Arterial stiffness and white matter integrity in the elderly: A diffusion tensor and magnetization transfer imaging...

Area of Science:

• Neuroscience
• Cardiovascular Science
• Aging Research

Background:

• Large artery stiffness and pulsatility can affect brain white matter (WM) microstructure.
• Mechanisms linking arterial stiffness to WM changes are not fully understood.

Purpose of the Study:

• Investigate the association between central artery stiffness and axonal/myelin integrity in cognitively unimpaired elderly individuals.
• Explore relationships between arterial stiffness, WM microstructure, and executive function.

Main Methods:

• Assessed WM integrity using diffusion tensor imaging (Fractional Anisotropy, Radial Diffusivity) and magnetization transfer imaging (Myelin Volume Fraction).
• Measured central artery stiffness via carotid-femoral pulse wave velocity (cfPWV).
• Analyzed 4 vulnerable WM regions: corpus callosum, internal capsule, corona radiata, superior longitudinal fasciculus.

Main Results:

• cfPWV significantly correlated with Fractional Anisotropy and Radial Diffusivity (p<0.05, corrected).
• No significant association found between cfPWV and Myelin Volume Fraction.
• Improved executive function correlated positively with Fractional Anisotropy and negatively with Myelin Volume Fraction and Radial Diffusivity (p<0.05, corrected).

Conclusions:

• Arterial stiffness is associated with axon degeneration, rather than demyelination, in the aging brain.
• Controlling arterial stiffness may be crucial for maintaining WM axon health in older adults.