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Magnetic and electrical stimulation in the rehabilitative treatment of patients with organic lesions of the nervous system

Tyshkevich TG, Nikitina VV.

A. L. Polenov Russian Science Research Neurosurgical Institute, St. Petersburg.

Studies were performed on 89 patients with organic lesions of the nervous system in which the leading clinical symptoms consisted of paralysis and pareses. Patients received complex treatment, including pulsed magnetic fields and an electrical stimulation regime producing multilevel stimulation. A control group of 49 patients with similar conditions was included, and these patients received only sinusoidal currents. Combined treatment with magnetic and electrical stimulation was more effective, as indicated by radiographic and electromyographic investigations.

Electromagnetic interventions in musculoskeletal disorders

Bachl N, Ruoff G, Wessner B, Tschan H.

Department of Sports and Exercise Physiology, Institute of Sports Science, University of Vienna, Austria. 

Electromagnetic interventions in general and those considering the musculoskeletal system in particular hold many obscurities. Several studies revealing positive effects of electromagnetic fields oppose those showing no beneficial effects. After a historical review and a discussion of basic details on electromagnetic signals, this article provides information on the effects of electromagnetic fields on a cellular level and gives an account of preclinical and clinical studies focused on electromagnetic interventions by means of weak pulsed electromagnetic fields on musculoskeletal disorders.

Deconvolution of transcranial magnetic stimulation (TMS) maps

Bohning DE, He L, George MS, Epstein CM.

Department of Radiology, Medical University of South Carolina

Transcranial magnetic stimulation (TMS) is a noninvasive method for local stimulation of cerebral cortex using a small coil's pulsed magnetic field. TMS response maps consist of measured responses to stimulations at points on a scalp-referenced grid and are used to study the topography of the brain's inhibitory and excitatory response. Because the magnetic field distributions of stimulation coils are 1-2 centimeters wide and 2-3 centimeters long, and the induced electric fields are even broader, the resolution of TMS maps is limited and the actual region of cortical stimulation is poorly defined. To better characterize the activation pattern, a practical mathematical procedure was developed for deconvolving a spherical model approximation of the coil's induced electric field distribution (here measured in a phantom) from the TMS response maps. This procedure offers an integrated, internally consistent method for processing TMS response maps to estimate the spatial distribution of motor cortex activations and inhibitions.

Alzheimer's disease: improvement of visual memory and visuoconstructive performance by treatment with picotesla range magnetic fields

Sandyk R.

NeuroCommunication Research Laboratories, Danbury, CT

Impairments in visual memory and visuoconstructive functions commonly occur in patients with Alzheimer's disease (AD). Recently, I reported that external application of electromagnetic fields (EMF) of extremely low intensity (in the picotesla range) and of low frequency (in the range of 5Hz-8Hz) improved visual memory and visuoperceptive functions in patients with Parkinson's disease. Since a subgroup of Parkinsonian patients, specifically those with dementia, have coexisting pathological and clinical features of AD, I investigated in two AD patients the effects of these extremely weak EMF on visual memory and visuoconstructive performance. The Rey-Osterrieth Complex Figure Test as well as sequential drawings from memory of a house, a bicycle, and a man were employed to evaluate the effects of EMF on visual memory and visuoconstructive functions, respectively. In both patients treatment with EMF resulted in a dramatic improvement in visual memory and enhancement of visuoconstructive performance which was associated clinically with improvement in other cognitive functions such as short term memory, calculations, spatial orientation, judgement and reasoning as well as level of energy, social interactions, and mood. The report demonstrates, for the first time, that specific cognitive symptoms of AD are improved by treatment with EMF of a specific intensity and frequency. The rapid improvement in cognitive functions in response to EMF suggests that some of the mental deficits of AD are reversible being caused by a functional (i.e., synaptic transmission) rather than a structural (i.e., neuritic plaques) disruption of neuronal communication in the central nervous system.

A comparison of rheumatoid arthritis and fibromyalgia patients and healthy controls exposed to a pulsed (200 microT) magnetic field: effects on normal standing balance.

Thomas AW, White KP, Drost DJ, Cook CM, Prato FS.

The Lawson Health Research Institute, Department of Nuclear Medicine & MR, St. Joseph's Health Care, 268 Grosvenor Street, London, N6A 4V2, Ontario, Canada. 

Specific weak time varying pulsed magnetic fields (MF) have been shown to alter animal and human behaviors, including pain perception and postural sway. Here we demonstrate an objective assessment of exposure to pulsed MF's on Rheumatoid Arthritis (RA) and Fibromyalgia (FM) patients and healthy controls using standing balance. 15 RA and 15 FM patients were recruited from a university hospital outpatient Rheumatology Clinic and 15 healthy controls from university students and personnel. Each subject stood on the center of a 3-D forceplate to record postural sway within three square orthogonal coil pairs (2 m, 1.75 m, 1.5 m) which generated a spatially uniform MF centered at head level. Four 2-min exposure conditions (eyes open/eyes closed, sham/MF) were applied in a random order. With eyes open and during sham exposure, FM patients and controls appeared to have similar standing balance, with RA patients worse. With eyes closed, postural sway worsened for all three groups, but more for RA and FM patients than controls. The Romberg Quotient (eyes closed/eyes open) was highest among FM patients. Mixed design analysis of variance on the center of pressure (COP) movements showed a significant interaction of eyes open/closed and sham/MF conditions [F=8.78(1,42), P<0.006]. Romberg Quotients of COP movements improved significantly with MF exposure [F=9.5(1,42), P<0.005] and COP path length showed an interaction approaching significance with clinical diagnosis [F=3.2(1,28), P<0.09]. Therefore RA and FM patients, and healthy controls, have significantly different postural sway in response to a specific pulsed MF.

Long term beneficial effects of weak electromagnetic fields in multiple sclerosis

Sandyk R.

NeuroCommunication Research Laboratories, Danbury

A 39 year-old severely disabled woman with a 19 year history of chronic relapsing-remitting multiple sclerosis (MS) began to experience improvement in symptoms within 24 hours after she received experimental treatment with picotesla electromagnetic fields (EMFs). Pattern reversal visual evoked potential (VEP) study obtained three weeks after the initiation of the first magnetic treatment showed a return to normal of the P100 latencies in each eye. The patient continued to receive 1-2 EMFs treatments per week and during the following 32 months she made a dramatic recovery with resolution of diplopia, blurring of vision, dysarthria, ataxia of gait, and bladder dysfunction as well as improvement in fatigue, heat tolerance, mood, sleep, libido, and cognitive functions. VEP studies, which were repeated in April of 1995 more than 2 1/2 years after the initiation of magnetic treatment, showed that P100 latencies remained normal in each eye providing objective documentation that continued application of these EMFs may sustain normal conduction in the damaged optic pathways over a long period of time. This is the first case report documenting the dramatic long term beneficial effects of treatment with picotesla range EMFs in a patient with MS.

Ice and pulsed electromagnetic field to reduce pain and swelling after distal radius fractures

Cheing GL, Wan JW, Kai Lo S.

Department of Rehabilitation Sciences, The Hong Kong Polytechnic University

OBJECTIVE:

To examine the relative effectiveness of ice therapy and/or pulsed electromagnetic field in reducing pain and swelling after the immobilization period following a distal radius fracture.

METHODS:

A total of 83 subjects were randomly allocated to receive 30 minutes of either ice plus pulsed electromagnetic field (group A); ice plus sham pulsed electromagnetic field (group B); pulsed electromagnetic field alone (group C), or sham pulsed electromagnetic field treatment for 5 consecutive days (group D). All subjects received a standard home exercise programme. A visual analogue scale was used for recording pain; volumetric displacement for measuring the swelling of the forearm; and a hand-held goniometer for measuring the range of wrist motions before treatment on days 1, 3 and 5.

RESULTS:

At day 5, a significantly greater cumulative reduction in the visual analogue scores as well as ulnar deviation range of motion was found in group A than the other 3 groups. For volumetric measurement and pronation, participants in group A performed better than subjects in group D but not those in group B.

CONCLUSION:

The addition of pulsed electromagnetic field to ice therapy produces better overall treatment outcomes than ice alone, or pulsed electromagnetic field alone in pain reduction and range of joint motion in ulnar deviation and flexion for a distal radius fracture after an immobilization period of 6 weeks.

A box coil for the stimulation of biological tissue and cells in vitro and in vivo by pulsed magnetic fields.

Battocletti JH, Macias MY, Pintar FA, Maiman DJ, Sutton CH.

Department of Neurosurgery (Froedtert West), Medical College of Wisconsin, Milwaukee 53226, USA

An alternative coil system to the Helmoholtz coil-pair is described for the stimulation of biological tissue and cells: a relatively large box coil made of copper or aluminum sheet stock. The design is based on the principal determinant of the induced electric field, namely, the magnetic vector potential (A), in the equation, [formula: see text]. The second term in the equation is needed when boundaries of the conducting medium are in close proximity to the region of interest, such as in a culture dish. An electric surface charge builds up on the boundaries to generate an electric field which cancels [formula: see text] at the surface. The effectiveness of the new coil is demonstrated in a study of the outgrowth enhancement of axons from rat embryonic dorsal root ganglia.

50 Hz extremely low frequency electromagnetic fields enhance protein carbonyl groups content in cancer cells: effects on proteasomal systems.

Eleuteri AM, Amici M, Bonfili L, Cecarini V, Cuccioloni M, Grimaldi S, Giuliani L, Angeletti M, Fioretti E

Department of Biology M.C.A., University of Camerino, 62032 Camerino (MC), Italy.

Electromagnetic fields are an assessed cause of prolonging free radicals lifespan. This study was carried out to investigate the influence of extremely low frequency electromagnetic fields on protein oxidation and on the 20S proteasome functionality, the complex responsible for the degradation of oxidized proteins. Caco 2 cells were exposed, for 24-72 hours, to 1 mT, 50 Hz electromagnetic fields. The treatment induced a time-dependent increase both in cell growth and in protein oxidation, more evident in the presence of TPA, while no changes in cell viability were detected. Exposing the cells to 50 Hz electromagnetic fields caused a global activation of the 20S proteasome catalytic components, particularly evident at 72 hours exposure and in the presence of TPA. The finding that EGCG, a natural antioxidant compound, counteracted the field-related pro-oxidant effects demonstrates that the increased proteasome activity was due to an enhancement in intracellular free radicals.

