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

Area of Science:

• Neuroimaging
• Neuroscience
• Radiology

Background:

• The thalamus, a deep gray matter structure, plays a crucial role in cognitive functions.
• Previous research suggests thalamic involvement in cognitive modulation.

Purpose of the Study:

• To investigate thalamus volume changes and functional connectivity (FC) alterations in Parkinson's disease (PD) patients with and without mild cognitive impairment (MCI).
• To explore the relationship between these neuroimaging findings and cognitive performance.

Main Methods:

• Prospective study involving 33 PD patients with MCI (PD-MCI), 36 PD patients without MCI (PD-NCI), and 21 healthy controls (HCs).
• Utilized 3.0T MRI with 3D T1-weighted imaging for voxel-based morphometry (VBM) to assess thalamus and subregion volumes.
• Resting-state fMRI was employed to analyze seed-based FC, with the total thalamus as the seed region.

Main Results:

• PD-MCI patients exhibited significantly reduced total thalamus and subregion volumes compared to PD-NCI and HCs.
• PD-MCI patients showed altered FC, including increased connectivity between the thalamus and cingulate cortex, and decreased connectivity with occipital regions.
• Thalamus volumes and FC values significantly correlated with neuropsychological test scores in PD patients.

Conclusions:

• Parkinson's disease patients with mild cognitive impairment (PD-MCI) demonstrate significant thalamus volume loss.
• Altered functional connectivity patterns involving the thalamus are observed in PD-MCI.
• These structural and functional brain changes in the thalamus are associated with global cognitive deficits in PD.