Key result
Multiple sclerosis linked to ~33% fewer type IIa MHC muscle fibers and lower peak force.
Case-Control (n=12)
Absolute Event Rate: 31% vs 46%
Muscle fibers from individuals with MS show a subtle shift in fast MHC isoform coexpression and a modest reduction in cross-bridge number, density, or average force, explaining part of the muscle weakness and fatigue.
No takes yet. Share an insight, caveat, or question.
Muscle fiber changes may underlie MS weakness; hypothesis-generating and should not yet change practice.
Garner et al. (2003) conducted a case-control in Multiple sclerosis (n=12). Multiple sclerosis vs. Age- and gender-matched individuals without MS was evaluated on Percentage of fibers containing the type IIa myosin heavy chain (MHC) isoform exclusively. Multiple sclerosis was associated with fewer muscle fibers exclusively containing type IIa MHC (31% vs. 46%) and an 11-13% lower peak Ca(2+)-activated force compared to matched controls.