Double site nerve lesion: ultrasound diagnosed musculocutaneous involvement in traumatic Brachial Plexus injury

Brachial plexus (BP) injury with non homogeneous involvement of muscles innervated by the same root, trunk or cord is common. Isolated musculocutaneous (MSC) nerve damage is instead rare, and electrophysiological demonstration is based mainly on needle EMG and sensory nerve conduction evaluation of lateral antebrachial cutaneous nerve. Conduction velocity study of MSC nerve is not feasible because of the nerve anatomical course. The electrodiagnostic evaluation of MSC nerve is even more difficult when BP damage coexists. Ultrasound (US) has recently been introduced as useful tool for the diagnosis of peripheral nerve lesions. Recently advances in US technology have made it possible to study very small nerves (also those not easily assessed through electrodiagnostic evaluation). Although US does not replace electrodiagnostic studies, it is a useful complementary investigation.