SNCA and Parkinson disease: Pal et al. (2017) carried out a semi-quantitative assessment of SN depigmentation and alpha-synuclein pathology and reported that STN-DBS subjects have higher alpha-synuclein density scores, but do not display differences in SN depigmentation. The study did not examine the STN and did not investigate changes in inflammation. In contrast, Pienaar et al. (2015) investigated microvascular integrity in PD patients with and without STN-DBS and reported significant vascular changes and lowered microglial activation following STN-DBS.