View source for Transcranial magnetic stimulation

{{Short description|Brain stimulation using magnetic fields}}
{{Infobox medical intervention |
  Name        = Transcranial magnetic stimulation |
  Image       = File:Transcranial magnetic stimulation.jpg|
  Caption     = Transcranial magnetic stimulation<br />(schematic diagram)|
  Speciality = [[Psychiatry]], [[neurology]] |
  ICD10       = |
  ICD9        = |
  MeshID      = D050781 |
  OtherCodes  = |
}}
'''Transcranial magnetic stimulation''' ('''TMS''') is a [[Non-invasive procedure|noninvasive]] [[neurostimulation]] technique in which a changing [[magnetic field]] is used to induce an [[electric current]] in a targeted area of the [[brain]] through [[electromagnetic induction]]. A device called a [[stimulator]] generates electric pulses that are delivered to a [[magnetic coil]] placed against the [[scalp]]. The resulting magnetic field penetrates the [[skull]] and induces a secondary electric current in the underlying brain tissue, modulating [[neural activity]].<ref name="NICE2014">{{cite web|publisher=National Institute for Health and Care Excellence|date=January 2014|url=https://www.nice.org.uk/guidance/IPG477|title=Transcranial magnetic stimulation for treating and preventing migraine}}</ref><ref name=Harvard>{{cite web|first1=Michael Craig|last1=Miller|publisher=Harvard Health Publishing|date=July 26, 2012|url=http://www.health.harvard.edu/blog/magnetic-stimulation-a-new-approach-to-treating-depression-201207265064|title=Magnetic stimulation: a new approach to treating depression?}}</ref>

<!-- Medical uses -->
Repetitive transcranial magnetic stimulation (rTMS) is a safe, effective, and [[FDA]]-approved treatment for [[major depressive disorder]] (approved in 2008), [[chronic pain]] (2013), and [[obsessive-compulsive disorder]] (2018).<ref>{{cite book
 | last1 = Mann
 | first1 = Sukhmanjeet Kaur
 | last2 = Malhi
 | first2 = Narpinder K.
 | chapter = Repetitive Transcranial Magnetic Stimulation (rTMS)
 | title = StatPearls
 | date = 6 March 2023
 | publisher = StatPearls Publishing
 | location = Treasure Island (FL)
 | pmid = 33760474
 | url = https://www.ncbi.nlm.nih.gov/books/NBK568715/
 | access-date = 1 May 2025
}}</ref> It has strong evidence for certain neurological and psychiatric conditions—especially [[Depression (mood)|depression]] (with a large [[effect size]]), [[neuropathic pain]], and [[stroke recovery]]—and emerging advancements like iTBS and image-guided targeting may improve its efficacy and efficiency.<ref name=upd>{{cite journal |vauthors=Lefaucheur JP, Aleman A, Baeken C, Benninger DH, Brunelin J, Di Lazzaro V, Filipović SR, Grefkes C, Hasan A, Hummel FC, Jääskeläinen SK, Langguth B, Leocani L, Londero A, Nardone R, Nguyen JP, Nyffeler T, Oliveira-Maia AJ, Oliviero A, Padberg F, Palm U, Paulus W, Poulet E, Quartarone A, Rachid F, Rektorová I, Rossi S, Sahlsten H, Schecklmann M, Szekely D, Ziemann U |title=Evidence-based guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS): An update (2014-2018) |journal=Clin Neurophysiol |volume=131 |issue=2 |pages=474–528 |date=February 2020 |pmid=31901449 |doi=10.1016/j.clinph.2019.11.002 |display-authors=5 |hdl=10362/147799 |hdl-access=free }}</ref><ref>McClintock, S. M.; Carpenter, L. L.; Downar, J.; et al. (2025). "Consensus review and considerations on TMS to treat depression". *Journal of the Neurological Sciences*. 459: 121579. doi:[10.1016/j.jns.2024.121579](https://doi.org/10.1016/j.jns.2024.121579).</ref>

<!-- Side effects -->
Adverse effects of TMS appear rare and include [[syncope (medicine)|fainting]] and [[epileptic seizure|seizure]], which occur in roughly 0.1% of patients and are usually attributable to administration error.<ref name=Rossi>{{cite journal |last1=Rossi |display-authors=et al. |title=Safety and recommendations for TMS use in healthy subjects and patient populations, with updates on training, ethical and regulatory issues: Expert Guidelines. |journal=Clinical Neurophysiology |date=January 2021 |volume=132 |issue=1 |pages=269–306 |doi=10.1016/j.clinph.2020.10.003 |pmid=33243615 |pmc=9094636 |s2cid=225049093 }}</ref>
{{TOC limit|3}}

== Medical uses ==
[[File:Neuro-ms.png|thumb|285x285px|A magnetic coil is positioned on the patient's head.<ref name=":0" />]]
TMS does not require surgery or electrode implantation.

Its use can be diagnostic and/or therapeutic. Effects vary based on frequency and intensity of the magnetic pulses as well as the length of treatment, which dictates the total number of pulses given.<ref>{{Cite journal|date=2015-09-01|title=Basic principles of transcranial magnetic stimulation (TMS) and repetitive TMS (rTMS)|journal=Annals of Physical and Rehabilitation Medicine|language=en|volume=58|issue=4|pages=208–213|doi=10.1016/j.rehab.2015.05.005|issn=1877-0657|doi-access=free|last1=Klomjai|first1=Wanalee|last2=Katz|first2=Rose|last3=Lackmy-Vallée|first3=Alexandra|pmid=26319963}}</ref> TMS treatments are approved by the FDA in the US and by [[National Institute for Health and Care Excellence|NICE]] in the UK for the treatment of depression and are provided by private clinics and some [[List of Veterans Affairs medical facilities|VA medical centers]]. TMS stimulates cortical tissue without the pain sensations produced in [[transcranial direct-current stimulation|transcranial electrical stimulation]].<ref>{{cite book |first=Jean-Pascal |last=Lefaucher |chapter=37. Transcranial magnetic stimulation |chapter-url=https://www.sciencedirect.com/science/article/abs/pii/B9780444640321000370 |editor-first=Kerry H. |editor-last=Levin |editor2-first=Patrick |editor2-last=Chauvel |series=Handbook of Clinical Neurology |publisher=Elsevier |doi=10.1016/B978-0-444-64032-1.00037-0 |date=2019 |isbn=978-0-444-64032-1 |pages=559–580 |volume=160 |title=Clinical Neurophysiology: Basis and Technical Aspects|pmid=31277876 }}</ref>

=== Diagnosis ===
TMS can be used clinically to measure activity and function of specific brain circuits in humans, most commonly with single or paired magnetic pulses.<ref name=diagnostic1>{{cite journal | vauthors = Groppa S, Oliviero A, Eisen A, Quartarone A, Cohen LG, Mall V, Kaelin-Lang A, Mima T, Rossi S, Thickbroom GW, Rossini PM, Ziemann U, Valls-Solé J, Siebner HR | display-authors = 6 | title = A practical guide to diagnostic transcranial magnetic stimulation: report of an IFCN committee | journal = Clinical Neurophysiology | volume = 123 | issue = 5 | pages = 858–882 | date = May 2012 | pmid = 22349304 | pmc = 4890546 | doi = 10.1016/j.clinph.2012.01.010 }}</ref> The most widely accepted use is in measuring the connection between the [[primary motor cortex]] of the [[central nervous system]] and the [[peripheral nervous system]] to evaluate damage related to past or progressive neurologic insult.<ref name=diagnostic1 /><ref>{{cite journal | vauthors = Rossini PM, Rossi S | title = Transcranial magnetic stimulation: diagnostic, therapeutic, and research potential | journal = Neurology | volume = 68 | issue = 7 | pages = 484–8 | date = February 2007 | pmid = 17296913 | doi = 10.1212/01.wnl.0000250268.13789.b2 | s2cid = 19629888 }}</ref><ref name="Dimyan">{{cite journal | vauthors = Dimyan MA, Cohen LG | title = Contribution of transcranial magnetic stimulation to the understanding of functional recovery mechanisms after stroke | journal = Neurorehabilitation and Neural Repair | volume = 24 | issue = 2 | pages = 125–135 | date = February 2010 | pmid = 19767591 | pmc = 2945387 | doi = 10.1177/1545968309345270 }}</ref><ref name="Nowak">{{cite journal | vauthors = Nowak DA, Bösl K, Podubeckà J, Carey JR | title = Noninvasive brain stimulation and motor recovery after stroke | journal = Restorative Neurology and Neuroscience | volume = 28 | issue = 4 | pages = 531–544 | year = 2010 | pmid = 20714076 | doi = 10.3233/RNN-2010-0552 }}</ref> TMS has utility as a diagnostic instrument for [[myelopathy]], [[amyotrophic lateral sclerosis]], and [[multiple sclerosis]].<ref name="Chen2008">{{cite journal |vauthors=Chen R, Cros D, Curra A, Di Lazzaro V, Lefaucheur JP, Magistris MR, Mills K, Rösler KM, Triggs WJ, Ugawa Y, Ziemann U |title=The clinical diagnostic utility of transcranial magnetic stimulation: report of an IFCN committee |journal=Clin Neurophysiol |volume=119 |issue=3 |pages=504–532 |date=March 2008 |pmid=18063409 |doi=10.1016/j.clinph.2007.10.014 }}</ref>

