Transcranial Magnetic Stimulation Essay

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Transcranial magnetic stimulation (TMS) is a non-invasive tool for the electrical stimulation of neural tissue, including cerebral cortex, spinal roots, and cranial and peripheral nerves. TMS can be applied as single pulses of stimulation, pairs of stimuli separated by variable intervals to the same or different brain areas, or as trains of repetitive stimuli at various frequencies. Single stimuli can depolarise neurons and evoke measurable effects. Trains of stimuli (repetitive TMS) can modify excitability of the cerebral cortex at the stimulated site and also at remote areas along functional anatomical connections. Transcranial magnetic stimulation might provide novel insights into the pathophysiology of the neural circuitry underlying neurological and psychiatric disorders, be developed into …show more content…

Since its introduction, the use of TMS in clinical neurophysiology, neurology, neuroscience, and psychiatry has spread widely, mostly in research applications, but increasingly with clinical aims in mind.
Transcranial magnetic stimulation is based on the principle of electromagnetic induction, as discovered by Michael Faraday in 1838. If a pulse of current passing through a coil placed over a person’s head has sufficient strength and short enough duration, rapidly changing magnetic pulses are generated that penetrate scalp and skull to reach the brain with negligible attenuation. These pulses induce a secondary ionic current in the brain. The site of stimulation of a nerve fibre is the point along its length at which sufficient current to cause depolarisation passes through its membrane. The capacity of Transcranial magnetic stimulation to depolarise neurons depends on the “activating function”, which causes Trans membrane current to flow and can be described