An email from Michelle Pearson at the NIH (because I had signed up for the online version of the workshop) alerted me today to a trove of TES (Transcranial Electric Stimulation) info being made available to us. Presenter slides (in PDF form) from the workshop were available for download. Because the download process was pretty wonky, involving many clicks and declined logins to Dropbox I thought to make them available here as well.
We developed a cellular brain stimulation device as part of our ELEC5622 Sensors, Signals & Health assessment at the University of Sydney. The technique, known as transcranial direct current stimulation (tDCS), uses weak electrical currents to modulate ongoing brain activity, and is a promising treatment for a range of neurological and psychiatric diseases. As the feasibility of administering tDCS at home has recently become an emerging area of research, there is a substantial need for a tDCS device which send data to the clinician in real time.
[Update 11/7/16 The video mentioned has been deleted.]
Lynne Malcolm: Colleen Loo says that this transcranial direct current stimulation treatment is best used for people with clinical depression who haven’t responded to other treatments. There are very few, if any, side-effects and some participants have even noticed benefits beyond changing their moods.
Colleen Loo: Yes, and this was very exciting. So when we did our first depression trial we were measuring things like memory and thinking…you know, it was just to be safe, to check these things. And one of the things we measured was we asked people to do a test which really showed you how quickly the brain was working. And as people went through the trial they were saying things like, ‘Gee, I don’t know what kind of stimulation I’m having, but it’s almost like my brain clears and I can concentrate and think so much more clearly after the stimulation.’
So we were very excited when we got the end of the study and we formally analysed the results of the formal test, that it showed exactly what people were saying to us, that after the act of stimulation the actual thinking speed was faster, and that has led our team to develop a whole parallel line of research of using TDCS to improve memory and thinking. So our main line of research is in treating depression, but I also have a very promising young researcher who is a clinical neuropsychologist, Dr Donel Martin, who is heading a whole program of research into using this to improve memory and thinking. For example, in people who are older and who are just starting to notice some changes in their memory and thinking.
Marom Bikson is CEO of Soterix Medical and Associate Professor at City College of New York in the Department of Biomedical Engineering. Marom is a distinguished tDCS scientist and prominent in the development of HD-tDCS. Download the interviewhere (zipped mp3). (Firefox users- there is an audio player here, but it’s displaying intermittently. Trying to track down the issue. In the meantime you can download the episode or open the page in another browser).
(We got a good forty minutes of interview in before the Skype gremlins caught up with us. I had to cobble an ending together.)
Perhaps depression studies are closest to FDA qualification for tDCS?
(Prediction is very hard, especially about the future – Yogi Berra.)
A device (NorDoc Smartstim) that can go to 4mA is being used in a smoking cessation trial? (Trial info indicates 2mA current dose.)
FDA tDCS approval would be device-specific at first. But would open the door to ‘me too’ mechanism, FDA 510(k)
HD tDCS can have multiple cathodes and or multiple anodes. An array of 4 small anodes splitting 2mA, for example (.5 mA each electrode), can function as an anodal ‘virtual pad’. Assumes cathode somewhere else on the body).
Image By Richard McKinley USAF
Tolerability is how tolerable in terms of side effects a medication is.
A Theory of tDCS (“Gross oversimplification”) As positive current flows into the cortex it passes neurons.
Because of the nature of neurons, this positive current depolarizes somas (cell’s body), increasing excitability, thereby increasing the functionality & plasticity of that region (hypothesis… “We really don’t know.”). Under the cathode, somas (cells) are being hyper-polarized – excitabilty decreases.
A synapse is a structure that permits a neuron (or nerve cell) to pass an electrical or chemical signal to another cell. Pyramidal neuron
Titration, also known as titrimetry, is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of an identified analyte.
TES Transcranial Electric Stimulation
“transcranial electrical stimulation” Merton and Morton 1980
“Priming the network in conjunction with applying tDCS makes a lot of sense, as a way to make the tDCS to do what you want.” (Co-priming – The idea that one would initiate an activity first, and THEN add tDCS.)