Brain Stimulation Clinic
tDCS: Transcranial Direct Current Stimulation
Transcranial Direct Current Stimulation (tDCS) is a safe, non-invasive neuromodulation procedure which provides relief for treatment-resistant neurologic, psychiatric and chronic pain conditions. tDCS also improves memory, enhances learning and boosts . Effective, easy-to-do, inexpensive and without side effects, tDCS is performed at the outpatient clinic or, for the appropriate patient, is available for at-home use. tDCS is done as an add-on, adjuvant or stand-alone procedure. It provides benefit for patients who do not respond to conventional treatments. Learning is enhanced for healthy individuals, patients with disabilities and the elderly.
tDCS utilizes a weak, direct electrical current to generate polar fields which modulate the activity and excitability of neurons beneath the electrodes. tDCS is a procedure which affects brain plasticity, the ability of the nervous system to change functionally and structurally.
tDCS provides relief for chronic pain (migraine, fibromyalgia, neuropathic pain, complex regional pain syndrome,temporomandibular joint disfunction and pelvic pain), depression, bipolar disorder, tinnitus, stroke and the addictions. tDCS also improves cognitive functioning, memory and learning. tDCS is an exciting new procedure which can be used by itself or combined with pharmacological, physical and behavioral treatments.
tDCS is easy-to-do. Moist sponge electrodes are placed on the scalp and held in place with an elastic headband, overlying the targeted areas of the brain. There is no perceptible sensation or only a temporary, slight tingling under the electrodes. tDCS can be done comfortably sitting or lying down.
tDCS is performed in the outpatient clinic, or for appropriate patients, may be self-administered at home which improves convenience, reduces cost and allows for longer protocols.
tDCS: Mechnism of Action
tDCS is a neuromodulation technique. It involves passing an imperceptibly weak, (1-2 milliamps, 1/1000 of an amp) direct current to the brain via two sponge electrodes to influence brain function. The current passes from the anode to the cathode. The neurons under the anode (+) are depolarized which facilitates function and the neurons beneath the cathode (-) are hyperpolarized which inhibits function. Transcranial direct current stimulation is site-specific and is used to up-modulate or down-regulate targeted areas the brain. By inducing excitability changes during the stimulation, multiple tDCS procedures evoke prolonged modulation of neural activity. The prolonged after-effects induced by tDCS are sought for clinical therapeutic benefit. tDCS influences neuronal function by several different mechanisms including alteration of synaptic activity, modulation of membrane function outside the synaptic cleft, changes of vascular motility and reactivity, and neurochemical changes beneath the stimulating electrodes. The tDCS induced inhibition or excitation persists beyond the period of stimulation, resulting in therapeutic changes that can endure for weeks, months or longer.
tDCS compared to rTMS
Whereas tDCS delivers low-intensity electrical current to the scalp and underlying brain, repetitive transcranial magnetic stimulation (rTMS) utilizes electromagnetic induction to generate electric currents in the brain. In general, low-frequency rTMS and cathodal tDCS reduce, and high-frequency rTMS anodal tDCS enhance the excitability of neurons in the targeted cortical areas. Both rTMS and tDCS promote snaptic plasticity, producing long-term potentiation (LTP) and long-term depression resulting in similar clinical effects.
Compared to rTMS, tDCS is safer, easier to do and much less expensive. Unlike rTMS, tDCS is painless and can be self-administered by the patient at home. tDCS can also be used simultaneously with cognitive training, as it produces no scalp sensation.
Because of the electrode size, tDCS is less focal than rTMS. On the other hand, the relatively large size of the electrodes promotes a more robust response, facilitates targeting and compensates for individual anatomical variation.
tDCS is not ECT
tDCS should not be confused with electroconvulsive or shock therapy (ECT), where a much larger current of 600-1000 milliamps is applied to the entire brain. ECT is designed to trigger a grand mal seizure and must be done under a general anesthetic. Multiple induced seizures can relieve symptoms of severe depression. ECT produces significant side-effects, including memory loss and confusion, and therefore it is only used for patients with severe treatment-resistant depression.
Undesirable side effects of tDCS are limited to reddening or slight irritation of the skin under the electrodes. This is eliminated or significantly reduced by saturating the sponges with saline. There is no injury or harm to the brain. An is an extremely wide margin of safety based on laboratory, clinical and computational modeling studies.
The mission of the Brain Stimulation Clinic is to provide transcranial direct current stimulation to patients who are treatment-resistant to traditional and conventional therapies. The Brain Stimulation Clinic strives to make tDCS available and affordable for the suffering, treatment-refractory patient.
Clinical Application of tDCS
tDCS provides relief for central chronic pain syndromes including:
- migraine headache
- complex regional pain
- neuropathic pain
- temporomandibular joint disorder
- chronic daily headache
- post-stroke pain
- multiple sclerosis
tDCS provides relief for:
- cognitive function
- recovery from stroke