3D imaging with a single-sided sensor: an open tomograph.

Perlo J, Casanova F, Blümich B.

Institut für Technische und Macromolekulare Chemie, RWTH Aachen D-52056, Germany.

An open tomograph to image volume regions near the surface of large objects is described. The central achievement in getting such a tomograph to work is the design of a fast two-dimensional pure phase encoding imaging method to produce a cross-sectional image in the presence of highly inhomogeneous fields. The method takes advantage of the multi-echo acquisition in a Carr-Purcell-Meiboom-Gill (CPMG)-like sequence to significantly reduce the experimental time to obtain a 2D image or to spatially resolve relaxation times across the sensitive volume in a single imaging experiment. Depending on T(2) the imaging time can be reduced by a factor of up to two orders of magnitude compared to the one needed by the single-echo imaging technique. The complete echo train decay has been also used to produce T(2) contrast in the images and to spatially resolve the T(2) distribution of an inhomogeneous object, showing that variations of structural properties like the cross-link density of rubber samples can be distinguished by this method. The sequence has been implemented on a single-sided sensor equipped with an optimized magnet geometry and a suitable gradient coil system that provides two perpendicular pulsed gradient fields. The static magnetic field defines flat planes of constant frequency parallel to the surface of the scanner that can be selected by retuning the probe frequency to achieve slice selection into the object. Combining the slice selection obtained under the presence of the static gradient of the open magnet with the two perpendicular pulsed gradient fields, 3D spatial resolution is obtained.

Features of anti-inflammatory effects of modulated extremely high-frequency electromagnetic radiation

Gapeyev AB, Mikhailik EN, Chemeris NK.

Institute of Cell Biophysics of Russian Academy of Sciences, Pushchino

Using a model of acute zymosan-induced paw edema in NMRI mice, we test the hypothesis that anti-inflammatory effects of extremely high-frequency electromagnetic radiation (EHF EMR) can be essentially modified by application of pulse modulation with certain frequencies. It has been revealed that a single exposure of animals to continuous EHF EMR for 20 min reduced the exudative edema of inflamed paw on average by 19% at intensities of 0.1-0.7 mW/cm(2) and frequencies from the range of 42.2-42.6 GHz. At fixed effective carrier frequency of 42.2 GHz, the anti-inflammatory effect of EHF EMR did not depend on modulation frequencies, that is, application of different modulation frequencies from the range of 0.03-100 Hz did not lead to considerable changes in the effect level. On the contrary, at "ineffective" carrier frequencies of 43.0 and 61.22 GHz, the use of modulation frequencies of 0.07-0.1 and 20-30 Hz has allowed us to restore the effect up to a maximal level. The results obtained show the critical dependence of anti-inflammatory action of low-intensity EHF EMR on carrier and modulation frequencies. Within the framework of this study, the possibility of changing the level of expected biological effect of modulated EMR by a special selection of combination of carrier and modulation frequencies is confirmed.

915 MHz microwaves and 50 Hz magnetic field affect chromatin conformation and 53BP1 foci in human lymphocytes from hypersensitive and healthy persons.

Belyaev IY, Hillert L, Protopopova M, Tamm C, Malmgren LO, Persson BR, Selivanova G, Harms-Ringdahl M..

Department of Genetics, Microbiology and Toxicology, Stockholm University, S-106 91 Stockholm, Sweden. 

We used exposure to microwaves from a global system for mobile communication (GSM) mobile phone (915 MHz, specific absorption rate (SAR) 37 mW/kg) and power frequency magnetic field (50 Hz, 15 muT peak value) to investigate the response of lymphocytes from healthy subjects and from persons reporting hypersensitivity to electromagnetic field (EMF). The hypersensitive and healthy donors were matched by gender and age and the data were analyzed blind to treatment condition. The changes in chromatin conformation were measured with the method of anomalous viscosity time dependencies (AVTD). 53BP1 protein, which has been shown to colocalize in foci with DNA double strand breaks (DSBs), was analyzed by immunostaining in situ. Exposure at room temperature to either 915 MHz or 50 Hz resulted in significant condensation of chromatin, shown as AVTD changes, which was similar to the effect of heat shock at 41 degrees C. No significant differences in responses between normal and hypersensitive subjects were detected. Neither 915 MHz nor 50 Hz exposure induced 53BP1 foci. On the contrary, a distinct decrease in background level of 53BP1 signaling was observed upon these exposures as well as after heat shock treatments. This decrease correlated with the AVTD data and may indicate decrease in accessibility of 53BP1 to antibodies because of stress-induced chromatin condensation. Apoptosis was determined by morphological changes and by apoptotic fragmentation of DNA as analyzed by pulsed-field gel electrophoresis (PFGE). No apoptosis was induced by exposure to 50 Hz and 915 MHz microwaves. In conclusion, 50 Hz magnetic field and 915 MHz microwaves under specified conditions of exposure induced comparable responses in lymphocytes from healthy and hypersensitive donors that were similar but not identical to stress response induced by heat shock.

Age-related disruption of circadian rhythms: possible relationship to memory impairment and implications for therapy with magnetic fields

Sandyk R, Anninos PA, Tsagas N.

Department of Psychiatry, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY

Disorganization of circadian rhythms, a hallmark of aging, may be related causally to the progressive deterioration of memory functions in senescence and possibly Alzheimer's disease (AD). In experimental animals, disruption of circadian rhythms produces retrograde amnesia by interfering with the circadian organization of memory processes. The circadian system is known to be synchronized to external 24 h periodicities of ambient light by a neural pathway extending from the retina to the suprachiasmatic nucleus (SCN) of the anterior hypothalamus. There is also evidence that the earth's magnetic field is a time cue ("Zeitgeber") of circadian organization and that shielding of the ambient magnetic field leads to disorganization of the circadian rhythms in humans. Since aging is associated with a delay of the circadian rhythm phase, and since light, which phase advances circadian rhythms, mimics the effects of magnetic fields on melatonin secretion, we postulate that application of magnetic fields might improve memory functions in the elderly as a result of resynchronization of the circadian rhythms. Moreover, since the circadian rhythm organization is more severely disrupted in patients with AD, it is possible that magnetic treatment might prove useful also in improving memory functions in these patients. If successful, application of magnetic fields might open new avenues in the management of memory disturbances in the elderly and possibly in AD.

A biomagnetic system for in vivo cancer imaging.

Flynn ER1, Bryant HC.

Senior Scientific, Albuquerque, NM 87111, USA. 

An array of highly sensitive biomagnetic sensors of the superconducting quantum interference detector (SQUID) type can identify disease in vivo by detecting and imaging microscopic amounts of nanoparticles. We describe in detail procedures and parameters necessary for implementation of in vivo detection through the use of antibody-labelled magnetic nanoparticles as well as methods of determining magnetic nanoparticle properties. We discuss the weak field magnetic sensor SQUID system, the method of generating the magnetic polarization pulse to align the magnetic moments of the nanoparticles, and the measurement techniques to measure their magnetic remanence fields following this pulsed field. We compare these results to theoretical calculations and predict optimal properties of nanoparticles for in vivo detection.

AC pulsed electromagnetic fields-induced sexual arousal and penile erections in Parkinson's disease

Sandyk R.

Department of Neuroscience at the Institute for Biomedical Engineering and Rehabilitation Services, Touro College, Bay Shore, NY

Sexual dysfunction is common in patients with Parkinson's disease (PD) since brain dopaminergic mechanisms are involved in the regulation of sexual behavior. Activation of dopamine D2 receptor sites, with resultant release of oxytocin from the paraventricular nucleus (PVN) of the hypothalamus, induces sexual arousal and erectile responses in experimental animals and humans. In Parkinsonian patients subcutaneous administration of apomorphine, a dopamine D2 receptor agonist, induces sexual arousal and penile erections. It has been suggested that the therapeutic efficacy of transcranial administration of AC pulsed electromagnetic fields (EMFs) in the picotesla flux density in PD involves the activation of dopamine D2 receptor sites which are the principal site of action of dopaminergic pharmacotherapy in PD. Here, 1 report 2 elderly male PD patients who experienced sexual dysfunction which was recalcitrant to treatment with anti Parkinsonian agents including selegiline, levodopa and tolcapone. However, brief transcranial administrations of AC pulsed EMFs in the picotesla flux density induced in these patients sexual arousal and spontaneous nocturnal erections. These findings support the notion that central activation of dopamine D2 receptor sites is associated with the therapeutic efficacy of AC pulsed EMFs in PD. In addition, since the right hemisphere is dominant for sexual activity, partly because of a dopaminergic bias of this hemisphere, these findings suggest that right hemispheric activation in response to administration of AC pulsed EMFs was associated in these patient with improved sexual functions.

A case cohort study of suicide in relation to exposure to electric and magnetic fields among electrical utility workers.

Baris D, Armstrong BG, Deadman J, Thériault G.

Department of Occupational Health, Faculty of Medicine, McGill University, Montrèal, Canada.

OBJECTIVES:

This case cohort study examines whether there is an association between exposure to electric and magnetic fields and suicide in a population of 21,744 male electrical utility workers from the Canadian Province of Québec.

METHODS:

49 deaths from suicide were identified between 1970 and 1988 and a subcohort was selected comprising a 1% random sample from this cohort as a basis for risk estimation. Cumulative and current exposures to electric fields, magnetic fields, and pulsed electromagnetic fields (as recorded by the POSITRON meter) were estimated for the subcohort and cases through a job exposure matrix. Two versions of each of these six indices were calculated, one based on the arithmetic mean (AM), and one on the geometric mean (GM) of field strengths.

RESULTS:

For cumulative exposure, rate ratios (RR) for all three fields showed mostly small non-significant increases in the medium and high exposure groups. The most increased risk was found in the medium exposure group for the GM of the electric field (RR = 2.76, 95% CI 1.15-6.62). The results did not differ after adjustment for socioeconomic state, alcohol use, marital state, and mental disorders. There was a little evidence for an association of risk with exposure immediately before the suicide.

