Flail arms in a parachutist: an unusual presentation of hereditary neuropathy with liability to pressure palsies

Bilateral musculocutaneous neuropathy: A case report

BACKGROUND

Isolated musculocutaneous nerve injury is a rare condition. Herein, we report the first case of bilateral musculocutaneous neuropathy after vigorous stretching of both upper extremities with normal results of sensory nerve action potential. Clinicians should be aware of this rare condition that can appear bilaterally. In addition, the interpretation of the aberrant electrodiagnostic study results of this case was discussed.

CASE SUMMARY

A 29-year-old male complaining of bilateral forearm tingling and upper extremity weakness visited the outpatient clinic. The symptoms began 6 mo prior, and he visited another hospital before visiting our department. The diagnosis was not made even after cervical spine magnetic resonance imaging, electrodiagnostic study, brain magnetic resonance imaging, and arteriography were conducted. The patient performed unique exercises that stretched the pectoralis minor and coracobrachialis muscles. On the follow-up electrodiagnostic study, abnormal spontaneous activities in the bilateral biceps and brachialis muscles were observed. The patient was diagnosed with bilateral musculocutaneous neuropathy. Steroid pulse therapy was administered for approximately 6 wk. After treatment, his muscle strength returned to the predisease condition.

CONCLUSION

Clinicians should be aware of this condition, have adequate understanding of anatomy, and advise to correct inappropriate exercises.

Musculocutaneous nerve injury after simulated freefall in a vertical wind-tunnel: a case report

We report a case of a skydiver with isolated musculocutaneous nerve injury, which occurred after prolonged positioning of the arm during simulated freefall in a vertical wind-tunnel. Musculocutaneous nerve injury is rare, and the mechanism of isolated injury to this nerve is not entirely understood. Isolated peripheral nerve injuries such as this easily mimic other injuries and can be difficult to diagnose. The skydiver complained of right arm weakness and numbness that began after training in a vertical wind-tunnel. Exam revealed weakness in right elbow flexion and forearm supination, and diminished sensation in the right lateral forearm. Electrodiagnostic testing revealed a decreased amplitude in the right lateral antebrachial cutaneous nerve sensory nerve action potential, and fibrillations and positive sharp waves in the biceps and brachialis muscles. By 5 months, the subject reported complete sensory and motor recovery. Physical and electrodiagnostic findings corresponded to the distribution of the musculocutaneous nerve. The mechanism of injury was likely the prolonged abducted, extended, and externally rotated position of the shoulder during simulated freefall. Although isolated nerve injuries are uncommon, unusual activities and physiologic demands of athletes can result in such injuries. It is important to be aware of peripheral nerve injuries to facilitate proper diagnosis and management.