I've started getting quite a few questions about the TMS work I'm participating in at Alvaro Pascual-Leone's lab in Boston http://www.tmslab.org/ I'm going to answer a few of them here. Feel free to ask your own questions in the comments. I'll try to answer, and I'll run any technical or medical questions past Alvaro, Shirley, and the other doctors to make sure I have the facts straight.
What is TMS?
As we think, our brains generate small electrical signals. These signals pass through our nerves to work our muscles, and the pass within our brains to create our thoughts and memories. All our nerves work on electricity - nerves in our eyes, ears, and even our nose generate electrical signals that our brain interprets and processes.
TMS uses the principle of electromagnetic induction to add its own signal to the signals running along our neural pathways. TMS is very precise, so we can aim it at fairly specific paths. For example, we can use TMS to stimulate one finger in the hand. By applying TMS pulses to the part of the brain that controls it, we can make the finger twitch.
These pulses can augment the function of a brain area, or they can inhibit it. So you might say they allow us to "speed up" or "slow down" small parts of the brain. The TMS equipment we're using in this work focuses on a bit less than 1% of the brain mass.
So how could it help people with autism?
Shirley and Alvaro developed a theory that some parts of the autistic mind are over-active, and those overactive parts sort of overwhelm the other parts. By "slowing down" the over-active areas they hoped to bring about an improvement in overall function.
In this first study, several areas were targeted over four sessions.
So far, my results look very, very promising. Really exciting stuff. We also have positive initial results from a few others in the study. But it's too soon to say more - we need to analyze the data and run more experiments.
Now, if I may, I'd like to show you what it looks like. Meet Shirley Fecteau, PhD, the leader of this particular study. She's an instructor at Harvard Medical School and a part of Dr. Pascual-Leone's team at Beth Israel Deaconess Medical Center.
Shirley is French-Canadian. One of the things I've noticed is that people have come from all over the world to work in these Harvard programs. They really do get the best and the brightest from all over.
In this image you can see me getting TMS to the right front of my brain.
She's holding the coil against the side of my head. The black headband has some targets on it that allow two computer cameras on the wall to track my head so she can keep the coil in the right spot. You'll notice I have a blank expression. That's because the TMS induces an almost meditative state in me. The picture you see is not a setup, it's real TMS.
This next shot shows a bit more of the setup. You can see the cameras on the wall, looking down at the chair. Those cameras feed the computer below, which tells Shirley where to hold the TMS coil. Fellow Aspergian Michael Wilcox is in the chair, and he's going to write about his TMS experience on his own site, which is http://www.mfw.us/ The fellow with the camera is filming is for a Canadian Television documentary based upon Dr. Norman Doidge's book The Brain That Changes Itself. Dr. Doidge and the crew came to see us 2 weeks ago and I took the chance to shoot a bunch of photos.
In this photo, you can see the brain map and the targets for stimulation.
The upper right view has some small colored dots . . . those are the target areas. The pair of cameras on the wall match points on my face with the MRI images to show them where to place the TMS coil.
The crosshairs on the left show the coil (the black) dot with the target area being the X
This shot shows the actual TMS machine:
Here's a better view of the TMS coil, on my son Cubby's head:
The hose coming out of the coil is an air line, to pass air through the coil to cool it. The coil is a figure 8 of wire in the blue plastic casing.
And a few more questions before I go . . .
Does TMS damage or kill brain cells?
In my previous post, I described some pretty dramatic effects from TMS. Someone on the http://www.ageofautism.com/ site asked if those vivid images were produced by "millions of neurons dying off."
TMS does not injure or kill brain cells. In this study, we are using what's called functional MRI imagery to watch brain activity before, after, and even during TMS. We can see areas become less active, or more active, and we see them return to their pre-TMS states. We can say with certainty that TMS is not killing brain cells.
We are able to watch the areas of the brain that we stimulate change and evolve.
In addition, Alvaro and other neuroscientists have observed the effects of TMS during open-brain surgical procedures in patients. TMS alters the signals passed through the neurons. It does not burn them out.
Is TMS like ECT, electro convulsive or shock treatment?
Not really. It's only similar in that they are both electrical processes. To use an analogy, TMS is like touching your fingers across the terminals of a AA battery. ECT is like throwing a cable over a high-tension electric powerline. Needless to say, both are electrical experiences but their effect on the person is drastically differrent.
TMS is a low-energy and highly focused procedure that's aimed at less than 1% of the brain mass. It's painless and in fact induces something of a tranquil state while it's being done. For me, TMS has produced a lasting elevation of mood and made me somewhat calmer overall.
ECT, on the other hand, is a very violent, high energy jolt to the whole brain. It induces seizures and it's so painful that people must be under general anesthesia. As you can see, none of that happens with TMS.
I'm aware that any tool that reaches into the brain and alters the way we think is scary. I guess it's not as scary for me because I have a good understanding of the electronic principles, and I'm seeing it unfold firsthand. And it's also exciting. The results I am seeing are truly like science fiction come to life.
For more of John's insights check out his blog Look Me in The Eye
Published On: April 28, 2011