Transcranial Magnetic Stimulation

Abstract

Transcranial magnetic stimulation (TMS) is gaining increasing prominence as a non‐invasive neuromodulation technique for the treatment of neurological and psychiatric conditions. Repetitive transcranial magnetic stimulation (rTMS) has therapeutic potential for a range of psychiatric disorders (e.g. depression, schizophrenia) as well as neurological disorders such as Parkinson's disease. The approach has advantages over pharmacological or electroconvulsive therapy due to its painlessness and limited side effects. The magnitude, duration and direction (increase or decrease) of TMS‐induced changes in brain excitability vary depending on the strength and timing of stimulation and the interaction of stimulation coil geometry with brain structures. The outcomes of TMS stimulation can also depend on the characteristics (e.g. age, exercise status) of the individual being treated. Despite increasing clinical use of rTMS, the cellular and network mechanisms underlying the clinical application of rTMS remain elusive and will need to be better understood to enable optimisation of clinical outcomes.

Key Concepts

  • Transcranial magnetic stimulation is a non‐invasive brain stimulation technique that uses a varying magnetic field to induce currents in the cortex and modulate brain function.
  • Single TMS pulses can be used to evoke immediate sensory or motor responses and test the speed or efficacy of conduction in a particular neural pathway.
  • Repetitive transcranial magnetic stimulation (rTMS) produces more subtle modulation of brain function that lasts beyond the end of stimulation.
  • Common rTMS protocols include regular trains of pulses at different frequencies (usually 1 or 10 Hz) or complex pulse trains that mimic endogenous patterns of activity in different brain regions (e.g. continuous and intermittent theta burst stimulation, biomimetic high‐frequency stimulation).
  • rTMS has been found to induce plasticity in the brain, with higher frequency (10–20 Hz) stimulus patterns generally associated with strengthening of cortical pathways, whereas low frequency (1 Hz) patterns usually depress the activity of a pathway.
  • rTMS is established as an effective therapy for major depression and for neuropathic pain and shows promise in treating some symptoms of stroke, Parkinson's Disease and schizophrenia.
  • Optimisation and expansion of the therapeutic utility of rTMS will require a better scientific understanding of the physiological mechanisms by which pulsed magnetic fields modulate the function of and interactions between neurons.

Keywords: transcranial magnetic stimulation; non‐invasive brain stimulation; plasticity; neural networks; neuropsychiatric disorders; functional connectivity

Figure 1. Neuronal activation by TMS using a ‘figure‐of‐eight’ coil. The electrical current in the coil (black arrows in the coil) generates a magnetic field (red), which induces a current in the brain (black arrows in brain). This causes stimulation of neurons, with the optimum site of activation being under the midpoint of the figure‐of‐eight. The electrical current in the coil and the current induced in the brain by the magnetic field flow in the same plane, tangential to the skull‐brain surface. TMS stimulates activity in neurons, affecting the functioning of the cortex (Walsh, ). The effects of TMS on neural function are then measured indirectly, for example by recording muscle activity in the thumb (Edwards et al., ; Walsh, ). Ridding and Rothwell . Reproduced with permission of Springer Nature.
Figure 2. Repetitive transcranial magnetic stimulation (rTMS) protocols. Simple frequencies (1 and 10 Hz) consist of identical stimuli spaced by an identical inter‐stimulus interval. Theta burst stimulation (TBS) involves bursts of high‐frequency stimulation (3 pulses at 50 Hz) repeated with an interval of 0.2 s (5 Hz). In continuous TBS (cTBS), bursts are applied continuously for 40 s (i.e. 600 stimuli) without breaks. In an intermittent TBS (iTBS) protocol, bursts are delivered for 2 s, then repeated every 10 s (2 s of TBS followed by a break of 8 s) for a total duration of 190 s (i.e. 600 stimuli).
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References

Arias‐Carrion O (2008) Basic mechanisms of rTMS: implications in Parkinson's disease. International Archives of Medicine 1 (1): 2.

Barker AT and Freeston I (2007) Transcranial magnetic stimulation. Scholarpedia journal 2 (10): 2936.

Bohning DE, Shastri A, Nahas Z, et al. (1998) Echoplanar BOLD fMRI of brain activation induced by concurrent transcranial magnetic stimulation. Investigative Radiology 33 (6): 336–340.

Bohning DE, Shastri A, McConnell KA, et al. (1999) A combined TMS/fMRI study of intensity‐dependent TMS over motor cortex. Biological Psychiatry 45 (4): 385–394.

Bramham CR (2008) Local protein synthesis, actin dynamics, and LTP consolidation. Current Opinion in Neurobiology 18 (5): 524–531.

Breden Crouse EL (2012) Transcranial magnetic stimulation for major depressive disorder: what a pharmacist should know. Mental Health Clinician 2 (6): 152–155.

Cárdenas‐Morales L, Nowak DA, Kammer T, et al. (2010) Mechanisms and applications of theta‐burst rTMS on the human motor cortex. Brain Topography 22 (4): 294–306.

