Studies in traumatic epilepsy. I. Factors influencing the incidence of epilepsy after brain wounds.

There is no doubt that epilepsy presents a valuable means of studying cerebral function. Apart from the problem of what factors cause the abnormal neuronal discharge which constitutes the fit, the pattern of attack can give information about the function of the area concerned when the site of injury is known. For this purpose the study of cases of post-traumatic epilepsy following the small penetrating brain wounds of modern warfare is of special value. In this type of injury high velocity metal fragments often cut into the brain without disturbing consciousness, or " explode " a group of bone fragments for a distance of a few centimetres into the brain, while the metal fragment glances away. In either case a highly localized lesion often results, and thanks to the advances of surgery and of the use of antibiotic drugs, most of these wounds were quickly rendered sterile and healed by first intention after debridement. The evidence for localization in these small wounds is often precise, and this can be correlated with the content and sequence of events in an epileptic fit. When the wound produces a recognizable neurological deficit, the behaviour of this during the attack can also provide information. For all these reasons traumatic epilepsy has been a constant source of interest, and after the first world war gave rise to many special studies both as regards the incidence of post-traumatic epilepsy and the clinical features of the fits. The study presented here is concerned with a follow-up of 820 surviving cases of penetrating brain wound suffered during the second world war by British service personnel. During the second war a special effort was made to collect accurate information of cases of brain wounds. The records of this group of cases are carefully preserved and a follow-up system has been kept in operation ever since, by means of a Head Injury Advice Bureau. The records must to some extent depend on postal enquiry, which includes a detailed questionnaire about the fits completed by witnesses, but doubtful cases are re-admitted for further study, and Ministry of Penisons documents are available for consultation. The evidence available as to the nature of faints or fits has been sifted by the writers themselves, and a decision as to the nature of " attacks " has been made on their clinical features, as this is still by far the most reliable method of diagnosis. Electroencephalographic evidence was excluded from the assessment.