The effects of sleep quality on cognition in Multiple Sclerosis : a longitudinal pilot study

Multiple Sclerosis (MS) is a debilitating disease which can negatively impact the cognitive functioning of people with Multiple Sclerosis (pwMS). Recently, sleep quality has emerged as a possible factor in MS. Observed relationships between sleep quality and cognition in research suggests that poor sleep quality may negatively impact cognition in pwMS. Cross-sectional research has associated poor subjective sleep quality with objective cognitive difficulties in working memory and spatial memory. While this relationship has been examined cross-sectionally, it is yet to be examined or established over time. The current pilot study examined the effects of subjective sleep quality on objective cognition in pwMS across a 5‚ÄövÑv¨6-year period. Baseline differences between pwMS and healthy individuals without MS, and differences between baseline and follow-up in pwMS, were also examined. Perceived sleep quality was assessed using the Pittsburgh Sleep Quality Index and cognitive function was measured using Rao‚ÄövÑv¥s Brief Repeatable Neuropsychological Battery. Results indicated that perceived sleep quality is not meaningfully related to objective cognition over time. PwMS displayed poorer cognition compared to individuals without MS at baseline. Neither sleep quality nor cognition declined in pwMS over 5-6 years. Future research should examine alternative sleep constructs such as objective sleep.