Multiparametric MRI Assessment of Morpho-Functional Muscle Changes Following a 6-Month FES-Cycling Training Program:...

Area of Science:

• Neurology
• Rehabilitation Medicine
• Biomedical Imaging

Background:

• Spinal cord injuries (SCIs) lead to severe secondary conditions, including muscle deterioration and metabolic dysfunction, diminishing quality of life.
• Functional electrical stimulation (FES) combined with cycling exercise (FES-cycling) shows potential for improving muscle function and overall health in SCI patients.

Purpose of the Study:

• To investigate the utility of multiparametric magnetic resonance imaging (MRI) in evaluating muscle health changes during and after FES-cycling rehabilitation.
• To assess the impact of a 6-month FES-cycling program on muscle volume, fat fraction, and tissue microstructure in individuals with chronic SCI.

Main Methods:

• Four male participants with chronic SCI completed a 6-month FES-cycling program (2x 30-minute sessions/week).
• Multiparametric MRI, including T1-weighted, Dixon, multi-echo spin echo, and diffusion tensor imaging, was performed at baseline, 3 months, 6 months, and 1 month post-training.
• MRI assessed muscle volume, fat fraction, T2 relaxation times, and diffusion parameters to analyze macroscopic and microscopic tissue changes.

Main Results:

• Significant muscle hypertrophy observed: average muscle volume increased by 36.7% at 6 months and remained 23.2% higher post-training.
• Muscle fat fraction decreased by 17.1% after 6 months of training.
• Diffusion tensor imaging indicated subtle microstructural changes, with decreased fractional anisotropy linked to increased radial diffusivity.

Conclusions:

• Six months of low-intensity FES-cycling effectively increases muscle volume and reduces fat infiltration in individuals with SCI.
• Multiparametric MRI provides comprehensive insights into muscle tissue changes, supporting its use in assessing rehabilitation efficacy.
• FES-cycling demonstrates potential as a therapeutic intervention for improving muscle health in SCI populations.