Both of my kids had/have Sandifer's Syndrome. My daughter is 2 now and her's is completely gone. But, my son is only 7 months, and his is still present. Basically for us, it was toticullis in the neck with GERD. We used Mylanta, Prevacid, and Zantac for his reflux along with Similac Alimentum for formula because he was sensitive (and still is) to breastmilk, soy, and milk/dairy products. My daughter used the Alimentum and soy, she was not as bad as he is, nor was she diagnosed.
We went to an orthopedist who diagnosed him, ask for a referal to one, because they will tell you for sure what it is. The longer you wait the worse it will be and the harder you will have to work to get it corrected. We go to physical therapy once a week, and we were going to the chiropracter who does cranial sacral massage therapy once a week also, but he has graduated out of that, so now we go every 3 to 4 weeks, but I started treating him at 6 weeks, so it will take longer for your litle guy. Mine also couldn't put his toes to his mouth, and when he hurt he would pull into a "C" shape on one side and his head would fall to one side as well. It still does, but not as badly.
I don't much about cp, but if it is Sandifer's then no one will have heard of it, no one knows what to do about it, but they do know how to treat the components, and that is what you need anyway. Don't wait to get in though, because time really does matter in this case, especially crawling...he has to do that for his muscles to develop correctly and so he's not clutzy later in life. If I can help at all, please message me. Good luck! It sounds scary, but maybe its not so bad. Sandifer's isn't. Take Care!