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Magnetic Therapy Research: Pain Relief

 

Chronic Pain

 

Exposure to static magnetic field ceases mechanical allodynia in neuropathic pain in mice.

Antal M, László J.
Department of Anatomy, Histology, and Embriology, University of Debrecen, Debrecen, Hungary.

Magnetic therapy as a self-care intervention has led to the conduct of numerous human trials and animal experiments. Results concerning the analgesic efficacy of magnetic exposure, however, are inconsistent.

By using a magnetic device generating an inhomogeneous static magnetic field (iSMF), here we studied how the whole-body exposure to iSMF may influence the mechanical withdrawal threshold (MWT) of the hind paw in different stages of neuropathic pain evoked by partial ligation of the sciatic nerve in mice.

It was found that iSMF exposure did not prevent the decrease of MWT in the first postoperative week. A 2-week long iSMF treatment that was started just after the nerve ligation elevated MWT values to a modest extent. However, the effectiveness of a daily exposure to iSMF was much more prominent when it was applied between postoperative days 15 and 28.

In this case, MWT was already noticeably increased after the first treatment and it practically reached the control values by the end of the 2-week long exposure period. The results suggest that exposure to iSMF cannot prevent the development of mechanical allodynia, but can inhibit processes that maintain the increased sensitivity to mechanical stimuli in neuropathic pain.

Antal M, László J (Sep 2009). "Exposure to inhomogeneous static magnetic field ceases mechanical allodynia in neuropathic pain in mice." Bioelectromagnetics. 30(6):438-45. PMID: 19405037


Definition: Allodynia - “other pain” not from an injury; pain due to a stimulus which does not normally provoke pain; pain from light touch, brushing, hot or cold temperatures; pain associated with neuropathy, fibromyalgia, neuralgia, and migraines

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A randomized, double-blinded, placebo-controlled pilot study to investigate the effectiveness of a static magnet to relieve dysmenorrhea.

Eccles NK.
The Chiron Clinic, London, England. drnyjon@hotmail.como

OBJECTIVES: The aim of this study was to investigate the hypothesis that a specially designed, static magnet of 2700 gauss, attached over the pelvic area, could relieve menstrual pain.

DESIGN: This was a randomized, double-blind, placebo-controlled, postal questionnaire study. SETTING: The study was conducted in a primary care, single center.

PARTICIPANTS: Sixty-five (65) women (mean age 29.1 +/- 1.52 years) were recruited from an advertisement in a London newspaper. The entry criterion was regular dysmenorrhea. The exclusion criterion was known secondary dysmenorrhea. Of the 65 women who were enrolled, 35 completed the study.

INTERVENTIONS: A questionnaire-based assessment was completed by each subject and checked by telephone before and after random allocation to use of either the static magnet device (2700 gauss) or an identical, weaker magnetic placebo device (140 gauss). Assessment was made by telephone before and after a complete menstrual cycle. None of the participants was examined or seen face-to-face.

MAIN OUTCOME MEASURES: The main outcome measures were level of pain, using the McGill Pain and Visual Analogue Scales, and ratings of associated symptoms such as irritability, restriction of usual activities, and painkiller consumption.

RESULTS: There was a significant reduction (p < 0.02) in pain in the magnet group compared to the placebo group. Pain score differences (McGill pain score before-pain score after use of device) were -17 (-53, 13) (median and interquartile ranges) in the magnet group and -5.0 (-29, 27) in the placebo group. The 95% Mann-Whitney confidence intervals for the median difference between the magnet and placebo groups (magnet-placebo) were -53.0 to 23.38. A reduction in irritability symptoms in the magnet group approached statistical significance (p = 0.056).

CONCLUSIONS: Despite the small number of participants, the level of significance reached in the reduction of pain merits reporting. This is a pilot study to a much larger study of the same device as an analgesic in women with primary dysmenorrhea.

PMID: 16131292 [PubMed - indexed for MEDLINE]

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Auriculotherapy on low back pain in the elderly

Suen LK, Wong TK, Chung JW, Yip VY.
The Nethersole School of Nursing, Esther Lee Building, The Chinese University of Hong Kong, Shatin, Hong Kong.

