Impact of disuse muscular atrophy on the compound muscle action potential.

Authors :: Mobach T
Brooks J
Breiner A
Warman-Chardon J
Papp S
Gammon B
Nandedkar SD
Bourque PR
Source :: Muscle & nerve [Muscle Nerve] 2020 Jan; Vol. 61 (1), pp. 58-62. Date of Electronic Publication: 2019 Oct 17.
Publication Year :: 2020
Abstract: Background: Disuse atrophy from immobilization is the result of decreased neural activity and muscle unloading.<br />Methods: We studied the impact of disuse on hand intrinsic compound muscle action potentials (CMAPs) in a cohort of 39 patients with unilateral 6-week immobilization of the hand in a cast, after distal radius fracture. We excluded patients with nerve injury. We compared side-to-side CMAP characteristics at the time of cast removal and at a subsequent follow-up visit, after a mean interval of 7.8 weeks.<br />Results: Statistically significant reductions in CMAP amplitude were noted for the abductor pollicis brevis (29.2%), abductor digiti minimi (19.0%), and first dorsal interosseus (24.9%). There was partial repair of the relative CMAP reduction at the follow-up visit (20.1%, 10.7%, and 8.7%, respectively). There was no significant change in CMAP duration.<br />Conclusions: These results provide a framework for quantifying the degree of hand intrinsic CMAP amplitude reduction attributed to disuse.<br /> (© 2019 Wiley Periodicals, Inc.)