2 × 2 ANCOVA. We accounted for the effects of age, sex, years of education, mean background intensity, and total intracranial volume. We used an explicit mask to constrain the analysis to voxels in which data for at least five subjects were available. Illustration: Glass brain projections display regions where we found evidence for a link between WMH probability and hypertension and Aβ positivity (top and middle rows, respectively). In the bottom row, we coloured regions blue if T values for hypertension were greater than for Aβ positivity and gold otherwise. We thresholded contrast maps at 5% and adjusted p-values for FDR. Findings. Subjects with hypertension had significantly greater WMH volumes throughout the whole brain than those with normotension (peak: superior longitudinal fasciculus, xyzMNI = [32, − 1, 18], T = 3.88, DoF = [1.0, 367.0], pFDR = 0.015). Moreover, WMH volume was significantly higher in subjects Aβ positivity versus negativity in posterior regions of the brain, particularly in segments of the forceps major and inferior fronto-occipital fasciculus (xyzMNI = [30, − 58, 4], T = 5.20, DoF = [1.0, 367.0], pFDR = 0.001)