Carpal Tunnel Syndrome is a disorder that affects the quality-of-life of a large portion of the population. Many patients suffer with carpal tunnel without realizing what their diagnosis really is, and what the treatment options are. Carpal tunnel syndrome has been associated with overuse type jobs. With the onset of the computer revolution, the keyboard has been a common source of blame for patients with carpal tunnel syndrome.
The symptoms of carpal tunnel include numbness and tingling in the hand. Specifically, the numbness and tingling involves the index finger, the long finger, the ring finger, and part of the thumb. This numbness, tingling, and burning are often associated with an aching pain that radiates into the forearm and occasionally even shoulder pain. The patients often complain that the symptoms awaken them from sleep at night. Many times they describe the sensation, when they awaken from sleep, with symptoms such as they need to shake their hand to make it “wake up.” If left untreated, carpal tunnel can progress to grip loss and atrophy of the hand muscles. When carpal tunnel symptoms begin, they are usually intermittent, but when left untreated they are typically progressive.
The underlying cause of carpal tunnel syndrome is compression of a nerve within the wrist called the Median Nerve. This nerve has 2 functions in the hand. First, it provides sensation to the index, long, and ring finger and portions of the thumb, thus resulting in the symptoms described above. Further, there is one branch of the Median Nerve that causes the muscles of the palm and thumb to function, and when affected it results in weakness in the hand and grip loss.
The anatomy of the carpal tunnel involves 9 tendons and a single nerve that traverse through a tunnel that has been named as the carpal tunnel. This tunnel is roughly located at the junction of the hand and wrist. The structure of the tunnel is a tight fibrous band of tissue that does not expand and will not accommodate for swelling. Because the canal does not have the ability to stretch, when swelling occurs within the tunnel it causes compression of the contents of the tunnel. The tendons tolerate this pressure, but the median nerve which traverses through the tunnel with the tendons does not. However, the cause of the swelling is usually from the tendons. The idea is that the tendons within the carpal tunnel become swollen from overuse. Each tendon is surrounded by a smooth slick layer called synovium, which when aggravated, it swells. It is this swelling that is the underlying cause of carpal tunnel and ultimately causes compression of the Median Nerve.
Evaluation of carpal tunnel syndrome occurs first with the physical exam. There are several specific physical exam findings that strongly indicate carpal tunnel syndrome. If physical exam findings are present, most physicians will proceed with a test called an EMG or nerve conduction velocity. This test is done by providing an impulse externally to the arm with electrodes that measure how fast impulse travels. If there is compression to a nerve such as in carpal tunnel syndrome, this will result in a positive test.
Treatment options for carpal tunnel include bracing. Bracing immobilizes the wrist and allows for the swelling within the carpal tunnel surrounding the tendons to improve with just simply rest. One issue that makes this less effective is that although we can immobilize the wrist itself, fingers still need to work. Some of the tendons traversing the canal, function to create movement within the fingers. So, despite bracing there is still motion within the carpal tunnel, and still a source for friction and swelling. However, bracing is effective and is a good option, especially early on. Anti-inflammatories also may be a good treatment option and function as a good adjunct to bracing.
Another conservative treatment option is to consider injection therapy. With this treatment, a steroid is injected directly into the carpal tunnel usually under needle guidance using ultrasound. The steroid acts as a very potent anti-inflammatory and reduces the swelling within the carpal tunnel. This takes pressure off the nerve and symptoms improve. Unfortunately, this may not be a permanent fix and often times symptoms will return. However it is a useful treatment option in some situations.
When conservative treatment fails, patients will likely be referred to an orthopedic surgeon for surgical treatment. The surgical treatment for carpal tunnel is an outpatient surgery which can be done under local or general anesthesia. Most surgeons prefer general anesthesia. A minimally invasive 2 cm incision is typically made over the base of the palm and wrist and the carpal tunnel is released. This effectively turns the tunnel into a trough. This does not affect the function of the contents of the canal but allows for release of pressure and removal of friction caused from the swelling within the canal. By removing the friction and pressure, the swelling resolves and the cycle of compression is stopped. Carpal tunnel surgery is extremely successful and most patients are able to return to full use of the hand within 3 weeks. Time off work is minimal, provided the patient can perform their work duties with minimal use of the operative hand for about 2-3 weeks. It is not uncommon for patients to have surgery on a Thursday or Friday, and return to limited duty work on Monday.
If you suffer from symptoms of carpal tunnel syndrome, I would encourage you to follow up with your orthopedic surgeon or your primary care doctor, and not ignore your symptoms. Without some type of treatment, your symptoms are likely to progress. However with treatment, there is a high rate of success and improvement in quality of life.
By: J. Patrick Boyett, DO – OrthoSports Athens, LLC