Pain Studies

Analgesic and behavioral effects of a 100 microT specific pulsed extremely low frequency magnetic field on control and morphine.

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 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 without the side effects often associated with opiates like morphine.

PMID: 14698475 [PubMed - indexed for MEDLINE]

Effects of a pulsed electromagnetic therapy on multiple sclerosis fatigue and quality of life: a double-blind, placebo controlled trial.

Lappin MS, Lawrie FW, Richards TL, Kramer ED.
Energy Medicine Developments, (North America), Inc., Burke, Va., USA.

CONTEXT: There is a growing literature on the biological and clinical effects of pulsed electromagnetic fields. Some studies suggest that electromagnetic therapies may be useful in the treatment of chronic illnesses. This study is a follow-up to a placebo controlled pilot study in which multiple sclerosis (MS) patients exposed to weak, extremely low frequency pulsed electromagnetic fields showed significant improvements on a composite symptom measure. OBJECTIVE: To evaluate the effects of a pulsed electromagnetic therapy on MS related fatigue, spasticity, bladder control, and overall quality of life. DESIGN: A multi-site, double-blind, placebo controlled, crossover trial. Each subject received 4 weeks of the active and placebo treatments separated by a 2-week washout period. SETTING: The University of Washington Medical Center in Seattle Wash, the Neurology Center of Fairfax in Fairfax, Va, and the headquarters of the Multiple Sclerosis Association of America in Cherry Hill, NJ. SUBJECTS: 117 patients with clinically definite MS. INTERVENTION: Daily exposure to a small, portable pulsing electromagnetic field generator. MAIN OUTCOME: The MS Quality of Life Inventory (MSQLI) was used to assess changes in fatigue, bladder control, spasticity, and a quality of life composite. RESULTS: Paired t-tests were used to assess treatment differences in the 117 subjects (81% of the initial sample) who completed both treatment sessions. Improvements in fatigue and overall quality of life were significantly greater on the active device. There were no treatment effects for bladder control and a disability composite, and mixed results for spasticity. CONCLUSIONS: Evidence from this randomized, double-bind, placebo controlled trial is consistent with results from smaller studies suggesting that exposure to pulsing, weak electromagnetic fields can alleviate symptoms of MS. The clinical effects were small, however, and need to be replicated. Additional research is also needed to examine the possibility that ambulatory patients and patients taking interferons for their MS may be most responsive to this kind of treatment.

PMID: 12868251 [PubMed - indexed for MEDLINE]

Pulsed magnetic field therapy for osteoarthritis of the knee--a double-blind sham-controlled trial.

Nicolakis P, Kollmitzer J, Crevenna R, Bittner C, Erdogmus CB, Nicolakis J.
Department of Physical Medicine and Rehabilitation, AKH Wien, University of Vienna, Vienna, Austria. Peter.nicolakis@akh-wien.ac.at

BACKGROUND AND METHODS: Pulsed magnetic field therapy is frequently used to treat the symptoms of osteoarthritis, although its efficacy has not been proven. We conducted a randomized, double-blind comparison of pulsed magnetic field and sham therapy in patients with symptomatic osteoarthritis of the knee. Patients were assigned to receive 84 sessions, each with a duration of 30 minutes, of either pulsed magnetic field or sham treatment. Patients administered the treatment on their own at home, twice a day for six weeks. RESULTS: According to a sample size estimation, 36 consecutive patients were enrolled. 34 patients completed the study, two of whom had to be excluded from the statistical analysis, as they had not applied the PMF sufficiently. Thus, 15 verum and 17 sham-treated patients were enrolled in the statistical analysis. After six weeks of treatment the WOMAC Osteoarthritis Index was reduced in the pulsed magnetic field-group from 84.1 (+/- 45.1) to 49.7 (+/- 31.6), and from 73.7 (+/- 43.3) to 66.9 (+/- 52.9) in the sham-treated group (p = 0.03). The following secondary parameters improved in the pulsed magnetic field group more than they did in the sham group: gait speed at fast walking [+6.0 meters per minute (1.6 to 10.4) vs. -3.2 (-8.5 to 2.2)], stride length at fast walking [+6.9 cm (0.2 to 13.7) vs. -2.9 (-8.8 to 2.9)], and acceleration time in the isokinetic dynamometry strength tests [-7.0% (-15.2 to 1.3) vs. 10.1% (-0.3 to 20.6)]. CONCLUSION: In patients with symptomatic osteoarthritis of the knee, PMF treatment can reduce impairment in activities of daily life and improve knee function.

