Acupuncturists See The Light, Go High Tech

By Narda Robinson, DO, DVM

A move is afoot across the globe to make acupuncture high tech.1 As stated by acupuncture’s most innovative researcher, Gerhard Litscher, "[N]ovel biomedical and neuroscientific methods are of paramount importance for the fast and efficient modernization of the ancient Asian healing method.”2

By bringing modern biomedical engineering technology to the field, Litscher propelled enthusiasm for the quantification of biologic responses to a host of interventions, including electroacupuncture, needle stimulation and now, laser activation.3

A 2008 systematic review of laser acupuncture research found evidence to support its application for myofascial pain, postoperative nausea and vomiting, and the alleviation of chronic tension headache.4 

Lasers

"Laser acupuncture” shines laser light into acupuncture points instead of inserting needles. While any laser therapy unit may be used for laser acupuncture, the high-tech acupuncture laboratory at the Medical University of Graz, Austria, has studied multichannel laser needle acupuncture, which allows for the stimulation of several acupuncture points simultaneously by multiple semiconductor injection laser diodes. 

Flexible optical fibers deliver the light to the site with minimal loss of intensity. Power density may reach 20 joules/cm2 per acupuncture points, with 30-40mW per needle, and 500 micron diameter spot size.5 Emission wavelengths vary, but have included 685 nm, 785 nm, and now violet laser (which appears blue to our eyes) at 405 nm.

In contrast to typical laser therapy treatments that target mainly injured areas, laser acupuncturists employ an equal or greater number of nonlocal sites.

In so doing, they recruit a variety of neural networks and fascial connections for participation in the healing process.6-9

For example, standard laser therapy approaches to temporomandibular joint (TMJ) disorders typically focus on the TMJ and/or muscles of mastication.10 In contrast, laser acupuncture for TMJ dysfunction may direct light to points on the forehead, hand, foot and leg in addition to the TMJ region.11,12
 
Although seemingly unrelated and extraneous to a laser therapist, this type of expanded treatment makes scientific sense to a medical acupuncturist. What’s more, an acupuncture-informed approach to laser therapy extends its clinical reach to a host of systemic and autonomic disorders, such as hypertension, depression and neuroendocrine dysfunction.13-16

Noninvasive Procedure

Laser acupuncture has many advantages over traditional needling. Its noninvasive nature raises the already high safety profile of acupuncture, aside from the risk of inadvertent, unprotected ocular exposure. Patients, especially young ones,17,18 may more readily accept laser treatment, especially when approaches aim at sensitive sites on the face, ear or perineum. Infrared heating offers an alternative to moxibustion, i.e., the burning of an herb near acupuncture points.19,20

This eliminates not only the risk of burn but also the heavy smoke and marijuana-esque odor associated with moxa and the herb Artemisia vulgaris. 

Brain Research

For brain research, laser acupuncture circumvents the hurdles of metal needles in the MRI suite, which may impair image quality and cause tissue heating.21 Needle-less acupuncture reduces risk of infection; certain types of laser light even inactivate bacteria or diminish their ability to reproduce.22,23

On the down side, eliminating the needle may reduce its effectiveness for trigger points, a staple of acupuncturists’ analgesic repertoire, meaning that many acupuncturists will want to maintain the metal instrument for musculoskeletal ailments.24 While laser acupuncture is showing effectiveness for a host of problems that needling traditionally treated, simply shining light cannot supplant the palpatory feedback delivered by a needle as it encounters the tone, tension and texture in muscle tissue.
 
Too, the stimulation itself may seem less robust to patients who have grown accustomed to the needle sensation, "de qi,” that creates the connective tissue grap leading to neuromodulation.25 That said, some argue that laser acupuncture, too, can produce a de qi sensation.26

Laser acupuncturists must guard against excessive heating of the skin with high power units, especially for neonates27 and others who cannot clearly communicate about sources or sites of discomfort, such as anesthetized or neurologically impaired patients and the veterinary population as a whole.

Nonetheless, research is building insight into ways to optimize treatment parameters for both laser therapy and acupuncture.28-32

For some problems, two or more wavelengths may offer roughly equivalent effects, such as red (660 nm) and infrared (830 nm) to improving muscle performance and reduce fatigue.33 On the other hand, 808 nm light reaches more deeply into tissue and thus may outweigh 980 nm for conditions such as spinal cord injury.34
 
Somatosensory evoked potentials change during high-dose laser irradiation when treating one locus along an axon as opposed to several sites along the same axon.35 This has relevance for laser acupuncturists who often select one or more points on an acupuncture channel, and channels commonly follow nerve axons.
 
Concerned about acupuncture losing its exotic Asian heritage by becoming high tech? If so, take heart.

Some of the earliest clinical research in laser acupuncture came from China (1979) when an oral surgeon irradiated acupuncture points for analgesia during minor procedures of the face and mouth, although it was first discussed by a Canadian in 1973.36,37 

Dr. Robinson, Dipl. ABMA, FAAMA, oversees complementary veterinary education at Colorado State University.