I use a cpap machine and it is AMAZING. My sleep apnea was not severe to begin with, maybe borderline mild/moderate. But the thing is that when you have poor sleep of any kind ALONG WITH MS I think it really compounds your symptoms. I used to be really sleepy all the time but worse, I had a ton of brain fog and I couldn't think clearly. I thought it was the MS attacking my brain. I cried all the time and was about to start a stimulant medication. But after I started using the cpap for a week or two I started noticing that I could think clearly all day long. I had more energy. Didn't need to take naps anymore. I was doing really well at work again. I feel cognitively "normal". I don't know if its just that I have better sleep or if its the extra oxygen that I get from the machine but I can't recommend it enough for at least a trial. It's really hard to get used to the machine and especially a mask but for me I went from thinking I lost my cognitive function to being super sharp and on top of things...it's been really worth it.