The neuropathological findings in LRRK2-PD patients could explain, at least partly, the better cognitive profile in LRRK2-PD compared with IPD, since a significant proportion of LRRK2-PD patients do not show the presence of abnormal aggregates of α-synuclein; e.g., Lewy bodies (LB) and clinicopathological correlations have shown that the presence of LB is associated with cognitive impairment and dementia [34, 35]. This evidence concerns the gene LRRK2 and dementia.