Hand and Wrist

Carpal Tunnel Syndrome

Anatomy

The carpal tunnel is a structure in the wrist shaped like a narrow tunnel. The bottom and sides are formed by wrist (carpal) bones and the top is covered by a strong band of connective tissue called the transverse carpal ligament. The median nerve controls feeling in the palm side of the thumb, index finger and long fingers, as well as the muscles around the base of the thumb. The flexor tendons are what bend the fingers and thumb. Tissues surrounding the flexor tendons in the wrist are called the synovium. The synovium lubricates the tendons, making finger movement easier. The carpal tunnel protects both the median nerve as it travels from the forearm into the hand, and the flexor tendons.

Symptoms

Common symptoms are: numbness, tingling and pain in the hand; a sensation similar to an electric shock, felt mostly in the thumb, index and long fingers; and strange sensations and pain traveling up the arm toward the shoulder. Symptoms are often more severe on the thumb side of the hand. Symptoms typically begin gradually and may come and go at first, growing more constant over time. During the day, symptoms often occur when holding a small object like a phone, turning pages of a book, gripping a steering wheel, or other simple daily tasks. A feeling of weakness or clumsiness may cause you to drop things or have problems with delicate motions, like buttoning a shirt. If you are one of the many people that sleep with your wrists curled, your symptoms may awaken you at night. Simply moving or shaking your hands often helps to decrease the intensity of symptoms. If the condition is severe, muscles at the base of the thumb may appear visibly flatter or smaller, atrophied, or wasted.

Causes

When something causes the synovium to swell, that swelling narrows the confined space inside the carpal tunnel, putting pressure on the median nerve and causing numbness and pain in the hand. This is carpal tunnel syndrome. Many things can lead to development of carpal tunnel syndrome, and in most cases, there is no single cause. Contributing factors may include: heredity (smaller carpal tunnels can be a family trait); hormonal changes due to pregnancy; age; medical conditions (such as diabetes, rheumatoid arthritis, and thyroid gland imbalance); and hand use over time, such as repeated tasks performed during work or sports.

Diagnosis

In addition to talking with you about your symptoms, activities and medical history, your physician may perform a variety of physical tests, such as: checking for muscle weakness at the base of the thumb; testing for numbness or tingling in the fingers and hands by pressing down on, or tapping along the median nerve, and bending and holding your wrists in position; and having you close your eyes before lightly touching your fingers to test their sensitivity. X-rays are sometimes used, and electrophysiological testing may be performed to help confirm the diagnosis and preferred treatment for your situation.

Nonsurgical Treatment

For many people, carpal tunnel syndrome can be relieved without surgery, particularly when the symptoms are the result of a particular activity that can be modified or discontinued. Without some form of treatment, however, symptoms usually grow progressively worse.

• Bracing or splinting—Worn at night, a brace or splint holds the wrist in a neutral position, preventing the nightly irritation to the median nerve that occurs when wrists are curled during sleep. Splints can also be helpful when worn during other daily activities that aggravate symptoms.
• Activity changes—Altering patterns of hand use can help you avoid positions that aggravate the condition. When work requirements cause symptoms, changing or modifying the job may occasionally help the symptoms to improve.
• Medications and steroids—Over-the-counter anti-inflammatory drugs (NSAIDS), such as aspirin or ibuprofen may be used to ease pain. For more severe symptoms, corticosteroid injections occasionally provide temporary relief.
• Physical therapy—Your physician or physical therapist may prescribe specific exercises to help you improve strength and flexibility, restore movement, and provide relief from uncomfortable symptoms. Physical therapy is often a key factor in successfully recovering from a wide range of conditions and disorders.

Surgery

Surgery may be appropriate when nonsurgical treatments do not offer relief, or in severe cases where nonsurgical options are unlikely to help. Severe, long-standing cases with constant numbness and wasting of thumb muscles may already have led to permanent damage to the nerve, and in these cases, full recovery or complete resolution of symptoms is less predictable, even with surgical treatment.

• Surgical techniques—This procedure is usually performed on an outpatient basis under local anesthesia. During traditional surgery, a cut is made in the palm and the roof of the carpal tunnel (the transverse carpal ligament) is divided to increase the size of the tunnel and decrease pressure on the nerve. After surgery, the new growth heals and grows across the division, allowing more space for the median nerve and flexor tendons. When the endoscopic technique is used, the surgeon makes a small incision in the skin and inserts a small camera (called an endoscope), making it possible to cut the ligament from inside the carpal tunnel and potentially reducing recovery time. Both traditional and endoscopic procedures offer the same results and your physician will recommend the surgery most appropriate for you.

Recovery

Following surgery, you will be instructed to frequently elevate your hand above your heart and move your fingers to reduce swelling and prevent stiffness, however some pain, swelling and stiffness should be expected. You may use your hand normally, but with caution, and you may be required to wear a wrist brace for up to three weeks. Minor soreness of the palm is common for several months after surgery, and weakness of pinch and grip may persist for as long as six months. Driving, self-care activities, light lifting and gripping may be permitted soon after surgery. Your doctor will determine when you can return to work and if there should be restrictions on your work activities.

Long-term Outcomes

Grip and pinch strength usually return after about two months, and complete recovery may take as long as a year. If significant pain and weakness persists for more than two months, your physician may have you work with a hand therapist. In long-standing cases with severe loss of feeling and/or muscle wasting around the base of the thumb, recovery is slower and may not be complete. Recovery can be gradual after surgery, but most patients experience an improvement in symptoms. Carpal tunnel syndrome can occasionally recur, requiring additional surgery.