TMS (Transcranial Magnetic Stimulation)
Transcranial magnetic stimulation (TMS) is a noninvasive procedure originally developed for treatment-resistant depression. TMS uses magnetic fields to stimulate nerve cells in the brain to improve dysphoric symptoms associated with depression and now substance-use disorders (SUDs), which share much the same pathophysiology and bi-directionally co-occur in 45-65% of patients with either disorder. TMS treats depression, but it is also being tried as a treatment for pain, cigarette smoking, opioid addiction, tinnitus and memory.
For addiction, TMS or (rTMS) influences neural activity and neuroplasticity, both locally, directly under the stimulating coil, and systemically, by improving neural connectivity that has been degraded by SUDs throughout the brain. We know that addiction hijacks the brain’s reward circuit. It floods the brain with dopamine—which gives us that warm, euphoric feeling. As a result, the brain’s dopamine receptors get accustomed to being flush with the feel good neurotransmitter. After awhile they get used to having a certain amount, a tolerance is built up, and so the person needs more and more just to get the same result, leading to addiction. Now, researchers at Medical University of South Carolina are the first to illustrate that TMS can reduce brain activity associated with addiction in cases of chronic cocaine and alcohol abuse. These findings were published in the journal Biological Psychiatry: Cognitive Neuroscience and Neuroimaging. TMS is opening novel modalities in addiction treatment.
More Rapid Form of Brain Stimulation for Resistant Depression Worked as Well as Conventional TMS
Since 2008, when transcranial magnetic stimulation was approved by FDA, it has been available to people whose depression has resisted conventional forms of treatment.
Despite its impressive clinical performance, TMS is not as convenient for patients as drug therapy, a factor that has limited its use, researchers say. Although treatments benefit from coverage by most insurance plans, they must be delivered in the office of a doctor or facility with the required equipment, and they do take time to administer. The current state-of-the- art treatment for depression using repetitive TMS (rTMS) calls for patients to receive stimulation for 37 minutes, through a coil placed on the scalp. Yet the duration of each session does impose an upper limit on how many patients can be treated in a single day with a single rTMS device. The entire session takes about 45 minutes per patient. But it may now be feasible to cut this to only 10 or 15 minutes, according to new research conducted by a team led by Daniel M. Blumberger, M.D., a 2010 BBRF Young Investigator at the Centre for Addiction and Mental Health at the University of Toronto.
Dr. Blumberger and colleagues report in The Lancet that they have successfully tested a new form of rTMS called iTBS (intermittent theta burst stimulation) that can deliver stimulation to a brain area affected by depression in only 3 minutes—delivering therapeutic benefits to patients that are just as effective as standard TMS treatments. iTBS is designed to deliver magnetic stimulation at a frequency that is similar to the brain’s natural theta rhythms, one of many types of oscillating patterns generated by the human brain.