Overt Agitation in Patients With Prolonged Disorders of Consciousness: Prevalence, Clinical Characterization and Predictive Value

Background Agitation is frequently observed in patients with severe acquired brain injury and prolonged disorders of consciousness. Objectives To evaluate the incidence of agitation and its diagnostic and predictive value, in patients with disorders of consciousness. Methods In this retrospective observational cohort study, data from patients in unresponsive wakefulness state, minimally conscious state and emerged from the minimally conscious state was analyzed. Demographic and clinical information on agitation, disability, and neurobehavioral condition (i.e., Overt Agitation Severity Scale, Disability Rating Scale, and the Coma Recovery Scale-Revised Index) were collected at admission to a rehabilitation facility and long-term acute care hospital, and 24 months post admission. Results One hundred and nineteen patients (unresponsive wakefulness state = 62, minimally conscious state = 57), of which 68.1% (unresponsive wakefulness state = 35, minimally conscious state = 46) exhibited signs of agitation with varying intensity. Patients in minimally conscious state showed significantly higher Overt Agitation Severity Scale scores in the upper and lower limb subscales, compared to patients in unresponsive wakefulness state ( p < .001 and p = .007, respectively). The Overt Agitation Severity Scale total score showed significant correlations with both the Coma Recovery Scale-Revised Index and the Disability Rating Scale total score. At 24 months after admission, 41 patients (11.3% unresponsive wakefulness state, 59.7% MCS) emerged from the minimally conscious state, whereas 78 patients were still in a disorder of consciousness. A logistic regression model found that traumatic etiology, higher Coma Recovery Scale-Revised Index and higher Overt Agitation Severity Scale total score increased the probability of emergence from the minimally conscious state at 24 months (accuracy = 80.7%). Conclusions Our results provide the first evidence for agitation as a diagnostic and prognostic marker of recovery of consciousness.