Prednisone is an entirely different treatment than the DMDs. Prednisone treats symptoms. DMDs treat the disease. That is hugely different.
Is there a reason why your neuro doesn't suggest a DMD for you? I'm unfamiliar with how the medical system works in South Africa.
As for the LDN - low dose naltrexone has been studied repeatedly as a treatment for MS and the studies consistently show it does not alter the disease course from what I understand.
I wrote a bit about the placebo effect and LDN at
http://www.medhelp.org/posts/Multiple-Sclerosis/LDN--/show/1311712
We have kicked LDN around here a lot and you can find plenty more posts on the subject by doing a search of this community for LDN.
be well, Lulu