CHAPTER 11 BIOPHYSICAL DEVICES: ELECTRICITY, LIGHT, AND MAGNETISM
There is a biophysical aspect to many healing modalities that has long been observed clinically. Contemporary fundamental physics is now in the process of providing explanatory models, mechanisms, and paradigm for the biophysical basis for many healing phenomena. These biophysical characteristics extend beyond the currently established basis of biomedical science in reductionist biochemical, molecular biological, and anatomical terms. Further, biophysics is consistent with many biomedical observations in whole-organism biology, physiology, and homeostasis.
Contemporary biophysics is important for understanding the basis of many contemporary diagnostic and therapeutic approaches. Biophysics, rather than biochemistry or molecular biology, may better provide explanatory mechanisms for the observed effectiveness of such clinical practices as acupuncture, homeopathy, touch, and meditation.
For example, nonthermal, non-ionizing electromagnetic fields in low frequencies have been observed to have the following effects on the physical body: stimulation of bone repair, nerve stimulation, promotion of soft tissue wound healing, treatment of osteoarthritis, tissue regeneration, immune system stimulation, and neuroendocrine modulation.
Contemporary biophysically based modalities include electrodermal screening, applied kinesiology, bioresonance, and radionics. Utilization of these approaches requires the availability of devices and practitioners.
Many well-established historical healing traditions have drawn on diagnostic and therapeutic approaches that may now be interpreted in light of contemporary biophysics. The ancient and complex healing traditions of China and India make reference to and use practices based primarily on biophysical modalities. Acupuncture, acupressure, jin shin do, t’ai chi, reiki, qigong, tui na, and yoga may be seen today to operate on a biophysical basis, but these methods have developed over three millennia in widespread clinical practice and observation. Contemporary outcomes-based clinical trials are demonstrating the efficacy of these modalities in management of many medical conditions (Wootton et al, 2003). In addition, Asian medical systems have used sound, light, and color for their healing properties, which may be viewed in biophysical perspective (see Chapter 2).
Biophysical medical modalities have also been prominent in the history of American medicine. Several schools of thought were created in the United States, or brought from Europe, that center around healing approaches which we may now associate in whole or in part with emerging biophysical explanations. Such schools and their founders have often influenced each other through time (Box 11-1).
BOX 11-1 Schools and Their Founders with Influence on the Development of Biophysical Devices (in Chronological Order)
In addition, interpretations of herbal, nutritional, and even pharmacological therapies have been extended to include “vibrational energy” as a mechanism of action.
There have been many adherents, practitioners, and clinical observations of these schools of thought and practice over time. They have been outside the realm of regular medical practice partially because the mechanisms of action of these approaches have not been explained within the biomedical paradigm. Hypnosis is an example of an effective therapeutic modality with widespread effectiveness and acceptance within medicine. However, there remains no explanation for its mechanism of action. An alternative approach to explaining hypnosis has been developed on a statistical basis, describing the profile of clients and conditions likely to benefit and developing “hypnotic susceptibility scales.” This same approach is available for the clinical study of any therapeutic modality with observable outcomes in the absence of an identified “mechanism of action.” Mechanism is always bounded by the prevailing scientific paradigm and may not be the most clinically useful question (see Chapter 5). With the development of new scientific observations, a new paradigm emerges that is more inclusive in its explanation of observed phenomena.
In addition to the fairly widespread, organized schools of thought and practice, there are many intuitive healers whose practices are highly individuated and highly eclectic. These practitioners represent important approaches used by many clients. The knowledge and practices of such gifted healers must be passed on or they will be lost. This represents a situation in the contemporary United States that is analogous to that of herbal remedies in the rain forest. Environmentalists are rightly concerned about the loss of biodiversity when unique plants disappear; ethnobotanists are concerned about the loss of the peoples whose cultural knowledge alone can convert the rain forest plants to cures.
Human awareness of magnetism extends back in time, with extravagant claims of “magnetic” healing traced back more than 4000 years. In more recent times, attempts to explain the efficacy of this invisible force by invoking unique and unfounded scientific principles and claims, as well as the commercial efforts to sell these products, produced an interesting history of pseudoscience, sensationalism, and controversy. Today in the twenty-first century, despite the fact that permanent magnets and electromagnetic therapies are currently riding the crest of public enthusiasm, it is not surprising that the scientific community remains somewhat skeptical of the current widespread claims. A major obstacle has been an inability to determine a mechanism of action. In addition, fundamental questions regarding efficacy can only be resolved by rigorous, randomized, double-blind, placebo-controlled trials, which have only recently come about in the scientific community. The scientific community can now look at this subject objectively and perhaps reverse the entrenched skepticism.
Historical perspectives on magnetism and healing are provided by a number of sources (Armstrong et al, 1991; Geddes, 1991; Macklis, 1993; Markov, 2007; Mourino, 1991; Rosch, 2004; Weintraub, 2001, 2004a, 2004b), which include several excellent reviews of this rich history. According to the Yellow Emperor’s Canon of Internal Medicine (or the Yellow Emperor’s Inner Classic) magnetic stones (lodestones) were applied to acupressure points as a means of pain reduction. Similarly, the ancient Hindu Vedas ascribed therapeutic powers of ashmana and siktavati (instruments of stone). The term magnet was probably derived from Magnes, a shepherd who, according to legend, was walking on Mt. Ida when suddenly the metallic tacks in his sandals were drawn to specific rocks. These rocks were mineral lodestones that contained magnetite, a magnetic oxide of iron (Fe3O4). These natural magnetic stones were noted to influence other similar adjacent stones that were brought into close proximity, producing movement. Thus, the ancients called them alive stones or Herculean stones because they were meant to lead the way. Various powers were attributed to these stones as noted in the writings and artifacts of the ancient Greek and Roman civilizations. For example, Plato, Euripides, and others indicated that these invisible powers of movement could be put to practical use, such as by building ships with iron nails and destroying opposing military ships and navies by maneuvering them close to magnetic mountains or magnetic rock.
Medicinal and healing properties were also attributed to these lodestones. Various magnetic rings and necklaces were sold in the marketplace in Samothrace around ad 200 to treat arthritis and pain. Similarly, lodestones were ground up to make powders and salves to treat various conditions. Numerous claims and anecdotal stories led to the public embrace of these magical devices. In 1289, the first major treatise on magnetism was written by Peter Peregrinus. He ascribed to lodestone curative properties for treating gout, baldness, and arthritis and spoke about its strong aphrodisiac powers. He also described drawing poison from wounds with close application. His work contains the first drawing and description of a compass in the Western world.
The Middle Ages witnessed the emergence of numerous myths that persist in certain segments of society. For example, it was believed that magnets could extract gold from wells and that application or ingestion of garlic could neutralize magnetic properties. The idea that magnets could be used therapeutically resurfaced in the early sixteenth century when Paracelsus (Philippus Aureolus Theophrastus Bombast von Hohenheim), considered to be one of the most influential physicians and alchemists of his time, used lodestones (magnets) to treat conditions such as epilepsy, diarrhea, and hemorrhage. He believed that every person is a living magnet, that they can attract good and evil, and that magnets are an important elixir of life.
Scientific enlightenment in the seventeenth century on this topic began with the work of Dr. William Gilbert, physician to Queen Elizabeth I of England. He wrote his classic text De Magnete in 1600 describing hundreds of detailed experiments concerning electricity and also terrestrial magnetism. He debunked many medicinal applications and was responsible for laying the groundwork for future research and study. Despite the fact that Luigi Galvani and Alessandro Volta made significant contributions, for the next 100 years there were no major advancements in the study of magnetism.
In the early eighteenth century, there was significant interest in both magnetism and electricity. Francis Hauksbee, in 1705, invented an electrostatic engine that, by rotating and spinning an attached globe, could transfer an electronic charge to various metallic objects brought close to it, such as chain, wire, and metal. This procedure induced electrical shocks. Refinements in this machine led to more general usage, and in 1743, traveling circuses throughout Europe and the American colonies provided individuals with shocks for a small fee. Legend suggests that Benjamin Franklin witnessed an “electrified boy” exhibition and thus became interested in both electricity and magnetic phenomena. Franklin is famed for his experiments on electricity, using lightning, in which he attached a key to an airborne kite in a thunderstorm (as depicted in the heroic portrait by Benjamin West entitled “Franklin Taming Lightning”) (See Chapter 1). In fact, it was actually Franklin’s young son who was sent out into the lightning storm with the kite, risking the exhibition of Franklin’s own version of an “electrified boy.”
Much of the current magnetic terminology regarding electricity originated with Franklin, such as charge, discharge, condenser, electric shock, electrician, positive, negative, plus and minus, and so on. Franklin distinguished himself in studies primarily of electric fluid and charges, and concluded that all matter contained magnetic fields that are uniformly distributed throughout the body. He believed that when an object is magnetized, the fluid condenses in one of its extremities. That extremity becomes positively magnetized, whereas the donor region of the object becomes negatively magnetized. He felt that the degree to which an object can be magnetized depends on the force necessary to start the fluid moving within it.
The scientific revolution came to Europe with the development of carbon-steel magnets (1743 to 1751). Father Maximilian Hell and later his student, Franz Anton Mesmer, applied these magnetic devices to patients, many of whom were experiencing hysterical or psychosomatic symptoms. Specifically in his major treatise “On the Medicinal Uses of the Magnet” Mesmer described how he fed a patient iron filings and then applied specially designed magnets over the vital organs to generally stop uncontrolled seizures. His cures were not only astounding but also good theater, because they were performed in front of large groups (see Chapter 9). The power of suggestion was clearly being displayed and ultimately transferred to nonferric objects such as paper, wood, silk, and stone. Mesmer reasoned that he was not dealing with ordinary mineral magnetism but rather with a special animal magnetism. The term mesmerization is often applied to his displays of people overcoming illness and disease by mesmerizing their bodies’ innate magnetic poles to induce a crisis, often in the form of convulsions. After this crisis, health would be restored. He hailed this animal magnetism as a specific natural force of healing. His claims of success infuriated his conservative colleagues and motivated the French Academy of Sciences under King Louis VI to convene a special study in 1784. The panel for this study included Antoine-Laurent Lavoisier, Joseph-I. Guillotin, and Benjamin Franklin, ambassador to France from the newly independent United States of America. In a controlled set of experiments, blindfolded patients were to be exposed to a series of magnets or sham magnetic objects and asked to describe the induced sensation. Although there remains controversy as to whether and what experimental observations were made, the committee “lost their heads” (a process that was soon to be facilitated by the invention of one of their members, Dr. Guillotin, in the coming French Revolution) in bickering about mechanism of action. They concluded that the efficacy of the magnetic healing resided entirely within the mind of the individual and that any healing was due to suggestion. Based on these conclusions, the medical establishment declared Mesmer’s theories fraudulent, and mesmerism was equated with medical quackery. Mesmer left France in disgrace. Some members of the panel who remained in France, such as Lavoisier, literally lost their heads.
