Disorders of consciousness: preliminary data supports added value of extended behavioural assessment.

BACKGROUND:The use of validated behavioural assessment scales in assessment of patients with Disorders of Consciousness (DOC) is well established. However, there is little evidence to guide decisions on total time spent in behavioural assessment. OBJECTIVE:To assess whether brief behavioural assessment was as effective as extended behavioural assessment in detecting non-vegetative behaviours. METHODS:Consecutive patients with suspected DOC were assessed with two standardized instruments: Coma Recovery Scale Revised (CRS-R) and Sensory Modality Assessment and Rehabilitation Technique (SMART). Assessors were blinded to results from the other scale at the point of assessment. Two administrations of CRS-R together took 50-60 minutes ('brief' assessment). One complete SMART assessment took 600 minutes ('extended' assessment). Patients were classified as being in a vegetative state (VS) or minimally conscious state (MCS)/emerged from minimally conscious state (EMCS), following brief and extended assessment. RESULTS:Ten patients were assessed. Brief and extended assessment yielded the same diagnostic category (VS or MCS) for six patients and different categories for four, with extended assessment detecting higher level behaviours. CONCLUSIONS:Brief behavioural assessment was not as effective as extended assessment in detecting non-vegetative behaviours. Total time spent in behavioural assessment is likely important. Further studies and clearer clinical guidance are needed.