Rehabilitation outcome of unconscious traumatic brain injury patients

Outcome prediction of traumatic brain injury (TBI) patients with severe disorders of consciousness (DOC) at the end of their time in an intensive care setting is important for clinical decision making and counseling of relatives, and constitutes a major challenge. Even the question of what constitutes an improved outcome is controversially discussed. We have conducted a retrospective cohort study for the rehabilitation dynamics and outcome of TBI patients with DOC. Out of 188 patients, 37.2% emerged from a minimally conscious state (MCS) and 16.5% achieved at least partial functional independence after a mean observation period of 107 days (range 1-399 days). This reflects that emergence from MCS is much easier to achieve than functional independence. Logistic regression analysis identified age and level of consciousness upon admission to neurorehabilitation as independent prognostic factors for both outcomes. The group who reached at least partial functional independence started to improve significantly more than the corresponding outcome group by post-injury week 7, and the average time to reach this functional status was 18 weeks. In contrast, the group who emerged from MCS started to improve after 6 weeks. The longest delay between brain injury and the beginning of functional improvement (measured by biweekly Functional Independence Measure [FIM] scores) still compatible with reaching at least partial functional independence was 18 weeks. In conclusion, despite a strong negative selection, a substantial proportion of severe TBI patients with DOC achieve functional improvements or at least emerge from MCS within the inpatient rehabilitation phase. In order to avoid self-fulfilling prophecies in decision making, it is important to be aware of the fact that the beginning of clinical improvement may take several months after brain injury. In this study, separation of both of the functional outcome groups started by 7 weeks post-injury.