CONCLUSION:

Some evidence for an association between suicide and cumulative exposure to the GM of the electric fields was found. This specific index was not initially identified as the most relevant index, but rather emerged afterwards as showing the most positive association with suicide among the 10 indices studied. Thus the evidence from this study for a causal association between exposure to electric fields and suicide is weak. Small sample size (deaths from suicide) and inability to control for all potential confounding factors were the main limitations of this study.

Healing of nonunion of a fractured lateral condyle of the humerus by pulsing electromagnetic induction

Das Sarkar S, Bassett CA.

Department of Orthopaedic Surgery, Sandwell District General Hospital, Lyndon.

Nonoperative salvage of a surgically resistant case of established nonunion of a fracture of the lateral condyle of the humerus in a child is described. Solid union was achieved by treatment with pulsed electromagnetic fields. A review of the literature indicates that this is the first published report of such a case.

1800 MHz electromagnetic field effects on melatonin release from isolated pineal glands.

Sukhotina I, Streckert JR, Bitz AK, Hansen VW, Lerchl A.

School of Engineering and Science, International University Bremen, Bremen, Germany.

Isolated pineal glands of Djungarian hamsters (Phodopus sungorus) were continuously perifused by Krebs-Ringer buffer, stimulated with the beta-adrenergic receptor agonist isoproterenol to induce melatonin synthesis, and exposed for 7 hr to a 1800 MHz continuous wave (CW) or pulsed GSM (Global System for Mobile Communications)-modulated electromagnetic signal at specific absorption rate (SAR) rates of 8, 80, 800, and 2700 mW/kg. Experiments were performed in a blind fashion. Perifusate samples were collected every hour, and melatonin concentrations were measured by a specific radioimmunoassay. Both types of signal significantly enhanced melatonin release at 800 mW/kg SAR, while at 2700 mW/kg SAR, melatonin levels were elevated in the CW, but suppressed in the GSM-exposed pineal glands. As a temperature rise of approximately 1.2 degrees C was measured at 2700 mW/kg SAR, effects at this level are thermal. With regard to radiofrequency electromagnetic fields, the data do not support the 'melatonin hypothesis,' according to which nonthermal exposure suppresses melatonin synthesis.

A detailed ethological analysis of the mouse open field test: effects of diazepam, chlordiazepoxide and an extremely low frequency pulsed magnetic field.

Choleris E, Thomas AW, Kavaliers M, Prato FS.

Department of Psychology, Social Science Center, University of Western Ontario, London, Ontario, Canada 

The open field test (OFT) is a widely used procedure for examining the behavioral effects of drugs and anxiety. Detailed ethological assessments of animal behavior are lacking. Here we present a detailed ethological assessment of the effects of acute treatment with the benzodiazepines, diazepam (DZ, 1.5mg/kg) and chlordiazepoxide (CDP, 5.0 and 10.0mg/kg), as well as exposure to a non-pharmacological agent, a specific pulsed extremely low frequency magnetic field (MAG) on open field behavior. We examined the duration, frequency and time course of various behaviors (i.e. exploration, walk, rear, stretch attend, return, groom, sit, spin turn, jump and sleep) exhibited by male mice in different regions of a novel open field. Both DZ and CDP consistently reduced the typical anxiety-like behaviors of stretch attend and wall-following (thigmotaxis), along with that of an additional new measure: 'returns', without producing any overall effects on total locomotion. The drugs also differed in their effects. CDP elicited a shift in the locomotor pattern from a 'high explore' to a 'high walk', while DZ mainly elicited alterations in sit and groom. The MAG treatment was repeated twice with both exposures reducing horizontal and vertical (rearing) activity and increasing grooming and spin turns. However, the anxiety-like behaviors of stretch attend and return were marginally reduced by only the first exposure. We conclude that a detailed ethological analysis of the OFT allows not only the detection of specific effects of drugs and non-pharmacological agents (i.e. pulsed magnetic field) on anxiety-like behaviors, but also permits the examination of non-specific effects, in particular those on general activity.

3H-noradrenaline release potentiated in a clonal nerve cell line by low-intensity pulsed magnetic fields.

Dixey R, Rein G.

Department of Medical Electronics, St Bartholomew's Hospital, West Smithfield, London EC1A 7BE, UK
Department of Chemical Pathology, Queen Charlotte's Maternity Hospital, London W6 0XG, UK

Recent studies have shown that extremely low-frequency (ELF) electric fields1 and radiofrequency amplitude-modulated electromagnetic fields2,3,25 can influence ion fluxes in neural tissue. Furthermore, the application of low-frequency magnetic (LFM) fields in the successful treatment of non-union fractures and pseudo-arthrosis has been widely reported4–6. Stimulated by these findings and the wide variety of effects reported in other biological systems7–10, we have set out to establish a model system for studying the biological effects of such low-frequencyfields that readily allows analysis of their mechanism of action. Clonal lines in tissue culture are an obvious choice for such a model, first, because the analysis is simplified by the presence of only one cell type and second, because the geometry of the biological sample can be specified to allow precise quantitation of applied field strengths and induced current densities. One such clonal line, designated PC12, is a likely candidate for such an approach as it expresses many properties of differentiated sympathetic neurones11–16, including calcium-dependent release of newotransmitters11,12,14. We report here that 3H-noradrenaline(NA) release from PC12 cells is stimulated by an inductively coupled 500-Hz LFM field with a magnitude comparable with certain cholinergic stimuli in this system.

A drug naive parkinsonian patient successfully treated with weak electromagnetic fields.

Sandyk R.

NeuroCommunication Research Laboratories, Danbury, CT 06811, USA.

Brief cerebral application of picotesla (pT) electromagnetic fields (EMF) has been demonstrated an efficacious, revolutionary treatment modality for the therapy of Parkinson's disease (PD) with clinical benefits being evident in all motor aspects of the disease as well as in nonmotor symptoms such as mood, sleep, pain, sexual dysfunction, autonomic regulation and cognitive functions. Since treatment with pT EMF has involved PD patients who were treated with dopaminergic agents at the time they received EMF there may have been a synergistic interaction between dopaminergic drugs and EMF. The present communication concerns a 49-year-old male Parkinsonian patient with stage 3 disability on the Hoehn and Yahr scale (1967) who, in response to brief extracranial applications of pT EMF, demonstrated a marked improvement in motor, depressive symptomatology and cognitive functions and was classified as stage 1 several weeks later. This case is remarkable in that the patient did not receive treatment with dopaminergic drugs prior to or during the course of EMF therapy. It suggests that (a) pT range EMF may be efficacious as a monotherapy for PD and should be considered also as a treatment modality for de novo diagnosed patients, and (b) application of these EMF improves Parkinsonism by a mechanism which involves, among others, augmentation of dopaminergic and serotonergic neurotransmission.

Analgesic and behavioral effects of a 100 microT specific pulsed extremely low frequency magnetic field on control and morphine treated CF-1 mice

Shupak NM, Hensel JM, Cross-Mellor SK, Kavaliers M, Prato FS, Thomas AW.

Bioelectromagnetics, Lawson Health Research Institute, Department of Nuclear Medicine, St. Joseph's Health Care

Diverse studies have shown that magnetic fields can affect behavioral and physiological functions. Previously, we have shown that sinusoidal extremely low frequency magnetic fields and specific pulsed magnetic fields (Cnps) can produce alterations in the analgesia-related behavior of the land snail. Here, we have extended these studies to show an induction of analgesia in mice equivalent to a moderate dose of morphine (5 mg/kg), and the effect of both Cnp exposure and morphine injection on some open-field activity. Cnp exposure was found to prolong the response latency to a nociceptive thermal stimulus (hot plate). Cnp+morphine offset the increased movement activity found with morphine alone. These results suggest that pulsed magnetic fields can induce analgesic behavior in mice without the side effects often associated with opiates like morphine.

A flexible infrastructure for delivering augmented reality enabled transcranial magnetic stimulation.

Hughes CJ, John NW.

University of Wales, Bangor, Gwynedd

Transcranial Magnetic Stimulation (TMS) is the process in which electrical activity in the brain is influenced by a pulsed magnetic field. Common practice is to align an electromagnetic coil with points of interest identified on the surface of the brain, from an MRI scan of the subject. The coil can be tracked using optical sensors, enabling the targeting information to be calculated and displayed on a local workstation. In this paper we explore the hypothesis that using an Augmented Reality (AR) interface for TMS will improve the efficiency of carrying out the procedure. We also aim to provide a flexible infrastructure that if required, can seamlessly deploy processing power from a remote high performance computing resource.

1439 MHz pulsed TDMA fields affect performance of rats in a T-maze task only when body temperature is elevated.

Yamaguchi H, Tsurita G, Ueno S, Watanabe S, Wake K, Taki M, Nagawa H.

Department of Surgical Oncology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan. 

This study sought to clarify the effects of exposure to electromagnetic waves (EMW) used in cellular phones on learning and memory processes. Sprague-Dawley rats were exposed for either 1 h daily for 4 days or for 4 weeks to a pulsed 1439 MHz time division multiple access (TDMA) field in a carousel type exposure system. At the brain, average specific absorption rate (SAR) was 7.5 W/kg, and the whole body average SAR was 1.7 W/kg. Other subjects were exposed at the brain average SAR of 25 W/kg and the whole body average SAR of 5.7 W/kg for 45 min daily for 4 days. Learning and memory were evaluated by reversal learning in a food rewarded T-maze, in which rats learned the location of food (right or left) by using environmental cues. The animals exposed to EMW with the brain average SAR of 25 W/kg for 4 days showed statistically significant decreases in the transition in number of correct choices in the reversal task, compared to sham exposed or cage control animals. However, rats exposed to the brain average SAR of 7.5 W/kg for either 4 days or for 4 weeks showed no T-maze performance impairments. Intraperitoneal temperatures, as measured by a fiber optic thermometer, increased in the rats exposed to the brain average SAR of 25 W/kg but remained the same for the brain average SAR of 7.5 W/kg. The SAR of a standard cellular phone is restricted to a maximum of 2 W/kg averaged over 10 g tissue. These results suggest that the exposure to a TDMA field at levels about four times stronger than emitted by cellular phones does not affect the learning and memory processes when there are no thermal effects.

Application of high amplitude alternating magnetic fields for heat induction of nanoparticles localized in cancer

Ivkov R, DeNardo SJ, Daum W, Foreman AR, Goldstein RC, Nemkov VS, DeNardo GL.

