Epilepsy and violence: medical and legal issues.

A possible relationship between epilepsy and violence has been debated for over a century. The debate has taken on new importance because of the increasing use of the "epilepsy defense" in criminal cases. In this review the following issues are addressed: (1) Is epilepsy more common among violent criminals and patients? (2) Is violence more common among epileptics? (3) Can directed violence or aggression occur as part of an epileptic seizure? (4) What medical and legal criteria should be used to determine whether a specific violent crime was the result of an epileptic seizure? Answers to these questions may be summarized as follows. (1) There is a two- to fourfold greater prevalence of epilepsy in prisoners than in control populations, but the prevalence is similar to the prevalence in other lower socioeconomic populations from which most prisoners come. There is no greater prevalence of epilepsy in persons convicted of violent crimes than in other prisoners matched as controls. (2) There is no evidence that violence is more common among epileptics than among non-epileptics, and no evidence that violence is more common in patients with temporal lobe epilepsy than in those with other types of epilepsy. (3) Ictal violence is rare, and when it does occur usually takes the form of "resistive violence" as the result of physical restraint at the end of a seizure, while the patient is still confused. Violence early in a seizure is extremely rare, stereotyped, and never supported by consecutive series of purposeful movements. (4) Five criteria should be used to determine if a specific violent act was the result of an epileptic seizure: a. the diagnosis of epilepsy should be established by a neurologist with special competence in epilepsy; b. the presence of epileptic automatisms should be documented by the case history and closed-circuit TV-EEG; c. aggression during epileptic automatisms should be documented on closed-circuit TV-EEG; d. the aggressive act should be characteristic of the patient's habitual seizures; and e. a clinical judgment should be made by the neurologist as to the possibility that the violent act was part of a seizure.