IEEE article on TMS

Nice article on TMS, and other neuromodulation technologies,in the IEEE Spectrum. The article was originally written in 2006 but it has some good insight into the world of neuromodulation. Reza Jalinous was interviewed for the TMS portion of the article as well as Dr. Pascual-Leone, whom I learned TMS and tDCS techniques from.

"Assuming that all the new brain stimulation techniques prove effective in the many upcoming trials, the psychiatrist's toolbox will look very different a decade from now. Patients will probably first be offered the less invasive techniques, such as transcranial direct current and magnetic stimulation; then the more invasive ones, such as the seizure therapies; and finally such surgical technologies as deep-brain stimulation and vagus nerve stimulation."

Illustration from IEEE Spectrum, by Matt Mahurin

TMS for Depression: a testimonial

Here is a testimonial from an NBC affiliate on the use of TMS for depression. It seems like the patient had some great results.
When I think about all of the patients I have seen that have had a miserable time with the side effects of antidepressants I can't help but think that one could make an argument for using non-invasive neuromodulation as a first-line treatment.

Head Wounds are Good For You!

At least that is what some studies have found about some Vietnam vets with certain head wounds.
Buzzle blogged about a study on vets with and without PTSD that found injuries to the prefrontal cortex or the amygdala were protective, at least with regard to developing PTSD.
Later in the article there is a suggestion that transcranial magnetic stimulation may play a role in the future treatment of PTSD based on these findings.

Postpartum Depression cured with TMS

The St. Louis Post-Dispatch had an article (Link) this morning about a trial going on at Washington University using rTMS for postpartum depression. Only four patients have been treated at this point, but all four had resolution of their symptoms.

Within a few days after receiving her first treatment in February with the device, Meinert said she began to feel better. After two weeks, her symptoms were gone.

"It honestly was incredible. I was shocked to be feeling that well after two weeks," Meinert said. "I was feeling like my old self, and I still feel great today."

One of the points that this article makes is that standard antidepressants take up to four weeks to work. And in reality they may take longer... In addition there are a number of less than savory side effects that are fairly common with these drugs including " diarrhea, dry mouth, lethargy, nervousness, a bad taste in the mouth and loss of libido...". The author is obliquely getting at a point that I have mentioned before: maybe rTMS is a better starting point than the typical antidepressants that we currently reach for. Fewer side effects, potentially less cost, fewer interactions with other medications, the list could go on.
Another interesting point brought up is that the TMS unit used in this study was made by Neuronetics, the outfit that is working on getting an FDA indication for TMS and depression. This will be the first FDA indication for the transcranial application of TMS (currently it is my understanding that it is only approved for peripheral nerve stimulation). The word on the street is that Neuronetics should be getting this indication relatively soon, but that has been the word for several years.
All of the politics of the FDA and their approval process aside, it is my opinion (and just like every opinion out there, you can take it with a grain of salt..) that this is a major step forward in our options to clinically induce neuroplasticity and make a positive difference in the quality of someone's life.

Fibromyalgia pain reduced by rTMS

A report from a group in France, published in the journal Brain, describes the effects of repetitive transcranial magnetic stimulation (rTMS) on self-reported average pain intensity recorded at baseline (before treatments), during 10 days of daily stimulation and then at 15, 30 and 60 days after the finish of treatments.
Thirty patients were divided up in a double blind fashion with one group getting sham treatment while the other got rTMS. Outcomes that were measured, meaning what effects were monitored during the study based on the researchers hypotheses, included depression monitoring scales, quality of life scales, scales that monitor how much pain interferes with the patient's functioning as well as the amount of pain a predetermined amount of pressure caused.
Twenty six of the original thirty, 13 in each group, were monitored through day 60 and the group that received the real rTMS had a significant reduction in pain , fatigue, morning tiredness, general activity and sleep at least two weeks after the last session was completed. The affective pain reduction was more long lasting than the sensory effects.
There were no significant side effects that occurred, as is the case with almost all of the studies that have been published in the last few years that adhere to published guidelines.
This group concluded that rTMS "...induces a long-lasting decrease in chronic widespread pain and may therefore constitute an effective alternative analgesic treatment for fibromyalgia."
Once again it seems that inducing neuroplasticity can help rebalance the maladaptive patterns that chronic pain syndromes have created. Is it the magic bullet we all hope for? Or is it snake oil? Or maybe something somewhere in between the two? Could this be another step in the right direction, opening the huge black box that is our brain just a little bit more?

