Severity of symptoms

My husband was experiencing muscle weakness in his legs for several years - needing to frequently "rest" between activities. We talked to several doctors with no real suggestions. Last year, he seemed to be experiencing an upper respiratory illness, and became extremely ill and was put on a ventilator for a month, with a diagnosis of sepsis. When he was being weaned off sedation, it was discovered he couldn't use his hands or lower arms. I'm sure since the focus was on saving his life (He had respiratory and kidney shutdown.), they didn't pay much attention to his situation. We are now a year out, and he has relearned to walk, off the trach, dialysis, and feeding tube, but still no use of his hands/lower arms. Neurologist just last week diagnosed MG. Dr's office trying to get approval for IVIG. We are trying to make sense of everything. Were the early weakness symptoms the beginning of MG? Was his illness a myasthenic crisis triggered by the infection/sepsis? Is there hope for regaining "any" function for his hands/arms? Has anyone else had weakness this severe? He has use of his shoulders, but no sensation/function from slightly above his elbows down to his fingers. I never really thought about how much we use our hands/arms! Any suggestions while we wait on insurance for approval of treatment? Thank you!