TMS: A Top-Down Process

February 6, 2018
David Carreon, MD

,
Jessica A. Gold, MD, MS

What are the major cortical networks we are trying to change with TMS? Where will TMS fit into psychiatry in the next decade? These questions and more are addressed in this podcast.

Here: Part 3 of a 3-part interview with Richard Bermudes, MD on transcranial magnetic stimulation (TMS). Dr. Bermudes is founder and medical director of TMS Health Solutions and founding member of the Clinical TMS society, Inc. Part 1 can be found here: Transcranial Magnetic Stimulation: A Look Under the Hood. Part 2 can be found here: Transcranial Magnetic Stimulation: The Procedure.

Some say antidepressants work from the bottom up. and cognitive therapy and TMS, from the top down. In this final of three podcasts on TMS, Dr. Richard Bermudes highlights why magnetic stimulation might be an effective treatment for depression, particularly for symptoms that are resistant to pharmacotherapy.

He addresses these questions and more:

. What are the major cortical networks we are trying to change with TMS?
. Where will TMS fit into psychiatry in the next decade?
. What is psychiatry gettimg wrong right now?

Although TMS gives us a third pillar of treatment along with medications and psychotherapy, we don't always know what's going with each individual patient. We need some way to measure a biomarker to measure efficacy, whether we're doing psychotherapy, medication, or some sort of neuromodulation.

TRANSCRIPT:

Psyched! Episode 2 - Part 3 of 3

Bermudes: Although TMS has improved and give us this sort of third pillar of treatment to have along with medications and psychotherapy, in a way we still don't really know what's going on, with each individual patient, what's going on under the hood. We need some way to measure a biomarker. I think that will help us sort patients and monitor what's going on with our patients, whether we're doing psychotherapy, medication, or some sort of neuromodulation.

Jessi Gold: What sort of symptom differences would mean that you move like, two spaces to the right, or two spaces to the left?

Bermudes: There's a lot of debate about that. You know, I would just say the clinical trials really haven't ... There's sort of this initially FDA approved protocol, stimulation protocol, that targeted at the left front part of the head, or the left dorsolateral prefrontal cortex. There are other stimulation protocols that are emerging, but we don't really have a superior. They all seem to be about the same. Some of the doctors we ... If one's not working, we'll change to another stimulation protocol, because I think we want to do something. When the patient gets better, we assume it's because of that change.
It's much like working with anti-depressants. This person needs some activation, I'm going to add a little Wellbutrin.

Jessi Gold: Prozac didn't work, but we'll try Zoloft because they're so different.

Bermudes: Yeah, or they've only been on Prozac for three weeks. Yeah, they still need a little more active ... You know, they could use like a little more than a cup of coffee. You add that touch of Wellbutrin, and then they come back three weeks later like, "Oh, that's great." It's like, "See?" Somehow my measurement of their symptoms, in this change ... With head-to-head trials, we know that, yeah, they all sort of end up at the same place. That's where we're at with the stimulation protocols, unfortunately.

David Carreon: I know that we can't go into ultimate depth on the neuroscience of it, I mean in the same sort of cartoonish way that anti-depressants ... The story was that there's low serotonin, and so we need to increase the serotonin, but of course there's a lot of problems with that as a theory. We've made adjustments in anti-depressants, and the SSRIs do work, but maybe not by that initial cartoon version. What is, I guess, an equivalent TMS circuit cartoon? What are the major networks that you're trying to change?

Bermudes: Without getting too much into the details, the way I describe it to patients and colleagues is there's sort of this top down approach to some of our psychiatric treatments. There's cortical and sub-cortical loops, or circuits, and generally with depressed patients, they have a lack of cortical control, or sort of decreased top down functioning, if you will, between these areas of the brain. Generally, when you stimulate or modulate the dorsolateral prefrontal cortex, there's sort of this window into this cortical control circuit. What you see in time is increased blood flow, increased metabolism, and downward sort of top down control of maybe hyperactive or hyper-functioning circuits.

