Detecting early recovery of consciousness: a comparison of methods

Early detection of the return of consciousness has important implications for prognosis and rehabilitation access. The aim of this study was to compare the Coma Recovery Scale-Revised (CRS-R) with individualised quantitative behavioural assessments (IQBA) to determine which method is capable of detecting command-following earlier and more consistently in persons with disorders of consciousness (DoC). Data from 27 patients with DoC, who underwent both assessments concurrently during inpatient rehabilitation, were retrospectively analysed. For each person, performance trajectories on the CRS-R auditory subscale item and IQBA dual command protocols were graphed together to identify earlier and more consistent evidence of consciousness; grouped data were analysed statistically. For 22 patients, IQBA more consistently documented consciousness than the CRS-R, whereas no patients showed the reverse pattern. For 14 of 20 analysable patients, IQBA provided earlier evidence of consciousness, for two patients CRS-R provided earlier evidence, and for four patients both methods provided initial evidence on the same day. These findings suggest that IQBA approaches can provide more consistent and earlier evidence of command-following than the comparable item on the CRS-R. Whether this advantage is due to the individualisation of IQBA or the greater volume of data gathered requires further research.