A new study found a link between sleep apnea severity and cognitive dysfunction in patients with MS. Researchers hope the discovery will inspire more conversations in clinics, neurologists will ask their patients with MS about sleep, and patients will be encouraged to openly discuss sleep concerns with their neurologist.

People with MS face an elevated risk of obstructive sleep apnea (OSA), a disorder in which the throat collapses during sleep, causing the patient to repeatedly stop breathing for periods of 10 seconds or longer throughout the night. OSA can lead to a decline in mental functioning.

University of Michigan researchers studied 38 adults with MS who had questions about their sleep or cognition. The patients performed seven cognitive tests, which included tasks of word list recall, calculation, and reproducing figures and pictures. They also spent a night in the Michael S. Aldrich Sleep Disorders Laboratory for polysomnography, an overnight sleep test. Thirty-three of the 38 patients met the criteria for OSA.

They found that apnea severity measures accounted for between 11 and 23 percent of the variance in cognitive test performance. The investigators also observed relationships between other sleep quality measures and poor cognitive performance.

The findings were published in published in the journal Sleep.