Electrical brain stimulation suppresses epileptic seizures in rats.

(HealthDay)–Researchers report that they have created a device that short-circuits epileptic seizures in rats.

The device, similar in design to an implantable defibrillator, is placed in the brain and responds only when seizures begin to occur, essentially interrupting the electrical activity of the seizures.

The self-regulating device electrically stimulates the brain at the beginning of a short but frequent type of seizure in rats and then automatically stops. The study was published in the August 10 issue of Science.

It’s like a game of ping pong,” explains study author Dr. Giorgi Buzaki, professor of neuroscience at New York University. Every time a ball comes toward you, you apply a disturbance pattern to knock it away.”

Epilepsy is a brain disorder that causes seizures that recur over a long period of time. According to the Epilepsy Foundation, it affects approximately 3 million Americans and is the third most common neurological disorder in the United States, after Alzheimer’s disease and stroke.

There are two types of seizures in epilepsy: minor seizures and major seizures. Small seizures last for a few seconds and may occur frequently, while major seizures are rare but are accompanied by severe muscle contractions and loss of consciousness.

Seizures are episodes of disturbed brain activity that cause changes in attention and behavior. Brain cells do not act in an organized fashion, but rather continue to fire. When the brain’s electrical system malfunctions, there is a surge of energy that causes impaired consciousness and muscle contractions.

Because this type of seizure occurs hundreds of times a day, researchers tested a new device against small seizures in rats. Because these seizures occur hundreds of times a day, the researchers were able to effectively test the system they designed against this huge volume of seizures. Normally, this device is not used to treat this type of seizure, as minor seizures are effectively treated with drugs.

In what Buzsaki describes as a simple closed-loop system, the firing of brain neurons produces a spike of neural activity, followed by a wave, which is detected by the device and only counterattacked when necessary. Called transcranial electrical stimulation, this system does not affect other aspects of brain function. Says Buzaki, “This system doesn’t prevent seizures, it just treats them immediately.” The stimulation reduced seizure length by about 60%.

In humans, two plates about the size of a pocket watch are placed in the skull, targeting the affected area of the brain. The electrodes are powered by an ultralight electrical circuit implanted in the skull, Buzaki explained.

The goal, Buzaki said, is to apply the system that worked in rats to people who have complex partial seizures–epileptic seizures that affect both sides of the brain and cause loss of consciousness. The device worked in rats, but the results may not be applicable to humans.

This type of seizure can also be caused by head trauma, brain infection, or stroke. The cause is usually unknown.

In 20 percent to 40 percent of people who have complex partial seizures, medications do not work and there is no treatment, Buzaki said. We don’t know exactly what kind of stimulation to give, or where in the brain to give it,” he explained.

Dr. Orrin Devinsky, director of the Epilepsy Program at New York University, said the research has great potential for treating epilepsy and other neurological disorders. The uniqueness of this technology is that it is a sophisticated way to identify the rhythm of the seizure itself and interrupt its cycle precisely,” he said. No existing deep brain stimulator can fine-tune the timing in this way.”

Debinski, who is not involved in the study, said the research could have applications for people with tremors, Parkinson’s disease, and even severe depression and other mental disorders.