Table of Contents Author Guidelines Submit a Manuscript
Behavioural Neurology
Volume 24 (2011), Issue 1, Pages 95-106
http://dx.doi.org/10.3233/BEN-2011-0315

Consciousness in Non-Epileptic Attack Disorder

M. Reuber1 and M. Kurthen2

1Academic Neurology Unit, University of Sheffield, Royal Hallamshire Hospital, Sheffield, UK
2Swiss Epilepsy Centre, Zürich, Switzerland

Received 23 March 2011; Accepted 23 March 2011

Copyright © 2011 Hindawi Publishing Corporation and the authors. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Non-epileptic attack disorder (NEAD) is one of the most important differential diagnoses of epilepsy. Impairment of consciousness is the key feature of non-epileptic attacks (NEAs). The first half of this review summarises the clinical research literature featuring observations relating to consciousness in NEAD. The second half places this evidence in the wider context of the recent discourse on consciousness in neuroscience and the philosophy of mind. We argue that studies of consciousness should not only distinguish between the ‘level’ and ‘content’ of consciousness but also between ‘phenomenal consciousness’ (consciousness of states it somehow “feels to be like”) and ‘access consciousness’ (having certain ‘higher’ cognitive processes at one’s disposal). The existing evidence shows that there is a great intra- and interindividual variability of NEA experience. However, in most NEAs phenomenal experience – and, as a precondition for that experience, vigilance or wakefulness – is reduced to a lesser degree than in those epileptic seizures involving impairment of consciousness. In fact, complete loss of “consciousness” is the exception rather than the rule in NEAs. Patients, as well as external observers, may have a tendency to overestimate impairments of consciousness during the seizures.