tDCs has a significant effect on targeted brain areas. Each device has a positively (anode) and negatively (cathode) charged electrode through which the electricity flows, creating a circuit. We can use tDCS to regulate brain activity by increasing the activity of neurons (if there is reduced functioning in a certain brain area) or decreasing the activity of neurons (in case of increased brain activity). Thus, there is Anodal stimulation which excites neuronal activity, while Cathodal stimulation inhibits or reduces neuronal activity. This is helpful in regulating imbalances in neuronal activity, which is a mediating factor in psychiatric illnesses. One of the most important aspects of tDCS is its ability to achieve and cause sustained brain activity changes even after the treatment has ended.
The duration of this change depends on the length of stimulation as well as the intensity of current.
Transcranial Direct Current Stimulation tDCS is a Non-Invasive Brain Stimulation technique in which a device sends a small Direct Current (DC) derived from a small 9V battery across the scalp to modulate brain function. Electrodes (sponges soaked in salt water) are placed over certain parts of the head. The electrodes are held in place using a headband. The direct current flows through the electrodes, penetrating the scalp, creating a flow of electrical current in the brain. Usually a slight itching or tingling sensation can be felt on the scalp in the first few seconds. The weak currents enhance brain activity under the site of the electrodes.
tDCS is considered to safely induce reversible changes in neuron excitation and can induce benefits in various conditions, such as:
tDCs has a significant effect on neurological activity in the targeted areas of the brain. Each device has an Anodal electrode and a Cathodal electrode. The Anodal electrode is the positively charged electrode and the Cathodal electrode is the negatively charged electrode. The current flows from the Cathodal electrode to the anodal electrode, creating a circuit.
Thus, there are two types of stimulation with tDCS -Anodal and Cathodal stimulation. Anodal stimulation acts to excite neuronal activity while Cathodal stimulation inhibits or reduces neuronal activity. In other words, tDCS stimulation changes brain function either by causing the neuron resting membrane potential to depolarize or hyper polarize. When positive stimulation is delivered, the current causes a depolarization of the resting membrane potential, which increases excitability of brain cells and allows for more spontaneous cell firing.
Negative stimulation causes a hyper polarization and decreases or inhibits neuron function. One of the most important aspects of tDCS is its ability to achieve and cause sustained cortical (brain activity) changes even after the stimulation is ended. The duration of this change depends on the length of stimulation as well as the intensity of current.
Safety, ease of use and general absence of severe side effects are the unique features of tDCS. This significantly reduces costs, increases accessibility to treatment, gives the option of longer treatment protocols and continuity of treatment is more easily maintained.
tDCS is an extremely safe technique. The most common report by clients is that of a tingling sensation under the electrodes. This transient sensation is present during and shortly after the period of stimulation for a few seconds and has no adverse effects or risks. Almost all clients have reported the sensation as quite mild.