CARPAL TUNNEL SYNDROME
Carpal Tunnel Syndrome (CTS) is condition where a nerve is compressed as it enters the hand near the base of the palm. When the nerve gets compressed, people experience a variety of symptoms including numbness, tingling, pain and weakness of the hand. The symptoms are often brought on by repetitive or prolonged hand activity. Frequently, people with CTS will notice that their hand gets numb or painful at night, causing them to wake up. Some will notice numbness when they first wake up in the morning. In more advanced cases, some degree of numbness or tingling may be present constantly.
The particular nerve involved is called the median nerve. It provides the feeling to the thumb, index, middle and ring fingers as well as the signal to move many of the muscles of the thumb. The median nerve (along with the tendons that make the fingers and thumb bend) enters the hand near the base of the palm through what is known at the carpal tunnel. The floor of the tunnel is made up of the bones at the base of the hand (carpal bones) that form a “U” shaped arch. The roof of the tunnel is a thick ligament that spans from one side of the “U” to the other.
The exact cause of CTS is not known, but ultimately comes down to a balance between the size of the tunnel versus the thickness of the structures passing through the tunnel. When the tissues are too thick (from inflammation of the finger tendons, for example), the tunnel becomes too tight and the nerve gets squeezed. CTS tends to be slightly more common in women, more common as we get older, and very common in certain diseases such as diabetes.
For patients with mild symptoms (occasional numbness without major impact on function), simply reducing repetitive activity or taking more frequent breaks to rest and stretch may be enough to keep things under control. Anti-inflammatory medications might be helpful to settle down a short-term flare up. If the night-time numbness is the main issue, wrist braces worn while sleeping can often keep people comfortable. Braces (available at your local pharmacy) can counteract the additional kinking and compression of the nerve that commonly occurs when the wrists are bent while sleeping. If a person has CTS for a short-term reason (pregnancy is a common example), steroid (“cortisone”) injections are sometimes considered. Even in pregnancy, a steroid injection can safely decrease the swelling of the tissues in the tunnel until the body gets back to normal.
If symptoms are not adequately controlled with the above treatments, consideration is sometimes made for surgery. Although many surgical techniques exist, they all aim to divide the roof of the tunnel to create more space. The roof of the tunnel does eventually heal back together, but in a more relaxed position similar to loosening the laces of a tight shoe. The surgery is a very safe and is typically done as an outpatient procedure that does not require general anesthesia. For most people, the surgery only needs to be done once.