Is tDCS Safe? – Neuroelectrics.com

Posted on November 20, 2012 by John

This comes to us via the Neuroelectrics.com blog. I’m very excited to see Neuroelectrics on the scene. I first noticed their device Starstim (pictured), popping up in news around Roi Cohen Kadish’s ongoing tDCS trials at his Oxford lab (see). I believe Neuroelectrics is a Spanish company. What’s especially exciting to me is that they also make an EEG device called Enobio and are working on the ability to map brain activity with EEG while undergoing tDCS. Think about that! Live, in-the-moment feedback on exactly what effect your tDCS is having.

More than 100 studies have been performed using tDCS in healthy controls and in patient populations, and no serious side effects have occurred for a review, see Nitsche and others 2008. Slight itching under the electrode, headache, fatigue, and nausea have been described in a minority of cases in a series of more than 550 subjects Poreisz and others 2007. Detailed studies have been performed to assess the safety of tDCS. These have shown that there was no evidence of neuronal damage as assessed by serum neuron-specific enolase after application of a 1 mA anodal current for 13 minutes Nitsche and Paulus 2001; Nitsche, Nitsche, and others 2003 or MRI measures of edema using contrast-enhanced and diffusion-weighted MRI measures after application of a 1 mA current for 13 minutes anodal or 9 minutes cathodal; Nitsche, Niehaus, and others 2004 […] In addition, a recent study was performed in rats using an epicranial electrode montage designed to be similar to that used in tDCS Liebetanz and others 2009. This demonstrated that brain lesions occurred only at current densities greater than 1429 mA/cm2 applied for durations longer than 10 minutes. In standard tDCS protocols in humans, a current density of approximately 0.05 mA/cm2 is produced.

More about the Neuroelectrics Enobio EEG device.

http://www.youtube.com/watch?v=fg_w6wPehss

via Is tDCS Safe?.

If She Were Your Daughter – Ritalin, Adderall or tDCS?

Posted on November 13, 2012 by John

Update 11/18/12 New Scientist has just posted a video showing (I believe) the device and test that will be used in Roi Cohen Kadosh’s upcoming study to study the efficacy of tDCS to enhance math abilities. Brain-zapping Kinect game boosts mathematical skills

The recent PBS article Boosting Kids’ Brain Power nicely documents the work of University of Oxford’s Dr. Roi Cohen Kadosh in testing and developing protocols for improving math and learning skills with tDCS. Through interviews, PBS follows the thinking of parents exploring the possibility of using tDCS to help their kid’s difficulties with learning math. One parent compares the possible harms of tDCS vs. pharmaceutical approaches and I think this is the key question. You can listen to the piece on the article page, or download the mp3 here.

The PBS story follows a trend on the uptick: Brain enhancement and the ethics thereof. In How Science Can Build a Better You, David Ewing Duncan tells us:

Over the last couple of years during talks and lectures, I have asked thousands of people a hypothetical question that goes like this: “If I could offer you a pill that allowed your child to increase his or her memory by 25 percent, would you give it to them?”

The show of hands in this informal poll has been overwhelming, with 80 percent or more voting no.

Then I asked a follow-up question. “What if this pill was safe and increased your kid’s grades from a B average to an A average?” People tittered nervously, looked around to see how others were voting as nearly half said yes. (Many didn’t vote at all.)

“And what if all of the other kids are taking the pill?” I asked. The tittering stopped and nearly everyone voted yes.

Another NY Times article Risky Rise of the Good-Grade Pill points out the extent to which kids are already using pharmaceuticals, illegally, to enhance brain power.

The boy exhaled. Before opening the car door, he recalled recently, he twisted open a capsule of orange powder and arranged it in a neat line on the armrest. He leaned over, closed one nostril and snorted it.

Throughout the parking lot, he said, eight of his friends did the same thing.

The drug was not cocaine or heroin, but Adderall, an amphetamine prescribed for attention deficit hyperactivity disorder that the boy said he and his friends routinely shared to study late into the night, focus during tests and ultimately get the grades worthy of their prestigious high school in an affluent suburb of New York City. The drug did more than just jolt them awake for the 8 a.m. SAT; it gave them a tunnel focus tailor-made for the marathon of tests long known to make or break college applications.

