URGENT HEALTH & SAFETY CONCERNS
Total tDCS is posting this Public Service Announcement in response to the recent manufacture and public sale of “4mA” tDCS devices.
There is insufficient evidence proving the safety & efficacy of tDCS current levels above 2mA.
Research into the safety and efficacy of tDCS current levels above 2mA is extremely limited. So far we have only identified five studies, all of them preliminary and three of them including conflicts of interest significantly lowering their credibility.
We urge tDCS users to stick with tDCS devices that conform to the standard maximum current output of 2 milliamps (2mA).
Please take note that the very companies selling these devices provide no evidence of the safety or efficacy of high current levels. They are using you as their test subject. This is completely unethical, dangerous, and unacceptable. We urge tDCS users to stick with tDCS devices that conform to the standard maximum current output of 2 milliamps (2mA).
Experimenting with higher current levels is to be done in the laboratory, not at home on your body.
By choosing to use 4mA tDCS devices, you are unwittingly agreeing to be the subject of a corporate experiment, The handful of studies we’ve found are preliminary and many lack credibility.
Over the past decade alone, more than 4,000 studies have been published on Transcranial Direct Current Stimulation (tDCS). Do not quickly dismiss this figure, as it represents a remarkable level of investigative research, far surpassing that of most prescription medications on the market.
One outcome of this research has been the development of, for all intents and purposes, a set of International standards for safe, appropriate tDCS research. Early on, researchers concluded 2 milliamperes is the upper current limit for effective and safe tDCS stimulation
Overtime, a set of safety parameters were formed to protect tDCS research participants. The most important parameter was that applied current levels should not exceed 2 milliamps.
Overtime, safety guidelines were developed to protect tDCS research participants from harm. The most widely accepted guideline is that applied current levels should not exceed 2 milliamps. The reason for this decision was based on many factors, most importantly the negative side effects that have been documented with higher current levels.
One of the most widely accepted and strictly followed rule regarding tDCS research has been:
researchers have worked to create a uniform set of standards by which all further studies should adhere to. research, many articles have been published on the topic of creating a uniform set of standards by which all researcher should adhere to. Of these articles, as well as the thousands of research studies already conducted, have concluded two facts to be true:
- Currents <0.5mA can induce cortical excitability.
- 2mA is the upper limit required for effective and safe tDCS stimulation
“A weak(< 0.5 mA, 7 s) anodal scalp DC, alternated with a cathodal DC, depressed the excitability of the human motor cortex, providing evidence that a minimum electric field crosses the skull and influences the brain. Given the known effects of CNS polarization in animal experiments,1–4 our finding may lead to the application of weak scalp DC in therapy, possibly in disorders associated with abnormal motor cortical excitability.”
This volume of scientific research has helped unify researcher’s understanding of tDCS and the suggested parameters for its application, concluding 2 milliamperes of current is the upper limit for effective and safe tDCS stimulation.
One important outcome of such a volume of research has been, for all intents and purposes, a set of “International standards” for the application of tDCS. The most important and strictly followed standard being the upper limit of current to use; 2mA.
We would like to educate the public about “4mA” tDCS device and why we have deep concerns regarding these products.
We believe it’s pertinent to educate the public regarding the significant risks associated with “4mA tDCS devices”, and why we believe you should steer clear of such high levels of electric current.
Recently a few companies have begun marketing “4mA” tDCS devices, as apposed to the normal 2mA limit or tDCS. We believe it’s pertinent to educate the public as to the potential safety risks associated with using tDCS at such high level of current.
1) Study → Adaptive current tDCS up to 4 mA.
The most recent study involving tDCS current up to 4mA was published in August of 20191. It appears to have been funded by a Korean company named Ybrain, Inc. in collaboration with Marom Bikson of the City College of New York. Bikson is also the co-founder and CEO of Soterix Medical Inc,, a large company that also designs and markets neuromodulation devices and accessories. This creates an obvious conflict of interest, greatly undermining Mr. Bikson’s credibility in such research.
Ybrain, Inc.’s current product lineup includes a single tDCS device which is marketed solely to healthcare professionals. and is not available for direct purchase. Ironically, the device sticks to the industry standard maximum current output limit of 2mA. This leads one to wonder if they are experimenting the possibility producing a new product potentially in collaboration with Soterix. Regardless of the specifics, this study provided no clinical evidence regarding 4mA. The most important take away is that for the study, “special Ybrain electrodes” were used, not the standard 3×3″ sponge electrodes you see nearly every tDCS company selling. It is for these reasons collectively we have to discredit this study.
This study included a VERY small sample size (18), and only limited the scope to participants who had experienced their first-ever ischemic stroke more than 6mo prior, were in active in physical therapy, and most importantly, those patients whom had undergone and experienced results from Transcranial Magnetic Stimulation. In addition, all applicants were given MRI and TMS prior to receiving tDCS, and the severity of any symptoms experienced then set the baseline for any symptoms reported during the tDCS session! After the tDCS sessions, TMS was applied within the hour, and an MRI 3-4hrs later. As a final comment, the participants also engaged in simultaneous upper extremity therapy for 30 minutes. A 10/20 EEG cap was used and C3 C4 positioning was used. 5-7cm (2-2.8in) sponges with carbon backing were used from Soterix medical, of whom Marom Bikson is co-founder and CEO.
The below was taken from “Low intensity transcranial electric stimulation: Safety, ethical, legal regulatory and application guidelines”
Altogether, the conclusions from a previous study by Bikson et al. (2013) seem appropriate: ‘‘. . .Controlled investigation of tDCS for treating neuropsychiatric disorders or for neurorehabilitation should not be confused with improvised devices or practices that apply electricity to the brain without reference to established protocols . . . Experimentation outside established and tested norms may put subjects at risk. . . . Meddling with the tDCS dose is potentially as dangerous as tampering with a drug’s chemical composition. Painstaking efforts by researchers to understand the risks and benefits of tDCS should never be interpreted as encouraging such practices.”
Transcranial Direct Current Stimulation Post-Stroke Upper Extremity Motor Recovery Studies Exhibit a Dose–Response Relationship (2015)
An apparent meta-analysis documenting a dose dependent improvement in efficacy, cited in the abstract of (3).
Low intensity transcranial electric stimulation: Safety, ethical, legal regulatory and application guidelines 2017 Sept. Paywall – Biksom, No conclusive statement on safety above 2mA
A Computational Assessment of Target Engagement in the Treatment of Auditory Hallucinations with Transcranial Direct Current Stimulation. 2018 Feb Abstract- Biksom, READ FURTHER
FOUND IN SEARCH BUT NOT APPLICABLE:
- Adaptive current tDCS up to 4 mA.
- Safety and tolerability of transcranial direct current stimulation to stroke patients – A phase I current escalation study.
1) Extending the Parameter Range for tDCS: Safety and Tolerability of 4 mA Stimulation
Michael A Nitsche 1, Marom Bikson 2
Editorial published in Brain Stimul (journal) around May-Jun 2017
2) The Tolerability and Efficacy of 4 mA Transcranial Direct Current Stimulation on Leg Muscle Fatigability
Craig D Workman 1, John Kamholz 2, Thorsten Rudroff 1 2
3) Transcranial Direct Current Stimulation at 4 mA Induces Greater Leg Muscle Fatigability in Women Compared to Men
Craig D Workman 1, Alexandra C Fietsam 1, Thorsten Rudroff 1 2
NO DIFFERENCES OBSERVED