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What is carpal tunnel syndrome (CTS)?
Carpal tunnel syndrome is caused by irritation of the median nerve as it travels through the wrist. The median nerve originates at the spinal cord and travels through your arm and down to your fingers. It travels through the carpal tunnel which is a canal on the palmar side of your wrist. The carpal tunnel is about an inch wide and is surrounded by small (carpal) bones in the wrist and a roof made up of a thick band of connective tissue, the transverse carpal ligament. The median nerve along with the tendons that bend your fingers run through the carpal tunnel. Carpal tunnel syndrome begins when this tunnel narrows or tissues around the tendons and nerves begin to swell, putting increased pressure on the median nerve. This increased pressure on the nerve can cause weakness, pain, numbness, and tingling in the hand. The median nerve supplies feeling to your thumb, index, middle and ring finger which is why people with CTS often report numbness and tingling in this area.
What can increase the risk of carpal tunnel syndrome?
Carpal tunnel syndrome can be caused by a variety and combination of factors including:
Heredity: some people are born with a smaller carpal tunnel putting them at increased risk for compression
Repetitive hand use: completing activities that cause a lot of finger bending such as typing or gripping, can cause increased swelling in the tendons that cause carpal tunnel
Public Safety employees are at increased risk of developing carpal tunnel due to repetitive work-related tasks such as gripping equipment, motorcycle use, carrying heavy objects, and increased computer use that can trigger carpal tunnel.
Pregnancy: hormonal changes can cause increased swelling in the carpal tunnel
Trauma or injury to the wrist that can cause increased swelling and irritation of the median nerve
Health conditions associated with increased risk for carpal tunnel are diabetes, rheumatoid arthritis, and thyroid gland imbalances.
Women are three times more likely to develop carpal tunnel than men.
How is carpal tunnel syndrome diagnosed?
Patient reports pain and/or paresthesias (numbness and tingling) in the thumb, index, middle finger, half of the ring finger
X-rays can not diagnose carpal tunnel but can rule out arthritis or fractures that could be causing similar symptoms.
Your provider can perform the Phalen's test to help confirm carpal tunnel. This test involves maximal bending of wrists holding the backs of the hands together.
Tinel’s test involves tapping at the median nerve which can reproduce symptoms.
Patients often report relief in symptoms when they shake their wrist which is called the Flick Sign.
Nerve Conduction Velocity (NCV) studies assess the speed at which a nerve conducts an impulse and can measure the extent of nerve damage. Another test called electromyography involves inserting a small needle into your muscle which can measure the electrical activity of the median nerve.
An ultrasound can detect changes in the median nerve.
See your primary care provider to rule out other conditions or to seek treatment guidance.
How can you treat carpal tunnel syndrome?
Wearing a wrist brace that provides a neutral wrist position can reduce pressure on the carpal tunnel.
Improving your workstation by adjusting mouse and keyboard location can improve your body alignment and promote improved positioning of your carpal tunnel.
A physical therapist can design a customized treatment program including tendon gliding, stretches and nerve gliding exercises as well as use manual therapy and mobilities to improve symptoms.
Tendon Gliding Exercises example
Median Nerve Gliding example
Your doctor may prescribe a corticosteroid injection or oral medication to reduce swelling and irritation.
If symptoms do not resolve with conservative treatment, carpal tunnel decompression surgery may be an option.
References
Carpal tunnel syndrome - symptoms and treatment - orthoinfo - AAOS. OrthoInfo. https://orthoinfo.aaos.org/en/diseases--conditions/carpal-tunnel-syndrome/. Accessed December 23, 2021.
Huisstede BM, Hoogvliet P, Randsdorp MS, Glerum S, van Middelkoop M, Koes BW. Carpal tunnel syndrome. Part I: effectiveness of nonsurgical treatments--a systematic review. Arch Phys Med Rehabil. 2010;91(7):981-1004. doi:10.1016/j.apmr.2010.03.022
Wipperman J, Goerl K. Carpal Tunnel Syndrome: Diagnosis and Management. Am Fam Physician. 2016;94(12):993-999.