All of this points to an alarming skewing of culture and values I have no business addressing. It is easy for me to say however, that if my son or daughter were facing issues around attention or learning abilities, I’d certainly want the option of a proven, effective, and safe tDCS treatment before I’d consider a pharmaceutical approach.

To that end I wish Roi Cohen Kadish and his team at Oxford the best in their ongoing trials. See Also: Electrical brain stimulation improves math skills New Scientist
‘Human enhancement’ comes a step closer BBC
Brain stimulation ‘not a magic pill’ BBC Audio
The ethics of brain boosting Oxford

Safety – Transcranial direct current stimulation tDCS

Posted on October 29, 2012 by John

Excellent overview article on tDCS from University of Munich who have a research group devoted to Transcranial brain stimulation and neuroplasticity.

Safety of the method
Several studies have been performed on the safety of tDCS and on side effects and have resulted in clear recommendations on its safe use. There is general agreement that if attention is paid to recommendations concerning contraindications and stimulation parameters, tDCS is a well tolerated method with minimal side effects Nitsche et al. 2003, Fregni et al. 2006, Iyer et al. 2005.
The physiological changes involve the modulation of spontaneous neuronal activity through polarity-specific shifts of the resting membrane potential in the direction of de- or hyperpolarisation. The direction of the change is governed by the direction of current flow, the spatial orientation of the neuron, the type of neuron and the total charge. This underlies the possible complication of inducing an epileptic seizure. In accordance with the safety protocol from Nitsche and Paulus 2000, the stimulation charges used here lie far below the charges necessary to trigger a seizure. Even a continuous stimulation just below the energy threshold for triggering a seizure was associated with only a 40% increased cortical excitability compared with baseline. Studies on the question of whether neuronal damage can be observed after tDCS and whether structural changes occur in the brain revealed no indications of damaging effects of tDCS. Thus, levels of neuron-specific enolase NSE, a marker for neuronal destruction, were not increased after tDCS Nitsche et al. 2003 and pathological changes could not be found in either contrast-enhanced MRT or in EEG Nitsche 2003.
Persistent disorders of motor and cognitive abilities have not been found. Electrically induced local muscle contractions during the stimulation can be unpleasant for the person undergoing tDCS. The electrical stimulation causes irritation of the scalp lasting just a few seconds, which has been described as more or less painful tingling and pulling Fregni et al. 2006. Cortical tissue damage has not been found, even after high stimulation intensities and frequencies. Stimulation with electrodes on the scalp could indeed result in a chemical reaction and in burning of the skin tissue. However, the risk of a skin burn is minimised if sponge electrodes soaked in salt water are used, in accordance with the safety protocol of Nitsche and Paulus 2000.
Fregni et al. did not describe any side effects in their studies Bip Disorders 2006, Clin Neurophysiol 2006, Depr and Anx 2006; the treatment was well tolerated by all the patients.

via Transcranial direct current stimulation tDCS.

Where To Find More Information

Posted on September 20, 2012 by John

I’m calling this the deep data page. I’ll collect links to collections of papers and abstracts that cover tDCS. There is really, a LOT, of information out there and lots more is on the way. I’ll update this page as I come across more articles. If you have a favorite tDCS stash, please share it in the comments.

Soterix Medical has an excellent collection of tDCS Abstracts it keeps updated.
Growing.com has a great collection of tDCS related Abstracts, and an extensive collection of full artitcles.
MIT Press links to tDCS abstracts.
PubMeb tDCS search return over 600 articles.
Some very interesting tDCS articles from MusiciansBrain.com.
Hundreds of results at Google Scholar.
Trans-Cranial Technologies has a great list of tDCS abstracts.

Where Do The Electrodes Go?

Posted on July 23, 2012 by John

Update 9/6/12: Found for the first time, a study which equates electrode placement directly with the 10/20 positioning system. The study, Modulating activity in the motor cortex affects performance for the two hands differently depending upon which hemisphere is stimulated, was published in the European Journal of Neuroscience in 2008 and is available to download as a pdf or read in Quick View.

