Hello. I am very worried about my little brother.

Today he was forced to pull his car to the side of the road from dizziness. He called my mother (she and I work at the same school) and we drove down to help him. He told my mother on the phone that he felt a sharp pain in the back of his head then dizziness and now he felt confused. On the drive down I called to calm him down and here is what he told me:

"it felt like someone stabbed me in the back of my head then the road seemed to turn. It felt like my car was lifted by a crane and I was going to fall out the driver's side door."

my mother drove him to the doctor and by the time he could get in (app. 3-3 1/2 hours after the first call) he felt well again. The doctor said severe tests were unneeded because the symptoms went away. They drew blood and here is a part that scares me. They had trouble finding a vein and when they did it burst. They call it a blowout or burstout, i'm not sure which he said. Then they finally got blood and told him "the tests were fine."

but here is the worst part. Bub no longer remembers having a pain in his head. He said he doesn't remember having it or telling us about it. My dad said they had an in depth discussion between my mother's call and mine in which my brother told my dad he was sure someone had shot him or hit the back of his car and driven off (the car is not even scratched and my brother has no outward wounds). Now he says he has no memory of this. The doc said that just proves it was a temporary situation. That makes no sense to me. Am I being too worried or is something serious (god help me, annurism?) going on and the doc just not getting it? Mom requested a cat-scan and he said it was unnecessary.

I understand no diagnoses here. I just want suggestions and advice before something worse happens. The doc said there was no explaination, but he should be fine.