Update on Compression Neuropathy of the Upper Extremity

Three major nerves supply the arm, wrist, and hand: the radial, median, and ulnar nerves. Pressure on the median nerve causes carpal tunnel syndrome. This is the most common type of compression neuropathy affected the upper extremity.

Nerve compression from entrapment of the ulnar nerve is the second most common cause of numbness, tingling, and weakness in the arm. In this article, hand surgeons from the Mayo Clinic provide an in-depth review of this condition.

Anatomy, type of compression syndromes, and long-term effects are discussed. History, exam, and diagnostic tests provide direction for treatment. X-rays of the neck and arm should be taken to look for any bone deformity or anatomical cause of the nerve entrapment. In some cases, an X-ray of the lung may be needed to rule out tumors.

Electromyography (EMG) studies help diagnose the severity of the compression. Nerve signals and electrical impulses from muscle contraction are recorded. The results can also help pinpoint the location of the problem.

Treatment is divided into nonsurgical and surgical approaches. Mild to moderate nerve entrapment may be helped by night splinting of the elbow, padding along the nerve, and anti-inflammatory medications. Many patients respond well to hand therapy. When these methods fail, steroid injections may be tried.

If conservative care doesn't change the picture, then surgery may be the next step. The surgeon can choose from a wide range of options. The goal is to take pressure off the nerve. This is called decompression. It is accomplished by cutting any bands of connective or fibrous tissue over and around the nerve.

It may be necessary to perform a decompression and medial epicondylectomy. Medial refers to the inside of the elbow closest to the body. With an epicondylectomy, the surgeon removes the bony bump we often refer to as the funny bone. The area is smoothed over and the muscles are reattached.

Transposition (moving) of the nerve may be required to relieve the traction or biomechanical pull exerted on the nerve. Moving the nerve changes the pressure on the nerve from muscle contraction and joint motion.

Surgery provides good to excellent results for many patients with ulnar nerve compression. But there can be problems post-operatively. Symptoms may persist if the nerve wasn't released fully or from scarring that develops around the nerve. Surgery can injure other nerves causing numbness and/or a painful surgical scar.

Ligaments can be damaged during the transposition process. And adhesions may occur after the nerve transfer when the elbow is immobilized to allow healing of the muscles.

Patients with persistent symptoms or symptoms that come back may need further (revision) surgery. Loss of motor function can result in limitations and disability.

For the most part, treatment for ulnar nerve compression is successful. Symptoms are relieved and motion and function are restored in all age groups. Throwing athletes are able to return to full play.

References: Bassem Elhassan, MD, and Scott P. Steinmann, MD. Entrapment Neuropathy of the Ulnar Nerve. In Journal of the American Academy of Orthopaedic Surgeons. November 2007. Vol. 15. No. 11. Pp. 672-681.