Over 70% of pwMS have a sleep disorder with about 40-45% having obstructive sleep apnoea. The latter is massively underdiagnosed and needs to be actively screened for to be detected. I suspect having MS increases one’s chances of developing OSA by affecting the tone and function of the so called bulbar or throat muscles. This problem is that OSA affects quality of sleep and leaves most people with daytime sleepiness, which exacerbates MS-related fatigue and cognitive impairment. This is why if you have daytime sleepiness, fatigue or cognition problems you need to be screened for one of the many sleep disorders that affect pwMS.
The simplest screen for OSA is the Epworth Sleepiness Scale, which takes about 2 minutes to complete. The following symptoms are also clues to having OSA:
- Stopping breathing or struggling to breathe
- Feeling of choking
- Tossing and turning
- Sudden jerky body movements
- Needing to go to the toilet in the night
Sometimes your partner might be more aware of your snoring and pauses in your breathing than you are. If you don’t have a partner you can download one the many sleep apps that monitors your sleep and records snoring. Some of my patients are surprised when they actually hear how bad their snoring is at night.
The good news is that OSA is treatable and many patients come back and say that their lives are transformed after getting a good night’s sleep. The study below documents that pwMS with OSA also improve their cognitive function when their OSA is treated.
McNicholas et al. Impact of obstructive sleep apnoea on cognitive function in multiple sclerosis: A longitudinal study. J Sleep Res. 2020 Aug 13;e13159. doi: 10.1111/jsr.13159.
Cognitive impairment (CI) and fatigue are common in people with multiple sclerosis (MS), with well-known profound effects on quality of life. Sleep disorders, including obstructive sleep apnoea (OSA), are also common in MS patients. The presence of CI has previously been shown to strongly correlate with OSA diagnosed using polysomnography in MS. Treatment of OSA has not previously been investigated as a potential modality to improve cognition in MS patients. Therefore, we sought to investigate the potential effects of OSA treatment on both cognitive function and fatigue in MS patients. Twenty-three participants with MS reporting significant fatigue were enrolled. CI was assessed by the Brief International Cognitive Assessment in MS and the 3-second Paced Auditory Serial Addition Test. All participants underwent overnight polysomnography to assess for possible OSA. Cognitive and fatigue measures were repeated in those subsequently treated for OSA and in a comparative untreated sample. Seven participants (30%) had a diagnosis of OSA based on an apnoea-hypopnea index greater than 5 per hour, with no correlation between the presence of CI and OSA. Verbal learning at follow-up assessment was seen to improve significantly in those treated for OSA, compared with those who were not treated for a sleep disorder. This small study demonstrates the potential for OSA treatment to improve verbal learning in people with MS, larger studies are indicated to further investigate the potential for cognitive and fatigue improvement in people with MS through treatment of comorbid OSA.