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| Transcranial Magnetic Stimulation |  Transcranial magnetic stimulation (TMS) is a technique, which used for softly stimulating the brain. It uses a specialized electromagnet put on the patient’s scalp that produces short magnetic pulses, roughly the strength of an MRI scanner’s magnetic field but much more concentrated. The magnetic pulses pass easily through the cranium just like the MRI scanner fields do, but because they are short pulses and not a static field, they can incite the underlying cerebral cortex (brain). Low frequency (once per second) TMS has been demonstrated to cause reductions in brain activation while stimulation at higher frequencies (> 5 pulses per second) has been shown to maximize brain activation. It has also been demonstrated that these changes can continue for periods of time after stimulation is stopped. TMS was first developed in 1985, and has been studied meaningly since 1995.
TMS is currently being studied as a potential treatment for patients with major depression, patients who suffer from hallucinated "voices" and a variety of other psychiatric and neurological disorders. Over 1500 patients have been investigated with TMS. For patients with major depression, many, but by no means all studies have demonstrated clinical amelioration following TMS. Recent researches that have employed newer technology and stronger stimulation have shown much better results. These experimental studies have taught researchers about how to better employ TMS for depression. This material is now being used in a large pivotal clinical trial which, if successful, will be employed to support Food and Drug Administration (FDA) clearance of TMS thus making it open to the general public.
For patients reporting ear hallucinations (voices), studies has not been as vast but primary results have been promising and offer that low frequency TMS administered to parts of the brain underlying speech perception may minimize these voices.
TMS has not been approved by The Food and Drug Administration for any psychiatric treatment at this time. Therefore TMS is only open as a research procedure. TMS has been approved in Canada and Israel as a treatment of depression for patients who have not reacted to medications and who might ordinarily be considered for a trial of electroconvulsive therapy (ECT).
Generally TMS produces a gentle knocking or tapping sensation on the head. This is also associated with a tapping sound created by the TMS device. When administered at some stimulation sites it can lead to contraction of the muscles of the scalp and sometimes the jaw. Slight headache and temporary lightheadedness may sometimes result from TMS. These symptoms usually disappear shortly after the treatment is over.
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