Altered Spontaneous Brain Activity In Patients With Parkinson’s Disease Accompanied By Depressive Symptoms, As Revealed By Regional Homogeneity And Functional Connectivity In Prefrontal-limbic System

As patients with Parkinson’s disease (PD) are at high risk forcomorbid depression, it is hypothesized that these two diseases are sharingcommon pathogenic pathways. Using regional homogeneity (ReHo) andfunctional connectivity approaches, we characterized human regional brainactivity at resting state to examine specific brain networks in patients withPD and those with PD and depression (PDD). This study comprised41PDhuman patients and25normal human subjects. The patients completed theHamilton Depression Rating Scale and were further divided into twogroups: patients with depressive symptoms and non-depressed PD patients(nD-PD). Compared with the non-depressed patients, those with depressivesymptoms exhibited significantly increased regional activity in the leftmiddle frontal gyrus and right inferior frontal gyrus, and decreased ReHoin the left amygdala and bilateral lingual gyrus. Brain network connectivity analysis revealed decreased functional connectivity within theprefrontal-limbic system and increased functional connectivity in theprefrontal cortex and lingual gyrus in PDD compared with the nD-PDgroup. In summary, the findings showed regional brain activity alterationsand disruption of the mood regulation network in PDD patients. Thepathogenesis of PDD may be attributed to abnormal neural activity inmultiple brain regions.