I really wish I knew what it was
I am out of ideas. The only other advice I can give is to try to consult an avian vet. The problem with that is, in my area anyways, is there really aren't any around here. Hopefully someone might see this post and have another idea. If it were my chickens, I would probably try the Sulmet. I really don't think it is Cocci. But the Sulmet covers a little bit broader of a spectrum and it treats some other ailments as well. E. Coli being one. I believe it is a Sulfa based drug. With paralysis and so many birds being affected it has to be something serious. I have never heard of worms causing paralysis, however, I could be wrong. Not to say the birds dont have worms...perhaps it could be a combination of things, but I would put worms on the bottom of the list to treat, and attack from a more aggressive angle. I don't like to treat my birds with antibiotics unless I know what the problem is, but at this point, with so many losses, throwing an antibiotic at them can't hurt. I would research which drugs cover the widest spectrum, and go with it. I would research what Tylan treats, as well as other Poultry antibiotics. If I have time tonight, I will see what I can come up with. You could also call your local extension office and ask if they know what diseases are prevalent in your area, so you might be able to come up with some ideas of what you might be dealing with. I really hate you all are having to deal with this, and I wish I could be more help. Atlease maybe I can keep bumping you until someone comes up with the right answer.
