Medial Cutaneous Nerve of the Forearm

nervus cutaneus antebrachii medialis

Arising from the medial cord of the brachial plexus (C8-T1), the medial cutaneous nerve of the forearm descends medial to the brachial artery in the arm before dividing at or just above the medial epicondyle into anterior and posterior branches. These branches supply sensation to the entire medial surface of the forearm from the elbow to the wrist, running in parallel with the basilic vein.

Region: Forearm

Clinical Relevance

Clinical Notes

This nerve is an important donor for nerve grafting given its length and superficial course along the medial forearm. It is at risk during cubital tunnel surgery, medial epicondylectomy, and basilic vein harvesting. Inadvertent injury produces a strip of medial forearm numbness or a painful neuroma that can be more bothersome than the original cubital tunnel pathology. Identification and protection of its main trunk and the anterior and posterior branches before incision significantly reduces the risk of injury.

Pathology

Common Injuries & Conditions

Cubital Tunnel Surgery Injury

Transection or stretch of the medial antebrachial cutaneous nerve during ulnar nerve decompression or transposition causes medial forearm numbness and sometimes a painful neuroma at the elbow incision, which can be avoided by meticulous identification of its branches before the skin incision.