Nonetheless, in the United States magnetic therapy flourished, with significant sales of magnets, magnetic salves, and liniments by traveling magnetic healers. Later in the nineteenth century Daniel David Palmer, the founder of chiropractic and self-described “magnetic healer,” stated that putting down his hands for physical manipulation of the patient produced better results than the simple “laying on of hands.”
In Europe, Hans Christian Ørsted (1777-1851), a physicist, continued studies and noted that a compass needle was deflected when a current flowed through a nearby wire. He also discovered that not only did a current-carrying wire coil exert a force on a magnet, but a magnet exerted a force on the coil of wire, inducing an electrical current. The coil behaved like a magnet, as if it possessed magnetic north and south poles. Magnetism and electricity were somehow connected. Ørsted was instrumental in creating a proper scientific environment that led to further study, with André-Marie Ampère deducing the quantitative relationship between magnetic force and electric current. In the 1820s, Michael Faraday and Joseph Henry (later founding secretary of the Smithsonian Institution in the 1850s) demonstrated more connections between magnetism and electricity, showing that a changing magnetic field could induce an electrical field perpendicularly.
In 1886, the Sears catalogue advertised numerous magnetic products such as magnetic rings, belts, caps, soles for boots, and girdles. In the 1920s, Thacher created a mail-order catalogue advertising over 700 specific magnetic garments and devices and products that he described as a “plain road to health without the use of medicine and was dependent on the magnetic energy of the sun.” He believed that the iron content of the blood made it the primary magnetic conductor of the body, and thus the most efficient way to recharge the body’s magnetic field was by wearing his magnetic garments. The complete set was said to “furnish full and complete protection of all the vital organs of the body.” Collier’s Weekly dubbed Thacher the “king of the magnetic quacks.” There was no government regulation of these devices or claims, and thus these types of promotion fueled skepticism. The U.S. Food and Drug Administration (FDA) had no jurisdiction over medical devices at that time and there were no good scientific trials, although problems with the purity of drugs had led to the passage of the Pure Food and Drug Act of 1906 and the subsequent formation of the FDA.
In 1896, Arsène D’Arsonval reported to the Société de Biologie in Paris that when a subject’s head was placed in a strong time-varying magnetic field, phosphenes (sensations of light caused by retinal stimulation) were perceived. Some 15 years later, Silvanus P. Thompson (1910) confirmed that not only could phosphenes be induced, but that exposure to a strong alternating magnetic field also produced taste sensation. Various coils were constructed by Dunlap and later Magnusson and Stevens. They noted that magnetophosphenes were brightest at a low frequency of about 25 Hz and became fainter at higher frequencies.
After World War II, there was heightened interest and research in magnetotherapy in Japan and the former Soviet Union. Specifically, in Japan magnetotherapeutic devices were accepted under the Drug Regulation Act of 1961, and by 1976, various devices were commonly and commercially employed to treat various illnesses and promote health. Similar interest in Bulgaria, Romania, and Russia led to development of various therapeutic approaches, so that the physician had available the use of magnetic fields to assist in treating disease. Today, Germany, Japan, Russia, Israel, and at least 45 other countries consider magnetic therapy to be an official medical procedure for the treatment of various neurological and inflammatory conditions (Whitaker et al, 1998). By contrast, magnetotherapy had limited acceptance in Western medicine. Unwarranted claims and its promotion by charlatans only led to further public and scientific skepticism.
The modern era of magnetic stimulation began with the work of R.G. Bickford and colleagues (Bickford et al 1965) who considered the possibility of stimulation of the nervous system (frog nerve and human peripheral nerves). He also discussed the generation of eddy currents in the brain that could reach a certain magnitude to stimulate cortical structures through an intact cranium (Bickford et al, 1965). Barker and colleagues at the University of Sheffield developed the first commercial cranial magnetic stimulator in 1985 (Barker, 1991; Barker et al, 1987). They gave a practical demonstration at Queen’s Square by stimulating “Dr. Merton’s brain,” which caused muscle twitches. As might be expected, the physiological and clinical possibilities became obvious (Merton, 1980). Although there were technical challenges, they were met with the development of devices capable of stimulating the brain focally at frequencies of up to 100 Hz using specific coil configurations (i.e., circular). Adaptations for focal therapy were created. Thus, a new discipline developed using high and low repetitive stimulation frequencies directed to previously inaccessible areas of the brain and body (George et al, 2003; Kobayashi et al, 2003; Pascual-Leone et al, 1994). As of July 1998, over 6000 publications existed that dealt with basic neurophysiology, clinical syndromes, and therapeutic implications. Although most of the initial papers were the results of open-label (nonplacebo) observations, many current publications report on randomized, double-blind, placebo-controlled trials. Thus, when all of this information is pooled, both experimental and clinical, the data strongly suggest that the application of exogenous magnetic fields at low levels does indeed induce a biological effect on a variety of systems, especially pain sensation and the musculoskeletal system.
Essential terms must be defined to understand the role of magnetism. Biomagnetics refers to the field of science dealing with the application of magnetic fields to living organisms. Basic research on cells in culture as well as clinical trials have provided a better understanding of mechanisms of action (Adey, 1992, 2004; Adey et al, 1999; Lednev, 1991; Markov, 2004; Markov et al, 2001; Pilla, 2003; Pilla et al, 1997; Timmell et al, 1998). Human tissues are dielectric and conductive and therefore can respond to electrical and magnetic fields that are oscillating or static. Cell membranes consist of paramagnetic and diamagnetic lipoprotein materials that respond to magnetic fields and serve as signaling (transduction) pathways by which external stimuli are sent and conveyed to the cell interior. Calcium ions are very important in transduction coupling at the cell membrane level. Electromagnetic fields can also alter the configuration of atoms and molecules in dielectric and paramagnetic-diamagnetic substances. Thus atoms in these substances polarize, to some degree, when placed in an electromagnetic field and act as a dipole and align accordingly (Adey, 1988, 1992; Blumenthal et al, 1997; DeLoecker et al, 1990; Engstrom et al, 1999; Farndale et al, 1987; Lednev, 1991; Maccabee et al, 1991; Pilla et al, 1997; Repacholi et al, 1999; Rosen, 1992; Rossini et al, 1994; Timmel et al, 1998). Adey feels that free radicals are important for signal transduction. Chemical bonds are essentially electromagnetic bonds formed between adjacent atoms. The breaking of the chemical bonds of a singlet pair allows electrons to influence adjacent electrons with similar or opposite spins, which thereby become triplet pairs, and so on. Thus, by imposing magnetic fields in this medium, one may influence the rate and amount of communication between cells. At the cell membrane level, free radicals of nitric oxide may play an essential role in this regulation of receptors specifically (Adey, 1988, 1992, 2004). It is known that free radicals are involved in the normal regulatory mechanisms in many tissues and that certain disorders are associated with disordered free radical regulation producing oxidative stress. These include Alzheimer disease, Parkinson disease, cancer, and coronary artery disease. This entire area is still incompletely understood yet under intense research scrutiny.
Magnetic field strength is indicated by magnetic flux density, which is the number of field lines (flux) that cross a unit of surface area. It is usually described in terms of the unit gauss (G) or tesla (T). There are 10,000 G in 1 T. Because there is an exponential decay of field strength with distance from a magnetic source according the inverse square law, the objective is to apply a static magnetic device as close to the skin as possible and to ensure that a magnet of sufficient size and surface field is used when the target is in deep tissue areas. Magnetotherapy is defined as the use of time-varying magnetic fields of low-frequency values (3 Hz to 3 KHz) to induce a sufficiently strong current to stimulate living tissue.
Faraday’s law (1831) defines the fundamental relationship between a changing magnetic field and a conductor (any medium that carries electrically charged particles). When a wire is used as an example of a conductor, Faraday’s law basically states that any change in the magnetic environment of the coil of wire with time will cause a voltage to be induced in the wire. No matter how the change is produced, a voltage will be generated. Thus, magnetic field amplitude may be varied by powering the electromagnet with sinusoidal or pulsing current or by moving a permanent magnet toward or away from the wire, moving the wire toward or away from the magnetic field, rotating the wire relative to the magnet, and so on (DeLoecker et al, 1990; Goodman et al, 2002; Serway, 1998; Smith, 1996; Wittig et al, 2002).
Lenz’s law states that the polarity of the voltage induced according to Faraday’s law is such that it produces a current whose magnetic field opposes the applied magnetic field (back EMF, or electromagnetic field). Therefore, if a current is passed through a coil that creates an expanding magnetic field around the coil, the induced voltage and associated current flow produce a magnetic field in opposition to the directly induced magnetic field.
Eddy currents are induced by the voltage generated according to Faraday’s law in any conducting medium. When the conducting medium does not contain defined current pathways, there is no induced current, only induced voltage. There is movement in a spiral, swirling fashion, and this in turn potentially penetrates the membranes of the neurons. If the induced current is of sufficient amplitude, an action potential or an excitatory or inhibitory postsynaptic potential may be produced.
The Hall effect and the Lorentz force are related to the same physical phenomenon of electromagnetism. In the Hall effect, when charged particles in a conductor move along a path that is transverse to a magnetic field, the particles experience a force that pushes them toward the outer walls of the conductor. The positively charged particles move to one side and the negatively charged particles move to the other side. This produces a voltage across the conductor known as the “Hall voltage.” Because the human body is replete with charged ions, the Hall effect would certainly occur to varying degrees when a magnetic field is passed through the body. The strength of the Hall voltage produced depends on three factors: (1) the strength of the magnetic field, (2) the number of charged particles moving transverse to the magnetic field, and (3) the velocity of movement of the charged particles (ions). The pulsing and static magnetic fields in current therapeutic applications are much too weak and the endogenous currents much too small for the Hall effect to be of any significance in magnetic field bioeffects (Pilla et al, 1992, 1993). However, this is somewhat controversial and not universally accepted. Clearly, cellular and neural components in the body provide conductive pathways for ions, so it is reasonable to assume that these components would be prime objects of attention in attempting to observe the Hall effect. It is presumed that this voltage might add to the nerve’s resting potential of −70 mV and make it harder to depolarize. Once the resting potential rises from its normal undisturbed voltage of about −70 mV to a voltage of approximately −55 mV (threshold potential), an action potential spike is initiated. When ions move under the influence of a voltage, they become an electric current the magnitude of which is determined by Ohm’s law, which states that electric current equals voltage divided by resistance.
This phenomenon predicts the effects of ions exposed to a combination of exogenous AC/DC magnetic fields at approximately 0.1 G and the dynamics of ions in a binding site. A bound ion in a static magnetic field will precess at the Larmour frequency and will accelerate faster to preferred orientations in the binding site with increased magnetic field strength. Thus, an increased binding rate can occur with a resultant acceleration in the downstream biochemical cascade.
