My friends 6 month old has been experiencing these episodes at night for about 4 months now. They said he would cry alot during the night and would get really mad and stiffen his body, etc. I witnessed this for the first time the other night, but he wasn't crying hard. He was a little fussy and his body would stiffen and straighten for a second or two, then it seemed to relax. Every few seconds, this would continue. At first, when he was fussy, it did look like he was mad and just throwing a little tantrum, but when he stopped fussing and was smiling at me, the intermittent stiffening continued and his face would tense up during the stiffness, then his whole body would relax again. The whole thing probably only lasted about 60-90 seconds and he may have stiffened up 10 or so times. Then, it just didn't happen any more. He never lost consciousness and his eyes never seemed roll back or anything.

Has anyone ever heard of something like this?