=== Treatment and efficacy===
Repetitive transcranial magnetic stimulation (rTMS) is a safe, effective, and [[FDA]]-approved treatment for [[major depressive disorder]] (approved in 2008), [[chronic pain]] (2013), and [[obsessive-compulsive disorder]] (2018).<ref>{{cite book
 | last1 = Mann
 | first1 = Sukhmanjeet Kaur
 | last2 = Malhi
 | first2 = Narpinder K.
 | chapter = Repetitive Transcranial Magnetic Stimulation (rTMS)
 | title = StatPearls
 | date = 6 March 2023
 | publisher = StatPearls Publishing
 | location = Treasure Island (FL)
 | pmid = 33760474
 | url = https://www.ncbi.nlm.nih.gov/books/NBK568715/
 | access-date = 1 May 2025
}}</ref>

Repetitive transcranial magnetic stimulation ([[rTMS]]) has been shown to produce significant clinical improvements in various neurological and psychiatric disorders. A group of European experts updated the therapeutic guidelines, reviewing studies up to the end of 2018. The highest level of evidence, Level A (definite efficacy), was found for high-frequency rTMS of the primary motor cortex ([[primary motor cortex]]) for [[neuropathic pain]], high-frequency rTMS of the left [[dorsolateral prefrontal cortex]] (DLPFC) for [[Depression (mood)|depression]], and low-frequency rTMS of the contralesional motor cortex for hand motor recovery after [[stroke]]. Level B evidence (probable efficacy) was found in conditions such as [[fibromyalgia]], [[Parkinson’s disease]], [[multiple sclerosis]], [[post-traumatic stress disorder]] (PTSD), depression, and post-stroke [[aphasia]], depending on the rTMS protocol used. No other conditions reached Level A or B evidence. These recommendations are based on differences in therapeutic outcomes between real and sham rTMS, replicated in multiple independent studies, although clinical relevance may still vary.<ref name=upd>{{cite journal |vauthors=Lefaucheur JP, Aleman A, Baeken C, Benninger DH, Brunelin J, Di Lazzaro V, Filipović SR, Grefkes C, Hasan A, Hummel FC, Jääskeläinen SK, Langguth B, Leocani L, Londero A, Nardone R, Nguyen JP, Nyffeler T, Oliveira-Maia AJ, Oliviero A, Padberg F, Palm U, Paulus W, Poulet E, Quartarone A, Rachid F, Rektorová I, Rossi S, Sahlsten H, Schecklmann M, Szekely D, Ziemann U |title=Evidence-based guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS): An update (2014-2018) |journal=Clin Neurophysiol |volume=131 |issue=2 |pages=474–528 |date=February 2020 |pmid=31901449 |doi=10.1016/j.clinph.2019.11.002 |display-authors=5 |hdl=10362/147799 |hdl-access=free }}</ref>

A 2025 consensus review published in the [[Journal of the Neurological Sciences]] evaluated current clinical practices and recent advancements in TMS for depression. The review confirms that TMS is a safe and effective treatment modality, with a growing body of evidence supporting its use in treatment-resistant depression. Repetitive transcranial magnetic stimulation (rTMS), particularly high-frequency stimulation of the left [[dorsolateral prefrontal cortex]], has demonstrated robust and reproducible acute [[antidepressant]] effects in major depressive disorder, with growing evidence supporting its efficacy, durability, and potential superiority over medication in treatment-resistant cases. Traditional repetitive TMS (rTMS) protocols have been well-established, while newer approaches—such as intermittent theta burst stimulation (iTBS) and individualized, image-guided targeting—have shown promise in reducing treatment time and potentially enhancing clinical outcomes.<ref>McClintock, S. M.; Carpenter, L. L.; Downar, J.; et al. (2025). "Consensus review and considerations on TMS to treat depression". *Journal of the Neurological Sciences*. 459: 121579. doi:[10.1016/j.jns.2024.121579](https://doi.org/10.1016/j.jns.2024.121579).</ref>

The effectiveness of TMS and [[quality of evidence]] behind it for treatment of depression have been questioned.<ref name="BriniBrudascaHodkinson2023">{{cite journal | vauthors = Brini S, Brudasca NI, Hodkinson A, Kaluzinska K, Wach A, Storman D, Prokop-Dorner A, Jemioło P, Bala MM | title = Efficacy and safety of transcranial magnetic stimulation for treating major depressive disorder: An umbrella review and re-analysis of published meta-analyses of randomised controlled trials | journal = Clin Psychol Rev | volume = 100 | issue = | pages = 102236 | date = March 2023 | pmid = 36587461 | doi = 10.1016/j.cpr.2022.102236 | url = }}</ref><ref name="MalhiBellOuthred2021">{{cite journal | vauthors = Malhi GS, Bell E, Outhred T, Singh AB, Hopwood M, Mulder R, Bassett D, Mannie Z | title = Is rTMS Ready for Primetime? | journal = Can J Psychiatry | volume = 66 | issue = 10 | pages = 873–877 | date = October 2021 | pmid = 33955792 | pmc = 8573708 | doi = 10.1177/07067437211016238 | url = }}</ref><ref name="AmadFovet2022">{{cite journal | vauthors = Amad A, Fovet T | title = rTMS for depression: The difficult transition from research to clinical practice | journal = Aust N Z J Psychiatry | volume = 56 | issue = 1 | pages = 14–15 | date = January 2022 | pmid = 33982627 | doi = 10.1177/00048674211011242 | url = }}</ref> As with [[antidepressant]]s and other interventions for depression, there is a large [[placebo response]] with sham [[control group]]s in TMS trials ([[Hedges's g]] = 0.8).<ref name="RazzaMoffaMoreno2018">{{cite journal | vauthors = Razza LB, Moffa AH, Moreno ML, Carvalho AF, Padberg F, Fregni F, Brunoni AR | title = A systematic review and meta-analysis on placebo response to repetitive transcranial magnetic stimulation for depression trials | journal = Prog Neuropsychopharmacol Biol Psychiatry | volume = 81 | issue = | pages = 105–113 | date = February 2018 | pmid = 29111404 | doi = 10.1016/j.pnpbp.2017.10.016 | url = }}</ref> In any case, in a 2023 [[meta-analysis]], TMS showed a large effect size advantage over sham for depression (Hedges' g = 0.791).<ref name="DalhuisenvanBrownswijkBors2022">{{cite journal | vauthors = Dalhuisen I, van Bronswijk S, Bors J, Smit F, Spijker J, Tendolkar I, Ruhé HG, van Eijndhoven P | title = The association between sample and treatment characteristics and the efficacy of repetitive transcranial magnetic stimulation in depression: A meta-analysis and meta-regression of sham-controlled trials | journal = Neurosci Biobehav Rev | volume = 141 | issue = | pages = 104848 | date = October 2022 | pmid = 36049675 | doi = 10.1016/j.neubiorev.2022.104848 | url = | hdl = 2066/253508 | hdl-access = free }}</ref>

== Adverse effects ==
TMS is generally advertised as a safe alternative to medications such as [[SSRI]]'s. The greatest immediate risk from TMS is [[syncope (medicine)|fainting]], though this is uncommon. [[Epileptic seizure|Seizure]]s have been reported, but are rare.<ref name = Rossi /><ref>{{cite journal | vauthors = Dobek CE, Blumberger DM, Downar J, Daskalakis ZJ, Vila-Rodriguez F | title = Risk of seizures in transcranial magnetic stimulation: a clinical review to inform consent process focused on bupropion | journal = Neuropsychiatric Disease and Treatment | volume = 11 | pages = 2975–87 | date = 2015 | pmid = 26664122 | pmc = 4670017 | doi = 10.2147/NDT.S91126 | doi-access = free }}</ref><ref name=Fitzgerald2>{{cite book| vauthors = Fitzgerald PB, Daskalakis ZJ |chapter-url=https://books.google.com/books?id=2VFEAAAAQBAJ |title=Repetitive Transcranial Magnetic Stimulation for Depressive Disorders|chapter=7. rTMS-Associated Adverse Events|pages=81–90 |publisher=Springer |year=2013|doi=10.1007/978-3-642-36467-9_7 |isbn=978-3-642-36466-2}}</ref>

