@jodeej I am so happy that his return to work went well, that must have been a hurdle. I am also very encouraged for him by the responses of others like @rosemarya who have suffered from some degree of brain fog from the immunosuppressants. That must be a relief for you. Hopefully if that's the problem they will be able to put him on a lesser amount.
Right now I am pretty much at the minimum dose of immunosuppressants that they feel comfortable with. They are keeping it low (but within range of course) because it was having an effect on my kidneys, but things seem great now, and I am sure they will be for you husband too. It will be certainly be a much better Christmas for you now that you can rest assured that it is not dementia or a brain tumor.
JK