Task-Related Reorganization of Cognitive Network in Parkinson's Disease Using Electrophysiology

BackgroundCognitive deficits in Parkinson's disease (PD) patients are well described, however, their underlying neural mechanisms as assessed by electrophysiology are not clear. ObjectivesTo reveal specific neural network alterations during the performance of cognitive tasks in PD patients using electroencephalography (EEG). MethodsNinety participants, 60 PD patients and 30 controls underwent EEG recording while performing a GO/NOGO task. Source localization of 16 regions of interest known to play a pivotal role in GO/NOGO task was performed to assess power density and connectivity within this cognitive network. The connectivity matrices were evaluated using a graph-theory approach that included measures of cluster-coefficient, degree, and global-efficiency. A mixed-model analysis, corrected for age and levodopa equivalent daily dose was performed to examine neural changes between PD patients and controls. ResultsPD patients performed worse in the GO/NOGO task (P < 0.001). The power density was higher in & delta; and & theta; bands, but lower in & alpha; and & beta; bands in PD patients compared to controls (interaction group x band: P < 0.001), indicating a general slowness within the network. Patients had more connections within the network (P < 0.034) than controls and these were used for graph-theory analysis. Differences between groups in graph-theory measures were found only in cluster-coefficient, which was higher in PD compared to controls (interaction group x band: P < 0.001). ConclusionsCognitive deficits in PD are underlined by alterations at the brain network level, including higher & delta; and & theta; activity, lower & alpha; and & beta; activity, increased connectivity, and segregated network organization. These findings may have important implications on future adaptive deep brain stimulation. & COPY; 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.