Brain Mechanics at MIT

Just read a very insightful article by Ed Boyden "an assistant professor in the MIT Media Lab and MIT Department of Biological Engineering, where he leads the Neuroengineering and Neuromedia Group." Link
He goes into some very insightful thoughts on how to approach the problems associated with fixing problems in the brain, particularly how to view the brain as a complex system that demand you approach a dysfunctional subsystem the same way a computer engineer would: by abstracting the problem and ignoring the surrounding complexity. He goes on to note that the tools could use to fix various problems will depend on what the nature of the problem is. Should we use something focal and invasive, or noninvasive yet cruder with regards to spatial resolution?
Boyden goes on with some nice thoughts about, you guessed it: TMS!
I have to admit I would love to have attended the Neuroengineering panel at the MIT Emerging Technologies Conference.
As I have said before, we are just starting to open the black box that is the brain and technology like TMS and fMRI, used by scientists like Boyden, are going to, at the very least, kick a wedge to keep that door cracked open.

Migraines Zapped with tDCS

The same group ( I trained with them learning the technical aspects of tDCS and TMS) at Harvard that I have written about in the past just had an article published about one of their trials in IEEE Spectrum Online .

The gist of the article is that by using tDCS (low voltage electricity that runs through the brain via a couple of electrodes at very specific locations on the skull) migraineurs were getting some serious relief. The study is currently ongoing so the results have yet to be seen.

"The investigators, Dr. Felipe Fregni and Soroush Zaghi, both of Harvard Medical School, have recruited 24 patients who suffer migraine headaches at least 15 times per month. At scheduled intervals, which may or may not coincide with migraines, Fregni attaches electrodes to a subject’s scalp and passes 2 milliamps of current through the brain, targeting the locus of pain. Two months into the study, he is encouraged by what he is seeing. “In the initial sample, the results went in the direction we predicted,” he says. One of the main themes that I walked away from my week at Harvard with was that the brain is a HUGE BLACK BOX!!!! The breadth and depth of our understanding of how and why the brain works the way it does is superficial at best. As a result of the basic science that is going on with all of the new tools available to researchers, including TMS and fMRI, we are starting to crack open the box. But every little tidbit we figure out just makes me realize that the volume of the box is staggering."

A colleague asked me recently what the proposed mechanism of action was for tDCS and TMS. My short answer was "I don't really know". The long answer has to do with re-balancing the excitatory and inhibitory inputs of certain areas of the brain that affect areas "down stream" from the area of action.

"Following that theory, what triggers migraines is just an extreme example of what causes ordinary headaches in the normal brain. “If you stay up all night, three days in a row, and there are loud sounds and bright lights, you’re going to get a headache, too,” Fregni says. For people with migraines it just takes much less stress because the baseline of activity in certain areas of the brain is much higher, he says.
 Neurons, the cells that carry messages throughout the brain, are constantly receiving electrical inputs from surrounding cells. They integrate the voltage signals, and if the total is strong enough the neuron fires—sending a pulse of voltage out to other neurons to which it’s connected.
 During tDCS, the current hyperpolarizes the afflicted area of the brain, making the neurons less likely to fire. In the short term, the treatment usually staves off an encroaching attack, but tDCS could have long-term benefits as well. Many studies have determined that when repeatedly exposed to a hyperpolarizing current, neurons eventually become less excitable, a process called long-term depression. The stimulation would take advantage of that phenomenon to prime the migraine-prone regions of the brain so that one great flash of light would not be enough to overload the whole system."