Risks are higher for therapeutic repetitive TMS (rTMS) than for single or paired diagnostic TMS.<ref>{{cite journal |vauthors=van den Noort M, Lim S, Bosch P |date=December 2014 |title=Recognizing the risks of brain stimulation |url=https://hwscenter.com/how-successful-is-tms-therapy-for-depression-your-full-guide-2025/ |journal=Science |volume=346 |issue=6215 |pages=1307 |doi=10.1126/science.346.6215.1307-a |pmid=25504707 |hdl-access=free |hdl=2066/133976}}</ref> Adverse effects generally increase with higher frequency stimulation.<ref name = Rossi />

==Procedure==
During the procedure, a magnetic coil is positioned at the head of the person receiving the treatment using anatomical [[10–20 system (EEG)|landmarks]] on the skull, in particular the [[External occipital protuberance|inion]] and [[nasion]].<ref name=":0">{{cite journal |vauthors = Nauczyciel C, Hellier P, Morandi X, Blestel S, Drapier D, Ferre JC, Barillot C, Millet B |display-authors = 6 |title = Assessment of standard coil positioning in transcranial magnetic stimulation in depression |journal = Psychiatry Research |volume = 186 |issue = 2–3 |pages = 232–8 |date = April 2011 |pmid = 20692709 |doi = 10.1016/j.psychres.2010.06.012 |s2cid = 25100990 }}</ref> The coil is then connected to a pulse generator, or stimulator, that delivers electric current to the coil.<ref name=Harvard />

== Physics ==
{{Main article|Electromagnetic induction}}
[[File:TMS focal field.png|right|150px]]
[[File:TMS Butterfly Coil HEAD.png|right|thumb|240px|TMS – butterfly coils]]
TMS uses [[electromagnetic induction]] to generate an electric current across the [[scalp]] and [[Human skull|skull]].<ref>{{cite journal | vauthors = Cavaleri R, Schabrun SM, Chipchase LS | title = The number of stimuli required to reliably assess corticomotor excitability and primary motor cortical representations using transcranial magnetic stimulation (TMS): a systematic review and meta-analysis | journal = Systematic Reviews | volume = 6 | issue = 1 | pages = 48 | date = March 2017 | pmid = 28264713 | pmc = 5340029 | doi = 10.1186/s13643-017-0440-8 | doi-access = free }}</ref><ref name="NIMH">{{cite web |title=Brain Stimulation Therapies |url=https://www.nimh.nih.gov/health/topics/brain-stimulation-therapies/brain-stimulation-therapies.shtml |website=NIMH }}</ref> A plastic-enclosed coil of wire is held next to the skull and when activated, produces a varying [[magnetic field]] oriented [[Orthogonality|orthogonally]] to the plane of the coil. The changing magnetic field then induces an electric current in the brain that activates nearby nerve cells in a manner similar to a current applied superficially at the cortical surface.<ref>{{cite book |title=Handbook of psychophysiology |year=2007 |publisher=Cambridge University Press |isbn=978-0-521-84471-0 |edition=3rd | veditors = Cacioppo JT, Tassinary LG, Berntson GG |page=121 |doi=10.1017/CBO9780511546396}}</ref>

The magnetic field is about the same strength as [[magnetic resonance imaging]] (MRI), and the pulse generally reaches no more than 5 centimeters into the brain unless using a modified coil and technique for deeper stimulation.<ref name="NIMH"/>

Transcranial magnetic stimulation is achieved by quickly discharging current from a large [[capacitor]] into a coil to produce pulsed [[magnetic fields]] between 2 and 3 [[Tesla (unit)|teslas]] in strength.<ref name=Walsh>{{cite book |first1=V. |last1=Walsh |first2=A. |last2=Pascual-Leone |title=Transcranial Magnetic Stimulation: A Neurochronometrics of Mind |publisher=MIT Press |location=Cambridge, MA |date=2003 |isbn=978-0-262-28573-5 |oclc=53889320 |doi=10.7551/mitpress/6896.001.0001 }}</ref> Directing the magnetic field pulse at a targeted area in the brain causes a localized electrical current which can then either [[depolarization|depolarize]] or [[hyperpolarization (biology)|hyperpolarize]] neurons at that site. 
The induced electric field inside the brain tissue causes a change in transmembrane potentials resulting in depolarization or hyperpolarization of neurons, causing them to be more or less excitable, respectively.<ref name=Walsh />

TMS usually stimulates to a depth from 2 to 4&nbsp;cm below the surface, depending on the coil and intensity used. Consequently, only superficial brain areas can be affected.<ref>{{cite journal |vauthors=Lefaucheur JP, André-Obadia N, Antal A, Ayache SS, Baeken C, Benninger DH, Cantello RM, Cincotta M, de Carvalho M, De Ridder D, Devanne H, Di Lazzaro V, Filipović SR, Hummel FC, Jääskeläinen SK, Kimiskidis VK, Koch G, Langguth B, Nyffeler T, Oliviero A, Padberg F, Poulet E, Rossi S, Rossini PM, Rothwell JC, Schönfeldt-Lecuona C, Siebner HR, Slotema CW, Stagg CJ, Valls-Sole J, Ziemann U, Paulus W, Garcia-Larrea L |title=Evidence-based guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS) |journal=Clin Neurophysiol |volume=125 |issue=11 |pages=2150–2206 |date=November 2014 |pmid=25034472 |doi=10.1016/j.clinph.2014.05.021 |url=https://hal.archives-ouvertes.fr/hal-03183867/file/S1388245719312799.pdf }}</ref> Deep TMS can reach up to 6&nbsp;cm into the brain to stimulate deeper layers of the [[motor cortex]], such as that which controls leg motion. The path of this current can be difficult to model because the brain is irregularly shaped with variable internal density and water content, leading to a nonuniform magnetic field strength and [[Electrical conduction|conduction]] throughout its tissues.<ref>See:
# {{cite journal | vauthors = Zangen A, Roth Y, Voller B, Hallett M | title = Transcranial magnetic stimulation of deep brain regions: evidence for efficacy of the H-coil | journal = Clinical Neurophysiology | volume = 116 | issue = 4 | pages = 775–9 | date = April 2005 | pmid = 15792886 | doi = 10.1016/j.clinph.2004.11.008 | s2cid = 25101101 }}
# {{cite journal | vauthors = Huang YZ, Sommer M, Thickbroom G, Hamada M, Pascual-Leonne A, Paulus W, Classen J, Peterchev AV, Zangen A, Ugawa Y | display-authors = 6 | title = Consensus: New methodologies for brain stimulation | journal = Brain Stimulation | volume = 2 | issue = 1 | pages = 2–13 | date = January 2009 | pmid = 20633398 | pmc = 5507351 | doi = 10.1016/j.brs.2008.09.007 }}</ref>