Triton BioSystems, Inc., Chelmsford, Massachusetts, USA

Magnetic nanoparticles conjugated to a monoclonal antibody can be i.v. injected to target cancer tissue and will rapidly heat when activated by an external alternating magnetic field (AMF). The result is necrosis of the microenvironment provided the concentration of particles and AMF amplitude are sufficient. High-amplitude AMF causes nonspecific heating in tissues through induced eddy currents, which must be minimized. In this study, application of high-amplitude, confined, pulsed AMF to a mouse model is explored with the goal to provide data for a concomitant efficacy study of heating i.v. injected magnetic nanoparticles.

METHODS:

Thirty-seven female BALB/c athymic nude mice (5-8 weeks) were exposed to an AMF with frequency of 153 kHz, and amplitude (400-1,300 Oe), duration (1-20 minutes), duty (15-100%), and pulse ON time (2-1,200 seconds). Mice were placed in a water-cooled four-turn helical induction coil. Two additional mice, used as controls, were placed in the coil but received no AMF exposure. Tissue and core temperatures as the response were measured in situ and recorded at 1-second intervals.

RESULTS:

No adverse effects were observed for AMF amplitudes of < or = 700 Oe, even at continuous power application (100% duty) for up to 20 minutes. Mice exposed to AMF amplitudes in excess of 950 Oe experienced morbidity and injury when the duty exceeded 50%.

CONCLUSION:

High-amplitude AMF (up to 1,300 Oe) was well tolerated provided the duty was adjusted to dissipate heat. Results presented suggest that further tissue temperature regulation can be achieved with suitable variations of pulse width for a given amplitude and duty combination. These results suggest that it is possible to apply high-amplitude AMF (> 500 Oe) with pulsing for a time sufficient to treat cancer tissue in which magnetic nanoparticles have been embedded.

A birdcage model for the Chinese meridian system: part III. Possible mechanism of magnetic therapy.

Yung KT.

Magnetic Resonance Research Center, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA.

Based on the electromagnetic model of the transmission line for the channel and the birdcage resonator for the meridian network, we interpret two effects, seemingly incomprehensible in terms of current Western physiology, the lasting effect and the remote effect. For the lasting effect, acupuncture enhances the amplitude of the Qi standing wave, and this increased amplitude is retained and thus is able to sustain a gradual remodeling of the extracellular matrix in interstitial connective tissues, resulting in a lasting therapeutic effect. For the remote effect (acupuncture effect far from the site of needle insertion), our model puts the mechanism of magnetic therapy on an equal footing with that of acupuncture. It may not be a coincidence that accounts of investigators in both acupuncture and magnetotherapy about the depth of the effective site--along cleavage planes between muscles, or between muscle and bone or tendon--are in accord with that of the Huang Di Nei Jing about the course of channels: "they are embedded and travel between interstitial muscles, deep and invisible." A possible magnetic field generated outside the birdcage may be manipulated to produce local areas of higher temperature or very strong fields.

A literature review: the effects of magnetic field exposure on blood flow and blood vessels in the microvasculature.

McKay JC, Prato FS, Thomas AW.

Bioelectromagnetics, Imaging Program, Lawson Health Research Institute, London, Ontario, Canada.

The effect of magnetic field (MF) exposure on microcirculation and microvasculature is not clear or widely explored. In the limited body of data that exists, there are contradictions as to the effects of MFs on blood perfusion and pressure. Approximately half of the cited studies indicate a vasodilatory effect of MFs; the remaining half indicate that MFs could trigger either vasodilation or vasoconstriction depending on initial vessel tone. Few studies indicate that MFs cause a decrease in perfusion or no effect. There is a further lack of investigation into the cellular effects of MFs on microcirculation and microvasculature. The role of nitric oxide (NO) in mediating microcirculatory MF effects has been minimally explored and results are mixed, with four studies supporting an increase in NO activity, one supporting a biphasic effect, and five indicating no effect. MF effects on angiogenesis are also reported: seven studies supporting an increase and two a decrease. Possible reasons for these contradictions are explored. This review also considers the effects of magnetic resonance imaging (MRI) and anesthetics on microcirculation. Recommendations for future work include studies aimed at the cellular/mechanistic level, studies involving perfusion measurements both during and post-exposure, studies testing the effect of MFs on anesthetics, and investigation into the microcirculatory effects of MRI.

Beneficial effects of electromagnetic fields

Bassett CA.

Bioelectric Research Center, Columbia University, New York

Selective control of cell function by applying specifically configured, weak, time-varying magnetic fields has added a new, exciting dimension to biology and medicine. Field parameters for therapeutic, pulsed electromagnetic field (PEMFs) were designed to induce voltages similar to those produced, normally, during dynamic mechanical deformation of connective tissues. As a result, a wide variety of challenging musculoskeletal disorders have been treated successfully over the past two decades. More than a quarter million patients with chronically ununited fractures have benefitted, worldwide, from this surgically non-invasive method, without risk, discomfort, or the high costs of operative repair. Many of the athermal bioresponses, at the cellular and subcellular levels, have been identified and found appropriate to correct or modify the pathologic processes for which PEMFs have been used. Not only is efficacy supported by these basic studies but by a number of double-blind trials. As understanding of mechanisms expands, specific requirements for field energetics are being defined and the range of treatable ills broadened. These include nerve regeneration, wound healing, graft behavior, diabetes, and myocardial and cerebral ischemia (heart attack and stroke), among other conditions. Preliminary data even suggest possible benefits in controlling malignancy.

Accounting for human variability and sensitivity in setting standards for electromagnetic fields

Bailey WH, Erdreich LS.

Exponent Health Sciences Practice, New York, NY 

Biological sensitivity and variability are key issues for risk assessment and standard setting. Variability encompasses general inter-individual variations in population responses, while sensitivity relates to unusual or extreme responses based on genetic, congenital, medical, or environmental conditions. For risk assessment and standard setting, these factors affect estimates of thresholds for effects and dose-response relationships and inform efforts to protect the more sensitive members of the population, not just the typical or average person. While issues of variability and sensitivity can be addressed by experimental and clinical studies of electromagnetic fields, investigators have paid little attention to these important issues. This paper provides examples that illustrate how default assumptions regarding variability can be incorporated into estimates of 60-Hz magnetic field exposures with no risk of cardiac stimulation and how population thresholds and variability of peripheral nerve stimulation responses at 60-Hz can be estimated from studies of pulsed gradient magnetic fields in magnetic resonance imaging studies. In the setting of standards for radiofrequency exposures, the International Commission for Non-Ionizing Radiation Protection uses inter-individual differences in thermal sensitivity as one of the considerations in the development of "safety factors." However, neither the range of sensitivity nor the sufficiency or excess of the 10-fold and the additional 5-fold safety factors have been assessed quantitatively. Data on the range of responses between median and sensitive individuals regarding heat stress and cognitive function should be evaluated to inform a reassessment of these safety factors and to identify data gaps.

Echoplanar BOLD fMRI of brain activation induced by concurrent transcranial magnetic stimulation

Bohning DE, Shastri A, Nahas Z, Lorberbaum JP, Andersen SW, Dannels WR, Haxthausen EU, Vincent DJ, George MS.

Department of Radiology, Medical University of South Carolina

RATIONALE AND OBJECTIVES:

The authors demonstrate the feasibility of combining transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) inside an MR scanner to noninvasively stimulate and image regional brain activity.

METHODS:

Echoplanar blood oxygen level dependent (BOLD)-based fMRI studies of TMS response were performed on three human volunteers inside a standard 1.5 T MR scanner using independent computer control to interleave echoplanar image acquisition and stimulation of right thumb primary motor cortex with a nonferromagnetic TMS coil.

RESULTS:

Significant (P< 0.001) response was observed in motor cortex under the TMS coil during stimulation compared to rest, as well in auditory cortex, the latter presumably due to the loud "snap" when the coil was pulsed.

CONCLUSIONS:

Concurrent TMS stimulation and echoplanar BOLD fMRI imaging is possible. This method has potential for tracing neural circuits with brain imaging, as well as investigating the effects of TMS.

A mechanism for action of extremely low frequency electromagnetic fields on biological systems.

Balcavage WX, Alvager T, Swez J, Goff CW, Fox MT, Abdullyava S, King MW.

Indiana University School of Medicine, Indiana State University

This report outlines a simple mechanism, based on the Hall Effect, by which static and low frequency (50-60 Hz) pulsed electromagnetic fields (PEMFs) can modify cation flow across biological membranes and alter cell metabolism. We show that magnetic fields commonly found in the environment can be expected to cause biologically significant interactions between transported cations and basic domains of cation channel proteins. We calculate that these interactions generate forces of a magnitude similar to those created by normal transmembrane voltage changes known to gate cation channels. Thus PEMFs are shown to have the potential of regulating flow through cation channels, changing the steady state concentrations of cellular cations and thus the metabolic processes dependent on cation concentrations.

Alimentary hyperlipemia of rabbits is affected by exposure to low-intensity pulsed magnetic fields

Luo E, Shen G, Xie K, Wu X, Xu Q, Lu L, Jing X.

Department of Military Medical Equipment & Metrology, Faculty of Biomedical Engineering, The Fourth Military Medical University, Xi'an, China. 

An experimental study was carried out in rabbits to investigate the effects of exposing rabbits to low-intensity pulsed magnetic fields (PMFs) on alimentary hyperlipemia. Thirty female white big ear rabbits were randomly divided into three groups. The normal group was fed with a standard chow diet and the other two groups (hyperlipid and magnetic) were fed with the chow diet supplemented with cholesterol, yolk powder and lard. The magnetic group was exposed to 15 Hz pulsed magnetic fields. After 8 weeks, levels of blood lipid and indices of hemorheology were examined. In addition, histomorphologic changes of hepatic and myocardial tissues were compared across the groups respectively. Compared with the hyperlipid group, hemorheology indices of the magnetic group reduced significantly from 12.80% to 38.05% (P < 0.01) indicating lower blood viscosity. Similarly, compared with the hyperlipid group, the levels of total cholesterol and triglycerides in the magnetic group decreased 40.52% and 52.42% (P < 0.01). On the contrary, high density lipoprotein (HDL) value obviously increased 66.67% (P < 0.01). Furthermore, compared with the control group, the values of triglycerides and HDL of the magnetic group did not show statistical differences (P > 0.05). The deposit of fatty material on the inner lining of thoracic aorta wall of the magnetic group was significantly lighter than that of the hyperlipid group. Numerous aggregation of lipoids emerged among myocardial myofibrils in the hyperlipid group, while no notable change was found in both the magnetic and control group. The results indicate that low-intensity PMFs could be helpful for the treatment of alimentary hyperlipemia.

