Overview Of Carpal Tunnel Syndrome
Carpal tunnel syndrome (CTS) occurs when the median nerve, which runs from the forearm into the palm of the hand, becomes pressed or squeezed at the wrist. The carpal tunnel—a narrow, rigid passageway of ligament and bones at the base of the hand—houses the median nerve and the tendons that bend the fingers. The median nerve provides feeling to the palm side of the thumb and the index, middle, and part of the ring fingers (although not the little finger). It also controls some small muscles at the base of the thumb.
Sometimes, thickening from the lining of irritated tendons or other swelling narrows the tunnel and compresses the median nerve. The result may be numbness, weakness, or sometimes pain in the hand and wrist (some people may feel pain in the forearm and arm). CTS is the most common and widely known of the entrapment neuropathies, in which one of the body’s peripheral nerves is pressed on or squeezed.
Causes Of Carpal Tunnel Syndrome
The median nerve provides feeling and movement to the thumb side of the hand. This includes the palm, thumb, index finger, middle finger, and thumb side of the ring finger.
The area in your wrist where the nerve enters the hand is called the carpal tunnel. This tunnel is normally narrow. Any swelling can pinch the nerve and cause pain, numbness, tingling, or weakness. This is called carpal tunnel syndrome.
Some people who develop carpal tunnel syndrome were born with a small carpal tunnel.
Carpal tunnel syndrome can also be caused by making the same hand and wrist motion over and over. Using hand tools that vibrate may also lead to carpal tunnel syndrome.
Studies have not proved that carpal tunnel is caused by typing on a computer, using a mouse, or repeating movements while working, playing a musical instrument, or playing sports. But, these activities may cause tendinitis or bursitis in the hand, which can narrow the carpal tunnel and lead to symptoms.
Carpal tunnel syndrome occurs most often in people ages 30 to 60. It is more common in women than men.
Other factors that may lead to carpal tunnel syndrome include:
- Alcohol use
- Bone fractures and arthritis of the wrist
- Cyst or tumor that grows in the wrist
- If your body keeps extra fluids during pregnancy or menopause
- Rheumatoid arthritis
- Diseases that have abnormal deposits of protein in the body (amyloidosis)
Symptoms Of Carpal Tunnel Syndrome
The symptoms are usually found along the nerve path because of the compression of the median nerve. The hand may “fall asleep” frequently and drop objects.
Other symptoms include:
• numbness, tingling, and pain in the thumb and the first three fingers of the hand.
•pain and burning that travels up the arm.
•wrist pain at night that interferes with sleep.
•weakness in the muscles of the hand.
These symptoms often start slowly and come and go. They’re usually worse at night.
Treatment Of Carpal Tunnel Syndrome
Treatment may include:
• Splinting the hand. This helps keep the wrist from moving. It also eases the compression of the nerves inside the tunnel.
• Anti-inflammatory medication. These may be oral or injected into the carpal tunnel space. These reduce the swelling.
• Surgery. This eases compression on the nerves in the carpal tunnel.
• Worksite changes. Changing the position of the computer keyboard or making other ergonomic changes can help ease symptoms.
• Exercise. Stretching and strengthening exercises can be helpful in people whose symptoms have gotten better. These exercises may be supervised by a physical or occupational therapist.
Exams and Tests
During a physical exam, your health care provider may find:
- Numbness in the palm, thumb, index finger, middle finger, and thumb side of your ring finger
- Weak hand grip
- Tapping over the median nerve at your wrist may cause pain to shoot from your wrist to your hand (this is called the Tinel sign)
- Bending your wrist forward all the way for 60 seconds will usually result in numbness, tingling, or weakness (this is called the Phalen test)
Tests that may be ordered include:
- Wrist x-rays to rule out other problems, such as arthritis in your wrist
- Electromyography (EMG, a test to check muscles and the nerves that control them)
- Nerve conduction velocity (a test to see how fast electrical signals move through a nerve)