Welcome to BYC - so sorry about your losses.
The first thought that comes to mind when you mention paralysis is Mareks, but that is not the only thing that may have been going on. Can you tell us a bit more about what happened with the birds? How old were they when they passed and how long was it from the onset of symptoms to their death?
No. There is no known effective treatment. It is highly contagious. If one had it, they might all get it. If any survive, they will be immune, but might become carriers and able to infect non-immune birds. If you choose to get more chickens to replace the ones you've lost, make sure they are vaccinated against Marek's.