Antinociceptive effects of a pulsed magnetic field in the land snail, Cepaea nemoralis

Thomas AW, Kavaliers M, Prato FS, Ossenkopp KP.

Neuroscience Program, University of Western Ontario, London, Canada.

 

Pulsed magnetic fields (patent pending) consisting of approximately 100 microT (peak), frequency modulated, extremely low frequency magnetic fields (ELFMF) were shown to induce a significant degree of antinociception ('analgesia') in the land snail Cepaea nemoralis. Fifteen minute exposures to a specific magnetic field both increased enkephalinase inhibitor induced opioid analgesia and induced analgesia in untreated snails. Injection of the prototypic opioid antagonist naloxone, attenuated, but did not completely block, the pulsed magnetic field induced analgesia. Two other pulsed waveform designs failed to induce analgesia in untreated snails. These findings suggest that specific magnetic field exposure designs may be tailored to produce significant behavioral effects including, but certainly not limited to, the induction of analgesia.

A pilot investigation of the effect of extremely low frequency pulsed electromagnetic fields on humans' heart rate variability.

Baldi E, Baldi C, Lithgow BJ.

Diagnostic and Neurosignal Processing Research Group, Electrical & Computer System Engineering, Monash University, Victoria, Australia. 

The question whether pulsed electromagnetic field (PEMF) can affect the heart rhythm is still controversial. This study investigates the effects on the cardiocirculatory system of ELF-PEMFs. It is a follow-up to an investigation made of the possible therapeutic effect ELF-PEMFs, using a commercially available magneto therapeutic unit, had on soft tissue injury repair in humans. Modulation of heart rate (HR) or heart rate variability (HRV) can be detected from changes in periodicity of the R-R interval and/or from changes in the numbers of heart-beat/min (bpm), however, R-R interval analysis gives only a quantitative insight into HRV. A qualitative understanding of HRV can be obtained considering the power spectral density (PSD) of the R-R intervals Fourier transform. In this study PSD is the investigative tool used, more specifically the low frequency (LF) PSD and high frequency (HF) PSD ratio (LF/HF) which is an indicator of sympatho-vagal balance. To obtain the PSD value, variations of the R-R time intervals were evaluated from a continuously recorded ECG. The results show a HR variation in all the subjects when they are exposed to the same ELF-PEMF. This variation can be detected by observing the change in the sympatho-vagal equilibrium, which is an indicator of modulation of heart activity. Variation of the LF/HF PSD ratio mainly occurs at transition times from exposure to nonexposure, or vice versa. Also of interest are the results obtained during the exposure of one subject to a range of different ELF-PEMFs. This pilot study suggests that a full investigation into the effect of ELF-PEMFs on the cardiovascular system is justified.

Calculation of electric fields induced in the human knee by a coil applicator

Buechler DN, Christensen DA, Durney CH, Simon B.

Department of Electrical Engineering, University of Utah

Calculations are presented of the induced electric fields and current densities in the cartilage of the knee produced by a coil applicator developed for applying pulsed magnetic fields to osteoarthritic knees. This applicator produces a sawtooth-like magnetic field waveform composed of a series of 260-micros pulses with a peak to peak magnitude of approximately 0.12 mT in the cartilage region. The simulations were performed using a recently developed 3 dimensional finite difference frequency domain technique for solving Maxwell's equations with an equivalent circuit model. The tissue model was obtained from the anatomically segmented human body model of Gandhi. The temporal peak electric field magnitude was found to be -153 mV/m, averaged within the medial cartilage of the knee for the typical dB/dt excitation levels of this coil. The technique can be extended to analyze other excitation waveforms and applicator designs.

A portable pulsed electromagnetic field (PEMF) device to enhance healing of recalcitrant venous ulcers: a double-blind, placebo-controlled clinical trial

Stiller MJ, Pak GH, Shupack JL, Thaler S, Kenny C, Jondreau L.

Ronald O. Perelman Department of Dermatology, New York University Medical Center, New York

A prospective, randomized, double-blind, placebo-controlled multicentre study assessed the clinical efficacy and safety of pulsed electromagnetic limb ulcer therapy (PELUT) in the healing of recalcitrant, predominantly venous leg ulcers. The portable device was used at home for 3 h daily during this 8-week clinical trial as an adjunct to a wound dressing. Wound surface area, ulcer depth and pain intensity were assessed at weeks 0, 4 and 8. At week 8 the active group had a 47.7% decrease in wound surface area vs. a 42.3% increase for placebo (P < 0.0002). Investigators' global evaluations indicated that 50% of the ulcers in the active group healed or markedly improved vs. 0% in the placebo group, and 0% of the active group worsened vs. 54% of the placebo group (P < 0.001). Significant decreases in wound depth (P < 0.04) and pain intensity (P < 0.04) favouring the active group were seen. Patients whose ulcers improved significantly after 8 weeks were permitted to continue double-blind therapy for an additional 4 weeks. Eleven active and one placebo patient continued therapy until week 12, with the active treatment group continuing to show improvement. There were no reports of adverse events attributable to this device. We conclude that the PELUT device is a safe and effective adjunct to non-surgical therapy for recalcitrant venous leg ulcers.

A pulsed electric field enhances cutaneous delivery of methylene blue in excised full-thickness porcine skin

Johnson PG, Gallo SA, Hui SW, Oseroff AR.

Department of Molecular and Cellular Biophysics, Roswell Park Cancer Institute, Buffalo, New York 

We used electric pulses to permeabilize porcine stratum corneum and demonstrate enhanced epidermal transport of methylene blue, a water-soluble cationic dye. Electrodes were placed on the outer surface of excised full-thickness porcine skin, and methylene blue was applied to the skin beneath the positive electrode; 1 ms pulses of up to 240 V were delivered at frequencies of 20-100 Hz for up to 30 min. The amount of dye in a skin sample was determined from absorbance spectra of dissolved punch biopsy sections. Penetration depth and concentration of the dye were measured with light and fluorescence microscopy of cryosections. At an electric exposure dose VT (applied voltage x frequency x pulse width x treatment duration) of about 4700 Vs, there is a threshold for efficient drug delivery. Increasing the applied voltage or field application time resulted in increased dye penetration. Transport induced by electric pulses was more than an order of magnitude greater than that seen following iontophoresis. We believe that the enhanced cutaneous delivery of methylene blue is due to a combination of de novo permeabilization of the stratum corneum by electric pulses, passive diffusion through the permeabilization sites, and electrophoretic and electroosmotic transport by the electric pulses. Pulsed electric fields may have important applications for drug delivery in a variety of fields where topical drug delivery is a goal.

Analysis of the current distribution in bone produced by pulsed electro-magnetic field stimulation of bone

Chen II, Saha S.

Department of Physiology and Biophysics, Louisiana State University Medical Center, Shreveport 

Pulsed electromagnetic stimulation is being increasingly used by orthopaedic surgeons to treat non-unions and congenital pseudoarthrosis. In this paper a theoretical model is developed to analyze the distribution of induced current in bone due to a pulsed electromagnetic field, produced by a pair of Helmholtz coils. The result shows that the induced current density is dependent of the electrical properties of bone, geometry of the coils and their location.

Amplification of evoked potentials recorded from mouse hippocampal slices by very low repetition rate pulsed magnetic fields

Wieraszko A.

Department of Biology/Program in Neuroscience, The College of Staten Island/CUNY, Staten Island, NY

The influence of low repetition rate pulsed magnetic fields (LRMF) on the evoked potential (population spike) recorded from mouse hippocampal slices was investigated. LRMF were applied according to two protocols. In protocol A, LRMF applied with a constant strength (15 mT) and frequency ranging from 0.03 to 0.5 Hz resulted in an amplification of the potential. Although the frequency of 0.16 Hz was the most effective, enhancing the population spike by over 280%, it also caused an increase in spontaneous activity, seizures, and cessation of neuronal activity in 50% of the slices. In protocol B, LRMF were applied with a variable intensity (9-15 mT) and in cycles of different duration ranging from 5 to 20 min. While an increase in the amplitude of the population spike was observed in all slices exposed to LRMF applied according to protocol B, the longest exposure was the most effective. Neither seizures nor an increase in the spontaneous activity were observed in this group of the slices. These results support and extend our previous data and characterize further the relation between the pattern of applied magnetic fields and their influence on the nervous system.

Alignment of microscopic particles in electric fields and its biological implications

Takashima S, Schwan HP.

It is well known that electromagnetic fields cause mechanical forces. If one applies an electrical field to a suspension of microscopic particles, these particles realign themselves along the direction of the field and form pearl-chain-like aggregates. These chains are mostly single stranded but they are frequently multistranded. This phenomenon has been investigated by a number of groups. Here we discuss the dependence of threshold field strength on particle size and frequency. Also, pulsed fields have been thought to be more effective than continuous fields of the same average power in evoking biological effects. Our measurement of the threshold power requirement for the pearl-chain formation indicates that pulsed fields require as much power as continuous fields. The biological significance of pearl-chain formation is briefly discussed.

A pulsing electric field (PEF) increases human chondrocyte proliferation through a transduction pathway involving nitric oxide signaling

Fitzsimmons RJ, Gordon SL, Kronberg J, Ganey T, Pilla AA.

