Long ago if i got to intense in thinking or whatever I would start to feel throbbing intense pressure in my throat or heart. It would get stronger and stronger. I would then start to see violet / purple images and streaks until it took over my entire vision. It would last maybe 5 minutes and fade away. I wonder if this somehow related. Haven't had one in years, thankfully. It's gets very painful in the throat and chest, a lot of pressure as if they're going to explode.