Causes of carpal tunnel syndrome 'somewhat mysterious'

By CARREN BERSCH

Feeling Fit Correspondent

Stephen Helgemo, Jr., MD, of the Florida Hand Center located in Port Charlotte, has dedicated his practice to conditions affecting arms, wrists and hands and to restoration of their functions. Of his specialties, he explained, "The actual cause of carpal tunnel syndrome (CTS) is not clearly understood. Diabetes, hypothyroidism and arthritis are risk factors for the development of CTS -- but not direct causes." Repetitive motion is not thought to be a cause either, he said, but it might be an aggravating factor in some cases.

"We successfully treat CTS in large numbers of people that have no risk factors. What people perceive or do not perceive as causes for CTS presents a barrier for people when doctors and patients consider the diagnosis," Helgemo explained.

According to the doctor, CTS appears to develop through an interaction of two basic factors. The first is susceptibility which is determined through a poorly understood combination of genetics: "How your wrist is 'assembled,'" he said, and comorbid conditions: "Like diabetes."

The other factor is some type of exposure.

That could be occupational or from a hobby, like needlework, Helgemo said. For example, one person may be very susceptible (i.e., small wrists, diabetes, obesity) and require little or no exposure to develop CTS, while another may have very little susceptibility and not develop CTS with similar exposure factors.

"This provides an explanation," Helegemo explained, "as to why a person who does a 'repetitive' activity for years on end at high intensity and develops no hand problems compared to someone else who does a new activity for a relatively short time and has disabling symptoms."

He added, "CTS incidence rises with age, but we are not certain the precise reason. The incidence of risk factors such as arthritis also rises with age, but there are other things that change with age as well -- like tendons and the neurologic system itself."

Like many other musculoskeletal problems, CTS is more common in women.

"There are no 'advances' in diagnosing CTS, but by combining a detailed and specific look at symptoms, a focused physical examination and judicious use with careful interpretation of nerve tests, we are able to accurately diagnose and treat CTS with greater than 95 percent patient satisfaction," Helgemo said. "It is ultimately a clinical diagnosis that involves a well-thought out look at the big picture. The carpal compression test is highly accurate in our office, as well as in clinical studies, with sensitivity and specificity both more than 90 percent."

Several groups have looked at treatment for CTS, he said, including the Cochrane group (an independent group) and the American Academy of Orthopedic Surgeons. Their conclusions regarding the effectiveness of available treatments were that, although many methods are used, few are consistently effective. The "best" nonsurgical care is bracing, and steroid injections are at best 50 percent effective and do not usually give permanent relief. Surgical release is the only consistent, long-lasting method for established CTS.

"We use nonsurgical treatment judiciously," Helgemo said, "as sometimes it may result in patients tolerating symptoms longer which may lead to permanent nerve damage."

In most studies, he said, and in his own practice, most patients end up needing surgery. "Because of our large experience with surgery," he said, "it represents the safest treatment option because of its ability to reliably relieve the symptoms and prevent permanent nerve deterioration with minimal potential risks."

When asked about the risk of today's repetitive-motion computer activities, Helgemo said CTS is a topic replete with controversy. The Mayo Clinic's conclusions that repetitive activities do not cause CTS appear to be gathering more support in the literature as well as in clinical practice.

"From a conceptual standpoint, it may seem that improper keyboarding or excessive gaming, for example, may lead to problems; but as of yet, this has not been frequently observed in our practice."

Other factors such as obesity and diabetes, he noted, appear to play a larger role. As the frequency and intensity of these 21st-century activities continue, however, more may be revealed.

In general, Helgemo concluded, "anything that leads to pain when done excessively, especially over long period of time, may cause problems with the musculoskeletal system."

Helgemo is board-certified in orthopedics and hand surgery. Learn more about his practice at www.floridahandcenter.com/treatments/carpal-tunnel-syndrome.