Most people with epilepsy live normal lives, controlling their condition with drugs. But for 400 a year death can occur suddenly and inexplicably. A Pounds 220,000 study will now try to discover why. Geoff Watts reports.
If we read in the registrar-general's report for 1999 that 2,406 deaths were due to epilepsy, we get no definite idea as to the real cause of death and cannot tell whether the patients died directly as a result of the fit or in a quite different manner. Indeed, the only proper conclusion to be drawn is that an individual who was epileptic, among other faults, is dead."
That paragraph, taken from a back copy of The Lancet, includes one deliberate mistake: the year. The date should read 1864. But, according to Jane Hanna, director of the charity Epilepsy Bereaved, things have not changed all that much.
"What came through when we had a gathering of experts in 1996 was that the problem of death in epilepsy was recognised at the end of the last century. Then the subject got lost. I think the assumption was that the problem no longer existed because of the development of effective anti-epileptic medication."
Any death from epilepsy is distressing, but what most upsets the supporters of Epilepsy Bereaved is sudden unexpected death in epilepsy (Sudep). Of the 300,000 people in Britain, with epilepsy, 70-80 per cent find that their illness can be well controlled by drugs. But epilepsy still causes the death of about 1,000 individuals each year. Some of them drown or perish in other accidents directly attributable to a seizure. Others have an episode of the prolonged and threatening type of fit known as status epilepticus. But there remains maybe 400 that are unexpected and inexplicable - a problem into which the government has recently agreed to fund the first thorough national investigation.
"These people may have a single seizure, often quite a short one, and possibly only partial," says David Fish, professor of neurology at the National Hospital in London. "They don't fall to the ground. They may just go blank or become confused for a few minutes. Then, suddenly, they die." It can happen at night while they are in bed. Either way, nothing shows up at autopsy.
Research has already identified a number of possible mechanisms, three of which Professor Fish picks out as the mostly likely. They are not mutually exclusive.
"If you have an electrical storm in the brain and it spreads to areas that control heartbeat, it's easy to understand how you might die. Another possible mechanism is that the electrical storm could spread to the part of the brain responsible for respiration. An interruption in breathing is quite common in seizures. Getting on for half of those who have them stop breathing for a significant time, maybe 20 or 30 seconds. Or there's a third possibility. You might stop breathing because of the electrical storm, then become short of oxygen, and then your chin might flop down and block your airway."
Studies already carried out have shown that some people are more at risk than others. "The biggest risk factor by far is the frequency of seizures," says Professor Fish."Anyone with more than 50 in the previous year has something like a 20-fold increased risk of death compared with someone who has had no seizures in that time. People with bigger seizures are also more at risk. And you are more likely to have a problem if you are in the age range from older adolescent to young adult than if you are a child or elderly."
Someone with severe epilepsy resistant to drugs and attending a specialist centre might have an annual risk of one in 100. For someone with well-controlled illness it might be more like one in 1,000.
The Department of Health, acting through the National Institute for Clinical Excellence, has awarded Epilepsy Bereaved a grant of Pounds 220,000 to arrange for an audit of epilepsy-
related deaths. Each of the team of five auditors will spend up to a day going through case notes and filling out long and detailed questionnaires. It is unusual to hand the coordination of a scheme such as this to a voluntary support group, a role it has won by the part it played in campaigning for the study to be carried out.
The data will be collated and analysed by another team member, based at the Royal College of Pathologists. By studying every aspect of the patients' health and the way their care was handled, whether in hospital or in general practice, the scheme should reveal whether anything can be done to minimise the risk of future Sudeps.
Death for this reason is often compared with another disorder, sudden infant death syndrome. The two share the same quality of arbitrariness; the unanswered questions nag destructively at the mind.
"I can see how the impact on families can be similar in quite a lot of ways," says Professor Fish. "Things are going along quite well. Then, suddenly, it's all over. In both situations you are bound to ask yourself if anything could have been done to prevent what has happened."
Jane Hanna from Epilepsy Bereaved also sees the parallel. "The isolation of the relatives mirrors the isolation of families who experienced cot deaths maybe 30 years ago, before that began to interest the public."