Laser Acupuncture for Carpal Tunnel Syndrome

[Michael]

This information is provided in response to a request from the public for information on availability of an alternative therapy to treat the painful symptoms of Carpal Tunnel Syndrome (CTS) or Repetitive Strain Injury (RSI). It is not intended to replace medical advice.

1. About Carpal Tunnel Syndrome | Definition of Carpal Tunnel Syndrome (CTS)
2. Current Treatment for Carpal Tunnel Syndrome
3. Carpal Tunnel Syndrome Laser Acupuncture Research.
    The Purpose of this 4. Research Project
    Method used in this Research Project
    Results from this Research Project
    Conclusions and Summary for Future Research
4. Laser Acupuncture Frequently Asked Questions

[Michael]

About Carpal Tunnel Syndrome.
Definition of Carpal Tunnel Syndrome (CTS)Carpal Tunnel Syndrome (CTS) is an entrapment neuropathy of the median nerve at the wrist (Rosenbaum & Ochoa, 1993). In other words, the nerve that travels from one's arm to parts of the hand gets entrapped within the carpal tunnel. The carpal tunnel consists of some tissues (the transverse carpal ligament and 9 flexor tendons) that surround the median nerve as it passes through the wrist and palm area. If this median nerve gets compressed due, in part, to a repetitive stress, such as typing, then carpal tunnel syndrome is one disorder that may result.

Thus, CTS occurs when there is chronic pressure on the median nerve in the wrist area. Patients with CTS go to the doctor with pain in the wrist that radiates into the hand, and sometimes into the forearm; numbness and tingling in the thumb, index, and middle fingers; and weakness in the hand.

CTS occurs more commonly in workers whose tasks involve repetitive hand movements including computer keyboard operators. CTS is a particularly severe example of Repetitive Strain Injury (RSI).

A proposed definition of work-related CTS from the National Institute of Occupational Safety and Health (NIOSH) is provided in Table 1 (Matte et al., 1989). Patients who participate in this research project meet these NIOSH criteria for the diagnosis of CTS.

In 1988, the incidence of CTS was estimated to be 515 per 100,000 population (Occupational Disease Surveillance, 1989). Thus, it was estimated there were 1.3 million cases. In 1995, the U.S. National Center for Health Statistics estimated there were over 1.89 million cases of CTS in the U.S. Other debilitating forms of RSI are even more prevalent.

[Michael]

Current Treatment for Carpal Tunnel Syndrome.
In work-related CTS, a trial of abstinence from activities which incite the symptoms is tried, as well as analysis of work habits and tools (Feldman et al., 1987). The goal is to decrease exposure to provocative actions through patient education, as well as through appropriate ergonomic changes in the worksite area. The wrist may be splinted in a neutral position, especially at night and during activities that aggravate the symptoms.

Direct injection of steroids into the carpal tunnel may provide only temporary relief. After 2 to 4 months, between 65 and 90% of patients can be expected to have recurrence of symptoms (Slater, Jr. & Bynum, 1993). In one study, at 18 months after steroid injection, only 22% of patients were still free of symptoms (Gelberman, Aronson, Weisman, 1980).

In another study, only 11% of cases treated with steroid injection had permanent relief and these were the mildest cases in the series (Goodman & Foster, 1962). Operative release of the transverse carpal ligament is performed in approximately 40% of CTS cases, followed by a 2-3 month period of rehabilitation.

[Michael]

Carpal Tunnel Syndrome Laser Acupuncture Research.

The Purpose of this Research Project The purpose of this research project is to investigate whether red-beam low-energy laser and microamps TENS (painless transcutaneous electric nerve stimulation) can be used to stimulate acupuncture points on the hand, to treat the painful symptoms of CTS, under controlled research conditions. This research project uses a painless, non-invasive, non-surgical technique, which can also be applied by the patient him/herself, at home.

Method used in this Research Project. In the controlled research at the hospital, the patient's hand is treated behind a black curtain, and the patient does not know whether the laser beam and TENS devices are "on or off," because each device produces no feeling. The research at the hospital is a randomized, double-blind, placebo-controlled, cross-over design. There, patients receive 3 treatments per week (every other day), with 12 real and 12 sham treatments (each for 4 weeks), order randomized. Pre- and post-testing are performed with objective and subjective tests. These tests include nerve conduction studies; Melzack pain questionnaires; and hand strength and dexterity testing which are performed by hospital staff blind as to the treatment condition (real or sham).

