Journal Of Back And Musculoskeletal Rehabilitation

To evaluate the neurobiological effect of constant, subthreshold magnetic field exposure on symptomatic median nerve compression symptoms, neurophysiology and assess the role of placebo. {it Background:} Conservative treatment of moderate and severe CTS has been variable and often results in surgical decompression at the wrist. {it Design/methods:} Eight moderately symptomatic and intractable CTS hands constantly wore identical Elastomag wrist support wraps (unmagnetized vs. magnetized 350 gauss) for one month intervals. Identical wraps were then switched at the second month. Baseline assessments included the neurological exam, VAS scores for burning, numbness and tingling twice a day on a 10 point ordinal scale. CMAP/SNAP was determined at baseline and monthly intervals. Clinical follow-up at end of fourth and eighth weeks was compared to baseline. {it Results:} The mean pain scores improved in four patients (57%) which also correlated with clinical benefit. Improvement in Tinel and Phalen sign as well as sensory changes was similarly noted. Placebo effect was detected in one patient (13%). Electrophysiological improvement in distal latencies in 5/8 hands using magnetic treatment was noted compared to no change or worsening in all placebo cases. {it Conclusions:} Percutaneous magnetic stimulation induced palliative pain relief, presumably via modulation of the unmyelinated C-fibers. Prior studies have suggested an influence on K+ inward rectification excitability. These observations suggest that wearing magnetized wrist wraps appears to be a novel therapeutic agent. However, the underlying neuropathology tends to be progressive.

1. K.A. Cseuz, J.E. Thomas, E.H. Lambert, J.G. Love and P.R. Lipscomb, Long-term Results of Operations for Carpal Tunnel Syndrome, Mayo Clin Proc 41 (1966), 232-241.2. G. Omer, Median Nerve Compression at the Wrist, Hand Clin 8 (1992), 317-324.3. K. Nakagawa, Study on Clinical Effects of the Magnetic Necklace, in: TBK Magneto Medical Publication Series I, Beverly Hills (Cal), 1975, pp. 1-12.4. C.Z. Hong, J.C. Lin, L.P. Bender, J.N. Schaeffer, R.J. Mettzer and P. Causin, Magnetic Necklace: Its Therapeutic Effectiveness on Neck and Shoulder Pain, Arch Phys Med Rehab 63 (1982), 462-466.5. C. Vallbona, C.F. Hazelwood and G. Jurida, Response of Pain to Static Magnetic Fields in Postpolio Patients: A Double-Blind Pilot Study, Arch Phys Med Rehabil 78 (1997), 1200-1203.6. D.N. Dawson, Entrapment Neuropathies of the Upper Extremities, N Eng J Med 329 (1993), 2013-2018.7. A.V. Cavopol, M.J. McLean and R.R. Holcomb, An Explanatory Mechanism for Blockade of Action Potentials in Neural Cells by External Magnetic Fields. Fifteenth Annual Meeting of the Bioelectromagnetics Society. Abstract A-1-6, 1993.8. D.O. Carpenter and S. Ayrapetyan, eds, Biological Effects of Electric and Magnetic Fields, Academic Press, San Diego, 1994.9. M.J. McLean, R.R. Holcomb, A.W. Wamil, J.D. Pickett and A.V. Cavopol, Blockade of Sensory Neuron Action Potentials by a Static Magnetic Field in the 10 mT Rage, Bioelectromag-netics 16 (1995), 20-32.10. M.I. Weintraub, Chronic Submaximal Magnetic Stimulation in Peripheral Neuropathy: Is there a Beneficial Therapeutic Relationship? Amer J Pain Management 8 (1998), 12-16.11. M.I. Weintraub, Magnetic Bio-Stimulation in Painful Diabetic Peripheral Neuropathy: A Novel Intervention. A Randomized, Double-Placebo Crossover Study, Amer J Pain Management 9 (1999), 8-17.12. E.A. Collacott, J.T. Zimmerman, D.W. White and J.P. Rindone, Bipolar Permanent Magnets for the Treatment of Chronic Low Back Pain, JAMA 283 (2000), 1322-1325.