Median Compressive Neuropathy Proximal to the Carpal Tunnel

Abstract

Median nerve dysfunction at the elbow or proximal forearm is typically secondary to compression. These issues may present as pronator syndrome, anterior interosseous nerve (AIN) syndrome, or as a compressive neuropathy of the palmar cutaneous branch of the median nerve. Pronator syndrome is a purely sensory phenomenon and is characterized by vague volar forearm pain, with median nerve paresthesias and no motor findings. AIN syndrome is characterized by a pure motor nerve palsy of the flexor pollicis longus, the flexor digitorum profundus of the index and long finger, and the pronator quadratus. The sites of compression for both these syndromes are similar. Electrodiagnostic studies are frequently normal with pronator syndrome and abnormal with AIN syndrome. These syndromes are controversial. There is a lack of objective evidence and physical findings for pronator syndrome. AIN syndrome may be caused by simple neuritis that may resolve spontaneously. Therefore, both syndromes are initially managed nonsurgically. This nonsurgical management includes rest, activity modification, anti-inflammatory medications, therapy, etc. The indication for surgical nerve decompression is reserved for patients with persistent symptoms despite these measures.