===Frequency and duration===
The effects of TMS can be divided based on frequency, duration and intensity (amplitude) of stimulation:<ref>{{cite journal | vauthors = Rubens MT, Zanto TP | title = Parameterization of transcranial magnetic stimulation | journal = Journal of Neurophysiology | volume = 107 | issue = 5 | pages = 1257–9 | date = March 2012 | pmid = 22072509 | pmc = 3311692 | doi = 10.1152/jn.00716.2011 }}</ref>
* Single or paired pulse TMS causes neurons in the neocortex under the site of stimulation to [[Depolarization|depolarize]] and discharge an [[action potential]]. If used in the [[primary motor cortex]], it produces muscle activity referred to as a [[Evoked potential#Motor evoked potentials|motor evoked potential]] (MEP) which can be recorded on [[electromyography]]. If used on the [[occipital cortex]], '[[phosphene]]s' (flashes of light) might be perceived by the subject. In most other areas of the cortex, there is no conscious effect, but behaviour may be altered (e.g., slower reaction time on a cognitive task), or changes in brain activity may be detected using diagnostic equipment.<ref name="Handbook of Transcranial Magnetic Stimulation">{{cite book | author-link1 = Alvaro Pascual-Leone | vauthors = Pascual-Leone A, Davey N, Rothwell J, Wassermann EM, Puri BK | year = 2002 | title = Handbook of Transcranial Magnetic Stimulation | publisher = Edward Arnold|location=London | isbn = 978-0-340-72009-7 |oclc=47824021 }}</ref>
* Repetitive TMS (rTMS) produces longer-lasting effects which persist past the period of stimulation. rTMS can increase or decrease the excitability of the [[corticospinal tract]] depending on the intensity of stimulation, coil orientation, and frequency. Low frequency rTMS with a stimulus frequency less than 1&nbsp;Hz is believed to inhibit cortical firing, while a stimulus frequency greater than 1&nbsp;Hz, referred to as high frequency, is believed to provoke it.<ref name="ReferenceA">{{cite journal | vauthors = Cusin C, Dougherty DD | title = Somatic therapies for treatment-resistant depression: ECT, TMS, VNS, DBS | journal = Biology of Mood & Anxiety Disorders | volume = 2 | issue = 1 | pages = 14 | date = August 2012 | pmid = 22901565 | pmc = 3514332 | doi = 10.1186/2045-5380-2-14 | doi-access = free }}</ref>  Though its mechanism is not clear, it has been suggested as being due to a change in synaptic efficacy related to [[long-term potentiation]] (LTP) and long-term depression like plasticity (LTD-like plasticity).<ref name=Fitzgerald>{{cite journal | vauthors = Fitzgerald PB, Fountain S, Daskalakis ZJ | title = A comprehensive review of the effects of rTMS on motor cortical excitability and inhibition | journal = Clinical Neurophysiology | volume = 117 | issue = 12 | pages = 2584–96 | date = December 2006 | pmid = 16890483 | doi = 10.1016/j.clinph.2006.06.712 | s2cid = 31458874 }}</ref><ref>{{cite journal |vauthors=Baur D, Galevska D, Hussain S, Cohen LG, Ziemann U, Zrenner C |title=Induction of LTD-like corticospinal plasticity by low-frequency rTMS depends on pre-stimulus phase of sensorimotor μ-rhythm |journal=Brain Stimul |volume=13 |issue=6 |pages=1580–7 |date=2020 |pmid=32949780 |pmc=7710977 |doi=10.1016/j.brs.2020.09.005 }}</ref>

=== Coil types ===
Most devices use a coil shaped like a figure-eight to deliver a shallow magnetic field that affects more superficial neurons in the brain.<ref name=pmid22559998>{{cite journal |last1=Bersani |first1=F.S. |last2=Minichino |first2=A. |last3=Enticott |first3=P.G. |last4=Mazzarini |first4=L. |last5=Khan |first5=N. |last6=Antonacci |first6=G. |last7=Raccah |first7=R.N. |last8=Salviati |first8=M. |last9=Delle Chiaie |first9=R. |last10=Bersani |first10=G. |last11=Fitzgerald |first11=P.B. |last12=Biondi |first12=M. |title=Deep transcranial magnetic stimulation as a treatment for psychiatric disorders: A comprehensive review |journal=European Psychiatry |date=January 2013 |volume=28 |issue=1 |pages=30–39 |doi=10.1016/j.eurpsy.2012.02.006 |pmid=22559998 |s2cid=29053871 }}</ref> Differences in magnetic coil design are considered when comparing results, with important elements including the type of material, [[geometry]] and specific characteristics of the associated magnetic pulse.

The core material may be either a magnetically inert substrate ('air core'), or a solid, [[ferromagnetic]]ally active material ('solid core').  Solid cores result in more efficient transfer of electrical energy to a magnetic field and reduce energy loss to heat, and so can be operated with the higher volume of therapy protocols without interruption due to [[Overheating (electricity)|overheating]].  Varying the geometric shape of the coil itself can cause variations in [[Focus (geometry)|focality]], shape, and depth of penetration.  Differences in coil material and its power supply also affect magnetic pulse width and duration.<ref>{{cite book |title=Oxford Handbook of Transcranial Stimulation |veditors=Wassermann EM, Epstein CM, Ziemann U, Walsh V, Paus T, Lisanby SH |chapter=TMS Stimulator Design | vauthors = Riehl M |year=2008 |publisher=Oxford University Press |location=Oxford |isbn=978-0-19-856892-6 |chapter-url=https://books.google.com/books?id=YeKleGrKwC4C&pg=PA13  |pages=13–23, [https://books.google.com/books?id=YeKleGrKwC4C&pg=PA25 25–32] |doi=10.1093/oxfordhb/9780198568926.013.0003 }}</ref>

A number of different types of coils exist, each of which produce different magnetic fields. The round coil is the original used in TMS. Later, the figure-eight (butterfly) coil was developed to provide a more focal pattern of activation in the brain, and the four-leaf coil for focal stimulation of peripheral nerves. The double-cone coil conforms more to the shape of the head.<ref name=roth2>{{cite journal | vauthors = Roth BJ, Maccabee PJ, Eberle LP, Amassian VE, Hallett M, Cadwell J, Anselmi GD, Tatarian GT | display-authors = 6 | title = In vitro evaluation of a 4-leaf coil design for magnetic stimulation of peripheral nerve | journal = Electroencephalography and Clinical Neurophysiology | volume = 93 | issue = 1 | pages = 68–74 | date = February 1994 | pmid = 7511524 | doi = 10.1016/0168-5597(94)90093-0 }}</ref> The Hesed (H-core), circular crown and double cone coils allow more widespread activation and a deeper magnetic penetration. They are supposed to impact deeper areas in the motor cortex and [[cerebellum]] controlling the legs and [[pelvic floor]], for example, though the increased depth comes at the cost of a less focused magnetic pulse.<ref name = Rossi />

== Research directions ==
TMS is oftentimes combined with [[electroencephalography]] (EEG) to assess functional connectivity.<ref>{{Cite book |url=https://academic.oup.com/edited-volume/35468 |title=The Oxford Handbook of Transcranial Stimulation |date=2021-02-10 |publisher=Oxford University Press |isbn=978-0-19-883225-6 |editor-last=Wassermann |editor-first=Eric M. |language=en |doi=10.1093/oxfordhb/9780198832256.001.0001 |editor-last2=Peterchev |editor-first2=Angel V. |editor-last3=Ziemann |editor-first3=Ulf |editor-last4=Lisanby |editor-first4=Sarah H. |editor-last5=Siebner |editor-first5=Hartwig R. |editor-last6=Walsh |editor-first6=Vincent}}</ref>

For [[Parkinson's disease]], early results suggest that low frequency stimulation may have an effect on medication associated [[dyskinesia]], and that high frequency stimulation improves motor function.<ref>{{cite journal | vauthors = Machado S, Bittencourt J, Minc D, Portella CE, Velasques B, Cunha M, Budde H, Basile LF, Chadi G, Cagy M, Piedade R, Riberio P | display-authors = 6 | title = Therapeutic applications of repetitive transcranial magnetic stimulation in clinical neurorehabilitation | journal = Functional Neurology | volume = 23 | issue = 3 | pages = 113–122 | date = 2008 | pmid = 19152730 }}</ref><ref>{{Cite journal |last1=Liu |first1=Xuan |last2=Li |first2=Lei |last3=Liu |first3=Ye |date=2023-09-29 |title=Comparative motor effectiveness of non-invasive brain stimulation techniques in patients with Parkinson's disease: A network meta-analysis |journal=Medicine |volume=102 |issue=39 |pages=e34960 |doi=10.1097/MD.0000000000034960 |issn=1536-5964 |pmid=37773851|pmc=10545289 }}</ref>

