Basic principle of transcranial magnetic stimulation

J Med Assoc Thai. 2009 Nov;92(11):1560-6.

Abstract

Background: Transcranial Magnetic Stimulation (TMS) is a new neurophysiological technique based on the principle of electromagnetic induction. When a pulse of current passes through a coil, it becomes a magnetic field and penetrates the scalp and skull, and reach the brain painlessly.

Objective: Review TMS stimulator, types of stimulation, mechanism of action, and its application.

Material and method: There are three types of TMS stimulation: 1) Single pulse; used in studying of motor threshold and phosphene threshold. 2) Paired pulse; used in the study of intracortical inhibitory and facilitatory mechanisms. 3) Repetitive stimulation; changes corticospinal/corticocortical pathway.

Results: The mechanisms increases activity of synapse, changes the secretion of neurotransmitter and causes neuronal plasticity or long-term potentiation. Repetitive stimulation is used in fundamental basic science for brain mapping. It is a new therapeutic method for neuro-psychiatic disorders that does not respond to medications.

Conclusion: TMS study is rapidly increasing and accepted as a noninvasive technique. The most favorable treating outcomes are depression and Parkinson disease. Other neuro-psychiatic therapeutic outcomes are ongoing.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Depression / therapy
  • Humans
  • Parkinson Disease / therapy
  • Transcranial Magnetic Stimulation / methods*