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NOVA ScienceNOW Expert Q&A

The Uses of TMS: Expert Q&A

  • Posted 01.20.11
  • NOVA scienceNOW

On February 10, 2011 Mark George answered a wide range of questions about the current and potential future uses of transcranial magnetic stimulation (TMS) for treating depression and other disorders. He also addressed questions about how TMS stimulates the brain, whether the technology poses risks, and whether insurance companies cover the therapy.

Mark George

Mark George, M.D.

Prof. of Psychiatry, Radiology, and Neuroscience
Medical University of South Carolina, Charleston
Full Bio

Photo credit: Courtesy Mark George

Mark George

Dr. Mark George is Distinguished Professor of Psychiatry, Radiology, and Neuroscience as well as Director of the Brain Stimulation Laboratory and Founding Director of the Center for Advanced Imaging Research at the Medical University of South Carolina, Charleston. As an undergraduate in philosophy at Davidson College, George first began studying the relationship between mind and brain, or brain/behavior relationships. He went on to receive his M.D. from the Medical University of SC, Charleston in 1985. In the 1990s, George wrote one of the first textbooks on brain activation and imaging, and while working at the National Institute of Mental Health (NIMN) he used functional imaging to discover that specific brain regions change activity during normal emotions. He then started using imaging to understand brain changes that occur in depression and mania. This imaging work led to his pioneering use of a non-invasive brain stimulation method, transcranial magnetic stimulation (TMS), as a probe of neuronal circuits that regulate mood, and to clinical trials using TMS as an antidepressant. The FDA approved TMS as a treatment for depression in October 2008. George has also pioneered another treatment for depression, vagus nerve stimulation (VNS), which was FDA-approved in 2006. George has published over 300 scientific articles or book chapters, has eight patents, and has written or edited six books. In 2009 U.S. News and World Report named him one of 14 "medical pioneers who are not holding back."

Injury to prefrontal cortex / strokes

Q: Could an injury to the prefrontal cortex cause the type of depression you are working with? Might it respond to treatment with TMS? Did you find that TMS works with different levels of depression? Joann Barry, Sault Ste Marie, Michigan

Dear Joann:
Yes, many people who have strokes of the prefrontal cortex develop depression. Dr. Robert Robinson first found this out 25 years ago. The left side seems more important than the right for maintaining mood. That is one reason why we deliver TMS on the left side to treat depression. Dr. Robinson at Iowa has performed TMS studies in patients who have had strokes who get depression. It worked quite well, with no seizures and no cognitive side effects. (see Jorge RE, Moser DJ, Action L, Robinson RG. Treatment of Vascular Depression Using Repetitive Transcranial Magnetic Stimulation Arch Gen Psychiatry. 2008;65(3):268-76.)

TMS v. medication

Q: Would TMS be a better alternative for treating mental illness than psychotropic medication? I understand the doctors just hit and miss when it comes to medicating patients. Mary Tucker-Pettersen, Corpus Christi, TX

Dear Mary:
Right now TMS is only approved for treating treatment resistant depression, and medications are still the main way of treating most brain diseases including depression. We will have to see over time whether this shifts, but right now at least your suggestion is premature. We do not know enough about how various patients are like to respond to TMS therapy versus medications.


Q: Autism! Does TMS help with the core deficits of autism, and if so how? I've heard quite a bit of buzz on TMS, but still confused as to how it might help... Michelle Garcia Melind, Elmhurst, IL, USA

Dear Michelle:
There have been only a few small studies with TMS in autism, with inconclusive results. We really do not know which part of the brain is not working in autism, or how it is not working. We do not have the roadmap yet to know how to even think about using TMS to treat it. More research is needed, and maybe someday...

Stimulating empathy

Q: Could TMS help stimulate empathy in a sociopath or psycopath? Or is there nothing to arouse in the part of the brain that houses empathic emotions? Kathleen MacDowell, Framingham, MA

Dear Kathleen:
This is a most provocative question. Right now we do not know how to make TMS make someone more empathic, or loving, or caring, to make my teenagers make their bed... Seriously, we do not know enough about some basic behaviors like empathy to know how to potentially use TMS to knock it out or up. The study described on the show about moral judgment gets close to that. However, like most early experiments with TMS, we need to make sure that other scientists can replicate these findings before we assume they are true.

Paralysis & physical therapy

Q: Could TMS be used in the field of phyical therapy, to stimulate the nerves in areas where paralysis has occured? Could TMS help restore function to those areas? Patel, NJ

Dear Patel:
This is a most active area of research. We do not know the answer now, but we should in a few years. Several good studies are underway where stroke patients are given TMS in a way that we think might help the brain retrain or use new circuits. Stay tuned.

Improving skills

Q: Could TMS be used to improve our skills in some areas, such as skills in music or foreign language, by improving the certain parts of the brain dealing with those skills? Lyndsay , Oklahoma, USA

Dear Lyndsay:
This is certainly a possibility, although no one has shown anything definite yet. It generally is easier to restore the brain back to normal behavior after a problem or disease has occurred (like in treating depression) than it is to improve on peak performance. Stay tuned...