The [[Cerebellum|cerebellar cortex]] as a possible target of TMS has been investigated in combination with electromyography ([[Electromyography|EMG)]], and a reduction in the average amplitude of [[Motor evoked potentials|motor-evoked-potentials]] in small hand muscles has been observed when comparing paired-pulse TMS with a 6-8 ms interstimulus interval between cerebellar TMS and TMS to the primary motor cortex with single-pulse TMS to the primary motor cortex - a phenomenon termed cerebellum brain inhibition (CBI).<ref>{{Cite journal |last1=Ugawa |first1=Yoshikazu |last2=Uesaka |first2=Yoshikazu |last3=Terao |first3=Yasuo |last4=Hanajima |first4=Ritsuko |last5=Kanazawa |first5=Ichiro |date=1995 |title=Magnetic stimulation over the cerebellum in humans |url=https://onlinelibrary.wiley.com/doi/10.1002/ana.410370603 |journal=Annals of Neurology |language=en |volume=37 |issue=6 |pages=703–713 |doi=10.1002/ana.410370603 |pmid=7778843 |issn=1531-8249}}</ref><ref>{{Cite journal |last1=Fernandez |first1=Lara |last2=Major |first2=Brendan P. |last3=Teo |first3=Wei-Peng |last4=Byrne |first4=Linda K. |last5=Enticott |first5=Peter G. |date=2018-03-01 |title=Assessing cerebellar brain inhibition (CBI) via transcranial magnetic stimulation (TMS): A systematic review |url=https://linkinghub.elsevier.com/retrieve/pii/S014976341730698X |journal=Neuroscience & Biobehavioral Reviews |volume=86 |pages=176–206 |doi=10.1016/j.neubiorev.2017.11.018 |pmid=29208533 |issn=0149-7634}}</ref> Recent investigations have built upon this phenomenon to investigate the feasibility of combining EEG with cerebellar TMS to find signatures of the cerebellum-to-cerebrum functional connectivity in high temporal resultion.<ref>{{Cite journal |last1=Fernandez |first1=Lara |last2=Biabani |first2=Mana |last3=Do |first3=Michael |last4=Opie |first4=George M. |last5=Hill |first5=Aron T. |last6=Barham |first6=Michael P. |last7=Teo |first7=Wei-Peng |last8=Byrne |first8=Linda K. |last9=Rogasch |first9=Nigel C. |last10=Enticott |first10=Peter G. |date=2021-05-01 |title=Assessing cerebellar-cortical connectivity using concurrent TMS-EEG: a feasibility study |url=https://journals.physiology.org/doi/10.1152/jn.00617.2020 |journal=Journal of Neurophysiology |language=en |volume=125 |issue=5 |pages=1768–1787 |doi=10.1152/jn.00617.2020 |issn=0022-3077}}</ref> By applying control conditions accounting for multisensory input and concomitant occipital cortex stimulation, and confirming effective cerebellar TMS by assessing CBI beforehand and modelling the induced electric field, EEG signatures of cerebellar TMS were proposed - as they may be utilized as therapeutic [[Biomarker|biomarkers]] to test pharmacotherapy efficacy in [[spinocerebellar ataxia]] in the future.<ref>{{Cite journal |last1=Gassmann |first1=Lukas |last2=Gordon |first2=Pedro Caldana |last3=Ziemann |first3=Ulf |date=November 2022 |title=Assessing effective connectivity of the cerebellum with cerebral cortex using TMS-EEG |url=https://linkinghub.elsevier.com/retrieve/pii/S1935861X22002170 |journal=Brain Stimulation |language=en |volume=15 |issue=6 |pages=1354–1369 |doi=10.1016/j.brs.2022.09.013|doi-access=free }}</ref><ref>{{Cite journal |last1=Gaßmann |first1=Lukas |last2=Gordon |first2=Pedro Caldana |last3=Ziemann |first3=Ulf |date=November 2023 |title=Reflecting the causes of variability of EEG responses elicited by cerebellar TMS |url=https://linkinghub.elsevier.com/retrieve/pii/S1053811923005190 |journal=NeuroImage |language=en |volume=281 |pages=120368 |doi=10.1016/j.neuroimage.2023.120368|pmid=37696424 |doi-access=free }}</ref><ref>{{Cite journal |last1=Gassmann |first1=Lukas |last2=Gordon |first2=Pedro Caldana |last3=Roy |first3=Olivier |last4=Kaut |first4=Oliver |last5=Hömberg |first5=Volker |last6=Ziemann |first6=Ulf |date=August 2023 |title=Cerebellar TMS-EEG in a chronic stroke patient with connectional diaschisis of the dentato-thalamo-cortical tract |url=https://linkinghub.elsevier.com/retrieve/pii/S1388245723006284 |journal=Clinical Neurophysiology |language=en |volume=152 |pages=68–70 |doi=10.1016/j.clinph.2023.05.009|pmid=37329656 }}</ref><ref>{{Cite journal |last1=Fong |first1=Po-Yu |last2=Spampinato |first2=Danny |last3=Michell |first3=Kevin |last4=Mancuso |first4=Marco |last5=Brown |first5=Katlyn |last6=Ibáñez |first6=Jaime |last7=Santo |first7=Alessandro Di |last8=Latorre |first8=Anna |last9=Bhatia |first9=Kailash |last10=Rothwell |first10=John C |last11=Rocchi |first11=Lorenzo |date=July 2023 |title=EEG responses induced by cerebellar TMS at rest and during visuomotor adaptation |url=https://linkinghub.elsevier.com/retrieve/pii/S1053811923003397 |journal=NeuroImage |language=en |volume=275 |pages=120188 |doi=10.1016/j.neuroimage.2023.120188|pmid=37230209 |hdl=11584/367083 |hdl-access=free }}</ref> However, these EEG signatures are still openly debated in the field of Brain Stimulation due to their inconsistency - likely, differing stimulation targets due to the lack of [[neuronavigation]] in these studies explain these discrepancies in results.<ref>{{Cite journal |last1=Fong |first1=Po-Yu |last2=Rothwell |first2=John C. |last3=Rocchi |first3=Lorenzo |date=2024-04-26 |title=The Past, Current and Future Research in Cerebellar TMS Evoked Responses—A Narrative Review |journal=Brain Sciences |language=en |volume=14 |issue=5 |pages=432 |doi=10.3390/brainsci14050432 |doi-access=free |issn=2076-3425 |pmc=11118133 |pmid=38790411}}</ref><ref>{{Cite journal |last1=Gaßmann |first1=Lukas |last2=Gordon |first2=Pedro Caldana |last3=Ziemann |first3=Ulf |date=November 2023 |title=Reflecting the causes of variability of EEG responses elicited by cerebellar TMS |url=https://linkinghub.elsevier.com/retrieve/pii/S1053811923005190 |journal=NeuroImage |language=en |volume=281 |pages=120368 |doi=10.1016/j.neuroimage.2023.120368|pmid=37696424 |doi-access=free }}</ref> 

== History ==
[[Luigi Galvani]] (1737–1798) undertook research on the effects of electricity on the body in the late-eighteenth century and laid the foundations for the field of [[electrophysiology]].<ref name=Horvath>{{cite journal | vauthors = Horvath JC, Perez JM, Forrow L, Fregni F, Pascual-Leone A | title = Transcranial magnetic stimulation: a historical evaluation and future prognosis of therapeutically relevant ethical concerns | journal = Journal of Medical Ethics | volume = 37 | issue = 3 | pages = 137–143 | date = March 2011 | pmid = 21106996 | doi = 10.1136/jme.2010.039966 | jstor = 23034661 | s2cid = 13262044 }}</ref> In the 1830s, [[Michael Faraday]] (1791–1867) discovered that an [[electrical current]] had a corresponding [[magnetic field]], and that changing one could induce its counterpart.<ref name=Nooh>{{cite journal | vauthors = Noohi S, Amirsalari S | title = History, Studies and Specific Uses of Repetitive Transcranial Magnetic Stimulation (rTMS) in Treating Epilepsy | journal = Iranian Journal of Child Neurology | volume = 10 | issue = 1 | pages = 1–8 | date = 2016 | pmid = 27057180 | pmc = 4815479 }}</ref>

Work to directly stimulate the human brain with electricity started in the late 1800s, and by the 1930s the Italian physicians [[Ugo Cerletti|Cerletti]] and [[Lucio Bini|Bini]] had developed [[electroconvulsive therapy]] (ECT).<ref name=Horvath/> ECT became widely used to treat [[mental illness]], and ultimately overused, as it began to be seen as a [[panacea (medicine)|panacea]]. This led to a backlash in the 1970s.<ref name=Horvath/>

In 1980, Merton and Morton successfully used transcranial electrical stimulation (TES) to stimulate the motor cortex. However, this process was very uncomfortable, and subsequently Anthony T. Barker began to search for an alternative to TES.<ref>{{cite journal | vauthors = Klomjai W, Katz R, Lackmy-Vallée A | title = Basic principles of transcranial magnetic stimulation (TMS) and repetitive TMS (rTMS) | journal = Annals of Physical and Rehabilitation Medicine | volume = 58 | issue = 4 | pages = 208–213 | date = September 2015 | pmid = 26319963 | doi = 10.1016/j.rehab.2015.05.005 | doi-access = free }}</ref> He began exploring the use of magnetic fields to alter electrical signaling within the brain, and the first stable TMS devices were developed in 1985.<ref name=Horvath/><ref name=Nooh/> They were originally intended as diagnostic and research devices, with evaluation of their therapeutic potential being a later development.<ref name=Horvath/><ref name=Nooh/>  The United States' [[Food and Drug Administration|FDA]] first approved TMS devices in October 2008.<ref name=Horvath/>

