tDCS is one of the neuromodulation techniques used for therapeutic purposes in neuropsychiatry. It is also known as micro-stimulation therapy. It is administered only at the physician’s discretion in treatment-resistant neuropsychiatric cases. It generally works by stimulating the brain with low-intensity direct current via two electrodes placed on the forehead. The goal is to activate certain electrical brain activities and suppress others in the cerebral cortex stimulated by the direct current. Numerous studies have demonstrated that this method induces neuropsychological and psychophysiological changes in the targeted brain regions.
Mechanism of Action
The mechanism of action involves the applied electrical current modulating nerve cells in the brain known as neurons. The brain’s spontaneous electrical activity is modified through tDCS. The anode—one of the two electrodes placed on the forehead—imposes a positive charge on the targeted brain area, thereby increasing activity. The cathode, the negative electrode, imposes a negative charge and suppresses activity.
The device used in treatment is CE-certified.
Applications
Applications include depression, acute and chronic pain, dementia, post-stroke rehabilitation, substance use disorders, and certain other neurological and psychiatric conditions.
Advantages
tDCS stands out and offers advantages in three key areas:
- It is an advantage that it can be used as a non-pharmacological treatment when there is a medical condition that precludes medication, such as in elderly patients, those with organ failure, pregnant women, breastfeeding women, or those who cannot tolerate medication.
- It serves as an adjunct therapy to medication in the treatment of pain, post-stroke rehabilitation, and depression. It enhances the results that would otherwise be achieved with medication alone.
- It is a short-term, painless treatment with no drug interactions and no harmful effects on the body.
Application
Before starting the sessions, the patient’s blood pressure and pulse are measured during the first session; it is verified whether a QEEG has been performed; this information is recorded; and the necessary documents are provided and signed. Prior to treatment, the patient and his family members are informed, and the required written consents are obtained.
It can be used in pregnant and breastfeeding women; however, it cannot be administered to patients with pacemakers, intracranial metal implants, or ear tubes. Before starting the procedure, the patient is asked about these medical conditions once more. Although rare, necessary precautions—including the use of a resuscitation bag—are taken due to the risk of an epileptic seizure.
The areas where the electrodes will be placed are cleaned with alcohol swabs. If there is a wound in the area, a new application site is identified.
Treatment is typically performed daily and lasts 20–60 minutes. Many people report a mild, tingling-like discomfort during the session, but this sensation usually disappears by the 3rd or 4th session. The procedure is not painful. Once the sessions are complete, a follow-up QEEG is performed to monitor the treatment’s effectiveness, after which the physician evaluates the treatment outcome.
Side Effects
tDCS has been administered to thousands of people in various countries around the world. No harmful effects have been reported. Mild irritation and redness may occur at the application site due to electrical stimulation. In rare cases, mild burns have been observed in this area.
The rates of side effects reported in scientific studies are as follows:
mild tingling sensation (75%),
mild itching at the application site (30%),
fatigue (35%), and headache (0.8).
Contraindications
A history of epilepsy and the presence of an intracranial metal object near the treatment site are conditions that preclude psychiatric treatment.
Effects
It is known that tDCS temporarily enhances cognitive abilities in the human brain. For this purpose, it has been used in operations by the U.S. military. This effect is most pronounced when applied to the frontal region of the brain, specifically the dorsolateral prefrontal cortex. It has positive effects on decision-making, problem-solving, learning, and language skills. While these effects are short-lived after a single session, they become more pronounced and longer-lasting as the number of sessions increases.
Numerous studies have concluded that it is effective as an adjunct therapy, particularly in the treatment of depression.
Consult your doctor for personalized use and more detailed information.
Alternative Treatments
If tDCS treatment is not performed, tTMU or ECT may be administered. The suitability of these alternatives for the patient’s medical and mental condition is determined through a discussion between the doctor and the patient and/or the patient’s family members.
Potential Risks If Treatment Is Not Administered
If the recommended treatment is not administered, the current condition may worsen, leading to a longer treatment duration; there is also a risk that, due to the patient’s mental state, he may harm himself and/or others.
Duration of Treatment
Generally, 20 sessions are conducted. Unless otherwise specified, sessions are repeated daily. Follow-up sessions may be repeated at the doctor’s discretion. In such cases, additional information will be provided. Each tDCS session lasts 25–35 minutes, from the patient’s arrival at the unit until departure.
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 1):291-303.
- Kuo MF, Paulus W, Nitsche MA. Enhancing focally induced brain plasticity with dopamine. Cereb Cortex 2008;18(3):648–651.
- Wagner T, 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.
- Bikson M, Datta A, Elwassif M. Establishing safety limits for transcranial direct current stimulation. Clin Neurophysiol 2009; 120(6): 1033-1034.
