Localization of the atrophy.

<p>A. Schematic initial progression of Lewy body deposits in the first stages of Parkinson's Disease, as proposed by Braak and colleagues. B. Localization of the cluster of significant volume reduction in PD compared with HC. The significant cluster located in the medulla oblongata/pons is superimposed as a red blob on the mean normalized anatomical scan of all participants. The axial and sagital sections are centered on the peak of significance (−1; −36; −49).</p

Effect size at the peak of significance.

<p>Boxplot of the peak of significance value (arbitrary unit) for each participant in both groups, as obtained by SPM5 ‘fitted response’ plot function. Peak value was adjusted, meaning that the effect of age, gender and global WM volume were factored out, and only the effect of condition (Parkinson or Control) and the residuals remained, as assessed by the SPM model. For each group, bold line shows the median, central box includes the middle 50% of the data, and tails of the boxplot show the minimum and maximum values.</p