==Regulatory status ==

===Speech mapping prior to neurosurgery===
Nexstim obtained United States [[Federal Food, Drug, and Cosmetic Act#Section 510(k) and the device approval process|Federal Food, Drug, and Cosmetic Act§Section 510(k)]] clearance for the assessment of the primary motor cortex for pre-procedural planning in December 2009<ref name="NBS">{{cite web|url=http://www.nexstim.com/news-and-events/press-releases/press-releases-archive/fda-clears-nexstim-s-navigated-brain-stimulation-for-non-invasive-cortical-mapping-prior-to-neurosurgery/|title=FDA clears Nexstim´s Navigated Brain Stimulation for non-invasive cortical mapping prior to neurosurgery – Archive – Press Releases |work=nexstim.com}}</ref> and for neurosurgical planning in June 2011.<ref name="Nexspeech">{{cite web|url=http://www.businesswire.com/news/home/20120611005730/en/Nexstim-Announces-FDA-Clearance-NexSpeech%C2%AE-%E2%80%93-Enabling#.VGm4MGNjmnw/|title=Nexstim Announces FDA Clearance for NexSpeech® – Enabling Noninvasive Speech Mapping Prior to Neurosurgery |date=11 June 2012|work=businesswire.com}}</ref>

===Depression===
TMS is approved as a Class II medical device under the "''de novo'' pathway".<ref>Michael Drues, for Med Device Online. 5 February 2014 [http://www.meddeviceonline.com/doc/secrets-of-the-de-novo-pathway-part-why-aren-t-more-device-makers-using-it-0001 Secrets Of The De Novo Pathway, Part 1: Why Aren't More Device Makers Using It?]</ref><ref name=2015revPain>{{cite journal | vauthors = Schwedt TJ, Vargas B | title = Neurostimulation for Treatment of Migraine and Cluster Headache | journal = Pain Medicine | volume = 16 | issue = 9 | pages = 1827–34 | date = September 2015 | pmid = 26177612 | pmc = 4572909 | doi = 10.1111/pme.12792 }}</ref>

=== Obsessive–compulsive disorder (OCD) ===
In August 2018, the US Food and Drug Administration (US FDA) authorized the use of TMS developed by the [[Israel]]i company [[Brainsway]] in the treatment of [[obsessive–compulsive disorder]] (OCD).<ref>{{cite web |date=2020-02-20 |title=FDA permits marketing of transcranial magnetic stimulation for treatment of obsessive compulsive disorder |url=https://www.fda.gov/news-events/press-announcements/fda-permits-marketing-transcranial-magnetic-stimulation-treatment-obsessive-compulsive-disorder |website=[[Food and Drug Administration]]}}</ref>

In 2020, US FDA authorized the use of TMS developed by the U.S. company MagVenture Inc. in the treatment of OCD.<ref>{{Cite web |title=MagVenture receives FDA clearance for OCD {{!}} Clinical TMS Society |url=https://www.clinicaltmssociety.org/news/2020-08/magventure-receives-fda-clearance-ocd-0 |access-date=2023-10-11 |website=www.clinicaltmssociety.org}}</ref>

In 2023, US FDA authorized the use of TMS developed by the U.S. company Neuronetics Inc. in the treatment of OCD.<ref>{{Cite web |title=FDA clears OCD motor threshold cap for transcranial magnetic stimulation system |url=https://www.healio.com/news/neurology/20230613/fda-clears-ocd-motor-threshold-cap-for-transcranial-magnetic-stimulation-system |access-date=2023-10-11 |website=www.healio.com |language=en}}</ref>

===Other neurological areas===
In the [[European Economic Area]], various versions of deep TMS H-coils have [[CE marking]] for
[[Alzheimer's disease]],<ref name=OCD/>
[[autism]],<ref name=OCD/>
[[bipolar disorder]],<ref name=Chronicpain/>
[[epilepsy]],<ref>{{cite journal | vauthors = Gersner R, Oberman L, Sanchez MJ, Chiriboga N, Kaye HL, Pascual-Leone A, Libenson M, Roth Y, Zangen A, Rotenberg A | display-authors = 6 | title = H-coil repetitive transcranial magnetic stimulation for treatment of temporal lobe epilepsy: A case report | journal = Epilepsy & Behavior Case Reports | volume = 5 | issue = Supplement C | pages = 52–56 | date = 2016-01-01 | pmid = 27114902 | pmc = 4832041 | doi = 10.1016/j.ebcr.2016.03.001 }}</ref>
chronic pain,<ref name=Chronicpain/>
[[major depressive disorder]],<ref name=Chronicpain/>
[[Parkinson's disease]],<ref name="Chou YH 2014">{{cite journal | vauthors = Chou YH, Hickey PT, Sundman M, Song AW, Chen NK | title = Effects of repetitive transcranial magnetic stimulation on motor symptoms in Parkinson disease: a systematic review and meta-analysis | journal = JAMA Neurology | volume = 72 | issue = 4 | pages = 432–440 | date = April 2015 | pmid = 25686212 | pmc = 4425190 | doi = 10.1001/jamaneurol.2014.4380 }}</ref><ref>{{cite journal | vauthors = Torres F, Villalon E, Poblete P, Moraga-Amaro R, Linsambarth S, Riquelme R, Zangen A, Stehberg J | display-authors = 6 | title = Retrospective Evaluation of Deep Transcranial Magnetic Stimulation as Add-On Treatment for Parkinson's Disease | journal = Frontiers in Neurology | volume = 6 | pages = 210 | date = 2015-10-26 | pmid = 26579065 | pmc = 4620693 | doi = 10.3389/fneur.2015.00210 | doi-access = free }}</ref>
[[post-traumatic stress disorder]] (PTSD),<ref name=Chronicpain/><ref name=TMSPTSD>{{cite journal |title= Transcranial magnetic stimulation for post-traumatic stress disorder |pmid= 34733479 |doi= 10.1177/20451253211049921 | doi-access = free |first1= Nicholas J. |last1= Petrosino |first2= Camila |last2= Cosmo |first3= Yosef A. |last3= Berlow |first4= Amin |last4= Zandvakili |first5= Mascha |last5= van ’t Wout-Frank |first6= Noah S. |last6= Philip |journal= [[Therapeutic Advances in Psychopharmacology]] |date= 2021 |volume= 11 |pmc= 8558793 }}</ref>
[[schizophrenia]] (negative symptoms)<ref name=Chronicpain>{{cite web |url=http://www.medgadget.com/2012/07/brainsways-deep-tms-eu-cleared-for-neuropathic-chronic-pain.html|title= Brainsway's Deep TMS EU Cleared for Neuropathic Chronic Pain|work= Medgadget|date= July 3, 2012 |access-date=December 16, 2013}}</ref>
and to aid smoking cessation.<ref name=OCD>{{cite news |url=http://www.medicaldevice-network.com/news/newsbrainsway-reports-positive-deep-tms-system-trial-data-ocd|archive-url=https://web.archive.org/web/20131104100829/http://www.medicaldevice-network.com/news/newsbrainsway-reports-positive-deep-tms-system-trial-data-ocd|url-status=dead|archive-date=November 4, 2013|title= Brainsway reports positive Deep TMS system trial data for OCD|newspaper= Medical Device Network|date= September 6, 2013 |publisher= Medicaldevice-network |access-date= December 16, 2013}}</ref>
One review found tentative benefit for cognitive enhancement in healthy people.<ref>{{cite journal | vauthors = Luber B, Lisanby SH | title = Enhancement of human cognitive performance using transcranial magnetic stimulation (TMS) | journal = NeuroImage | volume = 85 Pt 3 | issue = 3 | pages = 961–970 | date = January 2014 | pmid = 23770409 | pmc = 4083569 | doi = 10.1016/j.neuroimage.2013.06.007 }}</ref>

===Coverage by health services and insurers===

==== United Kingdom ====
The United Kingdom's [[National Institute for Health and Care Excellence]] (NICE) issues guidance to the [[National Health Service]] (NHS) in England, Wales, Scotland and Northern Ireland (UK). NICE guidance does not cover whether or not the NHS should fund a procedure. Local NHS bodies ([[primary care trust]]s and [[hospital trust]]s) make decisions about funding after considering the clinical effectiveness of the procedure and whether the procedure represents value for money for the NHS.<ref>NICE [https://www.nice.org.uk/about/what-we-do About NICE: What we do]</ref>