Magnetic fields can penetrate all tissues, including epidermis, dermis, and subcutaneous tissue as well as tendons, muscles, and even bone. The specific amount of magnetic energy and its effect at the target organ depends on the size, strength, and duration of contact of the device. Magnetic fields fall into two broad categories: (1) static (DC) and (2) time varying (AC).
The strength of static magnetic devices varies from 1 to 4000 G. Static fields have zero frequency, because the polarity and field strength do not change with time but rather remain constant. Permanent magnets produce only static fields unless they are rotated or otherwise moved, which causes the magnetic field amplitude to change with time at the tissue target. Static magnetic fields that are either permanent or electromagnetic are in the range of 1 to 4000 G and have been reported to have significant biological effects (Colbert, 2004; Markov et al, 2001; Pilla, 2003; Pilla et al, 2003). The most common static magnets sold to the public are known as refrigerator or flat-button magnets. They are made of various materials and also have different designs. Configuration can be unidirectional so that only one magnetic pole is represented on one side of the surface (whereas the opposite pole is on the opposite side away from the applied surface) or the surface can have a bipolar north-south design that appears repetitively as concentric ring, multitriangular, or quadripolar configurations.
The term bipolar magnets refers to a repetitive north-south polarity created on the same side of a ceramic or plastic alloy or neodymium material, whereas the term unipolar refers to only one magnetic pole at a given surface, that is, north or south. Multipolar alterations of north and south have also been employed. Each specific manufacturer makes claims as to the superiority of its product. However, the most important characteristic of the magnetic field is the field strength at the target site and also the duration of exposure that leads to biological effects. It is believed that tissues, cells, and other structures have a “biological window” within which they can interact with these invisible fields. Static magnetic fields of 5 to 20 G have been felt to be pertinent. Thus, the gauss rating and field strength at the surface are irrelevant in predicting biological response. Bipolar magnets, using a small arc, are capable of inducing biologically significant fields at a relatively short distance from the surface (1 to 1.5 cm), whereas the penetration of unipolar magnets is much deeper (4 to 8 cm) (Markov, 2007).
As indicated earlier, review of the literature reveals that static magnetic fields in the 1 to 4000 G range have been reported to have significant biological effect. Basic science has demonstrated that static magnetic fields ranging from 23 to 3000 G can alter the electrical properties of solutions. In addition, weak static magnetic fields can modulate myosin phosphorylation at the molecular level in a cell-free preparation (Markov et al, 1997). At a cellular level, exposure to 300 G doubled alkaline phosphatase activity in osteoblast-like cells (McDonald, 1993). Neurite outgrowth from embryonic chick ganglia was significantly increased by exposure to 225 to 900 G (Macias et al, 2000; Sisken et al, 1993). McLean and coworkers, in several experiments using unidirectional and multipolar magnets, demonstrated a blockade of sensory nociceptive neuron action potentials by exposure to a static magnetic field in the 10 mT range. A minimum magnetic field gradient of 15 G/mm was required to cause approximately 80% action potential blockade in isolated nerve preparations (McLean et al, 1995). This blockade reversed when the magnetic exposure was removed. Protection against kainic acid–induced neuronal swelling was also demonstrated with magnetic exposure (McLean et al, 2003). Others have demonstrated a biphasic response of the acute microcirculation in rabbits exposed to static magnetic fields (10 G) (Ohkubo et al, 1997; Okano et al, 1999). Despite all this provocative and promising data in both in vitro and in vivo studies, skepticism prevails because of design flaws (Holcomb et al, 2002; Ramey, 1998). Specifically, a rigorous randomized, placebo-controlled, double-blind design has been lacking; basic mechanisms of action have not been identified; and optimum target dosage and optimum polarity have yet to be determined. The absence of nonmagnetic placebos as controls has also been described as a problem.
Colbert (2004) reviewed 22 therapeutic trials reported in the U.S. literature from 1982 to 2002. Clinical improvement in subjects who wore permanent magnets on various parts of their bodies was demonstrated in 15 studies, whereas 7 reported limited or no benefit. Magnetic field strength varied from 68 to 2000 G and time exposure varied from 45 minutes to constant wearing for 4 months. Thus the optimum treatment duration, as well as the optimal polarity (unidirectional, multipolar, etc.), has yet to be established. Complicating the issue even further is the observation by Blechman et al (2001) that a significant number of the static magnets sold to the public had lower field flux density measurements than the manufacturers claimed. It is known that a large amount of cancellation occurs in multipolar arrays. Similarly, Eccles (2005) conducted a critical review of the randomized controlled trials that used static magnets for pain relief. He found a 73% statistical reduction in pain. He also commented on the difficulty in performing double-blind studies using static magnets because of the obvious interaction with metallic objects.
Specific clinical trials using a double-blind, placebo-controlled design include that of Vallbona et al (1997), who applied 300- to 500-G concentric-circle bipolar magnets over painful joints in patients with postpolio syndrome for 45 minutes and reduced pain by 76%. Carter et al (2002) applied unipolar 1000-G static magnets and placebos over the carpal tunnel for 45 minutes and both groups experienced significant pain reduction. This was felt to represent a placebo effect. Unidirectional magnetic pads (150 to 400 G) were placed over liposuction sites immediately after the procedure and kept in place for 14 days; this treatment produced a 40% to 70% reduction of pain, edema, and discoloration (Man et al, 1999). Brown et al (2002) demonstrated statistical reduction of pelvic pain with magnetic therapy. Patients with fibromyalgia who slept on a unidirectional magnetic mattress pad (800-G ceramic magnets) for 4 months experienced a 40% improvement (Colbert et al, 1999). Weintraub (1999) noted a 90% reduction in neuropathic pain in patients with diabetic peripheral neuropathy with constant wearing of multipolar 475-G insole devices. There was also a 30% reduction in neuropathic pain associated with nondiabetic peripheral neuropathy (Man et al, 1999; Weintraub, 1999). A nationwide study using placebo controls also confirmed these results in 275 patients with diabetic peripheral neuropathy (Weintraub et al, 2003).
Hinman et al (2002) found a 30% response to short-term application of unipolar static magnets positioned over painful knees. Greater movement was also noted. Holcomb et al (2002), using a quadripolar array of static magnets with alternating polarity, demonstrated analgesic benefit in patients with low back pain and knee pain.
Saygili et al (1992), in an investigation of the effect of magnetic retention systems in dental prostheses on buccal mucosal blood flow, failed to detect changes in capillary blood flow after continuous exposure to a magnetic field for 45 days. Hong et al (1982) had 101 patients with chronic neck and shoulder pain wear magnetic necklaces or placebos for 3 consecutive weeks after baseline electrodiagnostic studies, but no significant improvement was seen in the magnetic therapy group. In a study using a randomized placebo crossover design Martel et al (2002) could not identify any change in forearm blood flow after 30 minutes of exposure to bipolar magnets. Other randomized placebo-controlled trials producing negative results should be mentioned, including Collacott et al’s study (2000) of the use of bipolar devices in patients with chronic low back pain and Winemiller et al’s study (2003) of the use of magnetic insoles by patients with plantar fasciitis. Weintraub and others commented on design flaws in both of these studies (Weintraub, 2000, 2004a, 2004b). Simultaneous application of static magnets to the back and feet in patient with failed back syndrome was also ineffective (Weintraub et al, 2005). Pilla independently assessed the strength of the magnetic devices and found them to be less than the manufacturer’s claims, thereby confirming the observations of Blechman et al (2001) regarding the discrepancy between claimed and measured field flux densities.
It is assumed that the biological benefits from static magnetic fields are similar to those from pulsed electromagnetic fields, but the correlation has been imperfect. The specific mechanism of biological benefit remains to be determined. At present, the most generally accepted theory is that static magnetic fields on the order of 1 to 10 G can affect ion-ligand binding, producing modulation (Pilla, 2003; Pilla et al, 1997, 2003). There may also be physical realignment and translational movement of diamagnetically anisotropic molecules. Despite these theoretical and scientific rationales for benefit, criticism and skepticism prevail. Critics allege that it is all placebo effects, yet a more enlightened and open-minded appraisal would accept the positive in vitro and in vivo observations. Ramey (1998), a veterinarian, has been a noted critic of static magnetic therapy, yet these devices are used extensively in veterinary medicine (e.g., magnetic blankets for race horses).
The World Health Organization has stated that there are no adverse effects on human health from exposure to static magnetic fields, even up to 2 T, which equals 20,000 G (United Nations Environment Programme MF, 1987). Similarly, in 2003 the FDA extended nonsignificant risk status to magnetic resonance imaging (MRI) using flux densities of up to 8 T (U.S. Food and Drug Administration, 2003).
The generation of pulsed electromagnetic fields (PEMFs) require an electric current to produce a pulsating (time-varying) magnetic field. This is because the coil that produces the magnetic field is stationary. Regardless of how the waveforms are transmitted through the coil, the ensuing magnetic flux lines appear in space in exactly the same manner as the flux lines from a permanent magnet. The magnetic field penetrates biological tissues without modification, and the induced electrical fields are produced at right angles to the flux lines. The ensuing current flow is determined by the tissue’s electrical properties (impedance) and determines the final spacial dosimetry. Peak magnetic fields from PEMF devices are typically 5 to 30 G at the target tissue with varying specific shapes and amplitudes of fields.
Cellular studies (in vitro, in vivo) have been most provocative. In reviewing this work, Markov has summarized various cellular and structural changes in response to this PEMF exposure (Markov, 2004; Markov et al, 2001). Specifically, changes in fibrinogen, fibroblasts, leukocytes, platelets, fibrin, cytokines, collagen, elastin, keratinocytes, osteoblasts, and free radicals are noted. In addition, magnetic fields influence vasoconstriction, vasodilatation, phagocytosis, cell proliferation, epithelialization, and scar formation.
Similarly, in a series of reviews, Pilla has summarized the effects of these weak PEMFs on both signal transduction and growth factor synthesis as it relates to fractures (Pilla, 2003; Pilla et al, 1992, 1993, 2003). He noted that there is upregulation of growth factor production, calcium ion transport, self-proliferation, insulinlike growth factor II release, and insulinlike growth factor II receptor expression in osteoblasts as a mechanism for bone repair. He also cited an increase in both transforming growth factor-β1 messenger RNA and protein in osteoblast cultures, producing an effect on a calcium/calmodulin-dependent pathway. Other studies with chondrocytes confirm similar increases in transforming growth factor-β1 messenger RNA and protein synthesis with PEMF exposure, which suggests a therapeutic application for joint repair (Ciombor et al, 2002; Pilla et al, 1996). PEMFs have also been successfully applied to stimulate nerve regeneration. Neurite outgrowth has been demonstrated in cell cultures exposed to electromagnetic fields. Eddy currents are generated that can depolarize, hyperpolarize, and repolarize nerve cells, which suggests that neuromodulation potentially can arise.
