Psychogenic nonepileptic seizures

Abstract

This review by three established clinicians/researchers and two 'rising stars' in the field of psychogenic nonepileptic seizures (PNES) describes recent progress in this area and highlights priorities for future research. Empirically testable models of PNES are emerging but many questions about the aetiology of PNES remain unanswered at present. Video-EEG has made it possible for doctors to make secured diagnoses of PNES in more cases. However, unacceptable diagnostic delays and misdiagnoses are still common. Non-specific EEG changes are often misinterpreted as evidence of epilepsy. A better understanding of the symptomatology of PNES may allow earlier and more accurate diagnoses using self-report questionnaires. The communication of the diagnosis and the engagement of patient in psychological treatment can be difficult. A recent pilot RCT has demonstrated the effectiveness of a psychological treatment in reducing seizures in the short term, but longer-term effectiveness is yet to be demonstrated.

Introduction

Psychogenic nonepileptic seizures (PNES) are episodes of altered movement, sensation, or experience resembling epileptic seizures, but not associated with ictal epileptiform discharges in the brain but which, instead, have a psychological origin. In the current diagnostic manuals most PNES are categorized as a manifestation of dissociative or somatoform (conversion) disorder [1], [2]. This means that they are interpreted as an involuntary response to emotional, physical, or social distress. It is appropriate to discuss PNES in this special issue because they are one of the commonest differential diagnoses of epilepsy and are typically diagnosed by physicians specializing in the treatment of seizures. They are by far the most common nonepileptic condition diagnosed in epilepsy (video/EEG) monitoring units. The fact that research interest in PNES has grown exponentially since the introduction of video/EEG monitoring is encouraging for the future. However, the impressive number of publications on this topic in the last two decades also demonstrates there still are many questions to answer. In 2 Diagnostic process, 2.1 Selim Benbadis, 2.1.1 Diagnostic challenges at the stage of clinical suspicion, 2.1.2 The issue of EEG interpretation errors, 2.1.3 Diagnostic challenges at the stage of confirmation by video/EEG monitoring, 2.1.4 Specific difficult situations, 3 Treatment issues, 3.1 W. Curt LaFrance, Jr., 3.1.1 Presentation of the diagnosis, 3.1.2 Further treatment, 4 Questions about the nature and experience of psychogenic nonepileptic seizures, three experienced clinicians who have followed the developments of PNES research closely over this period discuss some questions that future research needs to address most urgently. Selim Benbadis focuses on topics related to the diagnostic process, Curt LaFrance writes about issues related to treatment, and Markus Reuber discusses the nature and experience of PNES. In 5 Promising Areas of Research and Young Investigators, 6 Promising Areas of Research and Young Investigators, two “rising stars” describe how they got involved in research in this area and what their plans are for the future: Tanvir U. Syed focuses on his work aiming to reduce diagnostic delay, and Richard J. Brown, on his development of a psychological model for PNES.