Luigi Galvani did pioneering research on the effects of electricity on the body in the late 1700s, and laid the foundations for the field of electrophysiology.[51] In the 1800s Michael Faraday discovered that an electrical current had a corresponding magnetic field, and that changing one, could change the other.[52] Work to directly stimulate the human brain with electricity started in the late 1800s
Although TMS is generally regarded as safe, risks increase for therapeutic rTMS compared to single or paired TMS for diagnostic purposes.In the field of therapeutic TMS, risks increase with higher frequencies
The greatest immediate risk is the rare occurrence of syncope (fainting) and even less commonly, induced seizures
Other adverse short-term effects of TMS include discomfort or pain, transient induction of hypomania, transient cognitive changes, transient hearing loss, transient impairment of working memory, and induced currents in electrical circuits in implanted devices