Pacemaker may avert epileptic seizures, say US researchers

· Neurological device set for trials this summer
· Implant could be used to treat other disorders

Scientists in America have developed a treatment for epilepsy which they say could help millions of people with the condition. Researchers at the Massachusetts Institute of Technology hope to try out the neurological pacemaker, which detects and treats seizures before they happen, this summer.

"Unlike so many other illnesses where we can easily measure what's going on, epilepsy has been difficult to understand," said Professor John Guttag of MIT, who is supervising the project. "It's one of the main reasons there has been so much of a stigma attached to the condition - for centuries epileptics were even thought to be possessed by the devil."

The new procedure is based around an existing treatment known as vagus nerve stimulation (VNS). A small electrical device is planted in the body which sends regular electrical pulses to the brain, usually one every five minutes throughout the day. Experts at MIT say they have developed a method of analysing the brain's activity which can be used alongside VNS to prevent seizures from occurring.

By using electrodes attached to a cap, the system can monitor neurological activity and determine when an episode is likely. A message is then sent to the VNS implant, which sends a specific shock to prevent the incident, rather than the scatter-gun of electric shocks currently used.

Researchers say this will dramatically reduce the number of pulses sent to the brain and more effectively control epilepsy.

MIT researcher Ali Shoeb, who developed the system, and Steven Schacter, an expert in VNS, say they are preparing to test the procedure on a handful of patients over the next few months. Tests using existing data have encouraged them to think that success could lead to much wider adoption of VNS as a treatment for neurological problems.

Around 456,000 people have epilepsy in Britain, a third of whom cannot be treated with medication. Even those who can use medical controls are often plagued with unpleasant side-effects. Nerve stimulation has proved a successful alternative, with around two-thirds of all patients experiencing significant improvements.

Although VNS therapies involve a surgical procedure the success rates are high, and non-invasive diagnosis could not only revolutionise the way that epilepsy is treated, but also be applicable to a number of other neurological disorders.

There are some similarities to deep brain stimulation techniques which are being developed to help stop the symptoms of Parkinson's disease or severe depression, but these involve placing electrodes directly into the brain.

Experts say that if the new analytical technique is successful, it could provide similar kinds of relief without being so surgically invasive.

"All research has to be welcomed because we're still trying to understand exactly what is happening in epileptic seizures," said Margaret Thomas, a spokeswoman for the National Society for Epilepsy. "Vagus nerve stimulation works for some people but not everyone - but we are looking forward to the results of any clinical trials."

The team behind the new system say they are still some way from reaching the public, and each device will need to be tailored to the individual patient. "At the moment we have developed a diagnostic tool," said Professor Guttag. "But there will be some serious development work to make it small and portable, not in the sense of needing a scientific breakthrough but lots of hard engineering."