It's Guillain-Barré syndrome, named after two french neurologists who described it in 1916. Most patients recover but it can be fatal and some are left profoundly disabled.
It is not a single disease entity but describes a spectrum of neuropathy - illnesses of the peripheral nerves caused by a rogue immune reaction to a previous infection.
About 25% of patients become so paralysed that they need mechanical ventilation. These patients tend to do less well but I know many who have been ventilated and made excellent recoveries.
It would be reasonable to be optimistic.
Andy Leitch
Chairman GBS Support Group [UK]