Musculocutaneous neuropathy: case report and discussion

The musculocutaneous nerve arises from the lateral cord of the brachial plexus and contains fibers from the C5, C6, and C7 spinal nerve roots. It innervates such muscles as the biceps brachii and brachialis as well as supply branches to the skin over the lateral cubital and forearm regions via the lateral antebrachial cutaneous nerve. Musculocutaneous neuropathy can arise from exercise, participating in sports, strenuous activity, cast placement, trauma, and surgery in addition to other less understood causes such as Parsonage Turner syndrome. We present the case of a 55-year-old female who complained of numbness, weakness, and pain throughout the arm starting 1 day following a surgical procedure. Electrodiagnostic testing revealed a musculocutaneous neuropathy with significant axonal injury. Symptoms of musculocutaneous neuropathy may be similar to cervical spinal nerve root impingement or brachial plexus lesions. Therefore, magnetic resonance imaging and electrodiagnostic studies may be useful in differentiating between these conditions. Once the diagnosis of musculocutaneous neuropathy has been made, treatments include relative rest, nonsteroidal anti-inflammatory drugs, splinting, physical therapy, and surgical decompression in cases that do not respond to conservative management.