1. What is the carpal tunnel?
The carpal tunnel of the wrist houses the median nerve, which runs from the forearm into the hand, as well as nine tendons that bend the fingers and thumb. The floor and walls of the carpal tunnel are formed by the bones of the wrist. The roof is the transverse carpal ligament (TCL).
2. What is carpal tunnel syndrome?
Have you ever felt shooting pain through the wrist and up your arm while typing at the desk all day? Chances are you may have carpal tunnel syndrome (CTS). CTS is a common medical condition affecting 0.1% to 10% of the population. It is caused by progressive compression of the median nerve in the wrist. For example, the TCL can become thickened or the tendons can swell, or both.
3. What are the symptoms of carpal tunnel syndrome?
The symptoms gradually manifest, starting with pain, paresthesias (burning and tingling), itching, numbness or weakness in the hand and fingers, especially towards the thumb side of the hand. Sometimes sensations of electric-like shocks can travel up the arm toward the shoulder. Symptoms usually flare up at night. Most of us sleep with our wrists bent. Extreme flexion of the wrist will shrink the size of the carpal tunnel. Otherwise, during the daytime, CTS-like symptoms may occur when holding something or performing a task that inflicts repetitive stress to the wrist. Other symptoms range from clumsiness, to decreased grip strength, to visible muscle atrophy, to loss of feeling. Shaking out the hands often helps decrease the symptoms, but only temporarily. Since symptoms initially come and go, and there is no specific injury right away, many people wait too long to get proper diagnosis and treatment for the syndrome.
4. What are the causes of carpal tunnel syndrome?
It is often a combination of factors that cause an increase in pressure on the median nerve in the carpal tunnel. These factors include obesity, smoking, advanced age, swelling of the wrist (e.g., sprain or fracture), overactivity of the pituitary gland, hypothyroidism, diabetes, kidney disease, rheumatoid arthritis, mechanical joint problems, work stress, fluid retention during pregnancy or menopause, development of a cyst or tumor in the tunnel, or repeated motions over a long period of time (especially using vibrating hand tools). Even more than repetitive use, however, the most important factor is simply how you were born â the carpal tunnel is smaller in some people. Indeed, in 95% of cases, no apparent cause is found.
5. How is carpal tunnel syndrome diagnosed?
It is important to seek early diagnosis and treatment to avoid permanent damage to the median nerve. Routine tests and X-rays can identify diabetes, arthritis and fractures. Each finger is tested for sensation and the hands and wrists are examined for tenderness, swelling, warmth, atrophy and discoloration. In addition, a number of tests can be performed:
1. The Durkhan carpal tunnel compression test - Press down on the median nerve in the wrist to see if you feel numbness or tingling.
2. The Tinel test - Tap along the median nerve in the wrist to see if there is tingling or a shock-like sensation in the fingers.
3. The Phalen (wrist-flexion) maneuver - Hold out forearms with fingers down and backs of the hands together to see if you experience numbness or tingling within a minute.
Electrodiagnostic tests (nerve conduction studies and electromyography) can confirm the diagnosis. If there is a slowing of the nerve signal across the wrist, then the test is consistent with carpal tunnel syndrome.
