Consciousness in non-epileptic attack disorder.
Behavioural neurology January 1, 2011 DOI: 10.3233/ben-2011-0315 via PubMed
Summary
Non-epileptic attack disorder (NEAD) is a key condition to distinguish from epilepsy. This review examines clinical research on consciousness during non-epileptic attacks (NEAs) and places it within recent neuroscience and philosophy of mind debates. The authors argue that studies should differentiate between 'level' and 'content' of consciousness, as well as between 'phenomenal consciousness' and 'access consciousness'. Evidence shows great variability in NEA experiences, but in most attacks, phenomenal experience and vigilance are reduced less than in epileptic seizures involving consciousness impairment. Complete loss of consciousness is the exception, not the rule, and both patients and observers may overestimate consciousness impairments during seizures.
Study at a glance
| Characteristics | Review Peer reviewed |
|---|---|
| Citations | 23 |
| Key finding | In most non-epileptic attacks, phenomenal experience and vigilance are reduced to a lesser degree than in epileptic seizures with consciousness impairment, and complete loss of consciousness is the exception rather than the rule. |
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.