*Poster 27: Prognostic Significance of Motor Subtype During Acute Recovery From Traumatic Brain Injury

Objectives: (1) To evaluate the presence of a hypomotoric subtype of delirium (ie, acute confusional state) following traumatic brain injury (TBI); (2) to investigate the applicability of a motor subtyping schema (Meagher et al, 2008) for delirious patients following TBI; and (3) to examine the role of disturbed psychomotor functioning in rehabilitation outcomes. Design: Prospective design. Setting: Inpatient rehabilitation facility. Participants: 48 subjects with TBI (21 delirious, 27 nondelirious). Interventions: None. Main Outcome Measure: FIM at hospital discharge. Results: Principal components analyses, correlations, and Mann-Whitney U tests were performed to identify specific motor symptoms associated with delirium following TBI. 5 hyperactive and 6 hypoactive items were identified. Cutoff criteria of 2 items scored 2 or higher on a 0-to-3 point scale generated adequate sensitivity (86%) and specificity (85%) for identifying motor disturbance in delirious versus nondelirious patients. Of the delirious sample, 43% were designated as agitated, 33% hypomotoric, 10% mixed (displaying hyper and hypomotor disturbances), and 14% displayed no motor disturbance. t tests revealed that, compared to nondelirious patients, delirious patients demonstrated significantly lower cognitive, motor, and overall FIM scores at rehabilitation admission and discharge. Outcome comparisons of delirious patients designated as agitated versus hypomotoric based on the ascribed cutoff criteria indicated that, despite similar admission FIM scores, patients who displayed hypomotoric disturbances exhibited discharge FIM scores that were significantly lower than agitated patients (FIM Cognitive: t=2.06, P=.059; Motor: t=3.79, P=.002; Overall: t=3.28, P=.01). Conclusions: Consistent with extant literature on delirium in general medical populations, these results provide support for the presence of a hypomotoric subtype of delirium following TBI. The importance of this phenomenon is highlighted by the fact that hypo-motoric deficits appear to be associated with poorer inpatient rehabilitation discharge prognosis as measured by the FIM. Recommendations for utilizing the presented motor subtyping schema and directions for future research will be discussed.