Communications of the median nerve in foetuses

Communications between the median, ulnar and musculocutaneous nerves in the arm, forearm and hand were reported in adult cadaveric and electrophysiological studies. These communicant branches may lead conflicting clinical and electrodiagnostic outcomes. While there are many studies on adult patients or cadavers, there is poor regarding foetuses. The present study was conducted to examine the frequencies of these communications and their coexistences in human foetuses.

Anterior aspect of the forearms of 50 foetuses (29 females, 20 males, and 1 unknown) were dissected bilaterally (totally 100 sides) for this purpose.

Communications between the median and the musculocutaneous nerves in the arm were found unilaterally in 4%. Communications from the median to the ulnar nerve in the forearm were encountered unilaterally in 22%, and bilaterally in 12%; from the ulnar to the median nerve in the hand unilaterally in 28%, and bilaterally in 12%. Coexistence of all these variations was not encountered in any foetus. But coexistence of two different types of communicant branch was encountered in 4%.

Precise knowledge of nerve communications, variations and rate of coexistences in foetuses may have significance for clinicians and researchers dealing with subjects in foetal period.