Hi there, I have been having these same problems for awhile now. Just two days ago (again) had this sudden sharp pain that pulsed really hard. Hurt alot for about 10 -15 seconds. I almost lost consciousness, but ended up staying w/it. It dinged me out and made me quite dizzy.
The last time I went to the hospital for a bad headache and severe vertigo they did a cat scan (no dye contrast) but found nothing. Had thrown up four times while there and was throwing up on check out. They didnt find anything and sent me home telling me I should go to a ENT then to Neurologist if needed if ENT thinks I should go.
ENT said he thought it was a Neuro thing but Ive not had the money to go. This pain when it pulses feels like a blood vein. Im actually waiting to just drop over one day, dont think they will ever find out what it is till its too late. If anyone knows of a doctor who listens, and is interested in doing his job please let me know. I would also appreciate any advice, this is getting worse as time progresses.