ABSTRACT
The use of electromagnetism in nonthermal therapeutic procedures follows from an increasing number of laboratory observations suggesting a wide range of heretofore unsuspected physiological effects, observed both in vivo and in vitro, resulting from the application of electric or magnetic fields. Early therapeutic applications made use of surface or subcutaneous electrodes to produce appropriate current densities within selected tissues. However, it is now apparent that time-varying magnetic fields can be used to advantage to produce equivalent current densities in these tissues. This was first demonstrated by Bassett (1), who used a pulsed magnetic field (PMF) to obtain the same results in repairing bony nonunions as had been previously obtained with the use of electrodes embedded in the defect (2). Although the clinical use of electromagnetic fields may have initially surfaced in connection with bone repair, there is presently a good deal of interest in applying such fields within the central nervous system to treat both behavioral and neurological problems.
