[Psychogenic non epileptic events and frontal lobe seizures]

The distinction between epilepsy and psychogenic non epileptic events or seizures (PNES) has been made since the middle of the first millennium (B.C.) Psychogenic non epileptic seizures (PNES) resemble epileptic seizures presenting as paroxysmal, involuntary, time-limited alterations in behaviour, motor activity, autonomic function, consciousness, or sensation. However, unlike epilepsy, NES do not result from epileptogenic pathology and are not accompanied by an epileptiform pattern during an ictal electroencephalogram (EEG). This article reviews the concept of psychogenic non epileptic events, its contemporary assessment including diagnostic and therapeutic issues, as well as the complexity related to various nosological topics. The PNES are a hallmark of an ancient illness, hysteria, which wanders between the somatoform and the dissociative disorders in the contemporary classification systems. With the availability of video electroencephalography (video-EEG), it has been possible to define more strictly the limits between epileptic and non epileptic disorders, avoiding unnecessary and even iatrogenic and invasive treatments. We also describe the clinical presentation and diagnosis of frontal lobe seizures, especially those that might be mistakenly diagnosed as psychogenic events. The frontal lobes are the largest cortical region from which seizures can arise; complex and/ or bizarre behavioural clinical presentations are frequent. In addition, some patients with epilepsy can also present non epileptic events.