Rare case of median nerve and brachial artery entrapment by an abnormal musculo-fascial tunnel in the arm: possible cause of neurovascular compression syndrome / 대한해부학회지

Entrapment neuropathies of the peripheral nervous system are frequently encountered due to anatomical variations. Median nerve is the most vulnerable nerve to undergo entrapment neuropathies. The clinical complications are mostly manifested by median nerve impingement in forearm and wrist areas. Median nerve entrapment could also occur at the arm, due to the presence of ligament of Struthers. Here we report a rare case of proximal entrapment of median nerve and brachial artery in the arm by an abnormally formed musculo-fascial tunnel. The tunnel was formed by the muscle fibers of brachialis and medial intermuscular septum in the lower part of arm. Due to this, the median nerve coursed deep, below the tunnel and continued distally into the forearm, underneath the pronator teres muscle and hence did not appear as a content of cubital fossa. The present entrapment of neurovascular structures in the tunnel might lead to pronator syndromes or other neurovascular compression syndromes.

Presence of Additional Head of Pronator Teres Muscle and Associated Neurovascular Variations: A Rare Case Report

Arm is a site for frequent injuries and it is involved in many surgical procedures. Variations in the arm have immense clinical significance. During the dissection of a right upper limb, brachial artery was found to divide into radial and ulnar arteries, 3cm above the inter-epicondylar plane. The ulnar artery and the median nerve were then passing through a tunnel formed by an extensive additional humeral head of the pronator teres muscle. Two centimetres long fibromuscular tunnel formed by the humeral head of the pronator teres was found to arise from the medial intermuscular septum and also from the fibrous arch form the shaft of the humerus to the medial intermuscular septum. In the same cadaver, the superior ulnar collateral artery was found to arise from the profunda brachii artery which is otherwise a branch of the brachial artery. Accurate knowledge of these variation patterns is of considerable clinical significance in conduct of surgeries of arm, fracture management of humerus and diagnosis of various compressive neuropathies.