Sleep disruption after brain injury is associated with worse motor outcomes and slower functional recovery

Background and Aims: Sleep is important for consolidation of motor learning, but brain injury may affect sleep continuity and therefore rehabilitation outcomes. This study aims to assess the relationship between sleep quality and motor recovery in brain injury patients receiving inpatient rehabilitation. Methods: 59 patients with brain injury were recruited from two specialist inpatient rehabilitation units. Sleep quality was assessed (up to 3 times) objectively using actigraphy (7 nights) and subjectively using the Sleep Condition Indicator. Motor outcome assessments included: Action Research Arm test (upper limb function), Fugl Meyer assessment (motor impairment) and the Rivermead Mobility Index. The functional independence measure (FIM) was assessed at admission and discharge by the clinical team. 55 age and gender matched healthy controls completed one assessment. Results: Inpatients demonstrated lower self-reported sleep quality (p<0.001) and more fragmented sleep (p<0.001) than controls. For inpatients, sleep fragmentation explained significant additional variance in motor outcomes, over and above that explained by admission FIM score (p<0.017), such that more disrupted sleep was associated with poorer motor outcomes. Using stepwise linear regression, sleep fragmentation was the only variable found to explain variance in rate of change in FIM (R2adj = 0.12, p = 0.03), whereby more disrupted sleep was associated with slower recovery. Conclusions: Inpatients with brain injury demonstrate impaired sleep quality, and this is associated with poorer motor outcomes and slower functional recovery. Further investigation is needed to determine how sleep quality can be improved and whether this affects outcome