Case series on the differential diagnosis of pronator teres syndrome

Abstract

Introduction: Compression of the median nerve among the bellies of the pronator teres muscle is called pronator teres syndrome. This is a rare condition that may be accompanied by other compressive neuropathies; therefore, a differential diagnosis should be established.

Objective: To report three cases of pronator teres syndrome in middle-aged patients treated with conservative measures.

Case presentation: The first case was a guitar player with paresthesias in the right upper extremity. Electrophysiology confirmed entrapment of the median nerve at the wrist and the ulnar nerve at the elbow. Ultrasonography showed compression of the median nerve among the heads of the pronator teres muscle. The second patient was a delivery boy who, three months after surgery for a distal rupture of the right biceps brachii, presented pain and lost strength in his right wrist and hand. Ultrasonography showed compression of the ulnar nerve in the epitrochlear canal; while electromyography showed entrapment of the median nerve at the elbow and wrist, and the ulnar nerve at the elbow. The third case, a metalworker, presented with pain in the epitrochlea, with paresthesia and loss of strength in his right hand. Electromyography revealed entrapment of the median and ulnar nerves at the elbow, and the median nerve at the wrist. Imaging tests were normal.

Conclusions: Pronator teres syndrome should be suspected in patients with sensory disturbances in the upper limb. Differentiating it from other compressive neuropathies is considered essential because early detection allows for effective conservative treatment.