Carpal tunnel syndrome is essentially a pinched nerve in the wrist. There is a space in the wrist called the carpal tunnel where the median nerve and nine tendons pass from the forearm into the hand (Figure 1). Carpal tunnel syndrome happens when swelling in this tunnel puts pressure on the nerve.
Pressure on the nerve can happen several ways, including:
Swelling of the lining of the flexor tendons, called tenosynovitis
Fluid build-up during pregnancy
The scenarios listed above can narrow the carpal tunnel or cause swelling in the tunnel. Thyroid conditions, rheumatoid arthritis and diabetes can also be associated with carpal tunnel syndrome. Ultimately, there can be many causes of this condition.
Symptoms of this condition can include:
Tendency to drop things
The numbness or tingling most often takes place in the thumb, index, middle and ring fingers. The symptoms usually are felt during the night but may also be noticed during daily activities such as driving or reading a newspaper. In bad cases, sensation and strength may be permanently lost.
Treatment includes manipulation, ultrasound, and stretching to reduce inflammation and allow adequate space for the nerve.
Changing patterns of hand use (helps reduce pressure on the nerve)
Keeping the wrist splinted in a straight position (helps reduce pressure on the nerve)
Wearing wrist splints at night (helps relieve symptoms that may prevent sleep)
Steroid injections into the carpal tunnel (helps reduce swelling around the nerve)
When symptoms are severe or do not improve, surgery may be needed to make more room for the nerve. Pressure on the nerve is decreased by cutting the ligament that forms the top of the tunnel on the palm side of the hand (Figure 2). Following surgery, soreness around the cut area may last for several weeks or months. The numbness and tingling may disappear quickly or slowly. Recovery may take several months. Carpal tunnel symptoms may not completely go away after surgery, especially in severe cases.