OSA Could Contribute to Fatigue in MS Patients

Patients with multiple sclerosis (MS) often contend with fatigue—one of the most common and disabling chronic symptoms of this neurological condition. However, new findings from a University of Michigan study suggest undiagnosed obstructive sleep apnea (OSA) could be another major contributor to fatigue in a large number of these patients.

Overall, 56% of study participants showed increased risk for OSA, according to the new research in the Journal of Clinical Sleep Medicine. “Sleep problems are common among all patients, but may be particularly common in persons with MS,” says lead study author Tiffany Braley, MD, MS, an assistant professor of neurology at the University of Michigan Medical School, in Ann Arbor, Mich.
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Braley and her colleagues studied 195 patients with multiple sclerosis from the U-M Multiple Sclerosis Center to determine the prevalence and risk of OSA in the MS clinical setting and to assess how these findings may relate to fatigue.

Study participants had an average age of 47, had lived with MS for an average of 10 years, and 75% had the relapsing-remitting form of the disease. Two-thirds were female, consistent with the prevalence of the disease in the US, and two-thirds were taking medication to treat their MS.

The study authors used 4 validated instruments to assess daytime sleepiness, fatigue severity, insomnia severity, and OSA risk in the patients, as well as administering a sleep questionnaire they had designed. They also examined the patients’ medical records for clinical characteristics that may predict fatigue or OSA risk.

“Reports of snoring should certainly alert the provider to the possibility of sleep apnea,” Braley says. “In addition, although many patients with MS report being fatigued or tired, those who report a propensity to doze off during sedentary activities, or those who wake up unrefreshed after an adequate night’s sleep may also require a more thorough evaluation for OSA or other sleep problems, with the help of a sleep specialist.”

While 56% of the study participants exhibited signs of risk for OSA based on the STOP-Bang screening questionnaire, only 21% had an established sleep apnea diagnosis. And less than half of those were using the continuous positive airway pressure treatment prescribed. “We were surprised by this gap,” Braley says. “To us, this finding suggests that more efforts should be directed toward OSA screening for patients with MS.”

She and her colleagues also found that patients who were more fatigued were more likely to also be at higher risk for sleep apnea—even after considering other contributing factors, such as age, gender, body mass index, sleep duration, depression, and other nighttime symptoms.

“Primary care providers should be encouraged to discuss sleep-related issues, including OSA, with their MS patients,” she says. “As they may be the first or only source of health education for some patients, they could play a vital role in identifying patients who are at risk for OSA, and facilitating prompt referral to a sleep specialist.” 

—Colleen Mullarkey

Reference

Braley TJ, Segal BM, Chervin RD. Obstructive sleep apnea and fatigue in patients with multiple sclerosis. J Clin Sleep Med. 2014 Feb 15;10(2):155-62.