NICE evaluated TMS for severe depression in 2007, finding that TMS was safe, but with insufficient evidence for its efficacy.<ref name=TMSdepress>{{cite web|url=https://www.nice.org.uk/guidance/ipg242|title=Transcranial magnetic stimulation for severe depression|id=IPG242|location=London|publisher=National Institute for Health and Clinical Excellence|date=2011-03-04}}</ref> Guidance was updated and replaced in 2015, concluding that evidence for short‑term efficacy of repetitive transcranial magnetic stimulation (rTMS) for depression was adequate, although the clinical response is variable, and ruling that rTMS for depression may be used with arrangements for clinical governance and audit.<ref>{{cite web | title=Repetitive transcranial magnetic stimulation for depression|publisher=National Institute for Health and Clinical Excellence| date=16 December 2015|id=IPG542| url=https://www.nice.org.uk/guidance/ipg542|access-date=11 January 2025}}</ref>

In January 2014, NICE reported the results of an evaluation of TMS for treating and preventing migraine (IPG 477).  NICE found that short-term TMS is safe but there is insufficient evidence to evaluate safety for long-term and frequent uses.  It found that evidence on the efficacy of TMS for the treatment of migraine is limited in quantity, that evidence for the prevention of migraine is limited in both quality and quantity.<ref>{{cite web|url=https://www.nice.org.uk/guidance/ipg477|title=Transcranial magnetic stimulation for treating and preventing migraine|date=23 January 2014|location=London|publisher=National Institute for Health and Clinical Excellence|access-date=11 January 2025}}</ref>

{{As of|2025}}, use of rTMS in the UK was reported to have remained limited due to the cost of equipment and establishing treatment centres. Camilla Nord, head of the Mental Health Neuroscience Lab at the [[University of Cambridge]] said, "The NHS has unfortunately been far behind the US and Canada on rTMS, which is at least as effective as antidepressants, if not more".<ref>{{cite news| last=Cox | first=David | title=Is a brain-stimulation headset the answer to depression? | website=the Guardian | date=11 January 2025 | url=https://www.theguardian.com/society/2025/jan/11/is-a-brain-stimulation-headset-the-answer-to-depression }}</ref>

==== United States ====

;Commercial health insurance
In 2013, several commercial health insurance plans in the United States, including [[Anthem (company)|Anthem]], [[Health Net]], [[Kaiser Permanente]], and [[Blue Cross Blue Shield Association|Blue Cross Blue Shield]] of [[Nebraska]] and of [[Rhode Island]], covered TMS for the treatment of depression for the first time.<ref>{{cite web| publisher = Anthem, Inc. |archive-url=https://web.archive.org/web/20130729015624/http://www.anthem.com/ca/medicalpolicies/policies/mp_pw_a047769.htm|archive-date=2013-07-29|url=http://www.anthem.com/ca/medicalpolicies/policies/mp_pw_a047769.htm|title=Medical Policy: Transcranial Magnetic Stimulation for Depression and Other Neuropsychiatric Disorders|work=Policy No. BEH.00002 |date=2013-04-16|access-date=2013-12-11|url-status=dead}}</ref><ref>{{cite web|author=Health Net|archive-url=https://www.webcitation.org/6BLNdUZpk?url=https://www.healthnet.com/static/general/unprotected/pdfs/national/policies/Transcranial_Magnetic_Stimulation_Mar_12.pdf|archive-date=2012-10-11|url=https://www.healthnet.com/static/general/unprotected/pdfs/national/policies/Transcranial_Magnetic_Stimulation_Mar_12.pdf|title=National Medical Policy: Transcranial Magnetic Stimulation|work=Policy Number NMP 508|publisher=Health Net|date=March 2012|access-date=2012-09-05|url-status=dead}}</ref><ref>{{cite web| archive-url=https://web.archive.org/web/20121028032816/https://www.nebraskablue.com/~/media/pdf/Provider/Policy%20Procedure%20Manuals/MedicalPolicies.pdf|archive-date=2012-10-28|work=Section IV.67|title=Medical Policy Manual|date=2011-05-18|publisher=Blue Cross Blue Shield of Nebraska|url=https://www.nebraskablue.com/~/media/pdf/Provider/Policy%20Procedure%20Manuals/MedicalPolicies.pdf|url-status=dead}}</ref><ref>{{cite web |archive-url=https://web.archive.org/web/20130526210811/https://www.bcbsri.com/sites/default/files/polices/TranscranialMagneticStimulationasaTreatmentofDepressionandOtherPsychiatricNeurologicDisorders_0.pdf|archive-date=2013-05-26|url=https://www.bcbsri.com/sites/default/files/polices/TranscranialMagneticStimulationasaTreatmentofDepressionandOtherPsychiatricNeurologicDisorders_0.pdf|title=Medical Coverage Policy: Transcranial Magnetic Stimulation for Treatment of Depression and Other Psychiatric/Neurologic Disorders|publisher=Blue Cross Blue Shield of Rhode Island|date=2012-05-15|access-date=2012-09-05|url-status=dead}}</ref>  In contrast, [[UnitedHealth Group|UnitedHealthcare]] issued a medical policy for TMS in 2013 that stated there is insufficient evidence that the procedure is beneficial for health outcomes in patients with depression.  UnitedHealthcare noted that methodological concerns raised about the scientific evidence studying TMS for depression include small sample size, lack of a validated sham comparison in randomized controlled studies, and variable uses of outcome measures.<ref>{{cite web|author=UnitedHealthcare|archive-url=https://web.archive.org/web/20130520172341/https://www.unitedhealthcareonline.com/ccmcontent/ProviderII/UHC/en-US/Assets/ProviderStaticFiles/ProviderStaticFilesPdf/Tools%20and%20Resources/Policies%20and%20Protocols/Medical%20Policies/Medical%20Policies/Transcranial_Magnetic_Stimulation.pdf|archive-date=2013-05-20|url=https://www.unitedhealthcareonline.com/ccmcontent/ProviderII/UHC/en-US/Assets/ProviderStaticFiles/ProviderStaticFilesPdf/Tools%20and%20Resources/Policies%20and%20Protocols/Medical%20Policies/Medical%20Policies/Transcranial_Magnetic_Stimulation.pdf|title=Transcranial Magnetic Stimulation|date=2013-12-01|publisher=UnitedHealthCare|page=2|access-date=2013-12-11|url-status=dead|author-link = UnitedHealthcare}}</ref> Other commercial insurance plans whose 2013 medical coverage policies stated that the role of TMS in the treatment of depression and other disorders had not been clearly established or remained investigational included [[Aetna]], [[Cigna]] and [[The Regence Group|Regence]].<ref>{{cite web|author=Aetna|archive-url=https://web.archive.org/web/20131022055505/http://www.aetna.com/cpb/medical/data/400_499/0469.html|archive-date=2013-10-22|url=http://www.aetna.com/cpb/medical/data/400_499/0469.html|title=Clinical Policy Bulletin: Transcranial Magnetic Stimulation and Cranial Electrical Stimulation|date=2013-10-11|work=Number 0469|publisher=Aetna|access-date=2013-12-11|url-status=dead|author-link = Aetna}}</ref><ref>{{cite web|author=Cigna|archive-url=https://web.archive.org/web/20170204194830/https://cignaforhcp.cigna.com/public/content/pdf/coveragePolicies/medical/mm_0383_coveragepositioncriteria_transcranial_magnetic_stimulation.pdf|archive-date=2017-02-04|url=http://www.cigna.com/assets/docs/health-care-professionals/coverage_positions/mm_0383_coveragepositioncriteria_transcranial_magnetic_stimulation.pdf|title=Cigna Medical Coverage Policy: Transcranial Magnetic Stimulation|date=2013-01-15|work=Coverage Policy Number 0383|publisher=Cigna|access-date=2013-12-11|url-status=dead|author-link = Cigna}}</ref><ref>{{cite web|archive-url=https://web.archive.org/web/20141209145816/http://blue.regence.com/trgmedpol/medicine/med148.pdf|archive-date=2014-12-09|author=Regence|url=http://blue.regence.com/trgmedpol/medicine/med148.pdf|title=Medical Policy: Transcranial Magnetic Stimulation as a Treatment of Depression and Other Disorders|work=Policy No. 17|date=2013-06-01|publisher=Regence|access-date=2013-12-11|url-status=dead|author-link=The Regence Group}}</ref>

