Carpal tunnel syndrome is caused by pressure on the median nerve, which runs through the carpal tunnel, a narrow passage on the palm side of the wrist. The median nerve enervates the hand and fingers, so pressure on that nerve causes numbness, tingling, and weakness in the hand. The best tests for carpal tunnel are electrodiagnostic tests, which use electrical impulses to measure muscle strength and nerve conduction.
Electromyography tests for carpal tunnel syndrome are tests where conductive wires are used to measure the electrical signals in the muscles. These electrical signals show whether or not there is muscle damage in the hand and fingers due to carpal tunnel. Another electrodiagnostic test is a nerve conduction study. In this test, an electrical signal is sent through the median nerve. The speed of this signal is measured as it passes through the carpal tunnel to see if there is any pressure on or damage to the nerve in that area.
While these electrodiagnostic tests for carpal tunnel are very useful, there are factors that can limit their accuracy. Factors like age or obesity can change the speed of nerve impulses, making nerve conduction studies difficult. The benefit of these tests, however, is that they can rule out other problems that cause carpal tunnel symptoms. Pinched nerves in other parts of the body, such as the neck, can also cause numbness and tingling in the hand and fingers.
Physical tests for carpal tunnel can also be useful. For example, a physician may put pressure on the median nerve by bending the wrist or gently pressing on the nerve to see if this produces symptoms. He or she may also test the feeling in the fingers and the strength of the hand, as both can be affected by carpal tunnel.
The timing of hand and finger symptoms is another one of the tests for carpal tunnel. If symptoms occur during activities where the wrist is bent, such as prolonged use of a computer, then carpal tunnel syndrome is a likely cause. Carpal tunnel symptoms can also occur while gripping a steering wheel or holding a telephone.
There are a few simple treatments for carpal tunnel syndrome. Non-steroidal anti-inflammatory drugs (NSAIDs) can provide symptom relief, especially if a person is experiencing pain in his or her hands. Wearing a wrist splint to hold the wrist straight during sleep can also help relieve mild carpal tunnel symptoms.