THE DEFINITION OF EPILEPSY

April 28th, 2009

Although we hope that such gases will never be used, we have deliberately introduced the topic at this point to explain the difference between the diagnosis of ‘an epileptic seizure, and the diagnosis of ‘epilepsy’. It would clearly be ridiculous to label as ‘epileptics’ those soldiers who had convulsed on exposure to the nerve gas. The cause of their seizures is readily apparent, and, not only that, the tendency to convulse is present only in the presence of the nerve gas. Someone is said to suffer from epilepsy if he or she has a continuing tendency to epileptic seizures.

This example polarizes, as it were, the explanation, but there are many grey areas, some of which we explain here. Take for example the case of a young man who has a single seizure at the age of 19, after a rather-too-good office party at Christmas time. It would be justifiable to assume that alcohol played some part in the genesis of the seizure—but there were others who drank just as much who did not have a seizure. So we must presume that the man has a lower convulsive threshold than his colleagues. A single seizure is not considered sufficient to make the diagnosis of epilepsy, as, until time has passed, it will not be known whether or not this seizure will prove to be the first of others.

Doctors will make a diagnosis of epilepsy when they hear of more than one seizure of any type not associated with fever. Convulsions associated with illness. Clearly there is no difficulty in doing this if the time scale is short, but what do we call a man who has one fit at the age of 19 and another at the age of 80? It would seem a bit nonsensical to tell the elderly man that he had been an epileptic all his life, as we would be obliged to do if we followed rigidly the definition of ‘more than one non-febrile seizure’. Another problem—what do we call a woman aged 40, who has had ten seizures between the ages of 15 and 25? We cannot, unfortunately, say that she is a ‘woman cured of epilepsy’, as experience shows she is still slightly at risk from further seizures.

These examples clearly show that the label ‘epilepsy’ has to be applied with common sense. It is not one of those tidy diseases such as myocardial infarction, in which there is little argument about the heart attack or the coronary disease causing it.

These medical uncertainties are reflected in patients’ minds. After all, if a doctor cannot give a crystal-clear definition of a disease, how can the patient be expected to understand it? The uncertainties in peoples’ minds are compounded by a series of half-or un-truths that, perhaps because epilepsy is so common, are held in the collective imagination as folk lore—that epilepsy is inherited; that it begins in childhood; that it is always convulsive in nature; and that it is related in some ways to mental illness. Glimpses of this stereotype of epilepsy are seen in the clinic when a patient, or his relative, says ‘it can’t be epilepsy because . . . .’ We hope that this book will dispel some of these confusions.

Part of the difficulty in understanding about epilepsy is a hangover from the ideas of the great physicians of the nineteenth century. ‘Diseases’ were described—for example, Bright’s disease of the kidneys. Such diseases have proved unexpectedly more and more complex with further research. For example, Bright described the dilute urine containing protein, and changes associated with high blood pressure that are merely symptoms common to a number of processes resulting in chronic kidney failure.

With these comments in mind, an epileptic seizure should be regarded as a symptom—an event that is just one of the few ways that the brain has of reacting to untoward internal processes. The continuation of such reactions constitutes epilepsy. As to the causes of epilepsy, it is the doctor’s task to disentangle, if at all possible, the factors that result in seizures.

We have had some difficulty in deciding what to call the child or person with epilepsy. There are some who instinctively dislike the word—or label—’epileptic’. It is of course an adjective, and one does not talk about those with heart disease or multiple sclerosis as ‘cardiacs’ or ‘multiple sclerotics’. We admit, however, that those with diabetes seem quite happy to be known as ‘diabetics’. We find the word person too impersonal, but to write and read ‘a man, woman, or child with epilepsy’ takes too long, and to write each time ‘those with epilepsy’ seems archaic. We have avoided the use of the word patient, except in a medical context, as people with epilepsy should only become patients for brief moments in their lives. We therefore use whatever phrase seems most appropriate in the context.