Chung SW, Hill AT, Rogasch NC, et al. (2016) Use of theta‐burst stimulation in changing excitability of motor cortex: a systematic review and meta‐analysis. Neuroscience & Biobehavioral Reviews 63: 43–64.

Corti M, Patten C and Triggs W (2012) Repetitive transcranial magnetic stimulation of motor cortex after stroke: a focused review. American Journal of Physical Medicine and Rehabilitation 91 (3): 254–270.

Deng Z‐D, Lisanby SH and Peterchev AV (2014) Coil design considerations for deep transcranial magnetic stimulation. Clinical Neurophysiology 125 (6): 1202–1212.

Dlabač‐de Lange JJ, Knegtering R and Aleman A (2010) Repetitive transcranial magnetic stimulation for negative symptoms of schizophrenia: review and meta‐analysis. Journal of Clinical Psychiatry 71 (4): 411–418.

Edwards MJ, Talleli P and Rothwell JC (2008) Clinical applications of transcranial magnetic stimulation in patients with movement disorders. Lancet Neurology 7 (9): 827–840.

Faraday M (1840) Experimental Researches in Electricity. London: Taylor.

Fox MD, Halko MA, Eldaief MC, et al. (2012) Measuring and manipulating brain connectivity with resting state functional connectivity magnetic resonance imaging (fcMRI) and transcranial magnetic stimulation (TMS). NeuroImage 62 (4): 2232–2243.

Fujiki M and Steward O (1997) High frequency transcranial magnetic stimulation mimics the effects of ECS in upregulating astroglial gene expression in the murine CNS. Molecular Brain Research 44 (2): 301–308.

Gersner R, Kravetz E, Feil J, et al. (2011) Long‐term effects of repetitive transcranial magnetic stimulation on markers for neuroplasticity: differential outcomes in anesthetized and awake animals. The Journal of Neuroscience 31 (20): 7521–7526.

Hamada M, Terao Y, Hanajima R, et al. (2008) Bidirectional long‐term motor cortical plasticity and metaplasticity induced by quadripulse transcranial magnetic stimulation. The Journal of Physiology 586 (16): 3927–3947.

Hampson M and Hoffman RE (2010) Transcranial magnetic stimulation and connectivity mapping: tools for studying the neural bases of brain disorders. Frontiers in Systems Neuroscience 4: 40.

Herring BE and Nicoll RA (2016) Long‐term potentiation: From CaMKII to AMPA receptor trafficking. Annual Review of Physiology 78 (1): 351–365.

Houdayer E, Degardin A, Cassim F, et al. (2008) The effects of low‐ and high‐frequency repetitive TMS on the input/output properties of the human corticospinal pathway. Experimental Brain Research 187 (2): 207–217.

Huang Y‐Z, Edwards MJ, Rounis E, et al. (2005) Theta burst stimulation of the human motor cortex. Neuron 45 (2): 201–206.

Ilmoniemi RJ and Kičić D (2010) Methodology for combined TMS and EEG. Brain Topography 22 (4): 233–248.

Ji R‐R, Schlaepfer TE, Aizenman CD, et al. (1998) Repetitive transcranial magnetic stimulation activates specific regions in rat brain. Proceedings of the National Academy of Sciences of the United States of America 95 (26): 15635–15640.

Klomjai W, Katz R and Lackmy‐Vallée A (2015) Basic principles of transcranial magnetic stimulation (TMS) and repetitive TMS (rTMS). Annals of Physical and Rehabilitation Medicine 58 (4): 208–213.

Kole MHP, Fuchs E, Ziemann U, et al. (1999) Changes in 5‐HT1A and NMDA binding sites by a single rapid transcranial magnetic stimulation procedure in rats. Brain Research 826 (2): 309–312.

Larson J, Wong D and Lynch G (1986) Patterned stimulation at the theta frequency is optimal for the induction of hippocampal long‐term potentiation. Brain Research 368 (2): 347–350.

Lee L, Siebner H and Bestmann S (2006) Rapid modulation of distributed brain activity by transcranial magnetic stimulation of human motor cortex. Behavioural Neurology 17 (3–4): 135–148.

Lefaucheur J‐P (2008) Principles of therapeutic use of transcranial and epidural cortical stimulation. Clinical Neurophysiology 119 (10): 2179–2184.

Lefaucheur J‐P (2009) Methods of therapeutic cortical stimulation. Clinical Neurophysiology 39 (1): 1–14.

Ljubisavljevic MR, Javid A, Oommen J, et al. (2015) The effects of different repetitive transcranial magnetic stimulation (rTMS) protocols on cortical gene expression in a rat model of cerebral ischemic‐reperfusion injury. PloS One 10 (10): e0139892.

Lu B (2003) BDNF and activity‐dependent synaptic modulation. Learning and Memory 10 (2): 86–98.

Makowiecki K, Harvey AR, Sherrard RM, et al. (2014) Low‐intensity repetitive transcranial magnetic stimulation improves abnormal visual cortical circuit topography and upregulates BDNF in mice. Journal of Neuroscience 34 (32): 10780–10792.

