The structural changes of gray matter in Parkinson disease patients with mild cognitive impairments

Abstract

Objectives Parkinson disease (PD) is associated with cognitive impairments. However, the underlying neural mechanism of cognitive impairments in PD is still not clear. This study aimed to investigate the anatomic alternations of gray matter in PD patients with mild cognitive impairment (MCI) and their associations with neurocognitive measurements. Methods T1-weighted magnetic resonance imaging (MRI) data were acquired from 23 PD patients with MCI, 23 PD patients without MCI, and 23 matched healthy controls. The MRI data were analyzed using voxel-based morphometry (VBM) and surfaced-based morphometry (SBM) methods to assess the structural changes in gray matter volume and cortical thickness respectively. Receiver operating characteristic (ROC) analysis was used to examine the diagnostic accuracies of the indexes of interest. The correlations between the structural metrics and neurocognitive assessments (e.g., Montreal cognitive assessment, MOCA; Mini-mental state examination, MMSE) were further examined. Results PD patients with MCI showed reduced gray matter volume (GMV) in the frontal cortex (e.g., right inferior frontal gyrus and middle frontal gyrus) and extended to insula as well as cerebellum compared with the healthy controls and PD patients without MIC. Thinner of cortical thickens in the temporal lobe (e.g., left middle temporal gyrus and right superior temporal gyrus) extending to parietal cortex (e.g., precuneus) were found in the PD patients with MCI relative to the healthy controls and PD patients without MCI.ROC analysis indicated that the area under the ROC curve (AUC) values in the frontal, temporal, and subcortical structures (e.g., insula and cerebellum) could differentiate the PD patients with MCI and without MCI and healthy controls. Furthermore, GMV of the right middle frontal gyrus and cortical thickness of the right superior temporal gyrus were correlated with neurocognitive dysfunctions (e.g., MOCA and MMSE) in PD patients with MCI. Conclusion This study provided further evidence that PD with MCI was associated with structural alternations of brain. Morphometric analysis focusing on the cortical and subcortical regions could be biomarkers of cognitive impairments in PD patients.

Production of emotions conveyed by voice in Parkinson’s disease: Association between variability of fundamental frequency and gray matter volumes of regions involved in emotional prosody.

“…First, the direct comparison between HC and PD groups showed a significant gray matter volume difference between the two groups in a widespread bilateral network, covering especially frontal areas but also left cingulate cortex, bilateral parietal areas as well as occipital cortices. These findings are in line with previous cross-sectional studies describing a distributed pattern of structural reductions of gray matter in PD (see Xu et al, 2020, for a meta-analysis) related to neurocognitive dysfunctions (Li et al, 2022) and morphometric longitudinal imaging studies which report significantly greater annual brain volume loss in patients with PD compared to control subjects (Hu et al, 2001). In particular, frontal lobe atrophy associated with the duration of motor symptoms was described in late-onset PD (Double et al, 1996), and frontal lobe changes were found in patients with PD who had mild cognitive impairment and in those with dementia (Beyer et al, 2007;Burton et al, 2004), and This document is copyrighted by the American Psychological Association or one of its allied publishers.…”

Uncovering the Neuroanatomical Signature of the Transition from Normal Cognition to Mild Cognitive Impairment in Parkinson's Disease: A VBM and Brain Age Estimation Study

“…Nevertheless, increased cerebellar glucose metabolism has consistently been observed in the literature in cognitively impaired PD patients 29,30 , which has often been hypothesized to be related with compensatory mechanisms. Previous VBM studies have revealed that PD-MCI patients had a drastic GM decrease in the right insula, right inferior frontal gyrus middle frontal gyrus), and right cerebellum regions in comparison to PD patients who were cognitively healthy 31 . In this study, we observed an increase in GM within the cerebellum of PD-UHC patients compared to PD-SHC, even before they exhibited noticeable cognitive symptoms.…”

MRI-based Differentiation of Parkinson's Disease by Cerebellar Gray Matter Volume

“…This reduction extended from the frontal lobe, which was closely associated with cognitive function, to the cerebellum. Furthermore, the subcortical cerebellum area could serve as a neural biomarker to distinguish between HC, PD patients with MCI and PD patients without MCI [35]. Previous studies have demonstrated the discriminative power of the cerebellum as a feature in SVM to classify PD patients and different subtypes.…”

“…These aberrant brain regions including the basal ganglia, visual network, and auditory network, have provided morphological evidence for the pathophysiology of PD [34]. A recent study which combined VBM and surface-based morphometry (SBM) in PD patients with mild cognitive impairments (MCI) showed reduced gray matter volume in the frontal cortex, extending to the cerebellum, and cortical thinning in the temporal lobes, extending to the parietal cortex [35]. Further substantiating the association between PD and alterations in brain structure, morphometric analysis focused on subcortical and cortical regions may serve as important biomarkers for disease progression in PD patients.…”