It's mostly sleep deprivation though. I graduated with a 3.7 from a top 5 school in CS after I was treated. My apnea was SEVERE before treatment: 30 apneas per hour.
I doubt I had any brain damage, though my study only recorded a min SpO2 of 90%.
Once or twice. Usually you don't consciously wake up in a way that allows you to remember it whenever you have an apnea, you just go into a lighter and less restorative sleep stage.
