The doctor will ask about your symptoms and medical history. An examination of your neck, arms, wrists, and hands will be done. The physical exam will include tests of strength, sensation, and signs of nerve irritation or damage. The physical exam may include:
Phalen maneuver—Your wrists will be held fully flexed, usually one against the other, for about 60 seconds. The test is positive if it produces tingling and numbness in the hand.
Tinel's sign —The doctor will tap firmly on your wrist right over the carpal tunnel to see if it sends an electric shock feeling into your hand. You can also do this test yourself. Tap right over the creases on the inner side of your wrist between the two bones on either side of the base of your palm.
Compression test —Pressure is applied over your wrist for a minute or 2 to see if it causes tingling and numbness in your hand.
Other tests may include:
Nerve conduction study —The speed at which your nerves carry signals can be determined by stimulating them with tiny electrodes attached to special machines. If conduction is slowed through the carpal tunnel, you probably have a problem in the carpal tunnel.
Electromyogram (EMG) —In a similar fashion, tiny currents can be used to stimulate muscles. The muscles respond with electrical activity that can be measured. When the nerves connecting to muscles are damaged, the muscles give off abnormal signals.
X-rays, CT scan, and MRI scan —These imaging tests may identify other causes of carpal tunnel syndrome. They may also give more detailed information about your particular problem.
Ultrasound —An ultrasound uses sound waves to measure the diameter of the median nerve. It may be used as a screening test or to guide injections.
Arthroscopy —This procedure is useful in both diagnosing and treating carpal tunnel syndrome. This is a minor surgical procedure during which a thin, lighted tube (arthroscope) is inserted into your wrist. The surgeon can then look through the tube to see exactly what is wrong. The same tube can be used to repair the problem using tiny tools inserted through the arthroscope into the wrist.
Carpal tunnel syndrome. EBSCO DynaMed Plus website. Available at:http://www.dynamed.com/topics/dmp~AN~T113671/Carpal-tunnel-syndrome. Updated September 7, 2017.
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Fowler JR, Gaughan JP, Ilyas AM. The sensitivity and specificity of ultrasound for the diagnosis of carpal tunnel syndrome: a meta-analysis. Clin Orthop Relat Res. 2011;469(4):1089-94.
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Last reviewed September 2017 by EBSCO Medical Review Board James P. Cornell, MD Last Updated: 9/17/2014