The objective of the study was to examine the effectiveness of auriculotherapy using magnetic pellets for the elderly suffering from low back pain (LBP). Sixty participants who were 60-years old or above and had been suffering from LBP were recruited. Participants were randomly allocated to receive auriculotherapy on a 3-week basis using either Semen Vaccariae (control group=30) or magnetic pellets (experimental group=30). Seven auricular acupoints that are believed to have an effect on LBP were selected. Treatment effects were evaluated using the Chinese Pain Intensity Verbal Rating scale (VRS). The experimental group had indeed experienced a significant improvement in pain relief when compared with the control group; and the therapeutic effects were sustained at 2 and 4-week follow-up periods after the therapy. Findings of this study demonstrated that auriculotherapy using magnetic pellets significantly reduce the pain intensity level of the elderly suffering from non-specific LBP.

PMID: 17210513 [PubMed - in process]

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A critical review of randomized controlled trials of static magnets for pain relief

Eccles NK.
The Chiron Clinic, London, UK. drnyjon@hotmail.com

OBJECTIVE: The aim of this review was to establish whether there is evidence for or against the efficacy of static magnets to produce analgesia.

METHODS: A systematic literature review was undertaken of studies that compared the use of static magnets with an appropriate control for the treatment of pain. Study methods, their quality, and outcome were also reviewed.

RESULTS: Overall, 13 of the 21 studies reported a significant analgesic effect due to static magnets. Of the 18 better quality studies with 3 points or more on the quality assessment, 11 were positive and six were negative, and in one there was a non-significant trend towards a positive analgesic effect. In two of the negative studies, there are concerns over adequacy of magnet power for the type of pain, and in the other study of duration of exposure to the magnetic field. If these two studies are excluded on the grounds of inadequate treatment, then 11 out of 15 (73.3%) of the better quality studies demonstrated a positive effect of static magnets in achieving analgesia across a broad range of different types of pain (neuropathic, inflammatory, musculoskeletal, fibromyalgic, rheumatic, and postsurgical).

CONCLUSIONS: The weight of evidence from published, well-conducted controlled trials suggests that static magnetic fields are able to induce analgesia.

PMID: 15992236 [PubMed - indexed for MEDLINE]

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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, 268 Grosvenor Street, London, Ont. N6A 4V2, Canada.

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.

Neurosci Lett. 2004 Jan 2;354(1):30-3.

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Therapeutic effects of peripheral repetitive magnetic stimulation on myofascial pain syndrome.

Smania N, Corato E, Fiaschi A, Pietropoli P, Aglioti SM, Tinazzi M.

Centro di Rieducazione Funzionale Policlinico G.B. Rossi, Verona, Italy. nicola.smania@univr.it

OBJECTIVE: To evaluate short- and medium-term effects of peripheral repetitive magnetic stimulation (rMS) on myofascial pain.

METHODS: Eighteen patients who presented with myofascial trigger points (TPs) at the level of the superior trapezius were separated into two groups according to a restricted randomization scheme. Group 1 (n=9) underwent treatment with rMS that consisted of a total of 10 sessions, each lasting 20min, in which 4000 magnetic stimuli were administered in 5s trains at 20Hz at the TP. Group 2 (n=9) received a placebo treatment that consisted of the application of a non-functioning ultrasound therapy device to the TP. Patients were evaluated before treatment, at the end of treatment, and again 1 week and 1 month after the conclusion of the treatment. Clinical evaluation included parameters for measuring pain levels (VAS, NPDVAS and algometry), the myofascial TP characteristics and the range of cervical movement (ROM).

RESULTS: The rMS group showed a significant improvement in VAS, NPDVAS, algometry, as well as in the characteristics of the TP after conclusion of treatment. Improvements in the ROM were also present in rotation and controlateral bending. This improvement persisted after 1 month. On the other hand, the placebo group did not show any significant improvement in the tests considered.

CONCLUSIONS: The results of this study show that peripheral rMS may have positive short- and medium-term therapeutic effects on myofascial pain.