The Technical Basis LLC, Loma Linda, California

A potential treatment modality for joint pain due to cartilage degradation is electromagnetic fields (EMF) that can be delivered, noninvasively, to chondrocytes buried within cartilage. A pulsed EMF in clinical use for recalcitrant bone fracture healing has been modified to be delivered as a pulsed electric field (PEF) through capacitive coupling. It was the objective of this study to determine whether the PEF signal could have a direct effect on chondrocytes in vitro. This study shows that a 30-min PEF treatment can increase DNA content of chondrocyte monolayer by approximately 150% at 72 h poststimulus. Studies intended to explore the biological mechanism showed this PEF signal increased nitric oxide measured in culture medium and cGMP measured in cell extract within the 30-min exposure period. Increasing calcium in the culture media or adding the calcium ionophore A23187, without PEF treatment, also significantly increased short-term nitric oxide production. The inhibitor W7, which blocks calcium/calmodulin, prevented the PEF-stimulated increase in both nitric oxide and cGMP. The inhibitor L-NAME, which blocks nitric oxide synthase, prevented the PEF-stimulated increase in nitric oxide, cGMP, and DNA content. An inhibitor of guanylate cyclase (LY83583) blocked the PEF-stimulated increase in cGMP and DNA content. A nitric oxide donor, when present for only 30 min, increased DNA content 72 h later. Taken together, these results suggest the transduction pathway for PEF-stimulated chondrocyte proliferation involves nitric oxide and the production of nitric oxide may be the result of a cascade that involves calcium, calmodulin, and cGMP production.

A probe for measuring current density during magnetic stimulation

Tay G, Chilbert MA, Battocletti J, Sances A Jr, Swiontek T.

Department of Neurosurgery, Medical College of Wisconsin, Milwaukee

Time-varying magnetic fields induce currents in conductive media, and when the induced current is large enough in excitable tissue, stimulation occurs. This phenomenon has been applied to the human brain and peripheral nerves for diagnostic evaluation of the neural system. One important aspect that is presently unknown is the current level necessary in tissue for stimulation induced by magnetic fields. This study presents a method of measuring the induced current density from pulsed magnetic fields in vitro and in vivo. The current-density probe was inserted into three concentrations of saline and into the brains of ten anesthetized cats. Two stimulation systems with coils 9 cm and 5 cm in diameter were used. The two systems provided sinusoidal and pulsatile coil currents. Measurements made in saline were compared with those calculated theoretically for a semi-infinite medium. The measured values were within 5% of the calculated values. Measurements made in the cat brain showed a 67% decrease compared with the theoretic model. This variance is attributed to the finite bounds of the skull. The results indicate that direct measurement of current density is possible. Subsequent measurements will aid in the design of improved magnetic stimulation systems.

Alterations in adenylate kinase activity in human PBMCs after in vitro exposure to electromagnetic field: comparison between extremely low frequency electromagnetic field (ELF) and therapeutic application of a musically modulated electromagnetic field (TAMMEF)

Albanese A, Battisti E, Vannoni D, Aceto E, Galassi G, Giglioni S, Tommassini V, Giordano N.

TAMMEF Centre, University of Siena, Siena, Italy.

This study investigated the effects of electromagnetic fields on enzymes involved in purine metabolism in human peripheral blood mononuclear cells in vitro. Cells were obtained from 20 volunteers. We tested both low-energy, extremely low frequency (ELF; 100-Hz) electromagnetic fields and the Therapeutic Application of Musically Modulated Electromagnetic Fields (TAMMEFs); the latter is characterized by variable frequencies, intensities, and wave shapes. Adenylate kinase activity was increased after ELF field exposure but decreased slightly after TAMMEF exposure. Neither of the two electromagnetic field affected the activities of the purine metabolism enzymes ecto-5'-nucleotidase, adenosine deaminase, and adenosine kinase. We concluded that ELF fields may influence cellular electrical charge stability; stimulation of adenylate kinase activity could restore the cell to a state of equilibrium. In contrast, TAMMEF fields may be useful for maintaining and regulating the cellular electrical charge.

Alcoholism: newer methods of management

Subrahmanyam S, Satyanarayana M, Rajeswari KR.

Chronic alcoholics were selected from hospitals and A.A. Centres and subjected to different methods of treatment namely, psycho therapy, stereotaxic surgery, nonvolitional biofeedback, Yoga and meditation and extremely low frequency Pulsed Magnetic Field. Each group comprised a minimum of 20 subjects. All were males between the ages of 20 and 45 years. Investigations done were clinical, psychological, biochemical, neurochemical and electrophysiological. Improvement was noticed in all the patients, the degree varying with the different methods of treatment. The patients were followed up at least for a period of one year.

An increase in the negative surface charge of U937 cells exposed to a pulsed magnetic field

Smith OM, Goodman EM, Greenebaum B, Tipnis P.

Biomedical Research Institute, University of Wisconsin-Parkside, Kenosha

Pulsed magnetic fields have been used to enhance healing of bone fractures and purportedly of lesions in soft tissue. However, their mechanism of action is poorly understood. We report changes in the plasma membrane of a nonadherent mammalian cell line, U937, which was exposed to a 25-pps magnetic field for 48 hours. Aqueous polymer two-phase partition studies showed that magnetic-field-exposed cells exhibited an increased negative surface charge but membrane hydrophobicity was not significantly altered. The observed increase in membrane electronegativity of exposed cells did not reflect a significant change in growth rate.

A randomized, double-blind, placebo-controlled clinical trial using a low-frequency magnetic field in the treatment of musculoskeletal chronic pain

Thomas AW, Graham K, Prato FS, McKay J, Forster PM, Moulin DE, Chari S.

Bioelectromagnetics, Imaging Program, Lawson Health Research Institute, Department of Medical Biophysics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada.

Exposure to a specific pulsed electromagnetic field (PEMF) has been shown to produce analgesic (antinociceptive) effects in many organisms. In a randomized, double-blind, sham-controlled clinical trial, patients with either chronic generalized pain from fibromyalgia (FM) or chronic localized musculoskeletal or inflammatory pain were exposed to a PEMF (400 microT) through a portable device fitted to their head during twice-daily 40 min treatments over seven days. The effect of this PEMF on pain reduction was recorded using a visual analogue scale. A differential effect of PEMF over sham treatment was noticed in patients with FM, which approached statistical significance (P=0.06) despite low numbers (n=17); this effect was not evident in those without FM (P=0.93; n=15). PEMF may be a novel, safe and effective therapeutic tool for use in at least certain subsets of patients with chronic, nonmalignant pain. Clearly, however, a larger randomized, double-blind clinical trial with just FM patients is warranted.

A randomized double-blind prospective study of the efficacy of pulsed electromagnetic fields for interbody lumbar fusions

Mooney V.

Division of Orthopaedic Surgery, University of California, Irvine.

A randomized double-blind prospective study of pulsed electromagnetic fields for lumbar interbody fusions was performed on 195 subjects. There were 98 subjects in the active group and 97 subjects in the placebo group. A brace containing equipment to induce an electromagnetic field was applied to patients undergoing interbody fusion in the active group, and a sham brace was used in the control group. In the active group there was a 92% success rate, while the control group had a 65% success rate (P greater than 0.005). The effectiveness of bone graft stimulation with the device is thus established.

Analysis of Electric Field in Real Rat Head Model during Transcranial Magnetic Stimulation

Zheng J, Li L, Huo X.

Inst. of Electr. Eng., Chinese Acad. of Sci., Beijing.

Transcranial magnetic stimulation (TMS) is a non-invasive technique that uses the principle of electromagnetic induction to generate currents in the brain via pulsed magnetic fields. Although there are some researches about electric field and current density distribution induced by TMS on human brain, similar analyses on other species are rarely known. TMS is often used on rat models before used on human being, then how TMS affects the rat brain is critical information for researchers. In this paper, a real rat head model during transcranial magnetic stimulation is presented. 3D-reconstruction method and finite element method are carried out to calculate the spatial distribution of the electric field. This model is quite useful to design TMS experiments on rats and interpret these results.

A testable theoretical model for magnetotherapy potentially applicative to such diverse concerns as oncogenic, CNS trophic factor and viral disorders

Jacobson JI.

Perspectivism Foundation, Institute of Theoretical Physics & Advanced Studies for Biophysical Research, Jupiter, Florida 

Physiologic magnetic fields of the order 10(-8) gauss have been unified with their propitiators: quantum genetic particles, the gravitational potential of which is about an erg. As these fields are applied to the equation for solenoidal models, B = micro NI/L, currents of about a microampere are derived; in perfect accord with recent clinical data indicating the therapeutic efficacy of weak currents in repair and growth of soft tissue, bone and nerve. The mechanism of reorientation of spin angular momentum of leptons and baryons influencing molecular magnetic domains to bring about 'particle jumps' is presented so that a clinical picture results. The clinical picture is that of an organism placed at right angles to flux lines in the midst of a solenoid immersed in water exposed then to exogenously applied resonant physiologic magnetic fields which convert malalligned atomic lattices of oncogenes and associated particles to homologous normal structures.

A single molecule detection method for understanding mechanisms of electric field-mediated interstitial transport of genes

Henshaw JW, Zaharoff DA, Mossop BJ, Yuan F.

Department of Biomedical Engineering, Duke University

The interstitial space is a rate limiting physiological barrier to non-viral gene delivery. External pulsed electric fields have been proposed to increase DNA transport in the interstitium, thereby improving non-viral gene delivery. In order to characterize and improve the interstitial transport, we developed a reproducible single molecule detection method to observe the electromobility of DNA in a range of pulsed, high field strength electric fields typically used during electric field-mediated gene delivery. Using agarose gel as an interstitium phantom, we investigated the dependence of DNA electromobility on field magnitude, pulse duration, pulse interval, and pore size in the interstitial space. We observed that the characteristic electromobility behavior, exhibited under most pulsing conditions, consisted of three distinct phases: stretching, reptation, and relaxation. Electromobility depended strongly on the field magnitude, pulse duration, and pulse interval of the applied pulse sequences, as well as the pore size of the fibrous matrix through which the DNA migrated. Our data also suggest the existence of a minimum pulse amplitude required to initiate electrophoretic transport. These results are useful for understanding the mechanisms of DNA electromobility and improving interstitial transport of genes during electric field-mediated gene delivery.

Anthropometric and quantitative EMG status of femoral quadriceps before and after conventional kinesitherapy with and without magnetotherapy

Graberski Matasović M, Matasović T, Markovac Z.

Institute of Physical Medicine, Rehabilitation and Rheumatology, Holy Spirit General Hospital, Zagreb, Croatia.

