I'm almost certain I've seen this trope in (western) live action but can not for the life of me place it. Hopefully someone else does.
But yeah, I think as others have said, it's just dramatic effect of natural hand motions related to the face. "Holding the crazy in", head splitting apart, signifying a "sickness" inside their head, it also allows for dramatic framing of (usually smiling) mouths and eyes and hair (the other features of a face don't seem as important in visually distinguishing the characteristics anyway).