Clin Neurophysiol. 2003 Feb;114(2):350-8.

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Evaluation of electromagnetic fields in the treatment of pain in patients with lumbar radiculopathy or the whiplash syndrome.

Thuile Ch, Walzl M.

International Society of Energy Medicine, Vienna, Austria.

Back pain and the whiplash syndrome are very common diseases involving tremendous costs and extensive medical effort. A quick and effective reduction of symptoms, especially pain, is required. In two prospective randomized studies, patients with either lumbar radiculopathy in the segments L5/S1 or the whiplash syndrome were investigated. Inclusion criteria were as follows: either clinically verified painful lumbar radiculopathy in the segments L5/S1 and a Lasegue's sign of 30 degrees (or more), or typical signs of the whiplash syndrome such as painful restriction of rotation and flexion/extension. Exclusion criteria were prolapsed intervertebral discs, systemic neurological diseases, epilepsy, and pregnancy. A total of 100 patients with lumbar radiculopathy and 92 with the whiplash syndrome were selected and entered in the study following a 1:1 ratio. Both groups (magnetic field treatment and controls) received standard medication consisting of diclofenac and tizanidine, while the magnetic field was only applied in group 1, twice a day, for a period of two weeks. In patients suffering from radiculopathy, the average time until pain relief and painless walking was 8.2 +/- 0.5 days in the magnetic field group, and 11.7 +/- 0.5 days in controls (p < 0.04). In patients with the whiplash syndrome, pain was measured on a ten-point scale. Pain in the head was on average 4.6 before and 2.1 after treatment in those receiving magnetic field treatment, and 4.2/3.5 in controls. Neck pain was on average 6.3/1.9 as opposed to 5.3/4.6, and pain in the shoulder/arm was 2.4/0.8 as opposed to 2.8/2.2 (p < 0.03 for all regions). Hence, magnetic fields appear to have a considerable and statistically significant potential for reducing pain in cases of lumbar radiculopathy and the whiplash syndrome.

NeuroRehabilitation. 2002;17(1):63-7.

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A Double-Blind Study Demonstrating Therapeutic Benefit of Magnets In Heel Pain Symptomology

Larry Seaman, DPM

Barry University School of Podiatric Medicine, Miami, Florida

To determine the effectiveness of permanently magnetized pads for the treatment of heel pain syndrome. A double- blind study was performed on patients who have had symptoms in the above areas for at least two weeks. --- Permanently magnetized and demagnetized pads will be applied to the symptomatic feet without the patient of the clinician able to differentiate due to identical appearing pads. Only an impartial referee is aware of the true identity of each pad.

CHARACTERISTICS OF THE MATERIAL TO BE TESTED:

The bipolar pads to be used are rectangular and are 53 mm x 83 mm and produce about 300 gauss of magnetic current. An identical number of factory demagnetized pads of identical dimensions were also used for the study.

PATIENTS TO BE TESTED:

Twenty patients were initially studied using the bipolar pads on their symptomatic feet. All patients were seen at the foot clinics of the Barry University School of Podiatric Medicine. The age of patients varied from age 21 to age 78. The sex of the patients was noted, but not thought to be a significant factor in the study.

The patients tested had either heel spur or acute planter fascitis symptoms such as, acute, burning, or sharp pain on the heel area. All patients had local symptoms without neurological damage to their back or lower extremities. Patients who underwent foot surgery within the past year were not included. Patients who had metallic implants, such as screws or wires in their feet were excluded. All patients underwent two weeks of therapy and two weeks of minimum follow-up after the treatment.

CRITERIA FOR TEST DOCUMENTATION:

  • Criterion A: Subjective pain sensation.
  • Criterion B: Ability to ambulate without pain.
  • Criterion C: Need for pain or anti-inflammatory medication.
  • Criterion D: Accompanying therapy.

 

RESULTS OF CLINICAL TRIALS OF TWENTY PATIENTS

 

Criterion A: Subjective relief of symptoms.

