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Carpal Tunnel Syndrome

Carpal Tunnel Syndrome | American Association of Neurological Surgeons

A Neurosurgeon Explains: Carpal Tunnel Syndrome

Lawrence M. Shuer, MD, FAANS

Carpal Tunnel Syndrome (CTS) is a common problem affecting hand function, caused by compression of the median nerve at the wrist. The carpal tunnel is formed by the multiple bones in the wrist and the transverse carpal ligament that forms the roof of the carpal tunnel. The median nerve and nine tendons run through the carpal tunnel. Carpal tunnel syndrome can result from inflammation and enlargement of the median nerve, inflammation and enlargement of the tendons, thickening of the transverse carpal ligament or by the presence of a mass lesion (for example, a tumor or cyst) within the carpal tunnel or a combination. Regardless of the direct cause, the end result is pressure on the median nerve and dysfunction.

The median nerve in the carpal tunnel supplies sensation to the thumb, index, middle finger and half of the ring finger (digits one through four) and provides motion to four muscles of the hand (the first and second lumbricals, opponens pollicis, abductor pollicis brevis and flexor pollicis brevis). The symptoms that are commonly associated with carpal tunnel syndrome result from abnormalities in these functions.

  • Hand and wrist pain
  • Burning and tingling in digits 1-4 (thumb, index, middle, ring fingers)
  • Numbness in digits 1-4
  • An electric-like shock through the wrist and hand
  • Reduced hand dexterity
  • Poor sleep quality due to hand tingling and/or numbness
  • Weakness, particularly of the thumb

These symptoms are often exaggerated when the wrist is bent forward, since this position increases pressure on the median nerve in the carpal tunnel. The numbness or pain may be worse at night and may keep patients awake or wake them from sleep. This is often the case because of hand/wrist position while sleeping. During the day, these symptoms may occur more often when participating in activities that bend the wrist (talking on the phone, driving).

 

Diseases or conditions that may increase the chances of developing CTS include broken or dislocation of wrist bones, pregnancy, diabetes, thyroid problems, menopause and/or obesity. Repetitive and forceful grasping with the hands or repetitive bending of the wrist may also contribute. Repetitive motions can cause significant swelling, thickening or irritation of the membranes around the tendons in the carpal tunnel, resulting in enlargement of the tendons and increased pressure on the median nerve. These repetitive movements include typing on a computer keyboard, talking on the phone (holding phone to the ear), texting or playing the piano. Professional artists (sculptors, printmakers, violinists) who engage in repetitive movements are frequently affected. Finally, jobs or hobbies requiring the use of vibratory tools (e.g., jack hammer) can place a person at risk of developing CTS symptoms.

 

It is important to seek medical assistance when experiencing persistent symptoms. Do not wait for the pain to become intolerable.

Before a doctor can recommend a course of treatment, they will perform a thorough evaluation of the condition, including a medical history, physical examination and often diagnostic testing. The doctor will document symptoms and ask about the extent to which these symptoms affect daily living. The physical examination includes assessments of sensation, strength and reflexes.

If nonsurgical treatment, such as medication, bracing or physical therapy, does not provide sufficient relief, the doctor may perform diagnostic studies to determine if surgery is an effective option.

These diagnostic studies may include:

  • X-ray: To look at the bones of the wrist to determine if any abnormalities may contribute to CTS.
  • Ultrasound: To evaluate the median nerve and assess for any mass lesions that may be present in the carpal tunnel.
  • Electromyogram and Nerve Conduction Study (EMG/NCS): To show how the nerves and muscles are working together. They measure the electrical impulse along nerve roots, peripheral nerves and muscle tissues.
 

The main purpose of treatment is to reduce or eliminate repetitive injury to the median nerve. In some cases, CTS can be treated with immobilizing the wrist in a splint to minimize or stop pressure on the nerve. If that does not work, some patients may benefit from anti-inflammatory medications, icing the wrist or possible steroid injection in the wrist to reduce swelling. Specific hand and wrist exercises may be helpful; rest may be helpful. Adjusting the environment to minimize or eliminate aggravating factors may be helpful. Treatment or maximizing management of medical disorders such as diabetes and thyroid problems, and/or weight loss, where appropriate, is in the patient's best interest and may improve symptoms. Physical therapy, along with avoidance of aggravating activities whenever able, may prove beneficial. Nonsurgical measures are often used for up to three months to see if they are effective in alleviating symptoms.

 

Only a small percentage of patients require surgery. Factors leading to surgery include the presence of persistent neurological symptoms and lack of response to conservative measures. If the patient experiences severe pain that cannot be relieved through rest, rehabilitation or nonsurgical management and/or there is significant weakness or numbness, he or she may be a candidate for one of several surgical procedures that can be performed to relieve pressure on the median nerve. The most common procedure is called carpal tunnel release, which can be performed using an open incision or endoscopic techniques.

The open incision procedure involves the surgeon opening the wrist and cutting the ligament that forms the roof of the carpal tunnel to relieve pressure. The endoscopic procedure involves smaller incision(s), using a miniaturized camera to assist in viewing the carpal tunnel. The possibility of nerve injury is slightly higher with endoscopic surgery, but the patient’s recovery and return to work may be quicker. The relatives advantages and disadvantages of each technique should be discussed with a doctor.

 

At the end of surgery, a dressing will be applied to the patient's hand. He or she may require extra assistance at home with every-day activities, because the postop hand will need to be protected while healing. For good healing, avoid wetness on the stitches and skin. Stitches are removed about two weeks after surgery. Avoid both repetitive use of the hand and hyperextension of the wrist for one month after surgery. Pain and numbness often improve soon after surgery; tenderness in the area of the incision for several months is common. A majority of patients recover completely.

Recurrence of symptoms after surgery for CTS is rare, occurring in less than 5% of patients. To avoid recurring injury, it may help to change the way repetitive movements are performed, the frequency with which such movements are performed and the amount of time spent resting between periods when these movements must be performed.

AANS Patient Pages are edited by neurosurgical professionals. This page has been edited by:

Lawrence M. Shuer, MD, FAANS

Thomas J. Wilson, MD

The AANS does not endorse any treatments, procedures, products or physicians referenced in these patient fact sheets. The information provided is an educational service and is not intended to serve as medical advice. Anyone seeking specific neurosurgical advice or assistance should consult his or her neurosurgeon, or locate one in your area through the AANS Find a Board-certified Neurosurgeon online tool.

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