Diffusion tensor imaging and cognition in cerebral small vessel disease: the RUN DMC study

Area of Science:

• Neuroimaging
• Geriatric Medicine
• Cognitive Neuroscience

Background:

• Cerebral small vessel disease (SVD) is prevalent in the elderly, with a weak association to cognition.
• Conventional MRI (FLAIR) has limitations in assessing white matter lesion (WML) diversity and early microstructural changes in normal-appearing white matter (NAWM).
• Diffusion tensor imaging (DTI) offers novel insights into white matter microstructural integrity.

Purpose of the Study:

• To investigate the relationship between white matter integrity (in WML and NAWM) and cognitive function in elderly individuals with SVD using DTI.
• To explore DTI's potential in understanding cognitive decline mechanisms in SVD.

Main Methods:

• Prospective cohort study (RUN DMC) of 503 non-demented elderly individuals (50-85 years) with SVD.
• All participants underwent MRI and DTI scanning.
• Mean diffusivity (MD) and fractional anisotropy (FA) were measured in WML and NAWM.

Main Results:

• Inverse correlations were found between MD in WML and NAWM and global cognitive function, psychomotor speed, concept shifting, and attention.
• These DTI-cognition relationships were more pronounced in individuals with severe WML.
• DTI parameters in both WML and NAWM correlated with cognitive performance, independent of SVD severity.

Conclusions:

• DTI parameters in white matter lesions and normal-appearing white matter are associated with cognitive performance in elderly individuals with SVD.
• DTI shows promise for elucidating cognitive decline mechanisms and serving as a surrogate marker in SVD therapeutic trials.
• This research contributes to the understanding of brain aging and neurodegenerative diseases through advanced neuroimaging.