Median: Musculocutaneous Nerve Communication

Neuroanatomical variations of the brachium constitute an important anatomical and clinical entity. During the educational gross anatomy dissection of axilla and brachium for undergraduate medical students in a 50 yrs old male cadaver a neuroanatomical variation was encountered in the right lateral cord of brachial plexus and its branches. The nerves forming the letter 'M' were normal right under the pectoralis minor muscle. The musculocutaneus nerve passed through the coracobrachialis muscle and gave branches to biceps brachii and brachialis muscles. A communicating branch from the musculocutaneous nerve originated at the level of deltoid tuberosity and joined the median nerve. After having supplied the muscles of arm, the musculocutaneous nerve coursed normally as lateral cutaneous nerve of forearm. The observation of the current study are relevant as it may produce a perplexing situation to anaesthetists while attempting brachial plexus blocks and for surgeons operating upon this region. The variation is also important in median nerve lesions, if lesion is proximal to the communicating branch the muscles and cutaneous innervation to median nerve was normal.