  • Magnetized pads: Fourteen patients
  • Excellent = 5
  • Good = 3
  • Fair or no better = 6

  • Demagnetized pads: Six patients
  • Excellent = 1
  • Good = 0
  • Fair or no better = 5

 

Criterion B: Ability to ambulate without pain.

  • Magnetized pads: Fourteen patients
  • Excellent = 7
  • Good = 4
  • Fair or no better = 3

  • Demagnetized pads: Six patients
  • Excellent = 1
  • Good = 1
  • Fair or no better = 4

 

Criterion B and C = All patients in the study did not need medications or physiotherapy.

PERCENTAGE OF IMPROVEMENT WITH MAGNETIZED PADS

  • Criterion A: Subjective relief of pain = 57.2%
  • Criterion B: Improvement in walking = 77.1%
  • Criterion C: Need for medication = 0%
  • Criterion D: Need for physiotherapy = 0%

PERCENTAGE OF IMPROVEMENT WITH DEMAGNETIZED PADS

  • Criterion A: Subjective relief of pain = 16.6%
  • Criterion B: Improvement in walking = 16.6%
  • Criterion C: Need for medication = 0%
  • Criterion D: Need for physiotherapy = 0%

 

DISCUSSION OF RESULTS

The indication groups for all trial criteria showed a significantly higher therapeutic effectiveness with the magnetized pads than the control groups (demagnetized pads). The best results were achieved with reduction in subjective pain in the heel spur syndrome category. 57.2% of all test persons in this category treated with magnetized pads expressed significant relief of symptoms.

The patients who showed increase in ability to walk without pain after treatment represented a 77.1 % improvement rate ~with the magnetized pads versus a 16.6% improvement reported by those with the demagnetized pads. This percentage represented a placebo effect.

CONCLUSION

The patient group in all criteria showed a higher percentage of favorable results with the magnetized pads than the demagnetized pads. The application of the pads to the treatment areas produced no side effects or skin irritation.

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Interventional neurophysiology for pain control: duration of pain relief following repetitive transcranial magnetic stimulation of the motor cortex.

Lefaucheur JP, Drouot X, Nguyen JP.

Service de physiologie-explorations fonctionnelles, hopital Henri-Mondor, Inserm U421, faculte de medecine, 94010 Creteil, France. jean-pascal.lefaucheur@hmn.ap-hop-paris.fr

The chronic electrical stimulation of a motor cortical area corresponding to a painful region of the body, by means of surgically-implanted epidural electrodes is a validated therapeutical strategy to control medication-resistant neurogenic pain. Repetitive transcranial magnetic stimulation (rTMS) permits to stimulate non-invasively and precisely the motor cortex. We applied a 20-min session of rTMS of the motor cortex at 10 Hz using a 'real' or a 'sham' coil in a series of 14 patients with intractable pain due to thalamic stroke or trigeminal neuropathy. We studied the effects of rTMS on pain level assessed on a 0-10 visual analogue scale from day 1 to day 12 following the rTMS session. A significant pain decrease was observed up to 8 days after the 'real' rTMS session. This study shows that a transient pain relief can be induced in patients suffering from chronic neurogenic pain during about the week that follows a 20-min session of 10 Hz-rTMS applied over the motor cortex.

Neurophysiol Clin. 2001 Aug;31(4):247-52.

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Pain relief by low-intensity frequency-modulated millimeter waves acting on the acupuncture points.

Samosiuk IZ, Kulikovich IuN, Tamarova ZA, Samosiuk NI, Kazhanova AK.

Analgetic effect of low-intensive frequency-modulated millimetric waves (MW) was studied in mice with formalin induced nociceptive behavior reaction (licking of defeat hindpaw). MW were applied to the acupoint E 36 of the defeat hindpaw. The following MW were used: 60 GHz (1) and 118 GHz (2) which were modulated by 4 Hz; noise MW within the range of 42-95 GHz (3) and 90-140 GHz (4) which were modulated in accidental order by frequencies 1-60 Hz; combinations of fixed frequencies with noise - 60 GHz + noise 42-95 GHz (5) and 118 GHz + noise 90-140 GHz (6). All used MW combinations suppressed licking of the defeat hindpaw and increased duration of sleep and eating. The strongest analgesia was achieved in series 1-3 (42.4-69.7%), the weakest in series 6 and 4 of the experiment (12.2-19.7%).

