Closed Brachial Plexus Trauma
A 22-year-old, right-handed man was riding a snow-mobile when he hit a jump off balance and landed on his right neck and shoulder. He did not lose consciousness but immediately experienced pain and numbness on the lateral aspect of his right shoulder and upper arm as well as complete paralysis in not being able to either abduct his right arm at the shoulder or flex his arm at the elbow. He was taken to the emergency department, where he was seen by a neurologist who scheduled him for a follow-up exam and electromyography/nerve conduction velocity (EMG/NCV) and somatosensory evoked potentials (SSEPs) study in 3 weeks. This study demonstrated 4 + denervation changes in his right supraspinatus, infraspinatus, deltoid, and biceps muscles with no voluntary units. He had an absent median nerve sensory nerve action potential and somatosensory evoked cortical response over his contralateral scalp. Other changes were minimal.