Thalamocortical Functional Connectivity in Patients With White Matter Hyperintensities

Area of Science:

• Neuroimaging
• Cognitive Neuroscience
• Geriatric Neurology

Background:

• White matter hyperintensities (WMH) are common in the elderly, increasing dementia risk.
• The thalamocortical circuit's role in WMH-related cognitive decline is not well understood.
• Understanding these circuits is crucial for addressing cognitive deficits in aging populations.

Purpose of the Study:

• To investigate alterations in thalamocortical functional connectivity (FC) in patients with WMH.
• To explore the relationship between these FC changes and cognitive impairments.
• To clarify the impact of WMH severity on thalamocortical network function.

Main Methods:

• Eighty WMH patients and 37 healthy controls (HCs) underwent resting-state functional MRI (rs-fMRI).
• Patients were stratified into mild and moderate-severe WMH groups based on Fazekas scores.
• Thalamocortical FC was analyzed using seed-based approaches, with ROIs and thalamic subregions as seeds.

Main Results:

• Moderate-severe WMH showed increased precentral gyrus (PrCG)-interthalamic adhesion (ITA) FC compared to HCs and mild WMH.
• Increased ITA-medial frontal gyrus (MFG) FC was observed in both mild and moderate-severe WMH groups compared to HCs, with higher values in the moderate-severe group.
• WMH patients exhibited significant correlations between altered FC (PrCG-ITA, ITA-MFG) and deficits in memory, executive function, and attention.

Conclusions:

• Abnormal thalamocortical functional connectivity is a key feature in patients with WMH.
• These connectivity alterations are significantly associated with cognitive impairments, including memory, executive function, and attention deficits.
• The findings highlight the thalamocortical circuit's importance in the cognitive consequences of WMH.