オートバイ事故による筋皮神経損傷の３例

Abstract

We report three cases of a rare musculocutaneous nerve injury caused by a motor cycle accident. The first case was combined musculocutaneous and radial nerve palsy. The patient showed some recovery in his radial nerve palsy, but no recovery in musculocutaneous nerve palsy. Musculocutaneous nerve was explored 3 months after injury and was found to be ruptured proximal to the coracobrachialis muscle. Eight months after end-to-end repair, his biceps muscle had recovered to grade 4 on manual muscle testing. The second case was that of incomplete brachial plexus injury. Musculocutaneous nerve was explored because no recovery was seen after 3 months, while other nerves showed some recovery. Musculocutaneous nerve was ruptured proximal to the coracobrachialis muscle. Eight months after repair, the function of his biceps muscle had recovered to grade 3. The third case was an isolated musculocutaneous nerve palsy. Tinel sign was positive at the right medial upper arm, but did not progress over 3 months. Operative findings were that of a compression injury. Ten months after neurolysis, biceps muscle strength had recovered to grade 5. Isolated musculocutaneous nerve rupture proximal to the coracobrachialis muscle, which was seen in our first and second cases, has not been previously reported. This might be caused by forced lateral bending of the neck while contracting coracobracialis.