My Lady is an epileptic so I know too much about seizures.
How old is your little guy? If he is still a puppy, seizures are usually a sign of something else going on like a liver shunt or a thyroid imbalance. To be honest, it doesn't sound like a seizure to me.
Here is my "bible" on seizures. Maybe that will help you figure out if that is what you are seeing.
http://www.canine-epilepsy-guardian-angels.com/
Did your vet do a complete blood panel, thyroid panel? I'd also want a bile acids test to check liver function.
It almost sounds like something neurological to me.