That is one of the symptoms of my head fog. I just saw a neurologist who is referring me to a neuropsychiatrist for a battery of tests. Anyway, that sort of thing happens to me a few times a week. It is scary when I "come to" and I'm driving down the highway. Driving safely and going the right way but freaked out because I can barely remember getting on the road and driving to the point where I suddenly became more aware.