Many people are familiar with carpal tunnel syndrome (CTS) as a condition caused by repetitive stress injuries such as working with vibrating tools, heavy manual labor, and even less impactful but repeated movements such as typing. Within these categories, carpal tunnel syndrome is often a workplace injury. What is less well known, however, is traumatic carpal tunnel syndrome that can be triggered by a single injury to the hand or wrist from an event such as a motor vehicle collision, a sports injury, or a slip-and-fall injury.
Carpal tunnel syndrome in general results from compressing the median nerve where it passes through the wrist in the passage known as the “carpal tunnel.” This compression of the nerve can result in pain, tingling (paresthesias), and numbness in the fingers — thumb, index finger, middle finger, and part of the ring finger — and parts of the hand that are served by the median nerve, and in chronic or severe cases even much more serious symptoms such as muscle wasting. (There are also some non-trauma causes of CTS including arthritis, diabetes, certain drug reactions, or growths within the wrist — these can cause the same pressure on the median nerve that is associated with single traumatic and repetitive injury causes.)
Traumatic carpal tunnel syndrome — as well as the non-traumatic versions — is generally diagnosed based upon the reported symptoms and certain classic “signs” for the disease. Phalen’s Maneuver, for example, involves flexing the wrist and holding it in position — when pain or numbness appears within one minute in the fingers innervated by the median nerve, it is considered a positive sign, and the fast the symptoms appear the “more positive” the result is considered to be. Another test involves Tinel’s Sign in which the skin is gently tapped over the ligament band that forms part of the carpal tunnel. If this produces pain or tingling in the fingers of the median nerve distrution, the test is positive. Electrodiagnostic testing that examines the conductivity of the median nerve may often be used to confirm a suspected case of carpal tunnel syndrome.