On each day, there was one session for anodal and one for cathodal tDCS, administered while the participants sat in an office chair. On the first day, participants also underwent one session of sham tDCS. For the anodal and cathodal sessions, 1 mA tDCS was applied for 20 min. On one of the testing days, the active electrode was positioned over the participant’s left- hemisphere motor region, centered on C3 of the 10–20 international electroencephalogram system; on the other day, the active electrode was positioned over the motor region of the right hemisphere (centered on C4 of the 10–20 electroencephalogram system). The correspon- dence between C3, C4 and the primary motor cortices of the left and right hemispheres, respectively, has been confirmed by neuroimaging studies (Homan et al., 1987; Herwig et al., 2003; Okamoto et al., 2004)

[Source of the above image is probably http://www.bem.fi/book/13/13.htm
where it’s referred to as “Location and nomenclature of the intermediate 10% electrodes, as standardized by the American Electroencephalographic Society. (Redrawn from Sharbrough, 1991).” The author seems to also have it available on ResearchGate
https://www.researchgate.net/publication/321094865_Bioelectromagnetism_13_Electroencephalography ]

While the 10/20 positioning system (wikipedia, pdf) does seem straight-forward and easy to understand, most of the electrode sites mentioned in the publications I’m reading don’t refer to it in describing where electrodes are being placed. You’re more likely to see something like: “…after bifrontal tDCS with the anode over the right and the cathode over the left dorsolateral prefrontal cortex (DLPFC).”

But if laypeople are going to be experimenting on themselves, wouldn’t they need some sort of standard reference to enable sharing of specific electrode sites? Wouldn’t you like to be able to say something like, I placed the anode over the right dorsolateral prefronal cortex at F3 and the cathode over the left at F7? In that way it would be easy for someone else to replicate. I was looking for a diagram that would map the 10/20 system over brain regions, but didn’t find exactly what I was looking for. If you have any ideas about this please share in the comments.

In the meantime here are a couple of basic brain info sites I found. These tend toward more basic information.
Healthline Brain Map
Cold Springs Harbor 3d Brain Map

Transcranial Direct Current Stimulation (TDCS) Targeted Using Brain Imaging Accelerates Learning

Posted on August 20, 2012 by John

From (I believe) a talk in 2010 given at the Organization for Human Brain Mapping by Dr. Vince Clark, director of the Clinical Neuroscience Center at the University of New Mexico (and previously, director of the Mind Research Network). The slides reference a study where tDCS was used in training subjects to accurately detect hidden and camouflaged objects, as in a military setting. What caught my eye, something I don’t recall seeing anywhere else, is the comparison of effectiveness of different amounts of current. It begs the question: If 2 mA is ~~more effective than 1 mA~~, what about 3 mA? [As Peter points out in his comment, the chart actually contrasts effects of 2 mA and 0.1 mA as a control. I do still think it’s a good question: Why 2 mA?]. Much I don’t understand in the slides without the talk to go along with, but have a look pdf, Quick View. And a link (abstract) to what appears to me a follow-up study. P.S. After tracking all this down I can’t tell you how frustrating it is to not be able to access the full texts of these studies, especially when we (NiH, DOD) paid for them. If you can get me a copy I would
greatly appreciate it.

‘Thinking caps’ are pseudoscience masquerading as neuroscience | Science | guardian.co.uk

Posted on August 20, 2012 by John

Certainly a little perspective is warranted from time to time.

Instead, Chi and Snyder’s study suffers from a catalogue of confounding factors and logical flaws. The most important of these is the “Nostradamus” problem: that by failing to control for alternative explanations, their results – like the writings of the famous French prophet – are open to a multitude of possible interpretations.

Snyder’s participants solved maths puzzles that the researchers claim required “insight”, yet crucially the subjects did not perform any other tasks to show that only puzzles requiring “insight” were influenced by the brain stimulation. This flaw means that any interpretation of the results is defined chiefly by two words: “maybe” and “or”.

