Stroke risk modifies regional white matter differences in mild cognitive impairment.

Area of Science:

• Neuroimaging
• Gerontology
• Vascular Neurology

Background:

• White matter integrity is crucial for cognitive function in aging.
• Mild cognitive impairment (MCI) represents a transitional stage between normal aging and dementia.
• The relationship between vascular risk factors and white matter changes in MCI requires further investigation.

Purpose of the Study:

• To investigate white matter integrity differences in the corpus callosum between individuals with MCI and cognitively normal older adults.
• To examine the association between stroke risk and white matter integrity in these groups.
• To determine if white matter integrity predicts cognitive performance, particularly verbal memory.

Main Methods:

• Diffusion tensor imaging (DTI) was used to assess white matter integrity.
• Fractional anisotropy (FA) and mean diffusivity (MD) were measured in the genu and splenium of the corpus callosum.
• Participants were non-demented older adults, divided into MCI (n=20) and normal control (NC, n=20) groups.

Main Results:

• Splenium FA was significantly lower in the MCI group compared to the NC group.
• Higher stroke risk correlated with reduced white matter integrity, especially in the genu.
• Increased stroke risk showed a stronger association with lower splenium FA in MCI participants than in controls.
• Splenium FA significantly predicted verbal memory performance, even after adjusting for age, education, and whole brain volume.

Conclusions:

• Vascular burden is related to white matter microstructural changes in older adults.
• Reduced white matter integrity, particularly in the posterior corpus callosum (splenium), may contribute to cognitive decline in MCI.
• These findings highlight the potential role of vascular factors in the development of MCI.