Carpal Tunnel Syndrome

What is Carpal Tunnel Syndrome?

Carpal tunnel syndrome is a compressive neuropathy affecting the median nerve. Compressive neuropathy is characterized by a progressive injury to a nerve caused by pressure—either constant or intermittent—typically from surrounding soft tissues like muscles, ligaments and tendons. The median nerve relays nerve impulses from the hand and wrist along the arm, and it is commonly compressed at the carpal tunnel, which is formed at the wrist by the transverse carpal ligament. When this happens, the outer covering of the nerve, called the myelin sheath, is injured due to a lack of blood flow, reducing the nerves’ ability to conduct signals. Small nerve fibers, such as those that conduct light touch and temperature, are affected by compression of the median nerve first. If carpal tunnel syndrome progresses, the larger fibers, like those that conduct impulses to muscles, can be affected as well. Unfortunately, this condition is progressive: if left untreated, carpal tunnel syndrome will result in increased damage to the nerve until it no longer functions.

Symptoms & Causes

The most common symptoms of carpal tunnel syndrome are numbness and tingling in digits innervated by the median nerve—the thumb, index, long and half of the ring finger. This numbness and tingling may be especially present at night time, and can very often wake you up. Some patients also complain of weakness, loss of dexterity, and repeated instances of dropping objects. Pain can be present, but it is not always there; some people who suffer from carpal tunnel never experience pain outside of the discomfort of numbness and tingling.

Affected Populations

Carpal tunnel syndrome is the most common hand-related problem we treat. Despite it’s mythical status, the age-old idea that carpal tunnel syndrome is caused by typing has been disproven. Carpal tunnel syndrome is more accurately described as a disorder of aging. As we get older, our tissues become less compliant and therefore are less able to tolerate transient swelling (tendonitis) which can be aggravated by wrist position while sleeping. Sleeping with your wrists bent can cause irritation and swelling of the nerve, which will in turn increase the daytime symptoms of carpal tunnel syndrome. Furthermore, people with comorbidities like diabetes, thyroid disorders, rheumatoid arthritis and obesity are prone to carpal tunnel syndrome. Carpal tunnel syndrome can also present as a swelling-related complication of pregnancy, although it is relatively rare.

Treatment

There are a number of treatment options available to you, depending on how your carpal tunnel syndrome is graded. Mild carpal tunnel syndrome is often treated with nighttime splinting and reassessment at a later date to ensure there has been no progression of symptoms. Moderate and severe carpal tunnel syndrome often requires surgical intervention, known as carpal tunnel release (CTR). Unfortunately, there are many studies showing there is no significant benefit from steroid injections, therapy, ultrasound, or any other non-operative treatment for patients with moderate to severe carpal tunnel syndrome. We recently published an article in the Journal of Hand Surgery showing that those with moderate carpal tunnel syndrome have superior outcomes at any given time tested after surgery when compared to patients with severe carpal tunnel syndrome. This study also showed that if a patient has moderate carpal tunnel syndrome and has surgery the outcome is predictable, while those with severe carpal tunnel syndrome have a more unpredictable outcome.

Carpal Tunnel Syndrome