Carpal Tunnel

Carpal Tunnel syndrome (CTS) occurs when a large nerve—the median nerve—becomes entrapped at the wrist. This nerve runs from the arm into the hand through a small tunnel at the wrist called the carpal tunnel. The median nerve supplies sensation to the inside portion of the thumb, index, and middle fingers in most individuals and also to some fibers that control strength in the thumb.

A thick ligament that makes up part of this tunnel can sometimes become too thick and can compress the nerve. When the nerve is compressed, it becomes irritated and painful, and its function can be affected.

Carpal Tunnel is the most common nerve entrapment syndrome.

There are many conditions that can foster carpal tunnel syndrome such as rheumatoid arthritis, B6 deficiency, diabetes and genetics. But it is often caused by repetitive motion injuries that involve frequent bending or pounding of the wrist. Pregnant women often develop CTS but, in the majority of these cases, it disappears weeks or months after giving birth.


Carpal tunnel syndrome is a collection of symptoms rather than a distinct disease with a single mechanism or course.

Symptoms usually appear gradually in the wrist and hands and include:

  • Numbness
  • Pain in the wrists that may radiate through the forearm to the hand
  • Tingling sensation in the index, middle, and ring fingers, and sometimes the thumb
  • Weakness

Numbness can appear suddenly—for example, when you're driving a car with your hand on the steering wheel. If you shake your hand and the sensation returns reasonably quickly, you may have only mild CTS.

If those tingly sensations increase in duration for minutes or hours at a time, or they wake you up every night or maybe multiple times per night, it's time to seek medical care. It is very important to get help before damage to the median nerve becomes permanent.


Carpal tunnel syndrome is diagnosed by patient history, careful neurologic exam, and a Nerve Conduction Velocity (NCV) test — a standard tool used in evaluating CTS.

During the NCV test, a very small electrical stimulus is applied to the median nerve, then is recorded at another point once it crosses the wrist. The speed and strength of this electrical signal can indicate whether there is damage to the nerve and, if so, how severe.

Neurologists may also perform an electromyography (EMG) test, which involves inserting a very small needle into the muscles of the arm and hand to record electrical activity.

Both the NCV and the EMG help rule out other conditions and ensure that no other nerve is to blame—an important consideration that affects treatment.

Conservative treatment, typically nonsteroidal anti-inflammatory drugs and a wrist splint, is usually tried first. Your neurologist may also suggest some specific hand exercises that could help.

After that, the neurologist may suggest a steroid injection. Steroids can remove some buildup of fluid or swelling in the soft tissues and relieve symptoms permanently or for several months. However, repeated use of steroids may be counterproductive in the long run, as they often simply delay rather than eliminate the need for more definitive treatment.

The next likely step for patients who fail to improve with conservative therapy is carpal tunnel release surgery.

This operation expands the tunnel and creates more room for the nerve and tendon and, thus, removes the pressure on the median nerve. It is fairly simple and has relatively few complications, but still needs to be carefully discussed and considered.

Is there anything I can do to prevent Carpal Tunnel Syndrome?

Fortunately, most risk factors for CTS are within people's control. Experts suggest:

  • Making your workspace more ergonomic:
    • If possible, use ergonomic keyboards, keyboard trays, and adjustable chairs to help stabilize your wrist in a neutral position, with a little extension, elbows at 90 degrees, and shoulders relaxed.
  • Keeping your weight down
  • Gripping less forcefully
  • Seeing a doctor if you're at risk for type 2 diabetes
  • Yoga has been proven to be effective in improving some carpal tunnel symptoms, including loss of function.

This information was provided by the specialists at Semmes Murphey Clinic and the American Academy of Neurology. Readers are encouraged to research trustworthy organizations for information. Please talk with your physician for websites and sources that will enhance your knowledge and understanding of this issue and its treatments.

If you experience prolonged wrist or hand pain, tingling or numbness which is not alleviated by over-the-counter pain relievers, it’s time to see one of the neurologists at Semmes Murphey Clinic.

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