What is Carpal Tunnel Syndrome?
Carpal tunnel syndrome (CTS) is a common condition that can affect anyone who repetitively uses his or her forearms and hands. Symptoms include pain in the forearm and hand, and numbness in the thumb and first 3-4 fingers. Many people shake their hands awake in the morning. It is generally accepted that this condition is caused by repetitive hand and finger motion, leading to inflammation and swelling of tendons that go through the wrist canal. This theorized swelling and inflammation supposedly leads to compression of the median nerve at the wrist. Symptoms may include severe pain, and mild to severe numbness and tingling in the hand and fingers.
Treatment involves work and activity restriction, wrist braces worn at night, and cortisone injections into the wrist canal. Every year more than 500,000 people in the US undergo surgeries for carpal tunnel syndrome. In fact, surgery for CTS is among the most common hand surgery procedures. Sometimes the results are good, but often, the surgery leads to scar tissue, worsening symptoms and chronic disability.
Mechanism of Carpal tunnel syndrome
The theorized inflammatory cause of carpal tunnel syndrome is not supported by research. Indeed, when the tendon sheaths are closely examined during surgery, signs of inflammatory cells or reactions are not present. It makes more sense that carpal tunnel syndrome is really caused by a tightening of fascia in the upper extremity. The fascia is a tough tissue that runs contiguously between muscle fibers throughout the body.
Performing repetitive wrist motion requires a sustained contraction of the biceps muscle to keep the wrist still. Eventually, the upper extremity fascia tightens so much that the wrist ligament (called the transverse carpal ligament) also tightens— making the wrist canal smaller. This is the ligament that is cut and released during carpal tunnel surgery.
The primary nerve of the hand, the median nerve, passes right under this ligament. Adhesions or stickiness between the median nerve and the transverse carpal ligament can occur after surgery, and also occurs after trauma and with repetitive finger and wrist motion. The nerves and tendons to the fingers must be able to glide smoothly through the wrist canal, and any stickiness causes pulling on the nerve with finger and wrist motion. When the nerve does not smoothly glide under the ligament, movement of the fingers and wrist traumatizes the nerve and also causes carpal tunnel syndrome.
Rehabilitation of Carpal tunnel syndrome
Based on these mechanisms, we have developed a much different and highly effective approach to carpal tunnel syndrome. Our program starts with an office visit to examine the entire body. We frequently address issues going on with the upper extremity that may be contributing to symptoms of CTS.
We educate patients on important dietary changes, advising them to refrain from foods that cause inflammation and pain. We recommend vitamins to support nerve healing, and give instructions on how to stretch the entire upper extremity fascia from the chest to the wrist. Many people experience resolution of their carpal tunnel symptoms simply by adopting this program and maintaining the stretching program. This treatment alone often helps people maintain wrist health and avoid carpal tunnel surgery indefinitely.
If this conservative approach is not sufficient, the next step is a simple but delicate injection procedure under ultrasound guidance to separate the “stickiness” between the nerve and the transverse carpal ligament. The fluid in the injection serves to dilate the wrist canal and releases and separates the nerve from the tight ligament. The injection procedure causes some pressure and a “pinching” discomfort, but the discomfort is gone in a few minutes, and most symptoms resolve by the time patients leave the office.
Patients maintain the stretching program for as long as they remain at risk by their work activities, continue the nutritional supplements, and usually continue wearing their braces at night for a few days after the procedure.