Global Functional Network Connectivity Disturbances in Parkinson’s Disease with Mild Cognitive Impairment by Resting-State Functional MRI

Examining the spontaneous BOLD activity to understand the neural mechanism of Parkinson’s disease(PD)with mild cognitive impairment(MCI)is a focus in resting-state functional MRI(rs-fMRI)studies.This study aimed to investigate the alteration of brain functional connectivity in PD with MCI in a systematical way at two levels:functional connectivity analysis within resting state networks(RSNs)and functional network connectivity(FNC)analysis.Using group independent component analysis(ICA)on rs-fMRI data acquired from 30 participants(14 healthy controls and 16 PD patients with MCI),16 RSNs were identified,and functional connectivity analysis within the RSNs and FNC analysis were carried out between groups.Compared to controls,patients with PD showed decreased functional connectivity within putamen network,thalamus network,cerebellar network,attention network,and self-referential network,and increased functional connectivity within execution network.Globally disturbed,mostly increased functional connectivity of FNC was observed in PD group,and insular network and execution network were the dominant network with extensively increased functional connectivity with other RSNs.Cerebellar network showed decreased functional connectivity with caudate network,insular network,and self-referential network.In general,decreased functional connectivity within RSNs and globally disturbed,mostly increased functional connectivity of FNC may be characteristics of PD.Increased functional connectivity within execution network may be an early marker of PD.The multi-perspective study based on RSNs may be a valuable means to assess functional changes corresponding to specific RSN,contributing to the understanding of the neural mechanism of PD.

Resting-state functional connectivity in lifelong musicians

Background:It has been postulated that musicianship can lead to enhanced brain and cognitive reserve,but the neural mechanisms of this effect have been poorly understood.Lifelong professional musicianship in conjunction with novel brain imaging techniques offers a unique opportunity to examine brain network differences between musicians and matched controls.Objective:In this study we aim to investigate how resting-state functional networks(FNs)manifest in lifelong active musicians.We will evaluate the FNs of lifelong musicians and matched healthy controls using resting-state functional magnetic resonance imaging.Methods:We derive FNs using the data-driven independent component analysis approach and analyze the functional network con-nectivity(FNC)between the default mode(DMN),sensory-motor(SMN),visual(VSN),and auditory(AUN)networks.We examine whether the linear regressions between FNC and age are different between the musicians and the control group.Results:The age trajectory of average FNC across all six pairs of FNs shows significant differences between musicians and controls.Musicians show an increase in average FNC with age while controls show a decrease(P=0.013).When we evaluated each pair of FN,we note that in musicians FNC values increased with age in DMN–AUN,DMN–VSN,and SMN–VSN and in controls FNC values decreased with age in DMN–AUN,DMN–SMN,AUN–SMN,and SMN–VSN.Conclusion:This result provides early evidence that lifelong musicianship may contribute to enhanced brain and cognitive reserve.Results of this study are preliminary and need to be replicated with a larger number of participants.