A couple of months ago I was having trouble sleeping. After many sleep studies, I do not have sleep apnea but have oxygen desatuation. No doctor can figure out the problem. It is now affecting my brain where memory and concentration is a problem. The doctor is saying that I have slow circulation of oxygen in the brain. I am scared and since I have a stent, called cardiologist. He is saying to get my cholestrol down. I am frustrated... I am wondering if anyone with thyroid disease has experienced this.