Rather than encouraging novel thinking, maybe brain stimulation made participants less cautious in reaching a decision, or maybe it helped them recall a similar problem seen a few minutes earlier, or maybe it made them temporarily less distractible (or even dulled their hearing), or maybe it boosted general alertness (not surprisingly, people tend to do things faster and better when they are more awake).

via ‘Thinking caps’ are pseudoscience masquerading as neuroscience | Science | guardian.co.uk.

Juri Kropotov – Institute of the Human Brain of Russian Academy

Posted on August 16, 2012 by John

Another significant player popped up today. Juri Kropotov (bio) Institute of the Human Brain of the Russian Academy of Sciences. You can download his 2006 Powerpoint presentation, “Transcranial Direct Current Stimulation (tDCS): a new old tool in neurotherapy” Here. You can see the Google Quick View version (and print it) here. Of special interest may be Kropotov’s use of tDCS in treating ADHD.

Shinzen’s Blog: Meet My New Girlfriend: tDCS

Posted on August 15, 2012 by John

Recently, several people have called my attention to a very simple and quite old form of neuromodulation that is currently gathering a lot of research momentum—transcranial direct current stimulation (tDCS).

Here’s why I’m excited about tDCS.

Qualitative Significance:

The effects of tDCS seem to map directly to the core themes in mindfulness.

Enhanced ability to focus (this seems to relate to the concentration piece in my definition of mindfulness)

Enhanced ability to detect signals against a noisy background (this seems to relate to the sensory clarity piece)

Enhanced ability to deal with pain (this may be related to equanimity)

The turning off of mental talk (i.e., a samatha effect)

via Shinzen’s Blog: Meet My New Girlfriend: tDCS.

Imaging global brain connectivity can predict how intelligent you are | KurzweilAI

Posted on August 3, 2012 by John

Global hub of the brain

Prefrontal cortex (credit: Wikimedia Commons)

One possible explanation of the findings, the research team suggests, is that the lateral prefrontal region is a “flexible hub” that uses its extensive brain-wide connectivity to monitor and influence other brain regions in a goal-directed manner.

“There is evidence that the lateral prefrontal cortex is the brain region that ‘remembers’ (maintains) the goals and instructions that help you keep doing what is needed when you’re working on a task,” Cole says.

“So it makes sense that having this region communicating effectively with other regions (the ‘perceivers’ and ‘doers’ of the brain) would help you to accomplish tasks intelligently.”

While other regions of the brain make their own special contribution to cognitive processing, it is the lateral prefrontal cortex that helps coordinate these processes and maintain focus on the task at hand, in much the same way that the conductor of a symphony monitors and tweaks the real-time performance of an orchestra.

“We’re suggesting that the lateral prefrontal cortex functions like a feedback control system that is used often in engineering, that it helps implement cognitive control (which supports fluid intelligence), and that it doesn’t do this alone,” Cole says.

via Imaging global brain connectivity can predict how intelligent you are | KurzweilAI.
Abstract

Can Electrical Stimulation tDCS Enhance Your Brain Performance? Fact Vs. Myth | The ZocDoc Blog

Posted on July 25, 2012 by John

By way of Gareth at Trans-Cranial-Direct-Current.Blogspot.com this article from ZocDoc makes the case for caution…

Needless to say, tDCS should never be tried at home because of these potential risks. Scientists using tDCS in a laboratory setting have the expertise and high-quality equipment to assure the safety of their participants. They also have equipment like EEG and MRI that can help them localize the appropriate brain region for stimulation, as well as the training to understand how and when tDCS could be safe and effective. If you’re curious about tDCS your best bet is to find a local university that studies tDCS and volunteer for an experiment.

via Can Electrical Stimulation tDCS Enhance Your Brain Performance? Fact Vs. Myth | The ZocDoc Blog.

I must say though, that there seems very little to worry about in the publication abstracts cited in the article. Very well worth reading.
Modulating the brain at work using noninvasive transcranial stimulation.

tDCS polarity effects in motor and cognitive domains: a meta-analytical review.
Interesting…“When the anode electrode is applied over a non-motor area, in most cases, it will cause an excitation as measured by a relevant cognitive or perceptual task; however, the cathode electrode rarely causes an inhibition.”