Vopr Kurortol Fizioter Lech Fiz Kult. 2000 Jul-Aug;(4):7-11.

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Static magnetic field therapy for pain in the abdomen and genitals.

Holcomb RR; Worthington WB; McCullough BA; McLean MJ

Department of Neurology; Vanderbilt University Medical Center;, Nashville, Tennessee, USA.

Two adolescents with debilitating, medication-resistant, chronic pain of the low back and abdomen with intermittent pain of the genitalia were diagnosed with intervertebral disk disease at spinal cord levels that correlated with their signs. Both patients had undergone multiple evaluations by physicians of different specialties and both underwent appendectomy without relief of their pain. The history of the onset of pain was important in determining the affected levels. The pain of both individuals was mimicked and localized by percussion of the vertebral spines at the level of disk protrusion. This maneuver and careful review of the history were important in making the correct diagnosis in each case. In both patients, treatment with novel magnetic devices provided rapid relief that was sustained for more than 2 years. These cases highlight the need for careful evaluation and correct diagnosis of abdominal and genital pain in young patients to avoid costly and unnecessary medical intervention and the stigma of painful debility.

Pediatr Neurol 2000 Sep;23(3):261.

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Response of pain to static magnetic fields in postpolio patients: a double-blind pilot study.

Vallbona C, Hazlewood CF, Jurida G.

Department of Family and Community Medicine, Baylor College of Medicine, Houston, TX 77030, USA.

OBJECTIVE: To determine if the chronic pain frequently presented by postpolio patients can be relieved by application of magnetic fields applied directly over an identified pain trigger point.

DESIGN: Double-blind randomized clinical trial.

SETTING: The postpolio clinic of a large rehabilitation hospital.

PATIENTS: Fifty patients with diagnosed postpolio syndrome who reported muscular or arthritic-like pain.

INTERVENTION: Application of active or placebo 300 to 500 Gauss magnetic devices to the affected area for 45 minutes.

MAIN OUTCOME MEASURE: Score on the McGill Pain Questionnaire.

RESULTS: Patients who received the active device experienced an average pain score decrease of 4.4 +/- 3.1 (p < .0001) on a 10-point scale. Those with the placebo devices experienced a decrease of 1.1 +/- 1.6 points (p < .005). The proportion of patients in the active-device group who reported a pain score decrease greater than the average placebo effect was 76%, compared with 19% in the placebo-device group (p < .0001).

CONCLUSIONS: The application of a device delivering static magnetic fields of 300 to 500 Gauss over a pain trigger point results in significant and prompt relief of pain in postpolio subjects.

Arch Phys Med Rehabil. 1997 Nov;78(11):1200-3.

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Exposure to oscillating magnetic fields influences sensitivity to electrical stimuli. II. Experiments on humans.

Papi F, Ghione S, Rosa C, Del Seppia C, Luschi P.

Dipartimento di Scienze del Comportamento Animale e dell'Uomo, Universita di Pisa, Italy.

To assess the effect of a magnetic treatment on pain perception, we compared the sensory threshold in 18 healthy volunteers. We determined the threshold by noninvasive electrical stimulation of the tooth pulp and skin before and after exposure to an altered magnetic field of low intensity and to a sham treatment. Five different parameters were recorded: the sensory and pain thresholds for the tooth and the sensory, pain, and tolerance thresholds for the skin. Two hours of exposure to a weak, oscillating magnetic field induced a significant decrease in three parameters (dental sensory and cutaneous pain and tolerance thresholds), whereas the other two parameters showed a similar tendency. When the same subjects were exposed to a sham treatment, only marginal, nonsignificant variations in all parameters were observed. These results represent the first piece of evidence that weak alterations of the magnetic field may induce hyperalgesia in humans.

Bioelectromagnetics. 1995;16(5):295-300.