Alzheimer's disease

Q: I watched your show tonight my Mom has Alzheimer's disease, she has not been able to talk for around 6 or 8 months, do you think this would work on her, I would love to be able to talk to her one last time. Thank You David Brinkley david brinkley, conway arkansas

Dear David:
Some researchers are using TMS to look at improving language after stroke, but I don't know of anything with respect to Alzheimer's disease. I am so sorry.

Parkinson's, epilepsy & other conditions

Q: Parkinson's. Epilepsy. Depression. Schizophrenia. How many conditions could possibly be treated with TMS? Could the TMS "wand" be miniaturized to the point it could be embedded in, say, a baseball cap? Ron Millam, US

Dear Ron:
TMS might eventually prove useful to treat any brain disease where we can figure out a way to potentially identify the faulty region or circuit and use repeated stimulation to redo the wiring and correct the disease. There are several TMS studies in Parkinson's Disease, and a large scale study is launching (go to and search). There have been studies as well in focal cortical epilepsy.

Years ago we made a small TMS device that was the size of a small fishing tackle box, weighed less than 20 pounds, and could run on a battery. So, you can make small TMS devices and put them in a cap if there was a need and a therapeutic application.

(see Epstein CM. A six-pound battery-powered portable transcranial magnetic stimulator. BRAIN STIMULATION: Basic, Translational, and Clinical Research in Neuromodulation April 2008 (Vol. 1, Issue 2, Pages 128-130))

Depression study & long-term relief

Q: Patients in study who experienced relief from depression: how long were they followed? how long did their relief last? Does the treatment cause any short or long term harm? Karin Lowenthal, Buffalo, NY

Dear Karin:
This is a great question and is where the field is focusing its attention next. Most of the patients have been followed for at least 6 months after they got well. They commonly go back on medications, although we do not know if that is needed. At 6 months the relapse rate with electroconvulsive therapy (ECT) is over 50%, and it is similar for medications in patients with treatment resistant depression. The few studies done following TMS look to be slightly better than 50% relapse at 6 months, but they were not really good studies. We are applying to the NIH now to precisely answer this question of how long TMS effects last, and whether patients need to go back on medications.

We have not observed any short or long-term harm.

Accelerate learning / enhance memory

Q: Is there a way to ultilize a TMS unit to accelerate learning and or increase our memory capabilities. Will it ever be available to be purchased by the general public. randy heim, home

Dear Randy:
Right now it does not look like TMS can accelerate learning or increase memory. Some day that might be discovered.

TMS can accidentally cause seizures if not performed properly, so it would be dangerous to do it not supervised by a doctor in a medical setting. There are forms of TMS that are much weaker than those we have used in our trials. These forms cannot cause a seizure and may eventually be able to be used at home, if they are found effective.

How TMS stimulates the brain

Q: How does the magnet stimulate the brain? Does it stimulate the neurons to fire and/or does it inhibit reuptake of neurotransmitters? I never knew the brain had much of a magnetic field? Vincent Panzeca, Cincinnati, Ohio

Dear Vincent:
TMS causes nerve cells to fire, which then leads to the release of neurotransmitters. So it does both. You can think of TMS as 'focal pharmacology.' It changes neurotransmitters in specific regions. This is unlike a pill, which you take by mouth and goes to your stomach, some of which goes to your whole body, some of which then goes to the brain, and a little bit gets to where it is needed.

Wherever there is electricity, there is a corresponding magnetic field. That is why we call it 'electromagnetic field.' Electricity and magnetism are inseparable, and are merely different ways of talking about the same thing. The brain uses electricity for nerve cells to work, and they give off a magnetic field. There is a fancy imaging machine called a magneto encephalogram (MEG) that can measure these magnetic fields that we produce when we think.

(see Higgins E, George MS. Brain Stimulation Therapies for Clinicians. American Psychiatric Press, 2008.


Q: I participated in your trial - When will TMS be FDA approved for fibromyalgia treatment? Fred, Charleston, SC

Dear Fred:
You live in a really great town. In order for something to get FDA approval, a company needs to do a study and apply to the FDA. I am not aware of any company doing this at present for fibromyalgia. Some are looking at it however.

ICD or pacemaker

Q: Would someone who has an ICD or pacemaker device be able to gain benefits from TMS or is it too much of a risk of interfering with those other devices? Could treatment options include pain management to reduce addiction to opiate based drugs? Alison Murphy, Penfield, NY

Dear Alison Murphy:
If you put the TMS coil on top of a pacemaker there is a risk of it causing problems with the pacemaker. The magnetic field of the TMS coil is very local, and does not extend far from the TMS coil. So, if the coil is secured so that it could never get away from the head and near the chest, then things should be okay. (Some researchers who had hand-held TMS coils used to make patients with pacemakers wear a large lifesaver vest, called a "Mae West", to make sure the coil could not accidentally get near the chest.) So, check with your doctors if this might apply to you.