In 1979, the FDA approved the use of PEMF as a means of stimulating and recruiting osteoblast cells at a fracture site. Application of coils around the cast induces current flows through the fracture site, producing 80% success. It became apparent after early testing that intermittent exposure, rather continuous exposure, was the optimal technique. Currently, there are four FDA-approved devices for treatment of non-union fractures, and each has specific signal parameters, treatment time, and so on. It is not yet clear how long PEMF exposure must last to trigger a bioelectrical effect. Effective waveforms tend to be asymmetric, biphasic, and quasi-rectangular or quasi-triangular in shape. This indicates that tissues have various windows of vulnerability and susceptibility to PEMF. Based on the high success rate of PEMF therapy, it is currently considered part of the standard armamentarium of orthopedic spine surgeons and is recommended as an adjunct to standard fracture management. In addition, the results are equivalent to those of surgical repair with minimal risk, and the treatment is more cost effective.
PEMF therapy has also been used to treat other orthopedic conditions as well as painful musculoskeletal disorders. These include aseptic necrosis of the hips, osteoporosis, osteoarthritis, osteogenesis imperfecta, rotator cuff dysfunction, and low back pain (Aaron et al, 1989; Binder et al, 1984; Fukada et al, 1957; Jacobson et al, 2001; Linovitz et al, 2000; Mooney, 1990; Pipitone et al, 2001; Pujol et al, 1998; Wilson et al, 1974; Zdeblic, 1993). Markov, in his reviews (Markov, 2004, 2007; Markov et al, 2001), stated that with the exception of periarthritis, for which no difference was reported between treatment and control groups, reduced pain scores were noted in carpal tunnel pain (93%) (Battisti et al, 1998) and rotator cuff tendinitis (83%) (Binder et al, 1984), and 70% of multiple sclerosis patients had reduced spasticity (Lappin et al, 2003). Pilla reports double-blind studies claiming benefit for chronic wound repair (Battisti et al, 1998; Kloth et al, 1999; Mayrovitz et al, 1995; Todd et al, 1991), acute ankle sprain (Ciombor et al, 2002; Pilla et al, 1996), and acute whiplash injuries (Foley-Nolan et al, 1990, 1992).
Pujol et al (1998) targeted musculoskeletal pain using magnetic coils, which produced a benefit compared with placebo. Weintraub and Cole (2004) applied nine consecutive 1-hour treatments to patients with peripheral neuropathy, which induced a greater than 50% reduction in neuropathic pain. This was an open-label, nonplacebo trial.
Pickering et al (2003) demonstrated that gentamicin’s effect against Staphylococcus epidermidis could be augmented by exposure to a PEMF. In other research with a double-blind, placebo-controlled design, use of pulsed high-frequency (27-MHz) electromagnetic therapy to treat persistent neck pain produced significant improvement by the second week of therapy (Foley-Nolan et al, 1990, 1992).
In 1983 Raji and Boden applied 27-MHz pulsed electromagnetic therapy to the transected common peroneal nerve of rats; 15 minutes of treatment daily produced accelerated healing with reduced scar tissue, increased growth of blood vessels, and maturation of myelin (Fukada et al, 1957). Despite all the convincing data, the use of PEMF therapy does not enjoy universal acceptance. In addition, the large number of different commercially available PEMF devices, which generate low-frequency fields of different shapes and amplitudes, are a major variable in attempting to understand and analyze the putative biological clinical effects. It has been speculated that the target area receives 5 to 30 G and that each tissue has its own biophysical window and specific encoding susceptibility (Pilla et al, 2003).
Despite all these provocative data, there is considerable uncertainty about the specific mechanisms involved as well as the optimal approach in terms of frequency, amplitude, and duration of exposure. Of course, this issue may be moot based on available data, because several different devices generating different frequencies and amplitudes and used for different durations have been successful in producing similar non-union fracture healing. In addition, there is an abundance of experimental and clinical data demonstrating that extremely low frequency and static magnetic fields can have a profound effect on a large variety of biological systems, organisms, and tissues as well as cellular and subcellular structures. It is assumed that the target is the cell membrane with ion and ligand binding and that even small changes in transmembrane voltage can induce a significant modulation of cellular function. In a recent review, Pilla has attempted to provide a unifying approach for static and pulsating magnetic fields, as well as weak ultrasound, which also induces electrical fields comparable to those associated with PEMFs (Pilla, 2003). Pilla has also employed pulsed (nonthermal) radiofrequency fields at 27.12 Hz and has achieved soft tissue healing, reduction of edema, and postoperative pain relief. Pulsed radiofrequency therapy has recently been approved by the FDA (Mayrovitz et al, 1995).
A novel device has now been developed with time-varying, biaxial rotation that generates simultaneous static (DC) and oscillating (AC) fields. The fields are constantly changing and thus produce variable exposure to tissues and varying amplitudes at the target tissue. Weintraub and coworkers have recently found this type of therapy to be effective in reducing neuropathic pain from diabetic peripheral neuropathy and carpal tunnel syndrome (Weintraub and Cole, 2007a, 2007b).
Transcranial magnetic stimulation (TMS) is a specific adaptation of PEMF that creates a time-varying magnetic field over the surface of the head and depolarizes underlying superficial neurons, which induce electrical currents in the brain. High-intensity current is rapidly turned on and off in the electromagnetic coil through the discharge of capacitors. Thus, brief (microseconds) and powerful magnetic fields are produced, which in turn induce current in the brain. Two magnetic stimuli delivered in close sequence to the same cortical region through a single stimulating coil are used. The first is a conditioning stimulus at sub–motor threshold intensity that influences the intracortical neurons and exerts a significant modulating effect on the amplitude of the motor evoked potential induced by the second, supra–motor threshold stimulus. This modulating effect depends on the interval between the stimuli. Cortical inhibition consistently occurs at intervals between 1 and 5 msec, and facilitation is seen at intervals between 10 and 20 msec. TMS is simple to perform, inexpensive, generally safe, and provides useful measures of neuronal excitability. It has also been used along the neuraxis and continues to provide important insights into basic neurological functions, neurophysiology, and neurobiology. Although TMS is generally used as a research tool, it has been proposed that the therapeutic use of TMS be considered. The abnormalities that are revealed by TMS are not disease specific and need clinical correlation. Initially, stimulation directed to the primary motor cortex in individuals with a number of movement disorders helped investigators appreciate the role of the basal ganglia. Specific TMS studies looked at Parkinson disease, dystonia, Huntington chorea, essential tremor, Tourette syndrome, myoclonus, restless legs syndrome, progressive supranuclear palsy, Wilson disease, stiff-person syndrome, and Rett syndrome, among others. The results were promising, which suggests that future large multicenter trials are warranted.
TMS has also proved useful in investigating the mechanisms of epilepsy, and repetitive TMS may prove to have a therapeutic role in the future (Osenbach, 2006).
TMS also is used in preoperative assessment of specific brain areas to optimize the surgical procedure. Both inhibitory and facilitatory interactions in the cortex can be studied by combining a subthreshold conditioning stimulus with a suprathreshold test stimulus at different short (1- to 20-msec) intervals through the same coil. In addition, this paired-pulse TMS approach is used to investigate potential central nervous system–activating drugs, various neurological and psychological diseases, and so on. Left and right hemispheres often react differently (Cahn et al, 2003). The clinical utility of this aspect has not yet been demonstrated. If TMS pulses are delivered repetitively and rhythmically, the process is called “repetitive TMS” (rTMS) and can be modified further to induce excitatory or inhibitory effects. In rare cases seizures may be provoked in epileptic patients as well as in normal volunteers (Abbruzzese et al, 2002; Amassian et al, 1989; Cantello, 2002; Chae et al, in press; George et al, 1999; Kobayashi et al, 2003; Lisamby et al, 2001; Pascual-Leone et al, 2002; Rollnik et al, 2002; Terao et al, 2002; Theodore, 2003; Wasserman, 1998; Walsh et al, 1999).
Repetitive TMS leads to modulation of cortical excitability. For example, high-frequency rTMS of the dominant hemisphere, but not the nondominant hemisphere, can induce speech arrest (Orpin, 1982). This effect also correlates with results of the Wada test. The higher the stimulation frequency, the greater the disruption of cortical function. Lower frequencies of rTMS in a 1-Hz range can suppress excitability of the motor cortex, whereas 20-Hz stimulation trains lead to a temporary increase in cortical excitability. Pascual-Leone and coworkers have been studying these effects in patients with neurological disorders such as Parkinson disease, dystonia, epilepsy, and stroke. Osenbach (2006) provides a comprehensive review of the use of motor cortex stimulation (MCS) to manage intractable pain, concluding “there is little doubt that MCS provides excellent relief in carefully selected patients with a variety of neuropathic pain but leaves many unanswered questions.” Tinnitus has been recalcitrant to many therapies, but there has been increasing use of magnetic and electrical stimulation of the auditory cortex with benefit (DeRidder et al, 2004; Whitaker et al, 1998). Psychiatric conditions, including anxiety, mania, depression, and schizophrenia, are also being treated with TMS (George et al, 1999, 2003, 2004). These early observations and data suggest a rich potential therapeutic utility heretofore not known. Elucidation of the underlying neurobiology is still a work in progress in various neuropsychiatric syndromes. Creating sham TMS is difficult, and there is some evidence to suggest that tilting of the coils produces some biological effect on the brain with (George et al, 2004).
A controversial and legitimate concern relates to the possibility that exposure of living tissue to an electromagnetic field may play a causative role in malignancy and birth defects. Specifically, this concern has been raised because of the foci of childhood leukemia cases reported adjacent to high-power lines. During a 5-year period (1991 to 1996), Congress appropriated $60 million for dedicated research to look for such a causal association. The result was that no significant risk from power line frequencies could be confirmed and the fears did not appear justified. No funding was made available to explore and expand the beneficial effects of magnetics and electromagnetic fields!! The facts are that there is now a 30-year experience with and history of the approved use of PEMF in promoting repair of recalcitrant fractures with not one adverse effect reported. Similarly, static magnetic fields have been employed for therapeutic uses for centuries, and no adverse effects have been reported.
The FDA has received a number of reports and complaints through its Medical Device Reporting system concerning electromagnetic field interference with a variety of medical devices, such as pacemakers and defibrillators. In addition, the development of advanced magnetic resonance technology using ultra-high magnetic field systems of more than 3 T, although they were considered safe, led to a reassessment of biomedical implant devices, which were previously judged to be safe to use at 1.5 T; of the 109 implants and devices tested, 4% were considered to have a magnetic field interaction at 3 T and were potentially unsafe to use with fields of this magnitude (Shellock, 2002). Because of potential concerns regarding radiofrequency-induced magnetic fields with thermal effects at the cellular and molecular levels, the FDA has limited switching rates for generation of these gradient fields to a factor of three below the mean threshold of peripheral nerve stimulation (Shellock, 2004). Recently, Weintraub, Khoury, et al (2007) looked at the biological effects of 3-T MRI machines compared with 1.5-T and 0.6-T machines and found that 14% of subjects experienced sensory symptoms (new or altered) with both 3-T and 1.5-T systems.
