Neural pain processing in the brain was studied on 31 patients by J. A. Robertson and his team. Researchers applied pulsed magnetic field frequencies of 9, 5, 3 and 1 Hz.
The results of this study showed that low-frequency pulsed magnetic therapy affected neural processing of acute thermal pain which had been experimentally induced in patients. The imaging of hippocampus, anterior cingular cortex and ipsilateral insula (areas of brain associated with pain perception), which was done prior to and after the pulsed magnetic therapy, confirmed significant changes.
Functional magnetic resonance imaging (fMRI) allowed researchers to see neuromodulation in brain that had been induced by low-frequency pulsed magnetic field. These observations thus confirm the hypothesis of Robertson’s scientific team that decrease in pain perception which is caused by pulsed magnetic therapy does not depend on brain mechanisms of orientation and navigation (as previously assumed), but on central structures of the brain.
Source: Robertson, J. A. et al. (2010) Low-frequency pulsed electromagnetic field exposure can alter neuroprocessing in humans. Journal of the Royal Society Interface. [Online] 7 (44), 467–473.