Recent advances in behavioral assessment of individuals with disorders of consciousness

The burden of proof for establishing diagnosis and prognosis in patients with disorders of consciousness lies with behavioral assessment methods. The current review discusses recent advances in understanding the strengths and weaknesses of this methodology.

Behavioral assessment methods remain the 'gold standard' for establishing diagnosis and prognosis in patients with disorders of consciousness, although their psychometric integrity and clinical utility remain largely unproven. While the Glasgow Coma Scale maintains its standing in the trauma setting, there are ongoing concerns regarding testing confounds and interrater reliability. The Full Outline of UnResponsiveness, an emerging alternative, is more sensitive to detection of locked-in syndrome but may fail to identify patients in the minimally conscious state. Recent studies investigating the relationship between behavioral and neurophysiologic measures of conscious awareness have revealed important dissociations between behavioral response profiles and corresponding neural activity.

Further research is needed on the psychometric properties of existing behavioral assessment methods for disorders of consciousness. Although dissociations between behavioral and neurophysiologic findings caution against overreliance on behavioral metrics for detection of conscious awareness, we expect there will be increased effort toward combining these methodologies to increase diagnostic accuracy and prognostic specificity in patients with disorders of consciousness.