The group of neurological disorders known as epilepsy not only cause disruptive, alarming seizures, but those seizures also tend to increase in frequency and severity over time. While the majority of patients can gain some control of their condition via medication or surgery, approximately 30 percent cannot. Now, however, help may be on the way ... in the form of tiny pieces of silk implanted in the brain.
The silk is designed to store and subsequently release adenosine, a nucleoside that has been shown to decrease neuronal excitability and thus decrease seizures – studies have suggested that epileptics may have abnormally low adenosine levels. The substance is continuously released from the implant over the course of 10 days, after which the biodegradable silk harmlessly dissolves into the body.
A team of scientists from Portand, Oregon’s Legacy Research Institute, Oregon Health and Sciences University (OHSU) and Tufts University in Boston experimented with placing the implants in the brains of rats that were already in the early stages of epilepsy. Although the animals weren’t completely cured of their disorder, they did proceed to experience a four-fold reduction in seizures.
One specific type of epilepsy involves the formation of new excitatory circuits in an area of the brain where seizures often originate – a process known as mossy fiber sprouting. When compared to a control group of epileptic rats that didn’t receive the implants, the treated rats showed significantly less sprouting, and continued to so up to three months after the 10-day treatment.
Although the implants appear to be safe for rats, the scientists still need to find out how safe and effective they are for humans. They also have to determine the optimum dosage and release duration of the adenosine, along with establishing how long the effects last. Still, it is hoped that the implants will one day see therapeutic use.
“Clinical applications could be the prevention of epilepsy following head trauma or the prevention of seizures that often — in about 50 percent of patients — follow conventional epilepsy surgery,” says Dr. Detlev Boison of Legacy Research Institute and OHSU. “In this case, adenosine-releasing silk might be placed into the resection cavity in order to prevent future seizures.”
Source: National Institutes of Health