Functional connectivity studies of parkinson

Abstract

The aim of this study was to conduct a resting analysis in Parkinson`s disease and major depression disorder by means of analyzing fMRI and EEG datasets, respectively. Parkinson`s disease is a neurodegenerative brain disorder that leads to the impairment of the patients` motor function as well as cognition as it progresses. This study tried to investigate the impact of the progression of Parkinson’s disease and the resulting cognitive deficits on the functional connectivity of the resting state network of the brain, with a special focus on the default mode network and salience network. Among the 84 patients with Parkinson’s disease, 8 patients with and 9 without cognitive impairment were included in this study. The resting state fMRI data was analyzed by the methods of seed-based correlation analysis, independent component analysis as well as the persistent homology analysis. The results indicated certain alterations in the patterns of networks connectivity. The functional connectivity of the default mode network was decreased in the cognitively impaired patients compared to the intact group with decreased connectivity of the medial prefrontal cortex within the network. Similar results were observed for the salience network, with its functional connectivity decreased in the cognitively impaired group. Moreover, the results of the persistent homology analysis indicated that overall, the cognitively impaired group had a more globally connected and less locally connected network compared to the intact group. Our findings suggest that among the different resting state networks of the brain that might be affected by the progression of the disease, the default mode network and the salience network are two important resting state networks whose functional connectivity is altered in Parkinson’s disease. Major depressive disorder (MDD) is a mental disorder that is clinically characterized by one or more major depressive episodes and in most patients that may reoccur...