Forced normalization at the interface between epilepsy and psychiatry.

In 1953, Landolt described a group of patients with poorly controlled epilepsy who had psychotic episodes associated with remission of their seizures and disappearance of epileptiform activity on their EEGs. He called this phenomenon "forced normalization." Since then, neurologists and psychiatrists have been intrigued by this phenomenon, and although it has been also reported by others, its existence continues to be the source of much debate. In this article, we review the clinical characteristics and potential pathogenic mechanisms of forced normalization and illustrate the complexities inherent in reaching this diagnosis, as well as its differential diagnosis in two representative cases.