The study of magnetic fields (static and pulsed) has evolved from a medical curiosity into investigation of significant and specific medical applications.
There are at least five major professional and scientific societies involved in the study of the biological and clinical effects of electromagnetic fields (Markov et al, 2001): (1) the Bioelectromagnetics Society (BEMS), (2) the European Bioelectromagnetics Association (EBEA), (3) the Bioelectrochemical Society (BES), (4) the Society for Physical Regulation in Biology and Medicine (SPRBM), and (5) Engineering in Medicine and Biology (IEMB).
That PEMF and TMS can influence biological functions and serve as a therapeutic intervention is not in dispute. However, judging the efficacy of static magnets for treatment of various clinical conditions remains challenging, particularly because the important dosimetry component has not been documented. The ultimate question is what it will take to convince the scientific community of the merits of static magnetotherapy. Although the debate continues, more attention must be focused on creating strong randomized, placebo-controlled designs and looking for biological markers. This step should help reduce the skepticism of the medical community. A major obstacle to future progress has been the lack of research funding, especially National Institutes of Health (NIH) funding. When Senator Arlen Specter (R-Pennsylvania), a senior member of the Senate Appropriations Subcommittee on Health and Education, which had doubled the NIH budget, asked the leadership of the NIH about funding research on bioenergy, he was told that the NIH “does not believe in bioenergy.” Perhaps the U.S. Department of Energy should sponsor research in this field. Its leaders cannot respond that they don’t believe in energy. The medical device industry has been willing to support many innovative studies, but if major advancement of knowledge is to occur in the field of magnetotherapy, recent history shows that it will require a combination of support by both government and industry.
The application of light for medicinal purposes (healing) has been understood for thousands of years. The ancient Greeks observed that exposure to sunlight induced strength and health. During the Middle Ages, the disinfectant properties of sunlight were used to combat plague and other illnesses, and in the nineteenth century, cutaneous tuberculosis (scrofula) was treated with ultraviolet light exposure. Currently light therapy is used to treat psoriasis, hyperbilirubinemia, seasonal affective disorder, and vitamin D deficiency.
The Light Cure and Vitamin D
Although vitamin D has been understood only relatively recently, it has been a part of biology for a very long time. A microorganism that is estimated to have lived in the oceans for 750 million years is able to synthesize vitamin D, which possibly makes vitamin D the oldest hormone on the planet.
It was recognized over 150 years ago that people, especially children, who lived and worked in dark urban areas where there was little light were susceptible to bone diseases such as rickets. In Boston in 1889 it was estimated that 80% of infants had rickets. This pattern marked a shift away from a U.S. population that was primarily engaged in agriculture (Thomas Jefferson’s idea of an agrarian democracy) during the 1800s and exposed to plenty of light on the farms and in the fields. The lack of light in dank, dark urban environments was compounded by the unavailability of fresh foods and lack of food distribution.
At that time it was noted that an extended visit to the country with clean air, clean water, abundant sunlight, and the benefits of nature would often cure medical disorders. Thus the idea of the nature cure was born (see Chapter 2). One of the many famous beneficiaries of the nature cure in the late 1800s was future president Theodore Roosevelt, who was well known for saying that he was literally “Dee-lighted” with any number of things, including the results of his cure for his lung disease. One of the most common lung diseases in the late 1800s was tuberculosis (TB). Sanitoriums and solariums were created in wilderness areas away from the cities so that TB patients could benefit from the nature cure. Although no antibiotic treatments were available at that time, many patients with TB benefitted from exposure to nature, including sunlight.
As early as 1849, cod liver oil was also used in the treatment of TB, according to the Brompton Hospital Records, Volume 38 (Table 11-1). We now know cod liver oil to be one of the few dietary sources of vitamin D. We also now know that vitamin D activates the immune system cells that can fight TB. So the nature cure of sun and fish oil (also known to sailors as the “sun-fish” cure), which delivered increased vitamin D, was the right treatment for the times.
Year | Observation/Milestone | Vitamin D pioneers |
---|---|---|
1849 | Cod liver oil (vitamin D) treats tuberculosis | Brompton Hospital |
1889 | Nature cure treats rickets | S. Weir Mitchell et al |
1919 | Mercury arc lamp (ultraviolet B light) treats rickets | Huldschinsky |
1921 | Sun exposure cures rickets | Hess and Unger |
1920s | Vitamin D discovered | Adolf Windaus |
1920s | Vitamin D photosynthesized in laboratory | Adolf Windaus (Nobel Prize, 1928) |
1940s | Sunlight protects against cancer | Apperly |
1970 | 25-Hydroxyvitamin D3 isolated | Holick |
1971 | 1,25-Dihydroxyvitamin D3 isolated | Holick |
1979 | Vitamin D receptors found | De Luca et al |
1980 | Vitamin D treats psoriasis | Holick et al |
2002 | Vitamin D regulates blood pressure | Li et al |
The direct connection between sunlight and bone metabolism was also established in 1919 when Huldschinsky treated rickets with exposure to a mercury arc lamp. In 1921, Hess and Unger observed that sun exposure cured rickets.
In the 1930s medicine began to directly appreciate the connection between sunlight and the metabolic activities we now associate with vitamin D. This was also the decade that saw the actual identification and labeling of the many metabolically active constituents we now call vitamins. Vitamin D was discovered in the early 1920s by Windaus, who was later awarded the Nobel Prize for synthesizing vitamin D in the laboratory by replicating the photoactivation process that occurs in the skin.
In the 1930s the federal government set up an agency to recommend to parents, especially those living in the Northeast, that they send their children outside to play and get some sun exposure.
Fortification of milk with vitamin D also began at that time. Unfortunately, the last 40 years have actually seen a reversal of some of the sensible public health recommendations regarding adequate vitamin D and sun exposure.
Many physicians and public health organizations, including the biomedically oriented World Health Organization, have been trying to go one better on Moby Dick’s Captain Ahab, who “would strike the sun if it insulted” him. For 40 years there has been a concerted campaign to make people avoid sun exposure. Because ultraviolet B (UVB) light from the sun is responsible for the photoactivation of vitamin D in the skin, sun blockers that “protect” the skin also virtually eliminate photoactivation of vitamin D. A sunscreen with a sun protection factor (SPF) of 8 is supposed to absorb 92.5% of UVB light, whereas doubling the SPF to 16 absorbs 99%. This essentially shuts down vitamin D production. (It also demonstrates that SPF formulations above 16 have little marginal utility and calls into question the appropriateness of the ever-increasing SPF numbers found on the pharmacy shelves.) People have become photophobic, and dermatologists have been on a campaign to “strike the sun.”
A study in Australia, which has high levels of sunlight and high rates of skin cancer, found 100% of dermatologists to be deficient in vitamin D. In fact, most people should go outside in the sun for reasonable periods of time to get the many benefits of sunlight (Box 11-2). It is always wise to protect the face and head with a hat and sunglasses, because less than 10% of UVB light absorption happens above the neck and the face is the most cosmetically sensitive. It is best to expose the entire body in a bathing suit for 10 to 15 minutes at least three times per week. African Americans require more sun exposure because their natural skin pigmentation provides an SPF equivalent of 8 to 15.
Essentially little or no active vitamin D is available from regular dietary sources. It is principally found in fish oils, sun-dried mushrooms, and fortified foods like milk and orange juice. However, many countries worldwide forbid the fortification of foods. There is potentially plenty of vitamin D in the food chain, because both phytoplankton and zooplankton exposed to sunlight make vitamin D. Wild-caught salmon, which feeds on natural food sources, for example, has available vitamin D. However, farmed salmon fed food pellets with little nutritional value have only 10% of the vitamin D of wild fish. The “perfect storm” of photophobia, lack of exposure to sunlight, and insufficiency of available dietary vitamin D has led to a national and worldwide epidemic of vitamin D deficiency.
Estimates are that at least 30% and as much as 80% of the U.S. population is vitamin D deficient. In the United States, at latitudes north of Atlanta, the skin does not make (photoconvert) any vitamin D from November through March (i.e., essentially outside of daylight savings time; so although we shift the clock around, it does not salvage vitamin D synthesis). During this season the angle of the sun in the sky is too low to allow UVB light to penetrate the atmosphere, and it is absorbed by the ozone layer. Even in the late spring, summer, and early fall, most vitamin D is made between 10 am and 3 pm when UVB from the sun penetrates the atmosphere and reaches the earth’s surface.
It might be expected that vitamin D deficiency would be a problem limited to northern latitudes.
In Bangor, Maine, among young girls 9 to 11 years old, nearly 50% were deficient at the end of winter and nearly 20% remained deficient at the end of summer. At Boston Children’s Hospital, over 50% of adolescent girls and African American and Hispanic boys were found to be vitamin D deficient year round. In another study in Boston 34% of whites, 40% of Hispanics, and 84% of African American adults over age 50 were found to be deficient.
Vitamin D deficiency is also a national problem, however. The U.S. Centers for Disease Control and Prevention completed a national survey at the end of winter and found that nearly 50% of African American women aged 15 to 49 years were deficient. These are women in the critical childbearing years. A growing fetus must receive adequate vitamin D from the mother, especially because breast milk does not provide adequate vitamin D. A study of pregnant women in Boston found that in 40 mother-infant pairs at the time of labor and delivery, over 75% of mothers and 80% of newborns were deficient. This observation was made despite the fact that pregnant women were instructed to take a prenatal vitamin that included 400 IU of vitamin D and to drink two glasses of milk per day.
Further, vitamin D deficiency is a global problem. Even in India, home to 1 billion of the earth’s people, where there is plenty of sun, 30% to 50% of children, 50% to 80% of adults, and 90% of physicians are deficient. In South Africa, vitamin D deficiency is also a problem even though Cape Town is situated at 34 degrees latitude.
Although there are many new bilateral and multilateral governmental and private efforts to export Western medical technology and pharmaceuticals to the Third World to combat infectious diseases such as acquired immunodeficiency syndrome (AIDS), there is no comparable effort to acknowledge and address the global dimensions of the vitamin D deficiency epidemic. The U.S. Congress and president just deemed it as a great achievement to give $40 billion in tax dollars to U.S. pharmaceutical companies to send expensive drug treatments for AIDS (a preventable disease) overseas. By contrast, addressing the vitamin D deficiency epidemic could be accomplished with much safer and less expensive nutritional supplements together with sunlight, the only source of energy that is still free.
