LAUSR

There is some evidence suggesting that patients with hypersomnia have delayed circadian timing, which could explain, at least in part, the excessive sleepiness and impaired daytime performance experienced by these individuals. This study investigated the effects of bright light treatment on improving daytime alertness in patients with idiopathic hypersomnia. Participants were scheduled to two in-laboratory sessions (baseline and treatment) consisting of overnight sleep monitoring (polysomnography) followed by maintenance of wakefulness tests (MWT) and performance testing (10-min psychomotor vigilance task (PVT)). MWTs were performed at 10:00, 12:00, 14:00 and 16:00 and PVTs were performed at 11:00, 13:00, 15:00 and 15:00. In-laboratory sessions were separated by a two-week at-home treatment period during which participants were instructed to use commercially available light devices for 30-60 min each morning. Participants also completed the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS) at baseline and after treatment. Paired t-tests were performed to assess differences in sleep architecture, sleep quality, performance (lapses; reaction time >500ms) and alertness (MWT mean sleep latency) between baseline and treatment. To date, three participants (2 male) aged 62.7±13.2 (mean±SD) years have completed the study. Lapses (baseline: 17.9±11.9; treatment: 6.3±5.4), ESS (baseline: 17.3±3.1; treatment 12.3±6.8) and PSQI (baseline: 7.7±3.8; treatment: 4.0±1.0) all improved with light treatment, although this did not reach statistical significance. There were no statistical differences between baseline and treatment with regards to sleep architecture or mean sleep latency. Although preliminary, results suggest that bright light treatment may improve subjective sleepiness, subjective sleep quality and performance. There was some variability between individuals, indicating that this treatment may not offer the same benefits to all patients. Although ongoing, this study suggests that light therapy could be used as an alternative, non-pharmacological treatment option to improve waking functions and sleepiness in hypersomnia patients. This project is supported by a Hunter Medical Research Institute Research Project Grant