What is tDCS
tDCS explainer video outlining the basics of how the technology works. tDCS is a form of neurostimulation that uses a low electrical current. This current is used to specifically target different regions of the brain. Depending on the region of the brain that is targeted, tDCS can produce different results. The current used is a low-intensity direct current that does not trigger an action potential.
Transcranial direct current stimulation instead works by bringing a neuron closer to firing, also known as "priming" by facilitating the depolarization. The overall process is referred to as "neuroplasticity" which is the ability of the brain to reorganize itself and build/strengthen neural networks in response to an activity.
Consumer tDCS products are not medical devices and have not been approved by the FDA to diagnose, treat, cure, or prevent any disease. In the USA, the FDA status of tDCS is investigational. However, in Europe, transcranial direct current stimulation has received CE clearance for depression and chronic pain such as migraine and fibromyalgia. Transcranial direct current stimulation research is being done on aphasia, motor recovery, addiction, cognitive enhancement, and more.
Transcranial Direct Current Stimulation Overview
Transcranial Direct Current Stimulation (tDCS) is a form of non-invasive neurostimulation that delivers a constant low-level current to the brain through the use of electrodes typically placed on the head. This neuromodulation technique uses a steady current between 1 - 2 mA delivered through electrodes to targeted regions of the brain to modulate brain function. Using different electrode configurations, tDCS can be used to either excite or inhibit neuronal activity in the targeted region. Unlike transcranial magnetic stimulation (TMS), the current used in tDCS is not strong enough to trigger an action potential but rather affects the neurons resting membrane potential. When applying anodal (positive) stimulation, the electrode is used to facilitate depolarization of the neurons resulting in excitatory stimulation. Conversely, during cathodal (negative) stimulation, the electrode is used to induce hyper-polarization of the neurons resulting in inhibitory stimulation.
Electrode Mapping
The positioning of the electrodes is used to determine the flow of current through different regions of the brain. These different electrode placements are called montages. Depending on the montage used, different regions of the brain are targeted to elicit the various desired effects. To understand the electrode placements outlines in the available montages it is necessary to understand the International 10-20 EEG positioning system, further explained here. This system helps map out the locations on the head, allowing the user to correctly position the electrodes. When the electrodes are placed on the head they are held in place by headgear. This headgear is very important in ensuring a reliable and reproducible stimulation session. There are many options available but many users, including universities and clinics running trials, prefer the Caputron Universal Strap. This headgear provides ruler markings directly on the strap allowing you to quickly and accurately ensure your electrodes are placed in the correct location. Further information on the types of electrodes and how to properly care for them can be found on our Electrode Guide.
Electrode Placement
Conventional tDCS montages use two electrodes: the Anode electrode and the Cathode electrode. The Anode electrode has a positive voltage relative to the Cathode electrode. Current enters the body under the Anode electrode, flows through the brain, and exits the body at the Cathode electrode. By controlling the position of the anode and cathode electrode, the current flow through the brain can be targeted. Reliable current delivery and reproducible electrode placement are therefore critical for reproducible transcranial direct current stimulation outcomes.
As tDCS is an investigational technique, it is the responsibility of the user to determine the appropriate tDCS protocols and dose. While transcranial direct current stimulation is still investigational, research indicates that it has several advantages in the treatment of patients with a large variety of neurological and psychiatric disorders. tDCS safety is supported by literature to have common side effects limited to mild and reversible skin irritation when using standard tDCS protocols and guidelines.
What is a tDCS Device and Which tDCS Device Should I Buy?
They are special neurostimulation systems, which utilize a low-voltage electrical current to improve cognitive efficiency and wellness. In theory, they operate in a manner similar to giving a car a boost to help it perform at its peak; users equip themselves with the device, connected to special electrodes, to administer the current and stimulate key areas of the brain.
In regards to transcranial direct current stimulation. Caputron carries the largest selection of tDCS devices. Moreover, we only carry devices that have met certain quality standards and come from reliable manufacturers. We have compiled a detailed tDCS device comparison table that outlines the key features of the many devices we carry as well as those that did not meet certain standards. If you want the best transcranial direct current stimulation device year after year the Activadose tDCS Starter Kit.
Frequently Asked Questions About tDCS
What does tDCS help with?
Consumer tDCS devices are used to enhace brain function and general wellness. For medical use, tDCS is an investigational technology and not cleared for a medical indication by the FDA. Although it is still experimental, there have been several published studies to examine the results of transcranial direct current stimulation on various neurological conditions. Some examples are depression, anxiety, stroke, Parkinson's disease, chronic pain and much more.
What does tDCS feel like?
During tDCS, the user will feel a slight tingling sensation underneath the electrode. This feeling typically goes away after a few minutes as the skin becomes used to the sensation of stimulation.
How much does tDCS Cost?
Consumer tDCS devices range in from from $100 to $500. Research grade tDCS devices can cost between $1,500 to $30,000. Caputron has a tDCS device comparison table that provides pricing, specifications and reviews of all the tDCS devices available for home use.
What are the side effects of tDCS?
The side effects of transcranial direct current stimulation are still being researched but have been found to be minor and limited to electrode location. Side effects include skin redness and itchiness. Additionally, minor headaches, nausea and dizziness have been reported. The latter side effects have been shown to occur during sham (placebo) tDCS stimulation as well. When administered incorrectly, tDCS electrodes can cause slight burns. Hydrogel electrodes are not recommended for transcranial direct current stimulation
Is it normal to see a white flashing light during tDCS?
This is known as the phosphene effect and it is not dangerous. It occurs when the electrodes are placed too close to the eye and stimulate the optical nerve.
Is tDCS FDA Approved?
Currently, tDCS is not an FDA-approved treatment. In Europe, tDCS has been CE Marked for the treatment of depression and fibromyalgia.
How long is a tDCS session?
In most research studies a standard tDCS session will be between 20 - 30 minutes. It is best to refer to the specific study you would like to replicate for the most accurate information.
What is SHAM?
SHAM is just another word for placebo (fake). During a SHAM / placebo tDCS sessions. A user is made to believe they are receiving tDCS in order to form a control group for a research study.