Q: For a few years I have had arthritis in my left wrist, and lately I have been experiencing numbness in fingers and thumb. It is difficult to pick things up or even turn the pages of a book. Is there anything I can do to get the feeling back in these fingers?
A: Numbness in thumb and fingers is a classic symptom of carpal tunnel syndrome, also known as CTS. Other symptoms include burning pain or tingling in the hand.
To understand CTS, you must first understand the wrist's anatomy. The bones of the wrist are called the carpal bones and, along with a ligament, they form a tunnel through which the median nerve and several tendons run. The median nerve is the one that supplies sensation to the thumb side of the hand; if the nerve becomes compressed within that tunnel, numbness in thumb and fingers can occur.
Several factors may have caused your median nerve to become compressed. Your longstanding arthritis could have caused spurs to form on the carpal bones, trapping the nerve and resulting in numbness of fingers. Any inflammation from your disease may also cause swelling within the carpal tunnel, which compresses the nerve. In fact, arthritis-related diseases, such as rheumatoid arthritis, gout and pseudogout, are common causes of CTS.
If you have one of these diseases, the way to treat carpal tunnel syndrome is to treat that underlying disease process. Often, however, CTS occurs in the absence of underlying disease. Sometimes, the cause of carpal tunnel syndrome is simply overuse of the wrist.
Treatment of carpal tunnel syndrome can include using wrist braces, especially at night; having periodic injections of steroids to reduce swelling; and avoiding activities that aggravate the symptoms. Although these measures generally work for a while and may offer lasting relief in some cases, more severe cases require surgery. An operation that involves opening the transverse carpal ligament and releasing the median nerve from entrapment can often relieve the symptoms.
In my opinion, the best thing you can do is discuss your symptoms and possible treatment options with your physician.
Tim Lambert, MD, Family Practitioner