Abstract
Background and objectivesFatigue and sleep disturbance are debilitating problems following brain injury and there are no established treatments. Building on demonstrated efficacy of blue light delivered via a lightbox in reducing fatigue and daytime sleepiness after TBI, this study evaluated the efficacy of a novel in-home light intervention in alleviating fatigue, sleep disturbance, daytime sleepiness and depressive symptoms, and in improving psychomotor vigilance and participation in daily productive activity, following injuryMethodsThe impact of exposure to a dynamic light intervention (Treatment) was compared to usual lighting (Control) in a randomized within-subject, crossover trial. Outcomes were fatigue (primary outcome), daytime sleepiness, sleep disturbance, insomnia symptoms, psychomotor vigilance, mood and activity levels. Participants (N=24, MSDage=44.311.4) had mild-severe TBI or stroke3 months previously, and self-reported fatigue (Fatigue Severity Scale >= 4). Following 2-week baseline, participants completed each condition for 2 months in counter-balanced order, with 1-month follow-up. Treatment comprised daytime blue-enriched white light (CCT>5000 K) and blue-depleted light (<3000 K) 3 h prior to sleep.ResultsRandom-effects mixed-model analysis showed no significantly greater change in fatigue on the Brief Fatigue Inventory during Treatment, but a medium effect size of improvement (p=.33, d=-0.42). There were significantly greater decreases in sleep disturbance (p=.004), insomnia symptoms (p=.036), reaction time (p=.004) and improvements in productive activity (p=.005) at end of Treatment relative to Control, with large effect sizes (d>0.80). Changes in other outcomes were non-significant.Conclusions This pilot study provides preliminary support for in-home dynamic light therapy to address sleep-related symptoms in acquired brain injury.Trial registration This trial was registered with the Australian and New Zealand Clinical Trials Registry on 13 June 2017, www.anzctr.org.au, ACTRN12617000866303.