Transcranial Direct Current Stimulation (tDCS)

Transcranial Direct Current Stimulation (tDCS)

Brain powerTranscranial Direct Current Stimulation (tDCS) is a noninvasive technique which uses constant, low current delivered directly to the brain area of interest through two small electrodes placed on the scalp. Research in the last decade demonstrated that tDCS can increase cognitive performance on a variety of tasks, depending on the region of the brain being stimulated. Increasingly tDCS is used as an applied neuromodulation method to enhance language and mathematical ability, attention span, problem solving, memory, and coordination.

The basic design of this method has been around for over 100 years. Back in the 19th century, several psychiatrists conducted studies on depressive and psychotic patient groups. In the first half of the 20th century, with the introduction of pharmacological agents the interest in this method faded away. There was a brief rise of interest in the 1960s when it was shown that the stimulation could affect brain function by changing the cortical excitability. However, research in this area did not continue, as pharmaceutical agents proved to be a more effective and simple method of therapy. In the early 2000s electrical stimulation was rediscovered and has emerged as one of the major tools to induce neuroplastic cortical excitability changes in the brain.

tDCS works by sending a constant and low electrical direct current (1-2 milliamperes) between two electrodes. When current flows through brain tissue, the effect depends on polarity, with anode (positive electrode) exciting the underlying cerebral cortex and cathode (negative electrode) decreasing the excitability of neurones underneath. This change of neuronal excitability leads to alteration of brain function, which can be used for therapeutic purposes. The most important aspect of tDCS is its ability to achieve long-lasting cortical changes even after the stimulation is ended. The duration of this change depends on the therapy duration, session duration and intensity of stimulation. It is believed that tDCS changes the membrane excitability of neurones and promotes long-term synaptic changes, such as long-term potentiation (LTP) and long-term depression (LTD).

In addition to its increasing application for various cognitive enhancements, tDCS is also researched or used as a therapeutic tool in clinical disorders, such as stroke recovery, depression, Parkinson’s disease, epilepsy, tinnitus, Alzheimer’s disease, migraine aura symptoms, fibromyalgia and central neuropathic pain. As more results from clinical studies emerge, tDCS will become a routine therapeutic tool, at least in combination with drug therapy or other neuromodulation techniques, such as repetitive transcranial magnetic stimulation (rTMS).

In our clinic we utilise the potential benefits of tDCS in a number of cognitive and neurological disorders.