Sleep Disorders Contribute to Cognitive Decline in Multiple Sclerosis

FRIDAY, April 7, 2023 (HealthDay News) -- Sleep disorders may contribute to the perceived cognitive decline in women with multiple sclerosis (MS), according to a study published in the March issue of the Multiple Sclerosis Journal.

Tiffany J. Braley, M.D., from the University of Michigan in Ann Arbor, and colleagues assessed direct and indirect longitudinal associations between sleep disorders and perceived cognitive dysfunction in women with MS. Analysis included 63,866 participants in the 2013 and 2017 waves of the Nurses' Health Study, with 524 women self-reporting MS. As a marker of cognitive function, participants were asked four memory questions and three questions that assessed other situational difficulties (trouble following conversation, instructions, and street navigation).

The researchers found that the prevalence of diagnosed/suspected obstructive sleep apnea, sleepiness, and insomnia in 2013 were higher for nurses with MS. Additionally, nurses with MS were more likely to report cognitive difficulties in 2017. Roughly 5.4 to 15.1 percent of the total effect between MS and following instructions, conversations/plots, and memory impairment was mediated by insomnia. Sleepiness mediated 8.6 to 12.3 percent of the total effect for these outcomes. Obstructive sleep apnea significantly accounted for one-third (34 percent) of the total effect between MS and following instructions.

"Perceived cognitive decline, even in the absences of objective changes, could be an important window of opportunity to identify treatable exacerbating factors, such as sleep disorders," a coauthor said in a statement.

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