Static magnetic stimulation in the central nervous system: a systematic review

Abstract

Objective To systematically review the literature on the use of the transcranial static magnetic stimulation (tSMS) technique in humans and animals, its effects on different areas of the central nervous system (CNS), its influence on neural excitability and on the subject's behavior, and its biological effects and future possibilities. All static magnetic field applications that can be considered to have a physiologically similar effect have been reviewed. Methods We searched studies using key terms in NCBI PubMed, Scopus, PEDro, SciELO, Cochrane, and links to publications (inception to September 2019). Three reviewers independently selected the studies, extracted data, and assessed the methodological quality of the studies using the recommendations described in the Cochrane Handbook for Systematic Reviews of Interventions, PRISMA guidelines. ResultsWe analyzed 27 studies. The reviewed literature suggests that the use of these magnetic fields has an inhibitory effect on different areas of the CNS, such as motor, somatosensory, and visual cortex, cerebellum, and spinal cord. Regarding subject's behavior, the different effects of tSMS appear to be transient and dependent on the stimulated area, such as loss of visual discrimination or improvement of somatosensory perception. In addition, the technique has some therapeutic utility, specifically in pathologies with cortical hyperexcitability. Conclusions These results suggest that tSMS may be a promising tool to modulate cerebral excitability in a safe and non-invasive way. Further investigations could give a better explanation of its precise mechanisms of action and applications.

Synergistic effects of applying static magnetic fields and diazepam to improve EEG abnormalities in the pilocarpine epilepsy rat model

“…In the particular case of epilepsy, the results have been inconclusive probably due to the variability in the stimulation protocols and etiological heterogeneity (for a comprehensive review see 8 ). One of the most recently incorporated technique to the NIBS family is transcranial static magnetic stimulation (tSMS) 9 , whose application produces a clear and reproducible reduction of cortical excitability [10][11][12][13][14][15] . Following this line, in a recent paper we demonstrated that tSMS of moderate intensity (0.5 T) applied alone was able to delay and reduce the characteristic EEG signs of epileptiform discharges, both in rat and monkey 13 .…”