Light has one identity as electromagnetic waves characterized by wavelength but also exists as tiny energy bundles, or photons. Visible light, called the “visual spectrum,” is electromagnetic radiation at wavelengths of 400 to 700 nanometers (nm) appreciated by the human eye. The human eye is sensitive to approximately 90% of the spectrum of electromagnetic radiation that propagates through the atmosphere and reaches the earth’s surface. As a sensory organ, the eye evolved to detect that portion of the electromagnetic spectrum that is there to be seen in the terrestrial environment.
One nanometer equals one billionth of a meter. The shorter the wavelength, the higher the energy (from Planck’s law, the energy level is the inverse of the wavelength multiplied by the Planck constant) and the greater the ability of light to penetrate tissues. For example, a blue-violet light has a shorter wavelength, and a red light has a longer wavelength. Infrared light is even longer in wavelength (lower energy) and ultraviolet light is even shorter in wavelength (higher energy) than the visible spectrum. This is the reason for the concern of dermatologists that DNA-damaging ultraviolet light with a shorter wavelength and higher, “ionizing” energy is dangerous, and for the notion that using infrared light with a longer wavelength and lower energy for tanning is a “safer” form of exposure. (See the sidebar “The Light Cure and Vitamin D.”)
X-rays, gamma rays, ultraviolet rays, cosmic rays, and others all fall below visible light on the electromagnetic spectrum. Longer wavelengths such as infrared rays, microwaves, television signals, and FM/AM radio waves have different characteristics. Laser beams are a particular kind of amplified light. The atomic models that led to the discovery of lasers were conceptualized and developed in 1917 by Albert Einstein. His discovery became known as “LASER” for light amplification by stimulated emission of radiation. When an atom is in an excited state and an incoming light particle reaches it, it may eject an additional photon instead of absorbing the particle. This theory was a revolutionary concept that proved to be true, and Einstein received the Nobel Prize for explaining the photoelectric effect. By 1960, the first practical ruby red laser was developed by T.H. Maiman, who used crystals and mirrors to produce a monochromatic, nondivergent light beam in which all waves were parallel and in phase. These characteristics were subsequently referred to as “monochromaticity,” “collimation,” and “coherence,” respectively. The original ruby red beam was a visible red light with a wavelength of 694 nm. Since then, various crystals and gases have been used to develop lasers in other regions of the electromagnetic spectrum, including infrared and visible-light lasers (Box 11-3).
BOX 11-3 LASER (Light Amplification by Stimulated Emission of Radiation)
When light is directed onto an object, one (or more) of the following occurs:
Every object has optical properties that determine the effectiveness of light and the interaction of light with that object. For example, the light from mid-infrared and far-infrared lasers, such as carbon dioxide, holmium, and yttrium-aluminum-garnet lasers, is primarily absorbed by water in the tissues. This absorption of the infrared light energy produces heat, which leads to local vaporization that does not spread. The light from near-infrared and visible-light lasers such as neodymium and argon lasers is poorly absorbed by water but is rapidly absorbed by pigments such as hemoglobin and melanin. This optical property makes these lasers effective in the destruction of tissues that are rich in pigment, such as retina, gastric mucosa, and pigmented cutaneous lesions. It is easy to see how these so-called high-powered surgical lasers, using heat and energy, lead to specific tissue changes. Over the past 30 years, numerous animal and laboratory experiments were carried out using these high-energy lasers. These experiments produced results that ultimately led to human testing and approval by the FDA of the use of lasers in humans.
Despite more than 30 years of similar experiments using weak or low-level nonthermal lasers, there is still controversy concerning the effectiveness of low-level laser therapy (LLLT) as a treatment modality because of a lack of randomized, double-blind, placebo-controlled trials and publication of findings in peer-reviewed journals. Various articles have made claims, but the studies reported by many have flawed methodology, use different time and dosage schedules, and do not have a strict placebo-controlled design. Despite all these shortcomings, several investigations were brought to the attention of the FDA, and in 2002 the FDA approved an application for the use of laser light as a therapeutic device for pain relief.
Cold laser therapy, or LLLT, is based on the idea that monochromatic light energy, which depends on wavelength for its penetration, can alter cellular functions. Because the original European studies on wound healing in animals yielded positive results, the technique was described as “biostimulation.” Mester et al (1982), and Lyons (1987) found that light could be stimulatory at low power and could elicit an opposite inhibitory effect at higher power. In addition, the cumulative dosages of the radiation could sometimes be inhibitory. Today a variety of lasers are available, but the two most popular are helium-neon (HeNe) (632 nm) and gallium-aluminum-arsenide (GaAlAs) (830 nm). In practice, these visible and infrared lasers have powers of 30 to 90 mW and deliver from 1 to 9 J/cm2 to treatment sites. To date, they have been shown to be safe within this range, but they have also been used at higher doses.
Musculoskeletal tissues appear to have optical properties that respond to light between 500 and 1000 nm. Sufficient specific laser dose and the number of treatments needed are still the subject of controversy. It is hypothesized that light-sensitive organelles, or chromatophores, absorb light (Walsh, 1997) and that ultimately the energy produces a biological reaction. It has been suggested that chromatophores are present on the myelin sheath and in mitochondria, and that it is the monochromatic wavelength properties, rather than the coherency and collimation of laser light, that induce biological changes. It is presumed that the collimation and coherency lead to rapid degradation by scatter. Others have theorized that the primary photoreceptors are the flavins and porphyrins and that the therapeutic benefit of pain reduction produced by a combination of red and near-infrared light is caused by an increase in β-endorphins, blocking depolarization of C-fiber afferents, a reduction in bradykinin levels, and ionic channel stabilization.
Tissue penetration depends on the wavelength. The shorter HeNe laser beam (632 nm) penetrates several millimeters into tissue, whereas the GaAlAs (830 nm) at 30 mW allows photons to penetrate more than an inch (3 cm). Several authors have stated that an infrared laser beam travels about 2 mm into tissue and that this represents one penetration depth with a loss of 1/e (37%) of beam intensity (Basford, 1998). However, the shorter visible HeNe red beam is attenuated the same amount in 0.5 to 1 mm (Anderson et al, 1981; Basford, 1995; Kolari, 1985). How does one measure the decay in the amount of energy with distance? At the surface of the skin, the laser delivers from 1 to 9 J/cm2. Karu (1987) has demonstrated that light of 0.01 J/cm2 can alter cellular processes. As a result, approximately six penetration depths (3 to 6 mm for HeNe red light and about 24 mm for GaAlAs infrared light) are possible before the strength of the beam stream drops from 9 J/cm2 to 0.01 J/cm2. Thus, the threshold and specific therapeutic amount needed for stimulation differs for the superficial nerves and tissues and for the deeper structures. There is also a scattering of energy that influences nonneural adjacent tissues (i.e., flexor tendons in the forearm and wrist with stimulation at the level of the carpal tunnel).
It has been stated that tissue penetration and saturation with pulsed frequency settings of 1 to 100 Hz influenced pain and neuralgia, whereas setting of 1000 Hz influenced edema and swelling and 5000 Hz influenced inflammation. Light from a superpulsed laser using a gallium arsenide (GaAs) infrared diode provides the deepest penetration in body tissues. It operates at a wavelength of 904 nm. Superpulsing is defined as the generation of continuous bursts of very-high-power pulses of light energy (10 to 100 Watts) that are of extremely short duration (100 to 200 nanoseconds). This allows GaAs penetration to tissue depths of 3 to 5 cm and deeper. Some versions of GaAs therapeutic lasers actually penetrate to tissue depths of 10 to 14 cm (Kneebone, 2007). There have been many claims and studies regarding LLLT, but the varied quality of trials has led to controversy. Basford (1986, 1995, 1998), a major critic of the deficiencies of many studies, notes that LLLT research has developed along the following three separate lines:
Perhaps the strongest and most well-established research has been on changes in cellular functions. There is a strong body of direct evidence indicating that LLLT can significantly alter cellular processes. The following are specific areas of treatment in which benefits have been claimed:
Basic animal and cellular research with red-beam low-level lasers has produced both positive and negative results. Passarella (1989) believes that the optical properties of mitochondria are influenced by HeNe laser irradiation, with new mitochondrial conformations produced that ultimately lead to increased oxygen consumption. Walker (1983) has suggested that HeNe laser light affects serotonin metabolism, and Yu et al (1997) has demonstrated an increased phosphate potential and energy charge with light exposure. Further research continues at the cellular level. Fibroblast, lymphocyte, monocyte, and macrophage cells have been studied, and bacterial cell lines of Escherichia coli have served as models for investigation (Karu, 1988). The most popular laser in such cellular research has been the HeNe laser with a wavelength of 632.8 nm. However, some major discrepancies are found in the results reported in the existing literature because of the wide variation in the laser parameters employed, particularly dose and treatment time. Because imprecise dosimetry has clouded the issues, the optimal dose for achieving a biological benefit has yet to be determined.
Despite the problems posed by a lack of standardization, lack of controls, and imprecise dose and treatment schedules for in vivo experimental work, results from cellular research were extrapolated to research on animals. Subsequently, a wide variety of animal models were employed to assess the putative biostimulatory effects of laser irradiation on wound healing. Small, loose-skinned rodents such as mice, rats, and guinea pigs have been used most often, but studies using pig models have led to different results. It has been argued that pigskin represents a more suitable model for extrapolation to humans, because it is similar in character to human skin, which has led to its use in human skin grafts, for example (Basford, 1986; Hunter et al, 1984).
Baxter (1997) provides an excellent review of the animal models used in the wound-healing literature. The details of experimental and irradiation procedures are so numerous and variable, however, that reproduction of results and intertrial comparisons are usually not practical. Research groups reported either acceleration in healing or no effect on the healing process. Two criteria frequently used to assess wound healing were collagen content and tensile strength. Rochkind et al (1989) conducted one of the largest series of controlled animal trials, comparing the recovery of LLLT-treated crushed sciatic nerves with that of nonirradiated nerves in rats. Constant low-intensity laser irradiation (7.6 to 10 J/cm2 daily for up to 20 days) demonstrated highly beneficial effects as judged from recordings of compound action potentials. Wound-healing rates in both irradiated and nonirradiated wounds were accelerated, but the amplitude of action potentials in crushed sciatic nerves was raised substantially only in the irradiated groups. The laser treatment also greatly reduced the degeneration of motor neurons, which suggested that these results might be extrapolated for application in human research trials.
The information gained from trials of in vivo animal exposure to laser photobiostimulation indicated that, in certain animal models, wound healing could be achieved. The reader is cautioned to remain both critical and skeptical, however, because variations existed in methodology, techniques, dosimetry, exposure time, and frequency of treatments.
