High angular resolution diffusion imaging correlates of depression in Parkinson's disease: a connectometry study

Area of Science:

• Neuroscience
• Neurology
• Radiology

Background:

• Depression is a common and disabling comorbidity in Parkinson's disease (PD).
• The underlying neuropathology of depression in PD remains poorly understood.
• Previous studies often focused on specific brain regions, limiting a comprehensive understanding of white matter alterations.

Purpose of the Study:

• To investigate the neural correlates of depressive symptom severity in non-demented Parkinson's disease patients.
• To explore alterations in whole white matter pathways using diffusion MRI connectometry.
• To compare white matter connectivity in PD patients with depression to that of healthy controls.

Main Methods:

• Diffusion MRI connectometry was employed to analyze whole white matter pathways.
• A multiple regression model assessed the correlation between depressive symptom severity (Hospital Anxiety and Depression Scale) and white matter quantitative anisotropy (QA).
• The study included 27 non-demented PD patients and 26 matched healthy controls.

Main Results:

• Significant negative associations were found between the depression subscale scores of the HADS and QA in specific white matter tracts in PD patients.
• Affected areas included the left Cingulum, Genu and Splenium of the Corpus Callosum, and the anterior and posterior limbs of the right internal capsule.
• No significant associations between QA and depression scores were observed in healthy controls.

Conclusions:

• This study identifies specific white matter pathway alterations associated with depression severity in Parkinson's disease.
• Findings suggest that disruptions in the left Cingulum and right internal capsule may contribute to the neuropathology of depression in PD.
• This research enhances the understanding of the neural basis of comorbid depression in Parkinson's disease.