Bifid median nerve: a case report at the wrist

The median nerve is a terminal branch of the brachial plexus. It arises in the axilla and ends in the hand by dividing into three common palmar nerves after passing through the carpal tunnel deep to the flexor retinaculum at the wrist. The bifid median nerve corresponds to a bifurcation of the median nerve trunk inside the carpal tunnel. It is a rare variation that is often associated with the persistence of the wrist median artery. The authors report here a fortuitous discovery of a case of bifid median nerve during the wrist dissection of a cadaverous melanoderm belonging to the Wolof ethnic group in Senegal. The bifurcation started at about 14 cm distal and lateral to the medial bicipital groove with the medial trunk ending in the third interdigital space and the lateral trunk which gave four branches. There was neither the wrist median artery nor any other variations of the normal structures at the wrist. The bifid median nerve is rare but should be kept in mind. Being aware of this kind of variation is important to avoid nerve lesions during carpal tunnel surgery.