Bilateral Absence Of Musculocutaneous Nerve: Report Of Two Cases

ABSTRACT

Anatomical variations involving the brachial plexus are not uncommon. Abnormal communications among thebranches of musculocutaneous nerve especially those involving the posterior division are widely reported dueto their significance in various surgical procedures performed in this region. During the routine gross anatomicaldissection, we observed the bilateral absence of musculocutaneous nerve in two male cadavers aged 60 and 65years and the muscles of anterior compartment of arm were innervated by the braches from the Median nerve. Incase 1, it was observed that in the right and left arm, branches from the median nerve supplied the muscles of theanterior compartment namely the coracobrachialis, biceps brachii and brachialis. The branch which innervatedthe brachialis muscle later continued as lateral cutaneous nerve of forearm. In case 2, Absence of MCN observedbilaterally wherein right arm, wherein, a single branch from median nerve supplied the coracobrachialis muscle.Another branch from the median nerve, after passing through the lower end of coracobrachialis, divided into anoblique and a vertical branch which supplied the biceps brachii and brachialis respectively. These anatomicalvariations in the course of musculocutaneous and median nerve should be considered during surgical proceduresand while performing nerve conduction studies.