Over the course of the past 5 days, I have had a throbbing headache, which does not concern me too much. But the headache was instantly initiated by what felt like lighning bolts through my head to the rhythm of my heartbeat. It was crippling and I've never had sensations like that before. I had 3 episodes in 3 days and 2 minor episodes the last two.. Are these symptoms of an aneurysm?