SNCA and Parkinson disease: The observed association of GM intensity reduction with increasing motor severity in this early cohort of PD patients further points to early neural tissue damage in the anterior striatum, in keeping with neostriatal alpha synuclein pathology detected in stage III (Mori et al., 2008), and dendritic degeneration of medium spiny neurons (Zaja-Milatovic et al., 2005).