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Low intensity permanent magnets in the treatment of chronic lumbar radicular pain

Khoromi S, Blackman MR, Kingman A, Patsalides A, Matheny LA, Adams S, Pilla AA, Max MB.

National Center for Complementary and Alternative Medicine, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA.

We assessed the pain-relieving efficacy of static magnetic fields produced by 200 Gauss (G) magnets compared with 50G magnets in a double-blind, randomized, two-phase crossover study in patients with chronic lumbar radicular pain. The surface field strengths of the magnets were 200 and 50G.

Phase I included four random periods of two-week duration: two periods with 200G, one period with 50G, and one period of "no treatment." The magnets were positioned either vertically or horizontally in standard lumbosacral elastic corsets. Phase II consisted of two five-week periods with the most effective magnet from Phase I and its corresponding 50 or 200G device. The primary outcome was average daily leg pain score (0-10 scale) in each period of Phase II.

38 of 40 randomized patients completed Phase I, and 28 of 31 Phase II participants completed the study. In Phase I, pain scores did not differ significantly between 200 and 50G magnets. Phase II average leg pain scores tended to be lower with 200 vs. 50G magnets (3.2+/-2.1 for 200G vs. 3.9+/-2.2 for 50G magnets [P=0.08]) after excluding one unblinded patient. The relative treatment effect of the 200G magnets appeared to increase throughout the five-week period. Although these data cannot rule out a chance effect, the positive trends suggest that larger, longer-duration, sham-controlled trials with 200G magnets be considered in patients with chronic lumbar radicular pain.

Journal of Pain and Symptom Management. 2007 October; 34 (4):434-45. Epub 2007 Jul 9

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Efficacy of static magnetic field therapy in chronic pelvic pain: a double-blind pilot study.

Brown CS, Ling FW, Wan JY, Pilla AA.

Department of Pharmacy Practice and Pharmacoeconomics, University of Tennessee Health Sciences Center, Memphis, USA.

OBJECTIVE: The aim of the study was to determine the efficacy of static magnetic field therapy for the treatment of chronic pelvic pain (CPP) by measuring changes in pain relief and disability.

STUDY DESIGN: Thirty-two patients with CPP completed 2 weeks and 19 patients completed 4 weeks of randomized double-blind placebo-controlled treatment at a gynecology clinic. Active (500 G) or placebo magnets were applied to abdominal trigger points for 24 hour per day. The McGill Pain Questionnaire, Pain Disability Index, and Clinical Global Impressions Scale were outcome measures.

RESULTS: Patients receiving active magnets who completed 4 weeks of double-blind treatment had significantly lower Pain Disability Index (P <.05), Clinical Global Impressions-Severity (P <.05), and Clinical Global Impressions-Improvement (P <.01) scores than those receiving placebo magnets, but were more likely to correctly identify their treatment (P <.05).

CONCLUSION: SMF therapy significantly improves disability and may reduce pain when active magnets are worn continuously for 4 weeks in patients with CPP, but blinding efficacy is compromised.

Am J Obstet Gynecol 2002 Dec;187(6):1581-7

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Effect of magnets on chronic pelvic pain.

Brown CS; Parker N; Ling F; Wan J

University of Tennessee, Memphis, TN, USA

OBJECTIVE: Magnetic therapy has been used to manage a variety of chronic pain syndromes. Chronic pelvic pain (CPP) is a common disorder that does not always respond to conventional treatments. The primary aim of this study was to determine if applying magnets to abdominal trigger points would significantly relieve pain.

METHODS: Patients with CPP between 18 and 50 years of age were enrolled in a 2-week, double blind, placebo-controlled study with an optional 2-week blinded continuation phase. Women who completed single-blind treatment were randomized to receive either active or placebo 500 Gauss magnets for 24 hours per day. The McGill Pain Questionnaire (MPQ) and the Pain Disability Index (PDI) were used.

