tDCS is one of the neuromodulation techniques used for therapeutic purposes in neuropsychiatry. It is also known as microstimulation therapy. It is applied only at the physician's request in treatment-resistant neuropsychiatric cases. It works on the principle of stimulating the brain with low-intensity direct current through two electrodes, usually in the forehead area. It is aimed to stimulate some brain electrical activities and suppress some activities in the outer shell of the brain stimulated by direct current. Many studies have shown that neuropsychological and psychophysiological changes occur in the brain areas targeted by this method.
Mechanism of action
The mechanism of action is that the applied electric current regulates the nerve cells in the brain called neurons. Spontaneous nerve electrical activity is altered by tDCS. Of the two electrodes on the forehead, the anode, which is called anode, makes a positive charge in the brain area it affects, increasing activity. The negative electrode, called the cathode, gives a negative charge and suppresses the activity.
The device used in the treatment has CE certification.
Areas of use
Uses include depression, acute and chronic pain, dementia, post-stroke rehabilitation, substance abuse and some other neurological and psychiatric conditions.
Advantages
tDCS is prominent and advantageous in three areas:
- It has the advantage that it can be used as a drug-free treatment when there is a medical condition that prevents medication, such as elderly patients or those with organ failure, pregnant women, breastfeeding women, those who cannot tolerate medication.
- It is an adjunctive treatment for pain, post-stroke rehabilitation and depression. It strengthens the result to be obtained with medication alone.
- It is a short-term and painless treatment, there is no drug interaction, it does not harm the body.
Application
Before starting the sessions, the patient's blood pressure and pulse rate are measured in the first session, it is checked whether QEEG is taken, it is recorded in the records, the necessary documents are given and signed. Patients and their relatives are informed before the treatment and necessary written permissions are obtained.
It can be used in pregnant and breastfeeding women, but not in patients with pacemakers, metal implants in the head or ear tubes. The patient is asked once more about these medical conditions before the procedure is started. Since there is a rare risk of epileptic seizures, necessary precautions, including an ambu device, are taken.
The areas where the electrodes will be placed are cleaned with alcohol cotton. If there is a wound in the area, a new application area is determined.
The treatment is usually performed every day and lasts 20-60 minutes. Many people report a slight tingling-like discomfort during the application, but this sensation usually disappears in the 3-4th session. It is not a painful application. At the end of the sessions, a follow-up QEEG is performed to monitor the effect of the treatment and the physician evaluates the treatment result.
Side effects
tDCS has been administered to thousands of people in different countries around the world. No harmful effects have been reported. There may be mild irritation and redness at the site of application due to electrical stimulation. In rare cases, mild burns have been observed in this area.
Side effect rates reported in scientific studies are as follows:
slight tingling sensation (75%),
mild itching at the site of application (30%),
fatigue (35%) and headache (.8%).
Barriers to Implementation
Known epilepsy and the presence of an intracranial metal object close to the application area are barriers to psychiatric applications.
Effects
tDCS is known to temporarily increase cognitive skills in the human brain. For this purpose, it has been used in operations in the US army. This effect is most pronounced when applied to the frontal area of the brain, the dorsolateral prefrontal cortex. It has positive effects on decision-making skills, problem solving, learning and language skills. While these effects are short-term with a single session, they become more pronounced and longer lasting when the number of applications increases.
Many studies have concluded that it is particularly effective as an adjunct to medication in the treatment of depression.
Consult your physician for your specific use and for more detailed information.
Alternative Treatments
If tDCS treatment is not available, tTMU or ECT may be used. The appropriateness of these alternatives for the patient's medical and mental condition is determined in consultation between the doctor and the patient and/or the patient's relatives.
Possible Risks in the Absence of Treatment
If the recommended treatment is not carried out, there may be an aggravation of the existing disease, the treatment may take longer as a result of the aggravation, and the patient may be at risk of harming himself/herself and/or others due to his/her mental state.
Duration of Treatment
Generally, 20 sessions are performed. Sessions are repeated every day unless otherwise stated. Sessions can be repeated in follow-ups if the doctor deems appropriate. In this case, you will be informed separately. In each tDCS session, the time from the patient's entry to the unit to the exit is 25-35 minutes.
References:
- Nitsche MA, Paulus W. Excitability changes induced in the human motor cortex by weak transcranial direct current stimulation. J Physiol 2000;527(Pt 3):633-639.
- Fritsch B, Reis J, Martinowich K, et al. Direct current stimulation promotes BDNF-dependent synaptic plasticity: potential implications for motor learning. Neuron 2010;66(2): 198-204.
- Nitsche MA, Liebetanz D, Antal A, Lang N, Tergau F, Paulus W. Modulation of cortical excitability by weak direct current stimulation-technical, safety and functional aspects. Suppl Clin Neurophysiol 2003;56:255-276.
- Nitsche MA, Seeber A, Frommann K, et al. Modulating parameters of excitability during and after transcranial direct current stimulation of the human motor cortex. J Physiol 2005;568(Pt l):291-303.
- Kuo MF, Paulus W, Nitsche MA. Boosting focally-induced brain plasticity by dopamine. Cereb Cortex 2008;18(3):648- 651.
- WagnerT, Fregni F, Fecteau S, Grodzinsky A, Zahn M, Pascual- Leone A. Transcranial direct current stimulation: a computer- based human model study. Neuroimage 2007;35(3):1113-1124.
- Miranda PC, Lomarev M, Hallett M. Modeling the current distribution during transcranial direct current stimulation. Clin Neurophysiol 2006;117(7): 1623-1629.
- BiksonM,DattaA,ElwassifM.Establishing safety limits for transcranial direct current stimulation. Clin Neurophysiol 2009; 120(6): 1033-1034.
