A rare case of multiple neuromuscular variations in the axilla and arm

Abstract

During the dissection of a 73-year-old embalmed male cadaver, we noted unusual variations in the flexor compartment of the upper limb-bilateral axillary arch muscles, a three-headed biceps brachii muscle with two supernumerary bellies-and variations in the origin of the musculocutaneous and median nerves from the brachial plexus. The morphological and clinical significance of this unique coexistence of multiple neuromuscular variations are discussed.

The innervation of the axillary arch determined by surface stimulodetection electromyography

“…Axillary arch innervation has been extensively described, based on the analysis of cadaveric specimens (Takafuji et al 1991;Omar et al 2010;Wang et al 2011). The present in vivo study constitutes a novel approach, using SSEMG to demonstrate functional muscle innervation.…”

“…proximity of muscular and nerve structures) of the plexus brachialis (Guy et al. 2011; Wang et al. 2011).…”

“…This could be attributed to possible anatomical variations (e.g. proximity of muscular and nerve structures) of the plexus brachialis (Guy et al 2011;Wang et al 2011). Differences in depolarization, distinctive to muscle and nerve fibers, may also have played a role.…”