Behavioral assessment and diagnosis of disorders of consciousness

Abstract

Accurately diagnosing patients with a disorder of consciousness represents a real challenge. The recovery of consciousness is usually gradual, sometimes marked by clear signs of consciousness, but more often these signs are subtle. The assessment of residual cognitive functioning is complicated by vigilance fluctuations, motor deficits and other confounding factors. The knowledge of diagnostic criteria and the use of valid and sensitive standardized scales are therefore essential to establish a precise diagnosis. In this chapter, we will present the main disorders of consciousness (i.e., brain death, coma, vegetative state and minimally conscious state) that can occur in severely brain-injured patients and the commonly used behavioral instruments for the assessment of consciousness.