RESULTS: Fourteen subjects completed the 2-week study, and eight subjects completed the continuation phase. There was no significant treatment effect using repeated measures analysis. Of the eight treatment extenders, 60% with active magnets compared with 33% with placebo magnets had 50% reductions in MPQ and PDI scores. A power analysis revealed that 16 subjects were necessary to show a significant effect after 4 weeks of treatment. Blinding was more effective in the placebo group than in the active magnet group and at 2 weeks than at 4 weeks.

CONCLUSIONS: This first controlled study of magnetic therapy for CPP suggests that pain relief is related to duration of exposure. The ongoing trial will report on the effect of longer exposure periods and blinding efficacy with a larger sample.

Obstet Gynecol 2000 Apr 1;95(4 Suppi 1):529.

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Effects of static magnets on chronic knee pain and physical function: a double-blind study.

Hinman MR, Ford J, Heyl H.

Department of Physical Therapy, University of Texas Medical Branch, Galveston, USA.

CONTEXT: Static magnets have become an increasingly popular alternative therapy for individuals with musculoskeletal pain despite limited scientific evidence to support their efficacy or safety.

OBJECTIVE: To determine the effects of static magnets on the pain and functional limitations associated with chronic knee pain due to degenerative joint disease.

DESIGN: Double-blind, randomized, controlled clinical trial.

SETTING: Pretests and posttests were conducted in an academic health science center.

PARTICIPANTS: Forty-three ambulatory subjects with chronic pain in 1 or both knee joints who were recruited from outpatient clinics or who volunteered to participate.

INTERVENTION: Subjects wore pads containing magnets or placebos over their painful knee joints for 2 weeks.

MAIN OUTCOME MEASURES: Self-administered ratings of pain and physical function using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and a timed 15-m (50-ft) walk.

RESULTS: Multivariate analysis of covariance revealed significantly greater improvements in the group wearing magnets (P=.002). Univariate analyses indicated that comparative changes in self-rated pain and physical function (P=.002 and .001, respectively) were greater than changes in gait speed (P=.042).

CONCLUSIONS: The application of static magnets over painful knee joints appears to reduce pain and enhance functional movement. However, further study is needed to determine the physiological mechanisms responsible for this analgesic effect.

Alternative Therapies in Health and Medicine. 2002 Jul-Aug;8(4):50-5. PubMed ID: 12126173

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Extensive reorganization of primary somatosensory cortex in chronic back pain patients.

Flor H, Braun C, Elbert T, Birbaumer N.

Department of Psychology, Humboldt-University, Berlin, Germany. hflor@rz.hu-berlin.de

The hypothesis of reorganization of the primary somatosensory cortex in states of chronic pain was assessed in 10 low back pain patients and nine matched healthy controls. Intracutaneous electric stimuli were applied to the left back and index finger at a standard, a non-painful and a painful intensity. Magnetic fields were recorded by a 37-channel BTi biomagnetometer from the hemisphere contralateral to the site of stimulation. The power of the early evoked magnetic field (< 100 ms) elicited by painful stimulation of the painful back in very chronic patients was elevated relative to that elicited by painful back stimulation of healthy controls and showed a linear increase with chronicity (r = 0.74). The maximum activity elicited in primary somatosensory cortex was shifted more medially in the very chronic back pain subjects. These data suggest that chronic pain is accompanied by cortical reorganization and may serve an important function in the persistence of the pain experience.

Neurosci Lett. 1997 Mar 7;224(1):5-8.

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Pulsed high frequency (27MHz) electromagnetic therapy for persistent neck pain. A double blind, placebo-controlled study of 20 patients.

Foley-Nolan D, Barry C, Coughlan RJ, O'Connor P, Roden D.

Mater Misericordiae Hospital, Dublin, Ireland.

In the majority of patients with neck pain, symptoms will resolve spontaneously or quite quickly in response to therapy. However, some patients' symptoms persist for a long period, irrespective of therapy. In this study, 20 patients with persistent (greater than 8 weeks) neck pain were enrolled in a double blind, placebo-controlled trial of low energy, pulsed electromagnetic therapy (PEMT)--a treatment previously shown to be effective in soft tissue injuries. For the first 3-week period, group A (10 patients) received active PEMT units while group B (10 patients) received facsimile placebo units. After 3 weeks, both pain (visual analogue scale (P less than .023) and range of movement (P less than .002) had improved in the group on active treatment compared to the controls. After the second 3 weeks, during which both groups used active units, there were significant improvements in observed scores for pain and range of movement in both groups. PEMT, in the form described, can be used at home easily in the treatment of patients with neck pain. It is frequently successful and without side effects.