A systematic review on reporting and assessment of adverse effects associated with transcranial direct current stimulation.
(AE, adverse effects) “Although results suggest that tDCS is associated with mild AEs only, we identified a selective reporting bias for reporting, assessing and publishing AEs of tDCS that hinders further conclusions.”

Efficacy of repetitive transcranial magnetic stimulation/transcranial direct current stimulation in cognitive neurorehabilitation.

Joel and John Thread July 17, 2012

Posted on July 25, 2012 by John

Joel Portzer on July 17, 2012 at 10:20 am said:

Hi John,
This maybe isnt the normal theoretical question that you usually get, but you seem to know a LOT about this so i am hoping you can help and i dont know where else to turn.

I have a tDCS device and am not completely sure what montage to use for my purposes. I am learning to trade and specifically need tDCS to boost my pattern recognition skills. It seems this would be the primary, secondary, and associative visual cortex. So, these areas on the 10/20 are O1, OZ and O2 [given pages 26-30 here http://www.trans-cranial.com/local/manuals/cortical_functions_ref_v1_0_pdf.pdf and http://www.trans-cranial.com/local/manuals/10_20_pos_man_v1_0_pdf.pdf ] …. So should i place one electrode right above these areas and then one on my shoulder so that i know it covers these areas (i think i read that on fisher wallace website maybe?)

I really appreciate ANY help you can give. finding info for my purposes has been difficult and even if you can point me in the right direction it would be a great help.

THanks,
Joel

—————
John on July 17, 2012 at 4:23 pm said:

Hi Joel,
Fact is I don’t know that much about tDCS yet. I don’t own a device and I’m not a scientist, just very curious and in the information gathering stage. Probably the closest thing to an active tDCS board is this SubReddit http://www.reddit.com/r/tdcs. I’ll follow-up when I’ve read the manuals you linked to. Off hand though, I wonder how you’d know if tDCS was helping with your pattern recognition. Is there something you already have a lot of experience with that, were tDCS working for you, you’d be able to recognize the difference? I’m going to forward you comment to Petr at brmlab as well. He has more hands on experience.
Best,
JohnH

————————-
Joel Portzer on July 17, 2012 at 5:58 pm said:

Great! Thanks for forwarding my question on and the forum idea. Thats a very good question about knowing if its working- especially because i dont think there is a study that dealt with pattern recognition. Aside from paying upwards of 50 grand to fund a study i dont know what else to do to be absolutely sure, although i am fairly confident given all the other studies positive results. I will be doing the studying anyway, so i figure its a minor cost in time and money and a “probable?” huge benefit.

Thanks again!
Joel

————————-
John on July 17, 2012 at 7:06 pm said:

Hey Joel,
The top spot on the tDCS SubReddit right now is a guy who is doing self-experiments with the Cambridge Brain Science Challenge. They have tests that seem about perfect for our experiments in that many of them are generated by an algorithm, so they’re always different. I’m going to get a blog post up later this evening.
Best,
JohnH

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Joel Portzer on July 18, 2012 at 9:50 pm said:

Yeah i saw that- thanks! Im sure you saw i made my own post. Hopefully someone has some more knowedge on this than i do. Did you get a hold of the guy, Petr, you were talking about? He has some experience with this stuff?

————————-
John on July 18, 2012 at 10:09 pm said:

I sent him your comment so he may reply to you directly. Or you could email him directly. His is the first comment on this page with the address at seznam.cz
I may fold our conversation into a single comment. Good luck with your experiments and keep us posted.

————————-
Thanks John,

BTW, are you interested in getting a tDCS device?

I could get in touch with a guy who will make you one (thats safe) and inexpensive but I will have to introduce you (he’s touchy about who he sells to due to regulations etc.).

I think i got mine for $70 without the pads.

