Epileptics could be given advance warning of oncoming seizures, up to days before they occur, thanks to information gathered from new brain implants. A recent study looks like it may well represent an important breakthrough after researchers were able to forecast the storms of electrical activity that erupt in the brains of epilepsy sufferers. These ‘storms’ can cause hallucinations, convulsion and potentially fatal loss of consciousness.

Vikram Rao of the University of California, San Francisco, who led the study, explains:

“For 40 years efforts to predict seizures have focused on developing early warning systems, which at best could give patients warnings just a few seconds or minutes in advance of a seizure. This is the first time anyone has been able to forecast seizures reliably several days in advance, which could really allow people to start planning their lives around when they’re at high or low risk.”

The research team yesterday published their findings in The Lancet Neurology journal, detailing the development of a small device implanted just beneath the scalp, flush with the top of the skull. From the device, the researchers were able to sink wires deep into the areas of the brain where the electrical activity that leads to seizures takes place.

The device then works in a way similar to a pacemaker. It monitors the brain’s electrical activity and emits pulses of electrical stimulation when unusual activity is detected. This, studies indicate, can help to head off seizures in some patients who do not respond to drugs-based treatments. However, NHS England says more evidence of the effectiveness of the new treatment needs to be gathered before it might be made available on the NHS.

The research scientists who worked on the study believe that one day patients wearing the implants might be able to receive warning forecasts they are entering a high-risk period for seizures, up to days in advance. Signals would be sent from the device to a wireless hub which could then potentially send an alert to a smartphone app.

A similar device, the Neurospace RNS System, has already been recording the brain activity of epileptics for years, monitoring electrical activity as they get on with their day-to-day lives. Analysis of the data generated by 18 patients has alerted researchers to the fact seizures may be far from random.

Data from these patients was used to build a statistical tool. Cycles of “brain irritability” were identified which seem to predict that a seizure may be more likely over the coming period. Once this pattern of cause and effect was tracked over enough instances, the tool was able to forecast when the risk of seizure was high. This forecasting was then tested, based on data from another 157 patients.

The findings were that in 40% of cases, seizures were predictable up to several days in advance. The system was able to pinpoint periods during which the chances of a patient having a seizure were 10 times higher than normal.

There is no guarantee a forecast seizure will actually occur. And what triggers the storms of electrical activity in the brain that appears to cause them is also still not known. However epilepsy patients report that triggers often seem to include stress, a lack of sleep and alcohol.

Accurate forecasting of seizure risk could also be used to allow neurologists to adjust patients’ medication throughout cycles. Doses could be lowered outside of danger periods, and increased as the likelihood of a seizure rises. This would help minimise the side-effects of medications.

Professor Rao explained:

“Our findings in this study give me hope that I may some day be able to tell [a patient] that based on her brain activity, she has a 90 per cent chance of a seizure tomorrow so should consider avoiding triggers.”