PD and PDD metals comparison. (A) Direct comparison of metallomic findings in PD and PDD cases. Areas shaded in grey denote no observed case-control changes; areas shaded in blue denote lower metal concentrations in cases than in controls; no regions showed increased metal concentrations in cases compared to controls in either PD or PDD. Areas shaded with dots were only investigated in one of either PD or PDD, and so could not be directly compared. (B) Separation of PD and PDD cases by PCA (left) and PLS-DA (middle); PD cases are shown in pink, and PDD cases are shown in green. VIP scores for PLS-DA are shown on the right; regional metals with a VIP score >1 were considered to contribute significantly to PD–PDD separation on PLS-DA.