————————-
John on July 24, 2012 at 5:14 pm said:

I am definitely interested in a device. Right now I’m holding out for a GoFlow, or something like it. The reason being, I think it will be easier to build a solid body of data if most of us are using the same device. I’ll give GoFlow another month or so and if nothing emerges it’s good to know about your friend. Thanks

————————-
Joel Portzer on July 24, 2012 at 5:38 pm said:

yeah i was thinking the same thing but i finally gave in a month ago when they were denied by kickstarter. I dont think go flow is going to do it for legal reasons- they are in over their heads.

Do you think the results will be different though? The only variables i see 1) current flow – my ammeter shows the current flow on my device and its pretty steady 2) the type of electrodes people use which can vary greatly because goflow showed sticky TENS pads which dont work on a hairy scalp, and then if people buy sponge electrode pads there the big variable of 3) How wet they keep them with a saline solution and what type of saline solution they use.

Im kinda thinking out loud but in my mind it seems go flow is not going to provide a consistent tDCS experience.

Id like to hear your thoughts.

————————-
John on July 25, 2012 at 12:53 am said: Edit

We’re thinking along the same lines. And I agree, as I’m learning more about it, the electrodes are turning out to be more complicated than I thought at first. If not GoFlow, maybe a kit of some kind, or even a list of specific Radio Shack parts. I don’t think the results will be that different, but it would be great if we were all on the same page, exactly. Same device, same electrodes, same montage (I guess that’s what it’s called – where the electrodes are placed), and same tests. It would be amazing if we could get some oversight from a lab that wanted the data. Hey you’re welcome to contribute to this blog if you feel like sharing some of your experiences some time.
Best, JH

Transcranial Direct Current Stimulation (tDCS): The Most Effective Treatment for Depression You’ve Never Heard Of

Posted on July 22, 2012 by John

Timothy Sexton has been covering tDCS on the Yahoo Contributor Network.

You name an antidepressant and I have tried it. I have even been on the verge of getting electro-convulsive therapy to treat my depression. And yet not once-not one single time-have I ever heard any of these doctors bring up transcranial direct current stimulation or use the term tDCS.

As a writer and a victim of clinical depression, I have collected a small library of books related to health concerns. Many of these books specifically focus on alternatives to mainstream American approaches to treating illnesses. Not a single one of these books mentions tDCS at all. Not for improving cognition, not for treating pain and not for treating depression. Nada. Nothing. Zilch.

He ends the article with…

I am going to be undergoing tDCS treatment for depression myself and follow-ups to this article will provide a first-person investigation into how this alternative treatment actually affects mood and behavior.

I’ll be keeping an eye out for Timothy’s follow-up.

via Transcranial Direct Current Stimulation (tDCS): The Most Effective Treatment for Depression You’ve Never Heard Of – Yahoo! Voices – voices.yahoo.com.
See Also: Treatment of depression with transcranial direct current stimulation (tDCS): A Review (pdf)

Some interesting finds from the tDCS SubReddit

Posted on July 17, 2012 by John

Ranza, over at the tDCS SubReddit has a tDCS device and has found the perfect online resource for running tests. The Cambridge Brain Science website. One of their stated goals is:

To provide a web-based platform for the controlled assessment of cognitive function in targeted groups of individuals for the purposes of scientific investigation, including clinical and pharmaceutical trials. The Cambridge Brain Sciences platform has recently been used by a major pharmaceutical company to conduct an entirely web-based trial of a novel compound. Clinical trials involving various patient groups are also underway.

(Would like to know more about this ‘novel compound’.) And here’s an example of one of the tests.

The Odd One Out task differers from Raven’s and Cattell’s intelligence tests as the problems are generated on the fly using a complex set of algorithms. Due to this on the fly generation, and the ability of the task to generate many tens of thousands of novel problems, the task is suitable for training reasoning abilities or taking many repeated measures as the participants cannot learn the answers to specific problems by rote. Instead, they must solve a novel set of problems each time they undertake the task.

This seems to me the perfect solution for a standardized set of tests to measure our performance while using tDCS devices. What remains is some sort of methodology for setting up the electrodes. PS. I don’t own a tDCS device yet.

Unlock Your Inner Rain Man by Electrically Zapping Your Brain | Wired Science | Wired.com