Are These Seizures?

What I notice is that he will get very calm (no movement), his eyes will roll back briefly, then he will start screaming as you see in the video. This is the only time he makes this noise. When the episode is over he quiets down and continues with his arm movements.

It is hard to get video because they are very unpredictable. By the time I hear it and get my camera, it is almost over. I have noticed these episodes quite a bit after school and/or therapy sessions. Three yesterday afternoon.