Hi Ruth,
Hope that you have gone well in your negotiations. I think that if you present a resonable case, and have the leave owing, and advice from a medical person, then you should be able to negotiate a good arrangement.

I just organised for a girl working for me to reduce her daily hrs as she was having trouble coming in by 9, and by 4pm is looking very tired and ill - and taking public transport when it is crowed is a real struggle for her due to her MS. We have arranged that she will take the balance of her days hrs as sick leave, and we will review the situation every fortnight. I have also stopped her undertaking any long distance travel by herself as I was afraid that the MS was keeping from getting enough sleep and that her driving by herself while tired posed an unacceptable OH&S risk.

I think that if you are also willing to review the situation freqently so that your mgr knows how you are travelling, then it is a bonus. Also, is it an option for you to do any work from home? If so, would that help.

Good luck and really hope you MS improves soon!
FG