Brain structural network changes in Parkinson's disease with mild cognitive impairment:a diffusion tensor imaging study / 中华行为医学与脑科学杂志

ABSTRACT

Objective To explore the changes of brain structure network in patients with Parkinson's disease with mild cognitive impairment(PD-MCI),and to provide novel markers for the early recognition of PD-MCI. Methods Total 47 patients with primary PD were continuously enrolled at the De-partment of Neurology,Affiliated Hospital of Xuzhou Medical University from May 2017 to May 2018. Twenty-four healthy volunteers were selected as the healthy control (HC) group. General demographic data were col-lected from all subjects. The overall cognitive function and the five cognitive domains (attention and working memory,executive function,language,memory and visual spatial function) were comprehensively evaluated, then the patients with PD were further divided into PD-MCI group(n=22) and PD-NC group(n=25) based on their cognitive evaluation results. All subjects completed the diffusion tensor imaging( DTI) scan and the individual structural brain connection was obtained by deterministic diffusion-tensor tractography. By graph theory analysis technology,the network properties (global properties and node properties) and edge-wise dis- tributions were compared to assess structural connectivity differences among the three groups. Results Com-pared with the PD-NC and HC groups,the PD-MCI group had a larger characteristic path length(PD-NC(8. 33±0. 95),HC(8. 18±1. 35),PD-MCI(9. 20±1. 52),F=4. 14,P<0. 05) and reduced global efficien-cy (PD-NC(0. 13±0. 05),HC(0. 13±0. 04),PD-MCI(0. 10±0. 04),F=3. 73,P<0. 05) in addition to a lower nodal efficiency in frontoparietal areas,thalamus,cingulate gyrus,and insular(P=0 . 003-0. 040,FDR correction). Compared with the HC group,the PD-MCI group had a large frontotemporoparietal areas,basal ganglia,and insular network with decreased connection strength (P<0. 05,FDR correction). Compared with the PD-NC group,the PD-MCI group had a lower network connection strength in the frontoparietal areas (P<0. 05,FDR correction). Conclusion A disruption of structural connections that make up the brain network can lead to changes in information integration and delivery,leading to cognitive dysfunction in patients with PD. The distribution pattern of brain network structure connection changes is expected to become a new marker for identifying PD-MCI.