The frequency of femoral quadriceps muscle hypotrophy has become a significant therapeutic problem. Efforts are being made to improve the standard scheme of kinesitherapeutic treatment by using additional more effective therapeutic methods. Beside kinesitherapy, the authors have used magnetotherapy in 30 of the 60 patients. The total of 60 patients, both sexes, similar age groups and intensity of hypotrophy, were included in the study. They were divided into groups A and B, the experimental and the control one (30 patients each). The treatment was scheduled for the usual 5-6 weeks. Electromyographic quantitative analysis was used to check-up the treatment results achieved after 5 and 6 weeks of treatment period. Analysis of results has confirmed the assumption that magnetotherapy may yield better and faster treatment results, disappearance of pain and decreased risk of complications. The same results were obtained in the experimental group, only one week earlier than in the control group. The EMG quantitative analysis has not proved sufficiently reliable and objective method in the assessment of real condition of the muscle and effects of treatment.

A study of the effects of pulsed electromagnetic field therapy with respect to serological grouping in rheumatoid arthritis

Ganguly KS, Sarkar AK, Datta AK, Rakshit A.

National Institute for the Orthopaedically Handicapped (NIOH), Calcutta.

The positive role of pulsed electromagnetic field (PEMF) therapy in rheumatoid arthritis (RA) is known. The differential role of serological status of patients in RA is also well known. This paper presents a study of the differential effects of PEMF therapy on the two serological groups of patients. The responses of the seropositive patients are found to be more subdued. Varying effects of the therapy in alleviating the different symptomatologies indicate that the rheumatoid factor (RF) is more resistant to PEMF.

A multicenter clinical trial on the use of pulsed electromagnetic fields in the treatment of temporomandibular disorders.

Peroz I, Chun YH, Karageorgi G, Schwerin C, Bernhardt O, Roulet JF, Freesmeyer WB, Meyer G, Lange KP.

Department of Prosthetic Dentistry and Oral Gerontology, Humboldt University, Berlin, Germany.

STATEMENT OF THE PROBLEM:

Pulsed electromagnetic fields have shown therapeutic benefit in the treatment of numerous forms of osteoarthritis but have not been evaluated for their effects on the temporomandibular joint (TMJ).

PURPOSE:

The aim of this study was to examine the effects of pulsed electromagnetic fields in the treatment of patients with temporomandibular disorders (TMD).

MATERIALS AND METHODS:

A multicenter clinical trial compared active treatment of 36 patients using pulsed electromagnetic fields to placebo treatment of 42 patients with TMD with pain in 1 or both TMJs and/or limited opening of less than 40 mm. Subjective parameters including pain intensity, pain frequency, degree of limitation, restriction of daily life, and intensity and frequency of joint noises were evaluated using a visual analog scale. Trained, blinded examiners assessed the clinical parameters according to Research Diagnostic Criteria for temporomandibular disorders before treatment (baseline), directly after nine 1-hour treatments on consecutive working days, 6 weeks after treatment, and 4 months after treatment. Statistical evaluation was done using the Friedman test, and by paired comparison between baseline and follow-up examinations using the U test (P < .05).

RESULTS:

Seventy-six patients completed the study. For both the active and placebo treatment, significant improvements were seen in the subjective data (P < .01). Patients with anterior disk displacement without reduction also showed significant improvements in active mouth opening (P = .015), patients with ostheoarthritis only showed improvements in some of the subjective parameters (P < .03), and patients with anterior disk displacement with reduction showed no improvement at all.

CONCLUSIONS:

Pulsed electromagnetic fields had no specific treatment effects in patients with temporomandibular disorders.

A weak pulsed magnetic field affects adenine nucleotide oscillations, and related parameters in aggregating Dictyostelium discoideum amoebae

Davies E, Olliff C, Wright I, Woodward A, Kell D.

Pharmaceutical Sciences Research Group, University of Brighton, East Sussex, UK.

A model eukaryotic cell system was used to explore the effect of a weak pulsed magnetic field (PMF) on time-varying physiological parameters. Dictyostelium discoideum cells (V12 strain) were exposed to a pulsed magnetic field (PMF) of flux density 0.4 mT, generated via air-cored coils in trains of 2 ms pulses gated at 20 ms. This signal is similar to those used to treat non-uniting fractures. Samples were taken over periods of 20 min from harvested suspensions of amoebae during early aggregation phase, extracted and derivatised for HPLC fluorescent assay of adenine nucleotides. Analysis of variance showed a significant athermal damping effect (P < 0.002, n = 22) of the PMF on natural adenine nucleotide oscillations and some consistent changes in phase relationships. The technique of nonlinear dielectric spectroscopy (NLDS) revealed a distinctive effect of PMF, caffeine and EGTA in modulating the cellular harmonic response to an applied weak signal. Light scattering studies also showed altered frequency response of cells to PMF, EGTA and caffeine. PMF caused a significant reduction of caffeine induced cell contraction (P < 0.0006, n = 19 by paired t-test) as shown by Malvern particle size analyser, suggesting that intracellular calcium may be involved in mediating the effect of the PMF.

A distributed equivalent magnetic current based FDTD method for the calculation of E-fields induced by gradient coils.

Liu F, Crozier S.

The School of Information Technology and Electrical Engineering, The University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia.

This paper evaluates a new, low-frequency finite-difference time-domain method applied to the problem of induced E-fields/eddy currents in the human body resulting from the pulsed magnetic field gradients in MRI. In this algorithm, a distributed equivalent magnetic current is proposed as the electromagnetic source and is obtained by quasistatic calculation of the empty coil's vector potential or measurements therein. This technique circumvents the discretization of complicated gradient coil geometries into a mesh of Yee cells, and thereby enables any type of gradient coil modelling or other complex low frequency sources. The proposed method has been verified against an example with an analytical solution. Results are presented showing the spatial distribution of gradient-induced electric fields in a multi-layered spherical phantom model and a complete body model.

Amplitude windows and transiently augmented transcription from exposure to electromagnetic fields

Litovitz TA, Montrose CJ, Goodman R, Elson EC.

Vitreous State Laboratory, Catholic University of America, Washington, DC

The exposure of cells to relatively low-intensity, pulsed, low-frequency electromagnetic fields can result in a transient augmentation of mRNA synthesis. Under certain conditions of irradiation, the augmentation is a function of the strength of the electromagnetic field. A linear, multi-step, chemical-reaction model accounts for many of the principal features that are observed in both the time- and intensity-dependent variations of transcriptional effects. The crucial assumption in the model is that the direct effect of electromagnetic fields on exposed cells is an increase in the rate constant that characterizes one of the intermediate sequential reactions in the synthesis of mRNA.

An experimental study of the effects of pulsed electromagnetic field (Diapulse) on nerve repair

Raji AM.

This study investigates the effects of a pulsed electromagnetic field (PEMF) (Diapulse) on experimentally divided and sutured common peroneal nerves in rats. Evidence is presented to show that PEMF accelerates recovery of use of the injured limb and enhances regeneration of damaged nerves.

Autoradiographic evaluation of electromagnetic field effects on serotonin (5HT1A) receptors in rat brain

Johnson MT, McCullough J, Nindl G, Chamberlain JK.

Terre Haute Center for Medical Education, Indiana University School of Medicine

Serotonin (5HT1A) is a chemical mediator of inflammation and the largest single neurotransmitter system of the brain. Its secretion and physiological actions mediate stress and pain, affecting both immune and nervous system functions through the hypothalamic-pituitary-adrenal axis. Serotonin receptor dysfunction is well-characterized in mental disturbances like depression and anxiety. Transcranial magnetic stimulation has been used therapeutically to treat refractory disorders like non-responsive depression and may act in part through its effect on 5HT1A receptors. Previously we have shown that in vitro, 5HT1A receptor binding to a radioactive agonist can be modulated by specific intensity and frequency electromagnetic fields (EMFs). In the present report we have used quantitative receptor autoradiography to evaluate 5HT1A receptor density in rat brain and the impact of pulsed EMF exposure on receptor binding in key brain regions. Rats used in this study had whole body exposures to either a geofield control or to pulsed EMFs to evaluate the treatment for chemically-induced tendinitis. Since the brains were exposed coincidentally as a consequence of the main experiment, we investigated the potential for EMF-induced changes in areas such as the hippocampus. This pilot study should provide a detailed understanding of magnetic field effects on stress-responsive brain regions and will lead to a more coordinated approach to the use of such modalities for therapeutic intervention in humans.

An increase in cAMP concentration in mouse hippocampal slices exposed to low-frequency and pulsed magnetic fields

Hogan MV, Wieraszko A.

Clinical Laboratory Sciences, College of Allied Health Professions, University of South Alabama

Our previous studies revealed that magnetic fields amplified evoked potentials recorded from mouse hippocampal slices. In search for the mechanism of this effect, we evaluated the concentration of cAMP in slices exposed to low-frequency and pulsed magnetic fields. Low-frequency magnetic fields of 15 mT applied at 0.16 Hz for 30 min enhanced the concentration of cAMP almost three-fold. The concentration of cAMP continued to rise through the first hour after turning magnetic fields off, reaching almost a four-fold increase, and then returned to control levels at the end of the second hour. Neither static magnetic fields nor magnetic fields applied with the frequency of 0.5 Hz had any effect on cAMP concentration. The increase in cAMP levels was dependent on the strength of the magnetic field and required the presence of extracellular calcium. A pulsed magnetic field applied with variable intensity (9-15 mT) and in cycles lasting from 5 to 20 min doubled the cAMP concentration. These results support our previous electrophysiological observations and provide biochemical correlates for their interpretation.

A programmable ramp waveform generator for PEMF exposure studies on chondrocytes

Jahns M, Durdle N, Lou E, Raso VJ.

Dept. of Electr. & Comput. Eng., Alberta Univ., Edmonton, AB, Canada

Osteoarthritis is a debilitating joint disease where the surface of articular cartilage degrades and is unable to repair itself through natural processes. Controlling the migration of transplanted chondrocytes to the defective cartilage non-invasively could be a novel treatment for osteoarthritis. Our research group has performed an in-vitro investigation into the response of cultured human chondrocytes to pulsed electromagnetic fields (PEMF). Development of a treatment for osteoarthritis patients will require the use of a programmable waveform generator to generate the PEMF. This paper discusses the design and testing of a programmable ramp waveform generator for such purpose. When this ramp waveform generator is connected to the PEMF coil driver circuitry, it will be able to produce linearly ramping magnetic fields ranging in strength from 0.5 mT to 4.5 mT. It also has an attainable pulse width ranging from 6 ms to 100 ms, with a selectable duty cycle from 1% to 99%

Application of weak electromagnetic fields facilitates sensory-motor integration in patients with multiple sclerosis

Sandyk R.

