Structural and Functional Thalamic Changes in Parkinson's Disease With Mild Cognitive Impairment

Abstract

Background The thalamus is a key node of deep gray matter and previous studies have demonstrated that it is involved in the modulation of cognition. Purpose To investigate the volume changes of the thalamus and its subregions and altered thalamus functional connectivity patterns in Parkinson's disease (PD) patients with and without mild cognitive impairment (MCI). Study Type Prospective. Population Thirty‐three patients with MCI (PD‐MCI), 36 PD patients having no cognitive impairment (PD‐NCI), 21 healthy controls (HCs). Sequence 3.0T MRI scanner; 3D T1‐weighted fast spoiled gradient recalled echo (3D T1‐FSPGR); resting‐state fMRI Assessment Voxel‐based morphometry (VBM) was performed to calculate the volume of the thalamus and its subregions. The left and right total thalamus were considered seeds and seed‐based functional connectivity (FC) was analyzed. Additionally, correlations between volumes and cognitive performance and between FC values and cognitive performance were examined separately. Statistical Test Analysis of covariance (ANCOVA); two‐sample t‐tests; partial correlation analysis. Results The volumes of the total thalamus (PD‐MCI vs. PD‐NCI vs. HCs: 18.39 ± 1.67 vs. 19.63 ± 1.79 vs. 19.47 ± 1.35) and its subregions were significantly reduced in PD‐MCI as compared to PD‐NCI (total thalamus: P = 0.002) and HCs (total thalamus: P = 0.012). Compared with PD‐NCI, PD‐MCI showed increased FC between the thalamus and bilateral middle cingulate cortex and left posterior cingulate cortex, and decreased FC between thalamus and the left superior occipital gyrus, left cuneus, left precuneus, and left middle occipital gyrus. Volumes of thalamus and the subregions, as well as the FC of thalamus with the identified regions, were significantly correlated (P < 0.05, FDR‐corrected) with neuropsychological scores in PD patients. Data Conclusion We noted volume loss and altered FC of thalamus in PD‐MCI patients, and these changes were correlated with global cognitive performance. Level of Evidence 2 Technical Efficiency Stage 2 J. Magn. Reson. Imaging 2020;52:1207–1215.

Association Between REM Sleep Behavior Disorder and Cognitive Dysfunctions in Parkinson's Disease: A Systematic Review and Meta-Analysis of Observational Studies

“…Compared to PD-NRBD patients, smaller volumes of the hypothalamus, thalamus, amygdala, anterior cingulate cortex, left posterior cingulate, and hippocampus were found in PD-RBD patients (64,76). The volume loss of the thalamus and the accompanying damaged functional connectivity were also observed in PD patients with MCI (141). Elevations of peripheral inflammatory factors were found in the PD-RBD group compared with the PD-NRBD group (142).…”

Potential structural trait markers of depression in the form of alterations in the structures of subcortical nuclei and structural covariance network properties

“…Previous studies have only explored the whole GMV alterations of these three subcortical regions but not explored its subregion by themselves like exploring frontal subregions (e.g., DLPFC, VLPFC), which showed that the analysis of these three subcortical regions was not comprehensive. With the development of imaging analysis technology ( Iglesias et al, 2018 , Iglesias et al, 2015 , Saygin et al, 2017 ), morphological studies based on the amygdalar, hippocampal and thalamic subregions have been applied to explore the potential neural mechanisms of disorders, such as Alzheimer's disease ( Pardilla-Delgado et al, 2021 ), Parkinson's disease ( Li et al, 2020 ), obsessive–compulsive disorder ( Jurng et al, 2021 , Weeland et al, 2021 ) and MDD ( Brown et al, 2019 , Kim et al, 2021 , Yao et al, 2020 ). Exploration of the subregions in the thalamus, amygdala and hippocampus may provide more information to identify the potential subcortical MDD trait markers.…”

More Than Just Static: Dynamic Functional Connectivity Changes of the Thalamic Nuclei to Cortex in Parkinson's Disease With Freezing of Gait

“…The thalamus is a comprehensive relay node for transmitting diverse information, which includes multimodal sensory inputs as well as projections from motor, cognitive, and limbic structures (3,4). Moreover, the thalamus has reciprocal connections with extensive cortical and subcortical regions and functions as a subcortical processing hub for gating of multi-information and integrating of sensorimotor and cognitive functions.…”