Despite the aforementioned controversy and limitations, many clinicians were persuaded by the cellular and animal data to attempt human trials. A number of disorders, including neurological, rheumatological, and musculoskeletal conditions, have been treated with LLLT with various claims regarding results. The FDA had previously been a major obstacle because of the absence of randomized, placebo-controlled trials and the varying methodology, varying dosages and techniques, and absence of objective parameters. However, as described earlier, in February 2002 it approved the application for the use of LLLT for pain relief.
Carpal tunnel syndrome is a common clinical disorder, seen in 5% to 10% of the population, and is caused by compression of the median nerve at the wrist. Acroparesthesia (numbness, tingling, and burning) in the first three fingers often arises and may interfere with sleep. When resistant to conservative treatment, the disorder often progresses, with weakness and atrophy. There are nine flexor tendons adjacent to the median nerve, and they often intersect the nerve fascicles in the carpal tunnel. Thus, nerve compression or tendinitis may serve as a cause.
Basford et al (1993), using laser light of only 1 J of energy, found that both sensory and motor distal latencies could be significantly decreased in normal volunteers. Basford et al’s study was a double-blind controlled trial using a GaAlAs percutaneous laser. Weintraub (1997), who used a similar laser but at higher energy levels of 9 J and measured compound motor nerve action potential/sensory nerve action potential electrophysiological parameters, reported a nearly 80% success rate in resolving the symptoms of carpal tunnel syndrome with laser therapy. There were no control subjects in the study, but almost 1000 sensory and motor nerve latencies were analyzed before and after each treatment. Particularly interesting was the fact that the distal latency was prolonged in 40% of subjects, yet they remained asymptomatic. This prolonged latency suggests that nonneural tissues were stimulated and could be responsible for symptoms of tendonitis. At the dose used, a significant number of individuals showed immediate prolongation of distal latency (nerve conduction). They remained asymptomatic, however, and by the next visit, the distal latency was back to baseline or improved. A similar observation has also been made by others (Snyder-Mackler et al, 1988). Padua et al (1998) have validated Weintraub’s study, and currently three placebo-controlled trials are being conducted with preliminary reports of 70% success (Lasermedics, 1999). In addition, several reports of studies using higher doses of 10 to 12 J of infrared laser light (40 to 50 mW) revealed alterations in conduction in both the median and superficial radial nerves (Baxter et al, 1994; Bork et al, 1988; Walsh et al, 1991).
Naeser et al (1996) and Branco et al (1999) used a combination of two noninvasive, painless treatment modalities—red-beam laser and microampere-level transcutaneous electrical nerve stimulation (TENS)—to stimulate acupuncture points on the hand of patients with carpal tunnel syndrome or wrist pain. Sham treatments were used as a control. A significant reduction in median nerve sensory latencies in the treated hand and a 92% reduction in pain were observed. Postoperative failures also decreased with this protocol. Weintraub (n.d.) used his original laser treatment protocol (9 J/cm2) and also stimulated various acupressure points as did Naeser et al (1996) and Branco et al (1999) as well as the flexor tendons in the upper wrist. Up to 85% improvement in wrist pain was achieved in patients with carpal tunnel syndrome.
Other superficial nerves also respond to laser biostimulation. Disorders such as meralgia paresthetica, cubital tunnel syndrome, tarsal tunnel syndrome, radial nerve palsy, and traumatic digital neuralgias have responded to this treatment (Weintraub, 1998). Because of the small number of individuals treated, these observations are to be considered anecdotal. However, Weintraub believes that his observations that nonneural structures play an important yet unappreciated role in symptomatic carpal tunnel syndrome, and probably other nerve entrapments, are indeed significant. For example, the distal latency of the median nerve could be longer than 5 milliseconds in patients who have become asymptomatic with laser treatment. Either a threshold exists for the median nerve, or the tendons and blood vessels surrounding the median nerve exert some influence. Franzblau and Werner (1999) raised similar issues in a provocative editorial titled, “What Is Carpal Tunnel Syndrome?”
The efficacy of laser therapy in treating various pain syndromes has been investigated by several groups. Preliminary double-blind studies by Walker (1983) demonstrated improvement in seven out of nine patients with trigeminal neuralgia. Two out of five patients with postherpetic neuralgia showed improvement, and five out of six patients with radiculopathy improved. Baxter et al (1991) also believed that laser therapy was effective for postherpetic neuralgia. Moore et al (1988) investigated the efficacy of GaAlAs laser therapy in the treatment of postherpetic neuralgia in a double-blind, crossover trial involving 20 patients. The result was an apparently significant reduction in pain. Hong et al (1990) validated these results in their study, in which 60% of patients with postherpetic neuralgia felt improvement within 10 minutes. Friedman et al (1994) used an intraoral HeNe laser directed at a specific maxillary alveolar tender point to significantly abort atypical facial pain.
Trigeminal neuralgia was successfully treated with HeNe laser by Walker et al (1986). In the 35 patients studied in this double-blind, placebo-controlled trial, a significant difference was found in visual analogue scale pain ratings between patients receiving active laser treatment and placebo-treated patients.
Using an intraoral HeNe laser directed at a specific maxillary alveolar tender point, Weintraub (1996) was able to abort acute migraine headaches in 85% of cases in a study that included a sham-treatment control condition. These findings support the trigeminovascular theory of migraine with a maxillary (V2) provocative site. The results achieved rival those of pharmacotherapy. Interestingly, Friedman (1998) used cryotherapy (cold water) applied to the same maxillary alveolar tender point to treat atypical facial pain and migraine headache. The treatment produced a striking reduction in discomfort.
Several groups have investigated the efficacy of laser therapy in the treatment of radicular and pseudoradicular pain syndromes. Bieglio and Bisschop (1986) and Mizokami et al (1990) reported positive effects in treating these conditions. Low-power laser therapy has also been used successfully to induce preoperative anesthesia in both veterinary practice and dental surgery (Christensen, 1989). In contrast to the numerous clinical human studies of laser-mediated analgesia, there have been relatively few laboratory studies. Most of the experiments have been completed in China in a variety of animals, including rats, goats, rabbits, sheep, and horses. There are no English abstracts or translations of most of these works. Other studies in animals that were published in English and used tail-flick methodology to assess pain have reported variable findings.
Laser acupuncture using an HeNe diode was reported to be successful in the treatment of experimentally induced arthritis in rats. Vocalization and limb withdrawal in response to noxious stimulation were the parameters measured (Zhu et al, 1990). Although it is clear that problems exist in extrapolating the findings of laboratory work to humans, as noted earlier Naeser et al (1996) and Branco et al (1999) were successful in applying this procedure to treatment of carpal tunnel syndrome. Similarly, Weintraub (1997) saw additional improvement when he combined Naeser’s acupressure points with his protocol in treating this syndrome.
One of the major economic burdens in the United States has been caused by the high incidence of soft tissue injuries and low back pain and subsequent work disability l. Numerous studies using HeNe and infra-red (IR) laser diodes (830 nm range) have reported varying results (Basford, 1986, 1995; Gam et al, 1993; Klein et al, 1990), but randomized controlled and blinded studies have been difficult to carry out.
Rheumatologists in the United States have found encouraging results in laser treatment of rheumatoid arthritis (Goldman et al, 1980), and similar results have been reported in the Soviet Union/Russia, Eastern Europe, and Japan. Walker et al (1986) reported success after a 10-week course of treatment with HeNe lasers. Using a GaAlAs 830-nm laser, Asada et al 1989 found 90% improvement in an uncontrolled trial in 170 patients with rheumatoid arthritis. Despite these generally positive results, Bliddal et al (1987) did not see any significant change in symptoms of morning stiffness or joint function in such patients. However, slight improvement was noted in pain scale ratings. Similar positive results for laser therapy have been reported for osteoarthritis and other conditions. Critics have argued, however, that because rheumatoid arthritis is a disease of exacerbation and remission, it is difficult to assess the efficacy of the therapy.
A number of reports document the apparent efficacy of laser therapy in reducing pain associated with sports injuries. These reports initially came from Russia and Eastern Europe, but the results were subsequently confirmed by Morselli et al (1985) and Emmanoulidis et al (1986). It is notable that in the latter study improvement was accompanied by a decrease in thermographic readings.
The use of laser therapy to treat tendinopathies, especially lateral humeral epicondylitis (tennis elbow), has been studied by numerous groups. There has usually been a relatively rapid response to therapy; however, Haker and Lundberg (1990) failed to show any effect of laser acupuncture treatment on tennis elbow.
Chronic neck pain is common and is often associated specifically with a herniated disk, degenerative disk disease, degenerative spine disease, spinal stenosis, or facet joint dysfunction. The small C-nociceptive afferents and the larger myelinated A delta fibers usually innervate these areas. Local chemical dysfunction with release of substance P, phospholipase A, cytokines, nitric oxide, and so on is probably also involved. It is theorized that direct photoreception by cytochromes produces elevated production of adenosine triphosphate and changes in cell membrane permeability. Antiedema affects and antiinflammatory responses have been alleged to occur in response to laser therapy through reduction in bradykinin levels and increase in β-endorphin levels. The depth of penetration as well as the total dose influence the success of the laser treatment at the target tissue level. Thus, combinations of high-output (centiwatt) GaAlAs and GaAs (superpulsing) lasers can achieve penetration of 3 to 5 cm and even deeper (10 to 14 cm). In addition, acupressure point stimulation (2 to 4 J of energy) to the ear, hand, or body should be used.
Low back pain syndrome is the most common cause of disability in the United States, affecting 75% to 85% of Americans at some point in their lifetimes. Common causes include herniated disks, spinal stenosis, spondylosis, facet joint dysfunction, and failed back syndrome secondary to surgery. As with chronic neck pain, the small C-nociceptive afferents and A delta fibers are involved, with localized chemical dysfunction producing altered signal transduction. Use of a high-output GaAlAs infrared laser at 9 J/cm and/or a GaAs superpulsed infrared laser may be effective in treating the deeper tissues. Usually the nerve irritation occurs deep, around 60 mm, secondary to a herniated disk. Acupressure point stimulation should also be used.
Naeser et al (1995) improved blood flow in stroke patients using laser acupuncture treatment and noted improvement in symptoms.
Weintraub has achieved benefit by stimulating naguien acupressure points with an 830-nm laser Naeser (1999), in a review of the highlights of the Second Congress of the World Association for Laser Therapy, reported that Wilden treated inner ear disorders, including vertigo, tinnitus, and hearing loss, with a combination of 630- to 700-nm and 830-nm lasers. The total dose was at least 4000 J. Daily 1-hour laser treatments to both ears were performed for at least 3 weeks. The lasers were applied to the auditory canal and the mastoid and petrosal bones. Wilden said that he used this approach for more than 9 years in 800 patients, and except in very severe cases, most patients reported improvement in hearing.
