Which behaviours are first to emerge during recovery of consciousness after severe brain injury?

BACKGROUND:Early detection of consciousness after severe brain injury is critical for establishing an accurate prognosis and planning appropriate treatment. OBJECTIVES:To determine which behavioural signs of consciousness emerge first and to estimate the time course to recovery of consciousness in patients with severe acquired brain injury. METHODS:Retrospective observational study using the Coma Recovery Scale-Revised and days to recovery of consciousness in 79 patients (51 males; 34 with traumatic brain injury; median [IQR] age 48 [26-61] years; median time since injury 26 [20-36] days) who transitioned from coma or unresponsive wakefulness syndrome (UWS)/vegetative state (VS) to the minimally conscious state (MCS) or emerged from MCS during inpatient rehabilitation. RESULTS:Visual pursuit was the most common initial sign of MCS (41% of patients; 95% CI [30-52]), followed by reproducible command-following (25% [16-35]) and automatic movements (24% [15-33]). Ten other behaviours emerged first in less than 16% of cases. Median [IQR] time to recovery of consciousness was 44 [33-59] days. Etiology did not significantly affect time to recovered consciousness. CONCLUSION:Recovery of consciousness after severe brain injury is most often signalled by reemergence of visual pursuit, reproducible command-following and automatic movements. Clinicians should use assessment measures that are sensitive to these behaviours because early detection of consciousness is critical for accurate prognostication and treatment planning.