Noninvasive Brain Stimulation (NIBS)
Original Editor - Angeliki Chorti
Top Contributors - Angeliki Chorti
Introduction[edit | edit source]
Noninvasive Brain Stimulation (NIBS).
Noninvasive brain stimulation is of great interest to clinicians and researchers, because of its potential role in studying brain physiology and in treating diseases of the brain. [1] It has also advantages as a diagnostic tool to observe disease-related changes in brain activation, inhibition, or connectivity.
History of Brain Stimulation[edit | edit source]
The use of electricity for brain healing has been long documented; first, in stone carvings from the Fifth Dynasty of Egypt in which an electric fish was used to treat pain; and later, during the time of Socrates, when electric fish were used to treat headaches and arthritis. [1]
In 1831, Michael Faraday 's discovery of electromagnetic induction (i.e. a varying magnetic field induces electrical current in a conductor placed within the field) contributed to understanding this phenomenon. Besides, the brain uses electricity constantly to rapidly convey information via action potentials sent along axons, a biological example of electrical conductors. [1]
In the 1940s, electroconvulsive therapy (ECT), i.e. electrical brain stimulation over one or both hemispheres to create a seizure, was used in treating severe depression. [2]
In 1985, researchers stimulated with a pulsed magnetic field discrete regions on the surface of the brain through the skull. [3] By connecting a wire coil to a source of electric current and placing the coil on the scalp over the motor cortex, Barker et al. [3] provided the first application of transcranial magnetic stimulation (TMS). A few years later, development of stimulators able to deliver long trains of closely spaced pulses enabled repetitive transcranial magnetic stimulation (rTMS). This expansion of TMS scope from a neurophysiological probe to a tool with the potential for altering brain function increased its popularity. [4]
Growing interest in TMS and as a result, in noninvasive brain stimulation brought transcranial direct current stimulation (tDCS) into light, a technique originally applied to humans and animal models in the mid-20th century. Unlike TMS, which can produce a direct neurostimulatory effect, tDCS did not usually elicit action potentials. Instead, tDCS is thought to exhibit a modulatory effect on brain function: the externally applied electric field displaces ions within neurons, altering neuronal excitability and modulating the firing rate of individual neurons. [5]
Brain stimulation devices are now being sold directly to consumers with the promise they will enhance brain function or wellbeing; however, the short- and long-term impact of using these devices for medical and non-medical purposes is not yet clarified. [1] Most of the direct-to-consumer brain stimulation products are tDCS devices. [1]
Current Modes of Stimulation[edit | edit source]
Transcranial Electrical Stimulation (TES)[edit | edit source]
Transcranial Electrical Stimulation through tDCS devices involves the placement of two small electrodes on the head to deliver a constant low level of electric current, altering neural excitability.
Transcranial Magnetic Stimulation (TMS)[edit | edit source]
An electromagnet is placed on the scalp to generate magnetic field pulses. The mechanism by which TMS influences brain function is not completely understood, but we do know that TMS can activate axons and cause them to fire action potentials. TMS effects are not specific to inhibitory vs. excitatory neural activity, but may change the balance between excitation and inhibition. [6][7][8]In rTMS, TMS pulses are repeatedly applied.
References[edit | edit source]
- ↑ 1.0 1.1 1.2 1.3 1.4 National Institute of Neurological Disorders and Stroke. Noninvasive Brain Stimulation: Applications and Implications. 2015. Available from: https://www.ninds.nih.gov/news-events/directors-messages/all-directors-messages/noninvasive-brain-stimulation-applications-and-implications [accessed 6/12/2023]
- ↑ Kellner CH, Greenberg RM, Murrough JW, Bryson EO, Briggs MC, Pasculli RM. ECT in treatment-resistant depression. Am J Psychiatry. 2012 Dec;169(12):1238-44.
- ↑ 3.0 3.1 Barker AT, Jalinous R, Freeston IL. Non-invasive magnetic stimulation of human motor cortex. Lancet. 1985 May 11;1(8437):1106-7.
- ↑ Wassermann EM, Zimmermann T. Transcranial magnetic brain stimulation: therapeutic promises and scientific gaps. Pharmacol Ther. 2012 Jan;133(1):98-107.
- ↑ Ukueberuwa D, Wassermann EM. Direct current brain polarization: a simple, noninvasive technique for human neuromodulation. Neuromodulation. 2010 Jul;13(3):168-73.
- ↑ Huerta PT, Volpe BT. Transcranial magnetic stimulation, synaptic plasticity and network oscillations. J Neuroeng Rehabil. 2009 Mar 2;6:7.
- ↑ Perini F, Cattaneo L, Carrasco M, Schwarzbach JV. Occipital transcranial magnetic stimulation has an activity-dependent suppressive effect. J Neurosci. 2012 Sep 5;32(36):12361-5.
- ↑ Dayan E, Censor N, Buch ER, Sandrini M, Cohen LG. Noninvasive brain stimulation: from physiology to network dynamics and back. Nat Neurosci. 2013 Jul;16(7):838-44.
