This feeling is called Cognitive Disfunction. Brain fog and some of us call them brain farts! LOL! Many people with auto immune disorders get this with their diseases. Sometimes weather changes can cause it and you will notice it more when you see a weather change. Our blood vessels in our bodies are just like rubber bands. Put a rubber band out in the cold weather and it gets hard and freezes. Place it in heat and it softens. Extreme heat and it get’s very elasticy! Just like a door that expands and contracts with weather change! Humans do the same thing! People with auto immune disorders though it effects them more than a normal human being. When a person’s nerves get damaged it can cause our blood flow to go much slower than the average person. So what happens is our blood vessel constrict not getting enough oxygen to the brain on time and causes us to get cognitive. It comes and goes. In fact there is alot online about Cognitive disfunction and those that have this problem might pay to look it up! Very helpful in helping to understand what is going on. Can get scary if you don’t know what is happening but once you know what it is, it makes it easier to understand and deal with it. Some diseases can cause bad cognitive while others can cause only mild attacks. Hope this helped!