WHAT is Carpal Tunnel Syndrome (CTS)? CTS occurs when pressure is applied to the median nerve which travels from the neck, through the shoulder, upper arm, elbow, forearm, and through the carpal tunnel where the “pinch” is located. The median nerve innervates most of the palm of the hand, the thumb, the index finger, middle finger, and the thumb side of the ring finger. The carpal tunnel is made up of eight little bones in the wrist that form the arch and a ligament that forms the floor. There are nine muscle tendons, the median nerve, as well as blood vessels that travel through the tunnel.
WHAT are the symptoms of CTS? The “classic” symptoms include burning, itching, tingling, and/or numbness of the second to fourth fingers with the need to shake or “flick” the fingers to “wake up the hand.” When present long enough, or when the pressure is hard enough on the nerve, weakness in the grip occurs and accidental dropping of tools, coffee cups, and so on can occur. Pressure on the nerve increases when the wrist is bent backwards or forwards, especially for long time frames and/or when the wrist is moving in a fast, repetitive manner with jobs like carpentry using vibrating tools, a screw driver, hand drill, a hammer, line production work, waitressing, and so on. Often, symptoms are first noticed at night, as we tend to sleep with our wrists bent and tucked under our chin or neck. Symptoms can also occur during the day, especially when driving or when performing repetitive work. Difficulties buttoning a shirt, making a fist, grasping small objects and/or performing manual tasks are common complaints of CTS.
WHAT are some causes of CTS? CTS is most commonly caused by a combination of factors that result in swelling of the tendons that travel through the carpal tunnel. This includes over working the arm and hand in any of the jobs described above, but it is more likely to happen when conditions that create generalized swelling occur. Some of these conditions include trauma (like a sprained wrist), hypothyroidism, an over-active pituitary gland, during menstruation or pregnancy, menopause, rheumatoid arthritis, diabetes, mechanical wrist problems, repetitious work (work stress), or the repeated use of vibratory hand tools. It is also possible to develop a cyst (like a ganglion) or a fatty tumor within the tunnel. CTS is also more common with obesity, but sometimes, no logical cause can be identified!
WHO is at risk of developing CTS? Women are three to four times more likely to develop CTS. This may be because of the hormonal aspects described above and/or the relative smaller wrist, which results in a smaller carpal tunnel. There’s also an increased risk of CTS in people over the age of 50. Other at risk individuals include diabetics, people with hormonal imbalances (taking birth control pills, pregnancy, hypothyroid, etc.), and people who work on assembly lines.
How is CTS diagnosed? EARLY diagnosis and treatment is KEY to a successful outcome! The physical exam includes assessing the structures of the neck and entire upper extremity, as the pinch is often in more than one place. A blood test for thyroid disease, diabetes, and rheumatoid arthritis is also practical. Other tests that may help us diagnose CTS can include and EMG (nerve test) and/or x-ray/MRI. Next month, we’ll discuss treatment and prevention!