In the controlled research at the hospital, various lasers are used, but limited space here does not permit discussion of all lasers. Some of these larger lasers include a 15 mW red-beam, helium neon laser, Dynatronics Model 1620; or a 50 mW infrared-beam, diode laser, 830 nm wavelength, Dynatronics Model 1650.

Results from this Research ProjectAs of November, 1996, seven patients had completed the treatment under controlled research conditions at the hospital. These seven patients had significant reduction in pain scores after the series of real treatments, but no significant reduction in pain scores after the series of sham treatments. Following the real treatment condition, the Melzack pain scores were significantly reduced (p <.02). For example, before the real treatments were started, the average pain score was 17.3 points (S.D., 10.3). After the real treatments were finished, the average pain score was only 5.4 points (S.D., 6.9). Following the sham treatment condition where the lasers and microamps TENS devices were taped into place on the patient's hand (but not turned on), the Melzack pain scores were not significantly reduced. Before the sham treatments were started, the average pain score was 16.9 points (S.D., 12.2). After the sham treatments were finished, the average pain score was 11.0 (S.D., 11.8 ).

Also, these seven patients treated under controlled research conditions at the hospital, had significant improvement in their nerve conduction studies after the series of real treatments, but no significant improvement in their nerve conduction studies after the series of sham treatments. Following the real treatment condition, the sensory latency of the median nerve across the wrist was significantly reduced (p <.05). In the real condition, five of the seven patients showed improved, shorter latencies following treatment; two patients showed no change. Before the real treatments were started, the average median nerve sensory latency was 4.8 msec (S.D., 1.3). After the real treatments were finished, the average sensory latency was 4.5 msec (S.D., 1.3). Following the sham treatment condition, the sensory latency of the median nerve across the wrist was not significantly reduced. In the sham condition, data were available for only six patients. Following sham treatment, only two of the six patients showed improved, shorter latencies; three patients showed no change and one patient showed an increased, longer latency. Before the sham treatments were started, the average median nerve sensory latency was 4.7 msec (S.D., 1.2). After the sham treatments were finished, the average median nerve sensory latency was 4.4 msec (S.D., 1.1).

All patients were able to resume prior work activities with less, or no pain, including keyboard typing, handyman work (cement laying, electrical wiring), and plumbing. At one year follow-up, one patient (who was diabetic and had had a stroke), had a return of hand pain.

These data indicate that after the series of real treatments, there was a significant reduction in pain, and the function of the sensory aspect of the median nerve became significantly "closer to normal." These significant changes were not observed following the series of sham treatments. Hence, it appears that the treatments with the real laser and microamps TENS devices are promoting a positive change in the patient's condition (not observed with the sham devices), and the placebo effect is being controlled for.

Conclusions and Summary for Future Research. Conclusions from this pilot study are that research should continue. If this treatment protocol is successful in relieving the painful symptoms of CTS, then workers who have CTS can be treated at home, in approximately four weeks (without medications or surgery) and return to work in a more timely manner, at a much lower cost.

[Michael]

Laser Acupuncture Frequently Asked Questions

Table 1. Proposed Definition of Work-Related Carpal Tunnel Syndrome National Institute of Occupational Safety and Health (NIOSH) (Matte et al., 1989)Criteria A, B, and C must be met:

A. Symptoms suggestive of CTS:

"paresthesia, hypoesthesia, pain or numbness affecting at least part of the median nerve distribution of the hand."

B. Objective findings consistent with CTS:

EITHER

One or more of the following physical findings:

Tinel's sign
Phalen's sign, or
"decreased or absent sensation to pin prick in the median nerve distribution of the hand."

OR

"Electrodiagnostic findings of median nerve dysfunction across the carpal tunnel."

C. Evidence of work relatedness:

One or more of the following:

Frequent, repetitive or forceful hand work on affected side
Sustained awkward hand position
Use of vibrating tools
Prolonged pressure over wrist or base of palm
Temporal relationship of symptoms to work or association with CTS in co-workers


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