Electrical brain stimulation (EBS) is a form of electrotherapy that uses electric current to stimulate neurons in the brain. The procedure is also referred to in some circles as focal brain stimulation (FBS). Electrical brain stimulation is used in neurosurgery, experimental research, and treatment of psychological disorders. Unconventional applications of electrical brain stimulation include the enhancement of certain cognitive skills.
The procedure was first introduced in the early 19th century when researchers began their study of the localization of brain function. This led to the discovery that nerves and muscles are electrically excitable. In the following century, the invention of stereotactic method and the development of chronic electrode implants helped in improving electrical brain stimulation.
Deep brain stimulation (DBS), a type of electrical brain stimulation, is a neurosurgical procedure that involves implanting two wires, lead and extension, and a stimulator similar to a pacemaker. The stimulator sends electrical impulses to the electrodes at the tip of the lead wire. DBS is an elective neurosurgical procedure performed by neurosurgeons that are trained in functional stereotactic techniques. The procedure is used for the treatment of Parkinson’s disease, obsessive-compulsive disorder (OCD), and dystonia, among other disorders.
Electroconvulsive therapy (ECT), another type of electrical brain stimulation, is a procedure that briefly induces seizures by applying electric current from the scalp to the brain. It is used to treat patients with schizophrenia, bipolar disorder, and other mental illnesses. Studies have also shown that ECT has a higher success rate in treating depression than any other form of treatment; it is used, however, only when all other options have been exhausted. ECT is usually administered in the course of six to 12 treatments, two to three times a week, and is generally followed by a series of medications.
Magnetic seizure therapy (MST) is believed to be a safer form of ECT. In ECT, the scalp and skull shunt the flow of electricity, limiting control over current spread. In MST, on the other hand, magnetic fields enter the brain unhindered, allowing better control over the area of stimulation and seizure initiation. It was developed to decrease the cognitive side effect of ECT through focal seizure induction in the prefrontal cortex.
Studies have found that electrical brain stimulation can enhance a person’s mathematical performance for up to six months without influencing other cognitive functions. Researchers use a form of electrical brain stimulation called transcranial direct current stimulation (TDCS), a noninvasive technique wherein a weak current is applied to the brain often over time to improve or diminish the activity of neurons. Other applications for TDCS in improving cognitive function are continuously being researched.