Transcranial magnetic stimulation

Transcranial magnetic stimulation
Intervention
Transcranial magnetic stimulation (schematic diagram)
MeSH	D050781
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Transcranial magnetic stimulation (TMS) is a magnetic method used to stimulate small regions of the brain. During a TMS procedure, a magnetic field generator, or "coil", is placed near the head of the person receiving the treatment. The coil produces small electric currents in the region of the brain just under the coil via electromagnetic induction. The coil is connected to a pulse generator, or stimulator, that delivers electric current to the coil.

TMS is used diagnostically to measure the connection between the brain and a muscle to evaluate damage from stroke, multiple sclerosis, amyotrophic lateral sclerosis, movement disorders, motor neuron disease and injuries and other disorders affecting the facial and other cranial nerves and the spinal cord.

Evidence suggests it is useful for neuropathic pain and treatment-resistant major depressive disorder. A 2015 Cochrane review found not enough evidence to make any conclusions in schizophrenia. For negative symptoms another review found possible efficacy. As of 2014, all other investigated uses of repetitive TMS have only possible or no clinical efficacy.

Matching the discomfort of TMS to distinguish true effects from placebo is an important and challenging issue that influences the results of clinical trials. The greatest risks of TMS are the rare occurrence of syncope (fainting) and even less commonly, induced seizures. Other adverse 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.