Disorders of consciousness after severe traumatic brain injury: a Swedish-Icelandic study of incidence, outcomes and implications for optimizing care pathways.

BACKGROUND Very severe traumatic brain injury may cause disorders of consciousness in the form of coma, unresponsive wakefulness syndrome (also known as vegetative state) or minimally conscious state. Previous studies of outcome for these patients largely pre-date the 2002 definition of minimally conscious state. OBJECTIVES To establish the numbers of patients with disorder of consciousness at 3 weeks, 3 months and 1 year after severe traumatic brain injury, and to relate conscious state 3 weeks after injury to outcomes at 1 year. DESIGN Multi-centre, prospective, observational study of severe traumatic brain injury. INCLUSION CRITERIA lowest (non-sedated) Glasgow Coma Scale 3-8 during the first 24 h; requirement for neurosurgical intensive care; age 18-65 years; alive 3 weeks after injury. Diagnosis of coma, unresponsive wakefulness syndrome, minimally conscious state or emerged from minimally conscious state was based on clinical and Coma Recovery Scale Revised assessments 3 weeks, 3 months and 1 year after injury. One-year outcome was measured with Glasgow Outcome Scale Extended (GOSE). RESULTS A total of 103 patients was included in the study. Of these, 81% were followed up to 1 year (76% alive, 5% dead). Three weeks after injury 36 were in coma, unresponsive wakefulness syndrome or minimally conscious state and 11 were anaesthetized. Numbers of patients who had emerged from minimally conscious state 1 year after injury, according to status at 3 weeks were: coma (0/6), unresponsive wakefulness syndrome (9/17), minimally conscious state (13/13), anaesthetized (9/11). Outcome at 1 year was good (GOSE > 4) for half of patients in minimally conscious state or anaesthetized at 3 weeks, but for none of the patients in coma or unresponsive wakefulness syndrome. These differences in outcome were not revealed by prognostic predictions based on acute data. CONCLUSION Patients in minimally conscious state or anaesthetized 3 weeks after injury have a better prognosis than patients in coma or unresponsive wakefulness syndrome, which could not be explained by acute prognostic models.