Application of laser light to the hegu point on the side contralateral to the pain may be effective for treating migraine headaches. Treatment with an intraoral HeNe laser directed along the zone of maxillary alveolar tenderness also achieves success in the range of 78%. Stimulation is repeated three times at intervals of 1 to 1½ minutes.
Meralgia paresthetica is an often disabling symptom that is caused by compression of the lateral anterior femoral cutaneous nerve at the level of the inguinal ligament. The author (Weintraub) has treated 10 patients with this condition by applying laser stimulation from the level of the inguinal ligament to the level of the knee anterolaterally. Significant pain reduction was noted in 8 of the 10 patients by the fourth treatment, but there have been recurrences.
The soles of the feet and various acupressure points were stimulated by laser without providing relief in 10 cases of nondiabetic peripheral neuropathy. However, the use of monochromatic infrared and visible light phototherapy to treat diabetic peripheral neuropathy has been reported to be successful in inducing temporary or permanent relief from pain and inflammation (Leonard et al, 2004).
No detrimental effects are produced by low-output nonthermal lasers, although it is obvious that direct retinal exposure is to be avoided. Pregnancy does not appear to be a contraindication with LLLT, but investigators have been advised to avoid treating pregnant women and individuals with local tumors in the area of treatment. Individuals who are taking photosensitizing drugs such as tetracycline or who have photosensitive skin should probably avoid this treatment. It has also been suggested that the use of phototherapy after steroid injections is contraindicated, because antiinflammatory medicine is well documented to reduce the effectiveness of photobiostimulation (Lopes-Martins et al, 2006).
Medicine is faced with many conditions that respond poorly or marginally to pharmacological therapy. Thus, the appeal of noninvasive therapeutic laser and other phototherapy devices that are both effective and safe is evident, and they are a most welcome addition to the physician’s armamentarium. Therapeutic laser treatment has been used successfully in a number of fields and is a popular modality worldwide. Critical analysis of the literature indicates that the majority of studies suffer from methodological flaws such as the absence of controls, variable duration and intensity of laser treatment, and poor quality. Consequently, the majority of observations are to be considered anecdotal until appropriate randomized control trials have been undertaken. In the interim, laser therapy appears to be safe and worthy of further investigation for the management of pain and other medical conditions.
Practitioners using biophysical modalities employ a number of noninvasive devices (i.e., devices that do not penetrate the skin) to measure electrical charges and magnetic fields of particular low frequencies. Such devices are also believed to promote healing by interacting with the body.
Biophysical properties of the body have long been observed and utilized in healing. For example, these properties have been known as qi (chi) in traditional Chinese medicine, prana in Ayurvedic medicine, and vital force in homeopathy. Acupuncturists, homeopathic doctors, chiropractors, and practitioners of biophysical medicine and magnetic field therapy (including medical doctors) are among the practitioners who use noninvasive devices to detect and influence biophysical properties of the body.
Although conventional medicine recognizes the presence of electrical charges and magnetic forces in the body, certain biophysical properties, also referenced as “subtle energy,” have not generally been studied or utilized by Western science and medicine.
Unlike other medical devices regulated by the FDA, many of the noninvasive devices used to detect and influence these biophysical properties fall into a gray area from a regulatory standpoint. In 1976 the FDA set standards for the regulation of acupuncture needles as an experimental device, and the needle was reclassified as a therapeutic device in 1996, based partly on clinical evidence published in a series of articles in the new Journal of Alternative and Complementary Medicine: Research on Paradigm, Practice and Policy during 1995. The FDA team working on reclassification specifically requested the founding editor of the journal at that time (the editor of this textbook) to provide lists of references to accelerate the review process. That FDA action occurred before the NIH Consensus Conference on Acupuncture in 1997. However, the FDA did not adopt standards for electroacupuncture devices, a major category of biophysical devices. One of the challenges continues to be the inability of Western science to measure these biophysical properties. As a result, such devices, when cleared by the FDA, are generally approved for use for “investigational” purposes, as in research studies, but not in the diagnosis or treatment of illness.
The following sections discuss four categories of devices: (1) electrical and magnetic devices used in conventional medicine for conventional purposes, (2) conventional devices used in innovative applications, (3) conventional devices used for both innovative and conventional applications, and (4) unconventional devices.
Devices that measure the electrical and magnetic properties of the physical body have been used in conventional medicine for many years. These electrical devices include the electrocardiograph (ECG, EKG), electroencephalograph (EEG), and electromyograph (EMG), used to measure heart, brain, and muscle activity, respectively, for diagnostic purposes. The ECG reads the electrical rhythms of the heart, the EEG records electrical brain waves, and the EMG measures electrical properties of the muscles, which may be correlated to muscle performance. The EMG is often used in physical (rehabilitative) medicine to diagnose conditions that cause pain, weakness, and numbness.
In addition to devices that measure electrical charges, conventional medicine has made increasing use of magnetic resonance imaging (MRI) for diagnostic purposes. MRI measures the magnetic fields of the body to create images for the diagnosis of physical abnormalities. Another magnetic device, the superconducting quantum interference device (SQUID), combines magnetic flux quantization and Josephson tunneling to measure magnetic heart signals complementary to ECG signals.
Some of the devices just described have also been used in innovative ways (not as originally intended) for treatment purposes, such as the use of the ECG and EEG in biofeedback to monitor subconscious processes and “feed back” this information to support behavioral change. The ECG is also the basis of the Flexyx Neurotherapy System, an innovative approach to the modulation of central perception and the processing of afferent signals from the physical receptors in the body (pressure, pain, heat, cold).
MRI, used to diagnose a variety of medical abnormalities, is also being used in a number of innovative ways, as in neuroscience to show brain activity during performance of different tasks, such as reading or other language tasks, and during acupuncture. At the NIH, basic science researchers are currently investigating innovative uses of MRI to measure physiological changes, such as those involved in eye movement or brain activity.
Some devices that utilize electrical charges and magnetic fields are being used by both conventional and biophysical medical practitioners.
In addition to its use in conventional medicine, the SQUID has also been used to measure weak magnetic fields of the brain. In other studies, it has been used to measure large, frequency-pulsing biomagnetic fields that emanate from certain practitioners, such as polarity therapists. This biomagnetic field is thought to trigger biological processes at the cellular and molecular levels, helping the body repair itself.
Developed by Dr. C. Norman Shealy, the TENS unit is used by both conventional medical and biophysical practitioners for pain relief. The FDA approved the TENS unit as a device for pain management in the 1970s. The electronic unit sends pulsed currents to electrodes attached to the skin, displacing pain signals from the affected nerves and preventing the pain message from reaching the brain.
TENS has been suggested to stimulate the production of endorphins as one proposed mechanism of action. In 1990, TENS was the subject of a study published in the New England Journal of Medicine. Although it was found ineffective in this study, other studies have found TENS helpful for mild to moderate pain. TENS may have better results in relieving skin and connective tissue pain than muscle or bone pain.
Using a lower amplitude electrical current than the TENS unit, the Electro-Acuscope device reduces pain by stimulating tissue rather than by stimulating the nerves or causing muscle contractions. It is thought to relieve pain by running currents through damaged tissues. Medical doctors, chiropractors, and physical therapists use the Electro-Acuscope for treatment of muscle spasms, migraines, jaw pain, bursitis, arthritis, surgical incisions, sprains and strains, neuralgia, shingles, and bruises. As with the TENS unit, the Electro-Acuscope has been approved by the FDA as a device for pain management.
The Diapulse device emits radio waves that produce short, intense electromagnetic pulses which penetrate the tissue. It is said to improve blood flow, reduce pain, and promote healing. The Diapulse is used in a variety of health care settings, especially in the treatment of postoperative swelling and pain.
The following devices are some of the more popular devices used in biophysical medicine. The FDA has not set standards for these devices, but some may be registered with the FDA as “biofeedback” devices.
Voll, a German physician, introduced the Dermatron in the 1940s. Voll believed that acupuncture points have electrical conductivity, and he used this device to measure electrical changes in the body. This technique became known as “electroacupuncture according to Voll” (EAV) and is currently termed electroacupuncture biofeedback. Used for diagnosis, the Dermatron became the basis for a number of devices manufactured in Germany, France, Russia, Japan, Korea, the United Kingdom, and the United States.
Another modified electroacupuncture device similar to the Voll device, the Vega works much faster and is also used for diagnosis. Based on the belief that the first sign of abnormality in the body is a change in electrical charge, this device records the change in skin conductivity after the application of a small voltage. Computers have been added to recent models using different names, such as the Computron.
Franz Morel, MD, a colleague of Voll, developed the Mora, another variation of the Voll device. Morel believed that electromagnetic signals could be described by a complex waveform. The Mora reads “wave” information from the body. Proponents believe that the Mora can relieve headaches, migraines, muscular aches and pains, circulation disorders, and skin disease.
In addition to the electroacupuncture, biofeedback, and other devices that measure electrical charges described earlier, there are also therapeutic cymatic devices, in which a sound transducer replaces the electrodes of the EAV devices. Each organ and tissue in the body emits sound at a particular harmonic frequency. The cymatic device recognizes and records the emitted sound patterns associated with each body part and bathes the affected area with sound to balance the disturbance. These devices are used for diagnosis and treatment.
The sound probe emits a pulsed tone of three alternating frequencies. This device is thought to destroy bacteria, viruses, and fungi that are not in resonance with the body.
The light beam generator is thought to work by emitting photons of light that help to restore a normal energy state at the cellular level, allowing the body to heal. The light beam generator is believed to promote healing throughout the body and to help correct such problems as depression, insomnia, headaches, and menstrual disorders.
The Infratonic QGM uses electroacoustical technology to direct massagelike waves into the body. This device is employed as an effective pain management tool in China, Japan, Taiwan, Singapore, France, Spain, Mexico, and Argentina. The FDA has approved this device for therapeutic massage in the United States.
Named after the researcher Nikola Tesla, the Teslar watch was developed to modulate the harmful effects of “electronic” pollution from modern sources, such as computers, cell phones, televisions, hair dryers, and electric blankets. It is believed that these products create magnetic energy that may destabilize the body’s electromagnetic field. Although this energy is at extremely low frequencies, which range from 1 to 100 Hz, it is believed to affect humans adversely over time.
The Kirlian camera records and measures high-frequency, high-voltage electrons using the gas visualization discharge technique, also called the “corona discharge technique.” The most experienced researchers in this technique are Russian; Seymon and Valentina Kirlian pioneered this research in the 1970s. Other contributors include Nikola Tesla in the United States, J.J. Narkiewich-Jodko in Russia, and Pratt and Schlemmer in Prague. In 1995, Konstantin Korotkov and his team in St. Petersburg developed a new Kirlian camera using a Crown TV.
Chapter References can be found on the Evolve website at http://evolve.elsevier.com/Micozzi/complementary/