Median Nerve - Anatomic Anomalies

Anatomic Anomalies

There are multiple naturally occurring anomalies of the median nerve.

• Bifurcation of the median nerve typically occurs after the nerve exits the carpal tunnel; however, in a small percentage (5%-10%) of individuals, the median nerve bifurcates more proximal in the carpal tunnel, wrist, or forearm.
• During gestation, a median artery that serves the hand retracts. However, in some individuals the median artery does not retract and follows the course next to the median nerve into the hand.
• Martin-Gruber anastomoses can occur when branches of the median nerve cross-over in the forearm and merge with the ulnar nerve to innervate portions of the forehand.
• Riche-Cannieu anastomoses can occur when there is connection between reccurent branch of the median nerve and deep branch of the ulnar nerve of the hand.