Orthopedics. 1990 Apr;13(4):445-51.

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Summary of a 12-month double-blind, clinical test of magnetic mattress pads.

Carried out by Sanikukal Hospital, Tokyo Communications Hospital and Kouseikai Suzuki Hospital, by Dr. Kazuo Shimodaira. 1990.

The mattress pads used in this study were typical full-size pads containing 124 permanent ferrite magnets with magnetic field strengths of 750-950 gauss each. The pads themselves were made of two sheets of felt with the magnets sandwiched between them. The felt sheets were then wrapped in a cloth cover. The total number of subjects of this double-blind clinical experiment was 431 (216 male, 215 female). 375 subjects were given the magnetic pads, 56 were given non-magnetic pads. None of the 431 subjects knew which pad they were sleeping on. Subjects selected for the experiment were those with chief complaints related to:

  • Neck and Shoulder pain
  • Back and Lower Back Pain
  • Back Pain (general)
  • Lower Limb Pain
  • Insomnia
  • Fatigue

To determine the presence of any side effects, blood pressure, hemoglobin, number of erythrocytes, and number of leukocytes were examined before and after the use of the mattress pads. Besides blood sedimentation, and TP, COL, ALP, GOT, GPT, Na, and K were also examined, as were functions of the kidneys, liver, pancreas, and the entire circulatory system.

Results:

Symptom

Total Cases

# of Positive

% of Total

# of No Results

% of Total

Neck & Shoulder Pain

66 47

71.2%

19 28.8%

Lower Back Pain

76 61

80.3%

15 19.7%

General Back Pain

31 25

80.7%

6 19.3%

Lower Limb Pain

68 54

79.4%

14 20.6%

Insomnia

70 61

87.1%

9 12.9%

Fatigue

64 53

82.8%

11 17.2%

Out of 375 total subjects with symptoms, 301 (80.27%) reported positive results. 74 cases (19.73%) reported no results.

Time of Response:

The percentage of subjects who realized the effect of the magnetic mattress pad within 3 days:

Neck & Shoulder Pain

46.9%

Back & Lower Back Pain

50.0%

Back Pain (general)

38.7%

Lower Limb Pain

54.4%

Insomnia

64.3%

Fatigue

57.8%

Out of 375 total subjects who slept on the magnetic mattress pads, 200 (53.3%) realized the effects within 3 days. Over 70% realized the effects within 5 days.

Testing for side effects was conducted at the conclusion of the experiment. Symptoms such as tinnitus, headache, hearing problems, visual disturbances, vertigo, palpitation, perceptive abnormality, motorial disturbance, fever, digestive disturbance, coetaneous symptoms, and other clinical symptoms to suggest any side effects were found to be totally absent. Extensive testing was also done before and after the experiment to check functions of kidneys liver, pancreas, blood pressure, and the circulatory system. No clinical symptoms were found to indicate any side effects whatsoever.

Conclusion

Dr. Shimodaira's conclusion of this year-long study conducted in 3 of Japan's foremost hospitals: "The magnetized health mattress pad is proved to be effective on neck and shoulder pain, back and lower back pain, back pain, lower limb pain, insomnia, and fatigue, and to have no side effects."

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Use of magnetic therapy for chronic pain.

Summary:

A Johns Hopkins pain center treatment study compared magnetic therapy for chronic pain and a placebo therapy. While some individuals in placebo therapy improved minimally, people using the magnetic therapy showed a dramatic improvement. In addition, there were no side effects from magnetic therapy, thus making it an apparently reasonable choice for those who have tried and rejected traditional therapy.

The Arthritis Solution, Joseph Kandel, M.D. and David B. Sudderth, M.D.

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