Role of precuneus/cuneus in cognitive, mood changes in parkinson’s disease patients

Cognitive and emotional dysfunction is a major complication in the later stages of Parkinson’s disease (PD). we planned to measure brain regional homogeneity (ReHo) by comparison with normal controls. Peak points in the regions of difference were then selected as seed ROIs, and whole-brain network abnormalities due to differences in local functional connectivity in PD patients were analyzed using granger causality analysis (GCA) to characterize the functional connectivity in PD patients without dementia symptoms to identify potential factors affecting cognition and mood in the disease. And voxel-based morphometry (VBM) was used to compare brain volumes in these abnormal functional areas and analyzed the correlation between functional and volumetric signals.The final results showed significant increase of regional functional connectivity in the orbit of the left inferior frontal gyrus, the orbit of the middle frontal gyrus, and the triangle of the left inferior frontal gyrus; the left precuneus, cuneus, superior occipital gyrus, and bilateral part of pons showed regional functional connectivity decreased. In the GCA, PD patients showed elevated functional connectivity from the bilateral precuneus to the left orbitofrontal lobe and reduced functional connectivity from the left cuneus to the left temporal pole. Furthermore, there were no significant differences and correlations between volumetric comparisons, and between functional and volumetric signals. Thus, the precuneus/cuneus may be an important integrative brain region for cognitive and emotional coordination and is an important factor in causing cognitive impairment and depression in PD patients.