Sounds very familiar to me!!!! My boy, Dusty, experienced the same thing when he was about 4 or 5. We did the horrific hospital thing, various diagnosis etc. In our case we were told he would have seizures the rest of his life and that his condition was likely beyond medical help. Of course we were devastated. He was on medication for several years to control them, and the medicine worked much better than expected.
In a few years he did indeed outgrow the condition and has been seizure free for many years now. He is 15 years old now and doing very well. Were very close and not a day goes by we don't tell each other, "I love you" (just don't try to hug him in public when he's a teenager).
I know the fear and the wide range of emotions you have\will experience. I pray your outcome will be similiar to mine in good time.