1003 Daily Morning Blue Light Exposure for Alertness and Sleep Following Stroke

Abstract Introduction In the acute phase following a stroke, circadian rhythmicity is often disrupted, which undermines sleep, produces fatigue, and impedes recovery. Studies have reported post-stroke sleep architecture abnormalities, as well as acute sleep disorders which can range between extremes of clinically significant insomnia to hypersomnia, with sleep complaints sometimes persisting for months or years. Morning blue light exposure as an early, non-pharmacologic intervention targeted for strengthening circadian rhythmicity could provide acute relief and prevent disordered sleep from becoming chronic following stroke. Methods A randomized, single-blind, parallel group, placebo-controlled pilot study compared daily morning exposure to blue light or red light (placebo) for improving daytime sleepiness, fatigue, nocturnal sleep, and cognition in patients receiving inpatient rehabilitation for acute stroke. N=43 patients with disordered sleep secondary to first episode stroke (n=34 ischemic, n=9 hemorrhagic; ages 66.2±14.1y) were randomized to receive 25min of morning blue or red light for 5 or more days depending on inpatient rehabilitation length of stay (blue n=21, red n=22). At baseline and study discharge, daytime sleepiness was measured with the Karolinska Sleepiness Scale and Wits Pictorial Sleepiness Scale, fatigue with a visual analogue scale, and cognitive function with the Rey Auditory Verbal Learning Test and Trail Making Test (TMT). Actigraphy measured sleep continuously throughout participation with nighttime sleep defined as 21:00–05:59. Effect sizes per outcome were used to estimate sample sizes for larger follow-up studies. Results Participants with blue light exposure experienced significant improvements in daytime sleepiness, fatigue, and auditory verbal learning (all p.05) relative to red light exposure. There was a trend toward a greater mean duration of nighttime sleep (p=.076) and fewer awakenings after sleep onset (p=.092) in the blue light compared to red light group. Although change in TMT and nocturnal sleep parameters did not reach statistical significance, effect sizes favored blue-light exposure, ranging from .38–.57. Conclusion Morning blue light exposure for 5 or more days led to greater improvements in daytime sleepiness, fatigue, and cognitive outcomes than red light exposure after acute stroke. Effect sizes suggest a larger study is warranted to confirm generalizability of pilot findings. Support (if any) Empire Health Foundation