NeuroCommunication Research Laboratories, Danbury, USA.

Electrophysiological studies in behaving animals have shown the function of cerebral serotonin (5-HT) neurons to be altered in association with motor output in both the tonic and repetitive modes and also in relation to an orienting response. Brainstem 5-HT neurons increase their firing rate two to five-fold during repetitive motor activity to facilitate motor output while simultaneously suppressing transmission in sensory pathways. Reciprocally, during an orienting response motor activity is suppressed and 5-HT neuronal activity is inhibited to facilitate transmission of sensory information. These reciprocal changes in 5-HT neuronal activity serve to facilitate brainstem reticular sensory-motor integration which, due to 5-HT neurotransmission deficiency, may be disrupted in patients with multiple sclerosis (MS). For instance, MS patients are unable to process auditory information in the presence of competing ambient stimuli, while under a controlled laboratory environment they demonstrate unimpaired verbal information processing. This report concerns three MS patients who experienced rapid deterioration in balance resulting in falling when subjected, during ambulation, to distracting external auditory stimuli. After receiving a series of treatments with low frequency picotesla range intensity electromagnetic fields (EMFs), which were applied extracranially for brief periods, these patients experienced resolution of these symptoms with ambulation being unaffected by auditory stimuli. It is suggested that application of picotesla EMFs may restore abnormal reticular sensory-motor integration in MS patients with the effect being related to facilitation of 5-HT neurotransmission at both junctional (synaptic) and nonjunctional neuronal target sites.

Pulsing electromagnetic field treatment in ununited fractures and failed arthrodeses

Bassett CA, Mitchell SN, Gaston SR.

Pulsing electromagnetic fields (PEMFs) induce weak electric currents in bone by external coils on casts or skin. This surgically noninvasive, outpatient method, approved by the Food and Drug Administration in November 1979, produced confirmed end results in 1,007 ununited fractures and 71 failed arthrodeses, worldwide. Overall success at Columbia-Presbyterian Medical Center was 81%; internationally, 79%; and in other patients in the United States, 76%. Treatment with PEMFs was effective in 75% of 332 patients (a subset) with an average 4.7-year disability duration, an average of 3.4 previous operative failures to produce union, and a 35% rate of infection. Eighty-four percent of carpal naviculars and 82% of femoral neck-trochanteric nonunions were united. After attempted arthrodeses could not salvage a failed total-knee prosthesis, PEMFs promoted healing in 85% of patients. When coils were unsuccessful alone, combining them with surgical repair was effective.

Alternative, complementary, energy-based medicine for spinal cord injury

Johnston L.

Paralyzed Veterans of America's Education Foundation.

This paper provides an overview on various alternative, complementary, or energy-based therapies that expand the healing spectrum of individuals with spinal cord injury (SCI). Not only do they have the capability to help a variety of secondary conditions, they have the ability in some people, for certain injuries, to restore function, sometimes dramatically. After providing an overall contextual rationale for the use of alternative medicine, this paper briefly summarizes various Eastern-medicine healing modalities, laser-based therapies, nutritional and homeopathic approaches, and pulsed electromagnetic therapies.

Attenuation of epilepsy with application of external magnetic fields: a case report

Sandyk R, Anninos PA.

Democrition University of Thrace, Department of Medical Physics, Alexandroupolis, Greece

We have previously demonstrated that magnetoencephalographic (MEG) brain measurements in patients with seizure disorders show significant MEG activity often in the absence of conventional EEG abnormalities. We localized foci of seizure activity using the mapping technique characterized by the ISO-Spectral Amplitude (ISO-SA) on the scalp distribution of specified spectral components or frequency bands of the emitted MEG Fourier power spectrum. In addition, using an electronic device, we utilized the above recorded activity to emit back the same intensity and frequency of magnetic field to the presumed epileptic foci. Using this method we were able, over the past two and one-half years, successfully to attenuate seizure activity in a cohort of over 150 patients with various forms of epilepsy. We present a patient with severe epilepsy and behavioral disturbances in whom application of an external artificial magnetic field of low intensity produced a substantial attenuation of seizure frequency which coincided with an improvement in the patient's behavior. This case demonstrates that artificial magnetic treatment may be a valuable adjunctive procedure in the management of epilepsy.

A Cochrane review of electrotherapy for mechanical neck disorders.

Kroeling P, Gross AR, Goldsmith CH; Cervical Overview Group.

Ludwig-Maximilians-University, Munich, Germany.

Systematic review.

OBJECTIVE:

To assess whether electrotherapy relieves pain or improves function/disability in adults with mechanical neck disorders (MND).

SUMMARY OF BACKGROUND DATA:

The effectiveness of electrotherapy as a physiotherapy option has remained unclear.

METHODS:

Databases were searched from root to March 2003. Independent reviewers conducted selection, data abstraction, and quality assessment. Relative risk and standard mean differences were calculated.

RESULTS:

Fourteen comparisons were included. For the pain outcome, we found limited evidence of benefit, ie, pulsed electromagnetic field (PEMF) therapy resulted in only immediate post-treatment pain relief for chronic MND and acute whiplash (WAD). Other findings included unclear or conflicting evidence (Galvanic current for acute or chronic occipital headache; iontophoresis for acute, subacute WAD; TENS for acute WAD, chronic MND; PEMF for medium- or long-term effects in acute WAD, chronic MND); and limited evidence of no benefit (diadynamic current for reduction of trigger point tenderness in chronic MND, cervicogenic headache; permanent magnets for chronic MND; electrical muscle stimulation (EMS) for chronic MND).

CONCLUSIONS:

In pain as well as other outcomes, the evidence for treatment of acute or chronic MND by different forms of electrotherapy is either lacking, limited, or conflicting.

Augmentation of bone repair by pulsed elf magnetic fields in rats

Ottani V, De Pasquale V, Govoni P, Castellani PP, Ripani M, Gaudio E, Morocutti M.

Istituto di Anatomia Umana Normale, Bologna, Italy.

Tibial osteotomies in rats were exposed for 2, 3, 5 and 8 weeks to a pulsed extremely low frequency magnetic field. The shape of the pulse was a double halfwave (50 Hz, 70 G). The rate of bone healing was evaluated by light and electron microscopy. An increase of bone healing was found in rats treated with magnetic fields persisting throughout the tested time. The accelerated healing process produced a sequence of morphological appearances identical to those of a normal fracture callus being the enhancement of osteogenesis produced by an acceleration of preliminary ossification.

Autoradiographic study of the effects of pulsed electromagnetic fields on bone and cartilage growth in juvenile rats

Wilmot JJ, Chiego DJ Jr, Carlson DS, Hanks CT, Moskwa JJ.

Department of Orthodontics and Pediatric Dentistry, University of Michigan, School of Dentistry

Application of pulsed electromagnetic fields (PEMF) has been used in growth and repair of non-union bone fractures. The similarities between the fibrocartilage callus in non-union bone fractures and the secondary cartilage in the mandibular condyle, both histologically and functionally, lead naturally to study the effects of PEMFs on growth in the condyle. The purposes of this study were: (1) to describe the effects of PEMFs on the growth of the condyle using autoradiography, [3H]-proline and [3H]-thymidine, and (2) to differentiate between the effects of the magnetic and electrical components of the field. Male pre-adolescent Sprague-Dawley rats (28 days old) were divided into three experimental groups of five animals each: (1) PEMF-magnetic (M), (2) PEMF-electrical (E) and (3) control, and were examined at three different times-3, 7 and 14 days of exposure. Each animal was exposed to the field for 8 h per day. Histological coronal sections were processed for quantitative autoradiography to determine the mitotic activity of the condylar cartilage and the amount of bone deposition. The PEMF (magnetic or electrical) had statistically significant effects only on the thickness of the articular zone, with the thickness in the PEMF-M group being the most reduced. Length of treatment was associated with predictable significant changes in the thickness of the condylar cartilage zones and the amount of bone deposition.

Bioelectric repair of metatarsal nonunions

Fox IM, Smith SD.

 

An exciting new development in the field of bone physiology has been the discovery of electrical potentials in stressed bone and the relation of this knowledge to Wolff's law. The application of these discoveries for the treatment of nonunions by exogenous bioelectric potentials via direct current and pulsed electromagnetic fields has been a major development in orthopedic surgery. To date, the literature reports the use of this new treatment modality in the large long bones of the extremities. The authors have utilized these techniques to repair nonunions of the metatarsals and, in the process, have adapted some of the principles for the small bones of the foot.

Neuroelectric mechanisms applied to low frequency electric and magnetic field exposure guidelines--part II: non sinusoidal waveforms

Reilly JP, Diamant AM.

Metatec Associates, Silver Spring, MD, USA

Standards for human exposure to electromagnetic fields typically express maximum permissible exposure limits as a function of frequency. Often, these limits have been derived from experiments or theoretical models involving sinusoidal waveforms. In many practical situations, however, the relevant waveforms of interest may not be sinusoidal, such as with waveforms having harmonic distortion, or with pulsed waveforms. This paper evaluates methods for applying sinusoidal exposure standards to non-sinusoidal waveforms in the frequency regime below a few MHz where electrostimulation is the dominant mechanism. Waveforms treated include those of a pulsed or mixed frequency variety. We evaluate acceptance criteria for mixed frequency exposure using summation formulae cited by IEEE C95.1, ICNIRP, and NRPB. This is carried out using a Fourier synthesis of various waveshapes. Also evaluated is an acceptance criterion based on the peak of the exposure waveform. Excitation thresholds are evaluated using a myelinated nerve model that accounts for the nonlinear electrodynamics of the neural membrane. It is shown that a method based on the peak and phase duration of the in situ field waveform provides a typically conservative test for compliance with non sinusoidal waveforms. An alternate method, based on amplitude summation of the Fourier components of the applied waveforms, can also provide a meaningful test, albeit a more conservative one.

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PEMF Abstracts