Anatomic connectivity assessed using pathway radial diffusivity is related to functional connectivity in monosynaptic...

Area of Science:

• Neuroimaging
• Neurology
• Biomedical Engineering

Background:

• Multiple Sclerosis (MS) frequently impacts cognitive functions, especially memory.
• Understanding the relationship between structural (anatomic) and functional brain connectivity is crucial for MS research.
• The Papez circuit, vital for memory, is often affected in MS patients.

Purpose of the Study:

• To analyze pathway-dependent anatomic and functional connectivity in relapse-remitting MS patients.
• To investigate the correlation between anatomic and functional connectivity in MS and healthy individuals.
• To assess the utility of diffusion imaging measures for evaluating white matter integrity.

Main Methods:

• Combined resting-state functional MRI (fMRI) and high angular resolution diffusion imaging (HARDI).
• Analysis focused on three monosynaptic pathways: transcallosal and bilateral Papez circuit pathways.
• Comparison between 19 MS patients and 16 matched healthy controls.

Main Results:

• Significantly reduced anatomic and functional connectivity observed in MS patients compared to controls across specific pathways.
• A significant correlation between anatomic and functional connectivity was found in both MS patients and controls.
• Radial diffusivity, a diffusion tensor measure, proved to be a reliable indicator of anatomic connectivity.

Conclusions:

• Anatomic and functional connectivity are closely related in monosynaptic brain pathways.
• Diffusion imaging metrics, like radial diffusivity, offer robust assessment of white matter integrity in the general population.
• This study provides insights into the neurobiological underpinnings of cognitive deficits in MS.