Disorders of consciousness : clinical and ethical perspective

Disorders of consciousness are among the main consequences of severe brain injury. They are characterised by the disruption of the relationship between the quantitative (arousal, wakefulness) and the qualitative (awareness of the self and environment) aspects of consciousness. This includes conditions where a high level of arousal is not accompanied with retained awareness (and vice versa). An accurate diagnosis of patients with severe brain injuries who present with various forms of disorders of consciousness still poses a real clinical, scientific and ethical challenge. This paper describes those conditions as well as diagnostic criteria and behavioural tools commonly used for their discrimination. The authors discuss brain death, coma, vegetative state, minimally conscious state and locked-in syndrome. Ethical and prognostic issues associated with the diagnosis and treatment of such patients are also discussed. Moreover, a clear classification of disorders of consciousness is proposed, which is intended to eliminate some ambiguities in Polish nomenclature concerning this type of neurological disorders. Behavioural scales are standard clinical tools for bedside assessment of patients with disorders of consciousness. In this paper, we review several behavioural scales, and describe their diagnostic advantages and shortcomings. The JFK Coma Recovery Scale–Revised (CRS-R) appears to present high sensitivity and specificity of diagnosing disorders of consciousness. The use of scales, such as the CRS-R, along with neuroimaging approaches (which have been developing intensively in the recent years) may provide a way to obtain a complete and accurate diagnosis of disorders of consciousness. That is why translation of the CRS-R and its validation in Polish conditions might play an important role in the diagnosis of such patients in our country.