Bright Light Therapy for Sleep Disturbance in People With Multiple Sclerosis

Multiple sclerosis (MS), an inflammatory and neurodegenerative disorder of the central nervous system (CNS), is the most common cause of progressive neurologic dysfunction in early to middle adulthood. People with MS are a markedly high risk for sleep disturbance. Estimates of the lifetime prevalence of sleep disturbance in MS reach 50%; sleep disturbance is also associated with excess MS-associated morbidity and diminished quality of life. Despite the high burden of impaired sleep and its contribution to adverse MS outcomes, effective approaches to treat and ameliorate disturbed sleep in people with MS remain poorly understood. There is unmet need to develop safe and effective rehabilitative alternatives to mitigate sleep disturbance in MS. Prior research supports the use of timed bright light therapy (LT) as one such approach for insomnia and sleepiness in those with sleep disorders or other neurologic diseases. Yet, the safety and potential effectiveness of timed LT have yet to be tested in MS. The goal of the proposed study is to conduct a detailed intervention study testing if timed bright LT in people with MS is 1) safe (primary outcome) and 2) potentially effective for reducing sleep disturbance (specifically, reducing insomnia, fatigue and improving sleep efficiency, quantity and quality as secondary outcomes). The study will also explore whether LT stimulates a novel subtype of retinal ganglion cells which are central to the regulation of circadian rhythms and sleep.