Vol 63, No 3 (2004)
Original article
Published online: 2004-06-04
Anatomical variations of the median nerve distribution and communication in the arm
Folia Morphol 2004;63(3):313-318.
Abstract
Anatomical variations of peripheral nerves constitute a potentially important
clinical and surgical issue. The aim of this work is to study the variations of the
median nerve in the arm with respect to its branching pattern and distribution
as well as its possible communication with the musculocutaneous and/or ulnar
nerves. Sixty arms pertaining to 30 preserved human cadavers, ranging in age
from 30 to 67 years, were dissected in pursuit of this aim. In one limb out of 60
(1.7%) the median nerve gave off muscular branches to the brachialis muscle as
well as a branch from its lateral root to supply both heads of the biceps brachii
muscle. Concomitantly the musculocutaneous nerve was absent. The same limb
demonstrated a branch from the lateral cord of the brachial plexus supplying
the coracobrachialis muscle. Three limbs (5%) showed a communicating branch
between the median and the musculocutaneous nerves. These observations
should be considered when a high median nerve paralysis is shown to originate
in the axilla or proximal arm in a patient presenting with weakness of forearm
flexion and supination. Similarly, it can explain weakness of the arm flexor muscles
in thoracic outlet syndrome with median nerve affection.
Keywords: median nervevariationscommunicating branchesmusculocutaneous nerve