Get another opinion!
With your situation deteriorating, you can’t afford to wait until December to see what happens. My neurologist has decreased my treatments from every 3 weeks, to every 4 weeks then to every 6 weeks and now every 8 weeks. All along, my family doctor has monitored progress weekly to make sure there is no deterioration. Now my neurologist wants to see me monthly as well, getting ready to get off the treatments of IVIG all together. He has indicated that the first sign of going the wrong direction, I’ll be on the IVIG pronto because it can set things back substantially.
I hope this helps.