Martiny K, Lunde M and Bech P (2010) Transcranial low voltage pulsed electromagnetic fields in patients with treatment‐resistant depression. Biological Psychiatry 68 (2): 163–169.

McRobbie DW, Moore EA, Graves MJ, et al. (2007) MRI: From Picture to Proton. Cambridge: Cambridge University Press.

Moisset X, Andrade DC and Bouhassira D (2015) From pulses to pain relief: an update on the mechanisms of rTMS‐induced analgesic effects. European Journal of Pain 20 (5): 689–700.

Muller‐Dahlhaus F and Vlachos A (2013) Unraveling the cellular and molecular mechanisms of repetitive magnetic stimulation. Frontiers in Molecular Neuroscience 6: 50.

Nicoll RA (2017) A brief history of long‐term potentiation. Neuron 93 (2): 281–290.

Oberman L (2014) Repetitive transcranial magnetic stimulation (rTMS) protocols. Neuromethods 89: 129–139.

O'Reardon JP, Solvason HB, Janicak PG, et al. (2007) Efficacy and safety of transcranial magnetic stimulation in the acute treatment of major depression: A multisite randomized controlled trial. Biological Psychiatry 62 (11): 1208–1216.

Pashut T, Wolfus S, Friedman A, et al. (2011) Mechanisms of magnetic stimulation of central nervous system neurons. PLoS Computational Biology 7 (3): e1002022–e1002022.

Patterson SL, Abel T, Deuel TAS, et al. (1996) Recombinant BDNF rescues deficits in basal synaptic transmission and hippocampal LTP in BDNF knockout mice. Neuron 16 (6): 1137–1145.

Pridmore S and Belmaker R (1999) Transcranial magnetic stimulation in the treatment of psychiatric disorders. Psychiatry and Clinical Neurosciences 53 (5): 541–548.

Ridding MC and Rothwell JC (2007) Is there a future for therapeutic use of transcranial magnetic stimulation? Nature Reviews Neuroscience 8 (7): 559–567.

Ridding MC and Ziemann U (2010) Determinants of the induction of cortical plasticity by non‐invasive brain stimulation in healthy subjects. The Journal of Physiology 588 (13): 2291–2304.

Rodger J, Mo C, Wilks T, et al. (2012) Transcranial pulsed magnetic field stimulation facilitates reorganization of abnormal neural circuits and corrects behavioral deficits without disrupting normal connectivity. FASEB Journal 26 (4): 1593–1606.

Rossini PM, Barker AT, Berardelli A, et al. (1994) Non‐invasive electrical and magnetic stimulation of the brain, spinal cord and roots: basic principles and procedures for routine clinical application. Report of an IFCN committee. Electroencephalography and Clinical Neurophysiology 91 (2): 79–92.

Schneider SA, Pleger B, Draganski B, et al. (2010) Modulatory effects of 5Hz rTMS over the primary somatosensory cortex in focal dystonia – an fMRI‐TMS study. Movement Disorders 25 (1): 76–83.

Seewoo BJ, Etherington SJ, Feindel KW, et al. (2018) Combined rTMS/fMRI studies: an overlooked resource in animal models. Frontiers in Neuroscience 12: 180.

Thielscher A and Kammer T (2004) Electric field properties of two commercial figure‐8 coils in TMS: calculation of focality and efficiency. Clinical Neurophysiology 115 (7): 1697–1708.

Walsh V (1998) Brain mapping: Faradization of the mind. Current Biology 8 (1): R8–R11.

Wassermann EM and Zimmermann T (2012) Transcranial magnetic brain stimulation: therapeutic promises and scientific gaps. Pharmacology and Therapeutics 133 (1): 98–107.

Further Reading

Funk RHW and Monsees TK (2006) Effects of electromagnetic fields on cells: physiological and therapeutical approaches and molecular mechanisms of interaction. Cells Tissues Organs 182 (2): 59–78.

Lefaucheur J‐P, André‐Obadia N, Antal A, et al. (2014) Evidence‐based guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS). Clinical Neurophysiology 125 (11): 2150–2206.

Nordmann GC, Hochstoeger T and Keays DA (2017) Magnetoreception—a sense without a receptor. PLoS Biology 15 (10): e2003234.

Pell GS, Roth Y and Zangen A (2011) Modulation of cortical excitability induced by repetitive transcranial magnetic stimulation: influence of timing and geometrical parameters and underlying mechanisms. Progress in Neurobiology 93 (1): 59–98.

Tang A, Thickbroom G and Rodger J (2015) Repetitive transcranial magnetic stimulation of the brain: mechanisms from animal and experimental models. The Neuroscientist 23 (1): 82–94.

Vidal‐Dourado M, Conforto AB, Caboclo LOSF, et al. (2013) Magnetic fields in non‐invasive brain stimulation. The Neuroscientist 20 (2): 112–121.

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Seewoo, Bhedita J, Etherington, Sarah J, and Rodger, Jennifer(Apr 2019) Transcranial Magnetic Stimulation. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0028620]