Some people confuse these episodes with seizures. However, there are a few characteristics which make the distinction relatively easy. First, these episodes always follow crying. Most seizures happen essentially unannounced. The twitching or shaking the child does with a breath holding spell is usually minimal and not particularly rhythmic.
Seizures often have severe rhythmic jerking.
And finally, the child who has a breath holding spell usually fully recovers within a minute. Children are usually quite sleepy for about 10-15 minutes after a seizure. The good news is that these episodes cause no long lasting problems. The bad news is, there isn't much a parent can do in preventing them aside from avoiding the conflicts which tend to precipitate large tantrums. If the child gets hurt, a calm soothing voice or perhaps some distracting maneuvers may help prevent the escalation of anxiety which eventually lead to breath holding.