Breath-holding or Seizures?

Elijah, who is now two and a half, has had episodes in which he stops breathing until he looses consciousness. I am not sure if they are siezures or what is called "breath-holding." He had the first episode when he was about two months old. He has had a total of about 18 of these, though some were borderline. They usually come when he is under some type of stress, but not necesarrilly angry or scared. Sometimes something seems to trigger it, such as me walking out of the nursury, or him falling down, but other times there was no apparent trigger. He usually cries out first, but not always. I can tell when one is starting -- he becomes very stiff with an arched back, his face grows bright red, then purple. His eyes roll back and he stops breathing. Only on one occaision, he began to convulse at this point. (That time he was with my mother, and she called 911). After he has not breathed for a few seconds (it feels like much longer!) he catches his breath and begins to breath again, very shallow, and his body relaxes. At this point he becomes very gray all over and clammy. He will regain consiousness in about a minute, but is completely dopey -- as if he doesnt know where he is, but I usually hold him and nurse him at this point, and he will fall asleep for awhile.
Pretty wild, huh?
The good news is that he has not had an episode like this in five months, though he had a borderline spell where he seemed almost to go out about two months ago. I hope that the fact that he didnt go out then, and that they are getting more spaced out, means that he is outgrowing these.
He has seen a couple of neurologists, and when he was four months he had a MRI that didnt pick up any abnormalities, though that was before the worst episodes had developed. After his convulsive episode, we took him to the ER, and he had a normal EKG there. His doctors are leaning toward calling these "breath holding," but I think they are probably some wierd form of childhood seizures. Apparently, either way we can just wait to see if he grows out of them, since they are not so far interfering with his health or safety. I dont want to start any meds unless he really needs them.
Anyone have kids with similar experiences? I would love to hear about it.