TMS could theoretically potentially reduce opiate use, but the research needs to be done.

ECT v. TMS / memory loss / ADHD

Q: 1. Does TMS do something in the brain similar to what ECT does, and does it cause memory loss(which ECT does)? 2. Why are multiple sessions over a period of weeks needed? 3. Does TMS have a beneficial effect on ADHD? K.C. Hutchison, Gaithersburg, MD

TMS does not cause a seizure, while ECT does. So TMS does something quite different in terms of the initial impact on the brain. TMS and ECT may do something similar later on in terms of resetting a relationship between the governing cortex and deeper limbic regions. In numerous studies, TMS has never been shown to cause memory loss. In fact, most people are smarter after treatment, but that likely just reflects the fact that their depression is gone, and it was making them temporarily less smart.

When I first started doing TMS, I modeled it after ECT, where patients need 2-3 treatments per week for several weeks. [My wife, Eloise, threatened to divorce me if I gave TMS on weekends, so we call the weekends off policy 'Eloise's rule.' Some researchers are now starting to test the limits of this early model. Researchers at Emory recently admitted patients to the hospital and gave them about 10 days worth of TMS in just two days. Their patients did well, but it was not a controlled study, so it needs to be tested.

Wouldn't it be great if we could figure out how to reduce it all to one or a few days? We are doing a study now where we are delivering about 2 weeks worth of TMS in 3 days to patients who are admitted to a VA hospital with suicidal thinking, to see if we can make it work faster. I am pretty confident we can make it work faster, but it may be like baking a cake, and you cannot easily speed it up. Stay tuned.

There are not good studies yet using TMS for ADHD.

(see Holtzheimer PE 3rd, McDonald WM, Mufti M, Kelley ME, Quinn S, Corso G, Epstein CM. Accelerated repetitive transcranial magnetic stimulation for treatment-resistant depression. Depress Anxiety. 2010 Oct;27(10):960-3.)

Targetting specific areas

Q: How do you "aim" TMS in the brain? Can very specific areas of the brain be targeted without the TMS influencing other parts? Are there areas that can't be targeted well? Thanks. Jon Newman, Wisconsin, USA

Dear Jon:
With current technology, we can only stimulate the surface of the brain, directly under the coil, and not very deep. There is a company, Brainsway, that has created a large coil that can stimulate deep in the brain, but it stimulates much of the brain going in. It is thus not deep and focal. There is another company, NeoStim, that is proposing to focus the TMS deep in the brain.

This is an exciting area and important question. Stay tuned.



Q: I have been on many different anti-depressants, with minimal results and My Dr. now has TMS. Problem is that insurance, Medicare will not cover the cost... Why is that when this may be a treatment that could dramatically improve my life? katherine wierzbinski, oak lawn, illinois

Dear Katherine:
See below. Insurance companies have traditionally underpaid for mental disorders like depression. There are new parity laws requiring that they no longer discriminate. Insurance companies should pay for proven treatments for treatment resistant depressed patients who do not respond to medications.

Availability of treatment / insurance

Q: Hello, Can this treatment work on Dysthymia/cyclical depression? How can we find out which providers are offering this treatment,and where they're located? I presume insurance would not yet cover transcrainial magnetic stimulation? Thank you. Dee, Arizona

Dear Dee:
Most of the patients studied so far have been patients with severe depression who have not gotten well after taking medications. We thus do not know if it would work in mild depression, or cyclothymia. Generally things that work in treatment resistant, hard-to-treat patients also work, and work better, in milder depression. But we need to do the research to find out.

The FDA has only approved one device, made by Neuronetics. Their web page has a list of doctors with machines who are offering it clinically. Some, but not all, insurance companies are paying for TMS. In my opinion they all should, for appropriate patients, as it is no longer experimental, and we have strong prospective randomized controlled data showing safety and efficacy.


Potential dark side?

Q: For every positive breakthrough, there is a flip side of inherent abuse of that new found power. What might we need to be mindful of as far as the dark side of this new world? Thank you, - hopeful yet leery Linda, Elk Rapids, MI

Dear Linda:
Anything that is powerful enough to cure or treat an illness is likely also powerful enough to cause side effects or harm. We have had TMS in its modern form for over 20 years now, and as you saw on the show, I have given myself a lot of TMS over the years. (It obviously does not treat baldness!) It appears quite safe, except for a concern about accidentally causing a seizure, which is why it needs to be done in a medical setting under a doctor's supervision.

What other potential abuse or dark side might there be? Well, right now the coil needs to be near the scalp, so it would be very hard to deliver TMS against someone's will, or in a secret way that they did not know was happening.

When we make TMS coils that can stimulate the pleasure center, or which will improve performance or memory, then we will likely need to develop societal rules that help regulate this, just like we do with medications and drugs.

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