;Medicare
Policies for Medicare coverage vary among local jurisdictions within the Medicare system,<ref>{{cite web|url=https://www.cms.gov/Medicare/Medicare-Contracting/Medicare-Administrative-Contractors/MedicareAdministrativeContractors.html|archive-url=https://web.archive.org/web/20140214094931/http://cms.gov/Medicare/Medicare-Contracting/Medicare-Administrative-Contractors/MedicareAdministrativeContractors.html|archive-date=2014-02-14|title=Medicare Administrative Contractors|publisher=[[Centers for Medicare and Medicaid Services]]|date=2013-07-10|access-date=2014-02-14|url-status=dead}}</ref> and Medicare coverage for TMS has varied among jurisdictions and with time.  For example:
* In early 2012 in [[New England]], Medicare covered TMS for the first time in the United States.<ref>{{cite web|author=NHIC, Corp.|url=http://coverage.cms.fu.com/mcd_archive/viewlcd.asp?lcd_id=32228&lcd_version=5&basket=lcd%3A32228%3A5%3ARepetitive+Transcranial+Magnetic+Stimulation+%28rTMS%29%3AMAC+%2D+Part+B%3ANHIC%7C%7C+Corp%2E+%2814202%29%3A|archive-url=https://archive.today/20140217152734/http://coverage.cms.fu.com/mcd_archive/viewlcd.asp?lcd_id=32228&lcd_version=5&basket=lcd:32228:5:Repetitive+Transcranial+Magnetic+Stimulation+(rTMS):MAC+-+Part+B:NHIC%7C%7C+Corp.+(14202):|url-status=dead|archive-date=2014-02-17|title=Local Coverage Determination (LCD) for Repetitive Transcranial Magnetic Stimulation (rTMS) (L32228)|publisher=[[Centers for Medicare and Medicaid Services]]|date=2013-10-24|access-date=2014-02-17}}</ref><ref>{{cite web|archive-url=https://web.archive.org/web/20130405070836/http://www.pbn.com/Important-Treatment-Option-for-Depression-Receives-Medicare-Coverage,66462|archive-date=2013-04-05|access-date=2012-10-11|url=http://www.pbn.com/Important-Treatment-Option-for-Depression-Receives-Medicare-Coverage,66462|title=Important Treatment Option for Depression Receives Medicare Coverage|work=Press Release|date=2012-03-30|publisher=PBN.com: Providence Business News|url-status=dead}}</ref><ref>{{cite web|author=The Institute for Clinical and Economic Review|date=June 2012|archive-url=https://web.archive.org/web/20131213211022/http://cepac.icer-review.org/wp-content/uploads/2012/07/rTMS-Coverage-Policy-Analysis.pdf|archive-date=2013-12-13|url=http://cepac.icer-review.org/wp-content/uploads/2012/07/rTMS-Coverage-Policy-Analysis.pdf|title=Coverage Policy Analysis: Repetitive Transcranial Magnetic Stimulation (rTMS)|publisher=The New England Comparative Effectiveness Public Advisory Council (CEPAC)|access-date=2013-12-11|url-status=dead}}</ref><ref>{{cite web|archive-url=https://web.archive.org/web/20120325091400/http://www.cvmc.org/news/2012-theresa-fama-cepac|archive-date=2012-03-25|url=http://www.cvmc.org/news/2012-theresa-fama-cepac|title=Transcranial Magnetic Stimulation Cites Influence of New England Comparative Effectiveness Public Advisory Council (CEPAC)|date=2012-02-06|location=[[Berlin, Vermont]]|publisher=[[Central Vermont Medical Center]]|access-date=2012-10-12|url-status=dead}}</ref>  However, that jurisdiction later decided to end coverage after October, 2013.<ref>{{cite web|author=National Government Services, Inc. |url=http://www.cms.gov/medicare-coverage-database/details/lcd-details.aspx?LCDId=32038&ContrId=178&&bc=IAAAABAAAAAAAA%3d%3d&|date=2013-10-25|title=Local Coverage Determination (LCD): Transcranial Magnetic Stimulation (L32038)|publisher= [[Centers for Medicare and Medicaid Services]] |access-date=2014-02-17}}</ref>
* In August 2012, the jurisdiction covering Arkansas, Louisiana, Mississippi, Colorado, Texas, Oklahoma, and New Mexico determined that there was insufficient evidence to cover the treatment,<ref>{{cite web |author=Novitas Solutions, Inc. |date=2013-12-04 |title=LCD L32752 – Transcranial Magnetic Stimulation for Depression |url=https://hwscenter.com/treatments/#neuropsychology |access-date=2014-02-17 |work=Contractor's Determination Number L32752 |publisher=[[Centers for Medicare and Medicaid Services]]}}</ref> but the same jurisdiction subsequently determined that Medicare would cover TMS for the treatment of depression after December 2013.<ref>{{cite web|url=http://www.cms.gov/medicare-coverage-database/details/lcd-details.aspx?LCDId=33660&ContrId=259&bc=IAAAAAgAAAAAAA%3d%3d&|title=LCD L33660 – Transcranial Magnetic Stimulation (TMS) for the Treatment of Depression|author=Novitas Solutions, Inc.|work=Contractor's Determination Number L33660|publisher= [[Centers for Medicare and Medicaid Services]]|date=2013-12-05|access-date=2014-02-17}}</ref>

== Limitations ==

There are serious concerns about stimulating brain tissue using non-invasive magnetic field methods such as uncertainty in the dose and localisation of the stimulation effect.<ref>{{cite journal |vauthors=Benussi A, Pascual-Leone A, Borroni B |title=Non-Invasive Cerebellar Stimulation in Neurodegenerative Ataxia: A Literature Review |journal=Int J Mol Sci |volume=21 |issue=6 |pages=1948 |date=March 2020 |pmid=32178459 |pmc=7139863 |doi=10.3390/ijms21061948 |doi-access=free}}</ref><ref>{{cite journal |vauthors=Grimaldi G, Argyropoulos GP, Boehringer A, Celnik P, Edwards MJ, Ferrucci R, Galea JM, Groiss SJ, Hiraoka K, Kassavetis P, Lesage E, Manto M, Miall RC, Priori A, Sadnicka A, Ugawa Y, Ziemann U |title=Non-invasive cerebellar stimulation—a consensus paper |journal=Cerebellum |volume=13 |issue=1 |pages=121–38 |date=February 2014 |pmid=23943521 |doi=10.1007/s12311-013-0514-7 |url=https://research.birmingham.ac.uk/portal/en/publications/noninvasive-cerebellar-stimulation(1e9aaf7a-42a6-4879-a0cf-31742a773386).html }}</ref><ref>{{cite journal |vauthors=Siebner HR, Hartwigsen G, Kassuba T, Rothwell JC |title=How does transcranial magnetic stimulation modify neuronal activity in the brain? Implications for studies of cognition |journal=Cortex |volume=45 |issue=9 |pages=1035–42 |date=October 2009 |pmid=19371866 |pmc=2997692 |doi=10.1016/j.cortex.2009.02.007 }}</ref><ref name="Sparing and Mottaghy_2008">{{cite journal |vauthors=Sparing R, Mottaghy FM |title=Noninvasive brain stimulation with transcranial magnetic or direct current stimulation (TMS/tDCS)-From insights into human memory to therapy of its dysfunction |journal=Methods |volume=44 |issue=4 |pages=329–37 |date=April 2008 |pmid=18374276 |doi=10.1016/j.ymeth.2007.02.001 }}</ref>

== See also ==
{{col div|colwidth=30em}}
* [[Cortical stimulation mapping]]
* [[Cranial electrotherapy stimulation]]
* [[Electrical brain stimulation]]
* [[Electroconvulsive therapy]]
* [[Low field magnetic stimulation]]
* [[My Beautiful Broken Brain]]
* [[Neuromodulation (medicine)|Neuromodulation]]
* [[Neurostimulation]]
* [[Neurotechnology]]
* [[Non-invasive cerebellar stimulation]]
* [[Transcranial alternating current stimulation]]
* [[Transcranial direct-current stimulation]]
* [[Transcranial random noise stimulation]]
* [[Vagus nerve stimulation]]
{{colend}}

== References ==
{{reflist}}

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[[Category:Diagnostic neurology]]
[[Category:Physical psychiatric treatments]]
[[Category:Electrotherapy]]
[[Category:Magnetic devices]]
[[Category:Neurophysiology]]
[[Category:Neuropsychology]]
[[Category:Neurotechnology]]
[[Category:Treatment of bipolar disorder]]
[[Category:Treatment of depression]]
[[Category:Medical devices]]
[[Category:1985 introductions]]<!--1st stable TMS devices-->
[[Category:2008 introductions]]
[[Category:Bioelectromagnetics]]