Brain regions with gray matter atrophy between PD patients and HCs identified from the neuroimaging meta-analysis a) and the independent dataset b). The color bar represents the level of gray matter atrophy, respectively. The differential brain maps were both visualized with the BrainNet Viewer (Xia et al. 2013). Abbreviations: HC, healthy controls; L, left; PD, Parkinson’s disease; R, right.