I have a funny story when I was exposing my kids to cp, my daughter did not like the way her friend Julia looked with the spots! Lo and behold she only got it on her feet, a very mild case. (we tested her immunity, so yes it was cp). My husband treated her with acupuncture and she is very strong, so I guess that was it for her!
So I would say, though there is a normal progression, there's also different ways to get cp, my son got a more conventional case.