Transcranial Magnetic Stimulation uses high-intensity magnetic pulses that activate the brain cells in the dorsolateral prefrontal brain cortex. The magnetic fields generated by the TMS Therapy coil create an electrical impulse on the area treated, the dorsolateral prefrontal cortex. This area helps control mood and is found to be have low activity in depressed patients. The daily stimulation of the dorsolateral prefrontal cortex causes this area to become active and release neurotransmitters that control mood and depression.
In our practice we have heard patients state their doubt because they think this is "magnetic" therapy, as many holistic, non-traditional therapies that include the use of low-power magnets for arthritis, relaxation, headaches, etc. It is not. TMS is a scientific use of the relationship between magnetism and electricity which are in fact expressions of the same energy spectrum, the electromagnetic spectrum. Moving/alternating magnets are used to create electricity (hydroelectric plants, wind turbines, etc), and electricity is used to move magnets, which is how electrical motors work!.
If the above is understood, then the mechanism of action of TMS can be understood. The TMS magnet delivers an intense MRI-strength magnetic field that penetrates deep through the scalp, cranium, and cortex of the brain. This magnetic field stimulates the neurons in the area of the brain that controls mood. Neurons are highly-excitable cells that respond to the magnetic stimulus by depolarizing, that is, creating their own electrical impulse. This electrical impulse then travels even deeper in the brain, liberating needed neurotransmitters at the synapses that communicate with other brain cells.
In the following 1:18 minute video Drs. Karl Lanocha and Scott Aaronson explain how TMS works.
Note: Drs. Karl Lanoch and Scott Aaronson are not affiliated with TMS Therapy Centers or this website
The dorsolateral prefrontal cortex (see image) controls mood by communicating and controlling deeper areas of the brain. These deeper areas are known as the limbic system. The limbic system is itself composed of several regions that include the cingulate gyrus, the hippocampus, the amygdala, etc. Increased activity in the dorsolateral prefrontal cortex stimulates the limbic system through neural pathways. The following video explains how TMS Therapy stimulates the deep areas of the brain that control mood and depression as well as the release of neurotransmitters.
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