PMID: 12602111 [PubMed - indexed for MEDLINE]

Sacral magnetic stimulation for pain relief from pudendal neuralgia and sciatica.

Sato T, Nagai H.
Department of Surgery, Jichi Medical School, Minamikawachi-machi, Kawachi-gun, Tochigi-ken, Japan.

INTRODUCTION: Magnetic stimulation of the sacral nerve roots is used for neurologic examination. However, no one has reported therapeutic efficacy of pain relief from pudendal neuralgia with sacral magnetic stimulation. METHODS: Five patients with pudendal neuralgia or sciatica received 30 to 50 pulsed magnetic stimuli of the sacral nerve roots. The median age of the patients was 59 (range, 28-69) years; there were 3 females. RESULTS: Sacral magnetic stimulation immediately eliminated the pain. The pain relief lasted between 30 minutes and 56 days (median, 24 hours). Adverse effects were not observed. CONCLUSIONS: This pilot study indicates that magnetic stimulation of the sacral nerve roots may be a promising therapeutic modality for pain relief from pudendal neuralgia and sciatica. Further studies should be performed to determine the appropriate intensity and frequency, as well as the utility of a second course, of magnetic stimulation treatment.

PMID: 11852346 [PubMed - indexed for MEDLINE]

Magnetic pulse treatment for knee osteoarthritis: a randomised, double-blind, placebo-controlled study.

Pipitone N, Scott DL.
Rheumatology Department, King's College Hospital (Dulwich), London, UK.

We assessed the efficacy and tolerability of low-frequency pulsed electromagnetic fields (PEMF) therapy in patients with clinically symptomatic knee osteoarthritis (OA) in a randomised, placebo-controlled, double-blind study of six weeks' duration. Patients with radiographic evidence and symptoms of OA (incompletely relieved by conventional treatments), according to the criteria of the American College of Rheumatology, were recruited from a single tertiary referral centre. 75 patients fulfilling the above criteria were randomised to receive active PEMF treatment by unipolar magnetic devices (Medicur) manufactured by Snowden Healthcare (Nottingham, UK) or placebo. Six patients failed to attend after the screening and were excluded from analysis. The primary outcome measure was reduction in overall pain assessed on a four-point Likert scale ranging from nil to severe. Secondary outcome measures included the WOMAC Osteoarthritis Index (Likert scale) and the EuroQol (Euro-Quality of Life, EQ-5D). Baseline assessments showed that the treatment groups were equally matched. Although there were no significant differences between active and sham treatment groups in respect of any outcome measure after treatment, paired analysis of the follow-up observations on each patient showed significant improvements in the actively treated group in the WOMAC global score (p = 0.018), WOMAC pain score (p = 0.065), WOMAC disability score (p = 0.019) and EuroQol score (p = 0.001) at study end compared to baseline. In contrast, there were no improvements in any variable in the placebo-treated group. There were no clinically relevant adverse effects attributable to active treatment. These results suggest that the Medicur unipolar magnetic devices are beneficial in reducing pain and disability in patients with knee OA resistant to conventional treatment in the absence of significant side-effects. Further studies using different types of magnetic devices, treatment protocols and patient populations are warranted to confirm the general efficacy of PEMF therapy in OA and other conditions.

PMID: 11900312 [PubMed - indexed for MEDLINE]