By Robert Preidt
"Since obstructive sleep apnea is a treatable condition that is also commonly seen in MS, we wondered, 'What if some of the thinking and processing difficulties that MS patients experience do not stem directly from the MS itself, but from the effects of sleep apnea or other sleep problems?'" said study co-first author Dr. Tiffany Braley in a University of Michigan news release. Braley is an assistant professor of neurology at the university.
The study included 38 MS patients who underwent thinking and memory tests and were also assessed for sleep apnea. The results showed that 33 of them had the disorder, in which breathing repeatedly stops and starts during sleep.
Not only that, but "multiple measures of sleep apnea severity directly correlated with poorer performance on several [thinking] tests," said study co-first author Anna Kratz, an assistant professor of physical medicine and rehabilitation at the university.
"In particular, problems with attention and multiple aspects of memory, including memory for words and images and working memory, which plays a role in problem-solving and decision-making, were all associated with poorer sleep," Kratz explained.
Apnea severity was associated with 11 percent to 23 percent of variation in the participants' cognitive test performance, although the study could not prove that sleep apnea caused thinking deficits.
"Current MS treatments can prevent further neurological damage, but do little to help existing MS symptoms and damage," said Braley.
But diagnosing and treating conditions like sleep apnea could improve thinking abilities in these patients, she added.
Dr. Neeraj Kaplish, medical director of the University of Michigan Sleep Laboratories, said, "We hope neurologists will ask their patients with MS about sleep, and the patient should be encouraged to openly discuss sleep concerns with their neurologist."
The study was published recently in the journal Sleep.