Sleep Apnea May Contribute To Fatigue In Multiple Sclerosis

April Flowers for redOrbit.com Your Universe Online

The fatigue that many people with multiple sclerosis (MS) feel is often written off as just being part of the territory of their chronic neurological condition.

A new study from the University of Michigan, published in the Journal of Clinical Sleep Medicine, suggests that a large number of MS patients might have an undiagnosed and treatable sleep disorder, known to cause fatigue: obstructive sleep apnea, or OSA.

The research team, from the U-M Health Systems Sleep Disorders Center, conducted a study involving 195 patients at the U-M Multiple Sclerosis Center. Based on a method of screening for the condition known as the STOP-Bang questionnaire, they found that 56 percent were at an increased risk for OSA. Most of those had never had a formal diagnosis, however, and less than half who had been told they had sleep apnea were using standard treatment for it.

The results also showed that patients who were more fatigued were more likely to have an increased risk for sleep apnea. This was true even factoring in other aspects that might have contributed to feelings of fatigue, such as age, gender, body mass index (BMI), sleep duration, depression, and other nighttime symptoms.

The results are based on data gathered from one questionnaire designed by the authors, and four validated instruments designed to assess daytime sleepiness, fatigue severity, insomnia severity and obstructive sleep apnea risk. The researchers also accessed the patients medical records to examine clinical characteristics that may predict fatigue or obstructive sleep apnea risk.

We were particularly surprised by the difference between the proportion of patients who carried an established diagnosis of obstructive sleep apnea 21 percent and the proportion at risk for obstructive sleep apnea based on their STOP-Bang scores, which was 56 percent, says Tiffany Braley, MD, MS.

These findings suggest that OSA may be a highly prevalent and yet under-recognized contributor to fatigue in persons with MS. Our study suggests that clinicians should have a low threshold to evaluate MS patients for underlying sleep disturbances.

The research team consisted of Braley, who is an assistant professor of Neurology and multiple sclerosis specialist at the U-M Medical School; Ronald Chervin, MD, MS, director of the U-M Sleep Disorders Center; and Benjamin Segal, MD, director of the U-M MS Center.

MS is an immune-mediated disease of the central nervous system. It causes inflammation and damage of the brain and spinal cord, as well as a number of chronic symptoms. For MS patients, fatigue is one of the most disabling of the chronic symptoms.

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Sleep Apnea May Contribute To Fatigue In Multiple Sclerosis