All day, I've been feeling these brief, intense feeling of increased pressure (with an increase in tinnitus), like a zap, in my head. They come on and off, and are common while standing. Last for about 1 second at a time. I've felt them before, most notably if I'm falling asleep when I shouldn't be. It's like a zap...is this stress, MS, fatigue, or weather-related?Today, it's cold, rainy and damp, about 40F. There's changes in the weather coming with several weather systems converging on my area. I am trying not to freak out, but I can't stop.I feel also pricking on the side of my left hand. It's just not a good day today, I suppose. I appreciate any medical advice you may have.