Patient Information

CARPAL TUNNEL SYNDROME

Introduction

The hand has several nerves that supply sensation and movement. The two main nerves of the hand are the median and ulnar nerves. The median nerve is formed from multiple spinal nerves from the spinal cord that come together in the axilla. As the median nerve travels from the wrist into the hand, it travels beneath the carpal tunnel in the wrist. This carpal ligament is a tight fibrous band that holds several small bones together forming the wrist joint. Flexor tendons of muscles in the forearm that control finger movement also travel with the median nerve through the carpal tunnel. The median nerve can be compressed in this tunnel from swelling of the surrounding soft tissues or fibrosis of the carpal ligament itself. Pressure on the nerve causes pain and dysfunction of the nerve.

Risk factors for carpal tunnel syndrome include repetitive movements of the wrist in certain jobs such as assembly line work or typing. Retained fluid or soft tissue swelling can cause median nerve entrapment in pregnancy, diabetes, rheumatoid arthritis, degenerative arthritis, lupus, and trauma. Endocrinologic causes of carpal tunnel syndrome include acromegaly and hypothyroidism.

Other disorders that may cause similar pain are cervical spine disease, brachial plexus injuries and other peripheral nerve problems.

Symptoms

Patients may complain of tingling or "pins and needles" in their fingers and hand, most significantly in the thumb, index and middle fingers. Sensory loss and a burning sensation are also commonly reported. Pain may radiate up into the arm. Often patients notice difficulty with fine motor movements. Eventually, there is wasting of the muscles in the hands. Many times symptoms are worse at night.

Diagnosis

The diagnosis of carpal tunnel syndrome involves and neurological history and physical examination and diagnostic electrical studies. Tapping over the wrist (Tinel's sign) or placing the hand in a flexed position (Phalen's sign) may reproduce the tingling or pain. Wasting of the hand muscles may be seen as a late sign.

Electromyography (EMG) and nerve conduction studies (NCS) are done to confirm the diagnosis.

Treatment

Conservative treatment involves a extension wrist splint and the use of non-steroidal anti-inflammatory pain relievers. Many patients will have significant improvement with medical management. Steroid injections may also be helpful.
Wrist extension brace


Figure depicting surgery for CTS

Patients who fail conservative therapy and those with severe symptoms may be candidates for surgical decompression. This surgery is typically performed under local anesthesia with intravenous sedation. A one inch incision is made in the palm over the carpal ligament. The soft tissue is dissected to the level of the ligament and it is cut to relieve the pressure on the median nerve. This surgery is a short outpatient procedure with a very high success rate.