It kind of works in the opposite. Anti-depressants seem to, what they say, work from the bottom up. Where cognitive therapy and TMS seem to work from the top down. Where anti-depressants would sort of down regulate limbic systems, and then you'd get more cortical control that way. That's kind of how I try to keep it, sort of at these upper circuits and lower circuits. I got to point to my forehead and then…

Jessi Gold: I imagine it's not the easiest thing in the world to explain.

Bermudes: You know, I think when you keep it kind of, you kind of have these two ... There's obviously more than one network, but when you kind of keep it simple. I tend to be, I'm basically a general psychiatrist. I'm not a neuroscientist. I like to conceptualize things rather simply myself, and then sort of add to the model as I learn more and more about the neuroscience.

David Carreon: Where do you see TMS fitting into psychiatry, say in 10 or 20 years? What do you think this looks like when it's mature and developed?

Bermudes: I think that there's a few ways that our field can develop as a whole, and I think that TMS hopefully will be a part of that development. We talked about some sort of biomarker. I think there's a very big appetite with our field to find a biomarker that will help us sort patients into the right diagnostic categories. I think when we can get that, then hopefully that will help us get people to the right treatments quicker. There's really a big need for a biomarker to provide feedback into the treatments we're rendering. That's with TMS, [inaudible] therapy, as well as psychotherapy.

In terms of TMS specifically, I think one of the things that would be helpful is really finding other target, other, I call them cortical windows or windows into these networks. There are some emerging targets, depending on what's going on with the patient. We might want to move the coil over the supplementary motor area, for example. There's some indications that stimulating in that area of the brain helps people with a lot of obsessional symptoms. In terms of coil navigation, there's a lot of room for us to grow in terms of stimulation protocols, there's a whole variety that are being developed.
Targeting stimulation biomarkers, any of those three variables, that would change, I think the field, as well as TMS would improve.

Jessi Gold: TMS is just for depression, in your mind, or do you think that in 10 years, we'll be using TMS for other illnesses?

Bermudes: There's definitely a number of phase three trails that have been completed and are sort of going to the FDA in the next couple years. I think there will be an indication expansion. Both within psychiatric conditions as well as neurological conditions.

David Carreon: We're coming to the end of our time, and we like to ask our guests a few questions at the end about sort of, rapid fire. A question or two, a sentence or two, and then we'll cut you off after two sentences.

Bermudes: Yeah, sure.

David Carreon: We'll ask some of these questions. First off, what is something that psychiatry is getting wrong, or a major misconception in psychiatry right now?

Bermudes: Diagnosis.

Jessi Gold: Plain and simple, diagnosis.

David Carreon: There we go.

Jessi Gold: There we go.

David Carreon: I love it.

Jessi Gold: What's your favorite book?

Bermudes: Rapid fire, right?

David Carreon: We're doing it.

Jessi Gold: Yep, exactly. What's your favorite book?

Bermudes: What is it called, The Brain That Changes Itself.

David Carreon: Doidge.

Bermudes: Yep.

David Carreon: Fascinating book. Alright. Advice for a trainee?

Bermudes: Read.

Jessi Gold: Anything? Everything?

David Carreon: You're killing it. This is amazing. Most of our guests incapable of short answers.

Jessi Gold: Yeah, is it because you're a procedural person?

Bermudes: No, no. I really believe there's two things. Reading thirty minutes a day. It doesn't matter what you read. If you have a regular habit, you will change your brain. You will continually learn. It's about idea making. Reading, to me, is the way I keep up. It's not just about psychiatry, it's outside of that.

Jessi Gold: Would there be a person living or dead that you would consider a hero? It could also be a fictional character.

Bermudes: My father, actually. He was a teacher. He was an artist. He had his own construction company. He moved us to ten acres of land, without a well, without heat, electricity. Put a generator, single-wide trailer. It's a wonderful piece of property in northern California. He's passed, but just a really creative individual. He's someone who always told my brother and I that we could do anything.

David Carreon: Last, but not least. What's your favorite color?

Bermudes: Green.

David Carreon: Green. Thank you for joining us.

Jessi Gold: Thank you.

Bermudes: Thank you.