Case Report: POSTERIOR INTEROSSEOUS NERVE COMPRESSION SYNDROME

Radial nerve compression or injury can occur at any point along the course of the nerve within the upper extremity. Entrapment of the radial nerve or its branches is most common within the proximal forearm and at the elbow. Variations in anatomic structures at this level are an important cause of radial nerve entrapment syndromes. Compression of the radial nerve and its branches at the elbow can therefore result in motor, sensory, or mixed deficits. The motor branch is particularly vulnerable to compressive injury, and compression of this branch may result in a variety of clinical presentations. Posterior interosseous nerve syndrome can be mistaken for a C7 radiculopathy and lateral epicondylitis which has a burning sensation along the lateral aspect of the forearm. The clinical entities sometime are difficult to distinguish on physical examination. MR imaging plays an important role to depicting nerve entrapment by identifying muscle edema, atrophy, and fatty infiltration as well as detecting the cause of entrapment. This paper reported a case of male 25 year old with persistent pain at the forearm after a fall 2 years before admission. On physical examination, a weakening of the extension of the fingers and wrist was detected. There was no sensory deficit noted and no history of appropriate treatment taken previously. MRI examination was perfomed to detect the abnormality of the forearm and elbow. In conclusion, compression of the posterior interosseous nerve can result in a variety of clinical symptoms. The onset of pain or weakness is often insidious, resulting in a confusing clinical presentation. MRI is useful in identifying muscle signal changes in keeping with denervation, contributory anatomic factors, and masses or other lesions that may result in nerve entrapment. (FMI