A Randomized Trial of Positive Airway Pressure Therapy to Treat Cognitive Dysfunction in MS Patients With Obstructive Sleep Apnea

Up to 70% of patients with MS suffer from cognitive dysfunction (difficulties with thinking, information processing, verbal expression, or memory). Cognitive dysfunction is one of the most disabling symptoms of MS, that can profoundly affect job performance, family responsibilities, and quality of life. While no treatments have been shown to improve cognitive dysfunction in MS, many patients have not been evaluated or treated for other common health problems that could be contributing to their cognitive dysfunction.

Up to 50% of MS patients also suffer from obstructive sleep apnea (OSA). Obstructive sleep apnea is a common disorder in which the upper airway collapses during sleep, causing poor sleep quality and decreased oxygen levels in the blood. In patients without MS, OSA is a well-established cause of poor cognitive performance. Recent studies of non-MS patients also suggest that cognitive performance may improve with OSA treatment. Yet, despite the high number of MS patients with OSA, the relationship between OSA and cognitive performance, and the effects of OSA treatment on cognitive performance in MS, has not received sufficient study.

The objectives of this study are to determine the effects of obstructive sleep apnea (OSA) on cognitive function in patients with multiple sclerosis (MS); and to evaluate whether OSA treatment with positive airway pressure therapy could improve cognitive dysfunction in MS patients who also have OSA.

Interested participants with MS who screen positive on a commonly used screening tool used to detect those at high risk for OSA will be invited to participate. Consenting participants will have a baseline cognitive (memory and thinking) test to assess their cognitive function, and an overnight sleep study (polysomnogram, or PSG) to determine if they have obstructive sleep apnea. If the sleep study shows signs of sleep apnea, participants will be assigned treatment for their sleep apnea with positive airway pressure (PAP) therapy, either immediately (Group 1), or 3 months after the baseline sleep study (Group 2). Groups will be assigned at random (like flipping a coin). There is a 2/3 chance that participants will be assigned to Group 1. PAP therapy is considered standard clinical care for OSA. It involves wearing an apparatus that includes a hose and a mask (that covers the nose, or nose and mouth), connected to a small machine that blows air into the airway during sleep. In order to determine which airway pressure most effectively treats an individual's sleep apnea, and what type of mask is needed, a separate sleep study known as an overnight "PAP titration study" will also be performed. This study is similar to a PSG but also involves fitting of various masks which are then hooked up to the individual and PAP machine to test the effectiveness of various PAP settings, and to determine which mask is most tolerable for the individual.

Participants will also receive repeat cognitive testing at 3 months to see if the immediate sleep apnea treatment group (Group 1) shows improvements memory and thinking, as compared to the standard care treatment group (Group 2), who will not start apnea treatment until after their repeat cognitive test. Participants will be compensated for their travel and time throughout the course of the study.