I hope this finds you well? My reply is probably a bit late, and may be of limited use as I am in the Australian Defence Force, but I do hope it helps.
Clinically I only ever had one episode of left sided parasthesia, which resolved with methylprednisolone. This happened in 2009, and I was made non deployable for up to 12 months. Luckily I had excellent medical officers who after a further neuro review stating clinically stable, and no functional impairment, upgraded me to deployable again. At this point I was diagnosed with the MS precursor "Clinically Isolated Syndrome"
Unfortunately about two years later a routine MRI showed new lesion which according to McDonald criteria is diagnosable MS, despite being clinically stable. At this point my care was interfered with by a less desirable medical officer who pushed the chain of command to make me non deployable permanently. This was not consistent with my neurologists opinion.
I was consequently centrally reviewed and deemed medically unfit for further service by the Royal Australian Air Force. Being a medical officer myself, I suspect due to specialist resource management and perhaps collegial bias, I was offered the chance to stay in albeit non-deployable. Extremely grateful as I was, I felt not deploying would waste life potential I could fulfil in a civilian medical setting so I discharged from permanent service, but have continued reserve service with a waiver (I think your National Guard equivalent).
I have now been 5 years relapse free and am considering options to return full time in uniform having spent a few years in critical care medicine. I suspect if this happens it will involve a lot of paperwork and I will be non deployable.
I only know of a handful of others with demyelination in our Defence Force, who have all been discharged to my knowledge. However, others with equally unpredictable and even more serious conditions have stayed in due to their skill set in a garrison role, but will likely never deploy.
It's a tough one taken on an individual basis with regard to staying in uniform here in Australia, but deploying extremely unlikely.
If your not already aware of it, in Australia we have an organisation called Overcoming Multiple Sclerosis available to join online. Set up also by an Aussie doctor diagnosed with MS. An excellent source of up to date info on MS, and a forum similar to this.
There is so much money going into researching this disease due it's high prevalence in wealthy nations. Grossly unfair I know, but it is good for people who have it. I don't know if there will be a cure in our life time, but possibly there will be enough new information on individual prognosis that both our Defence Forces will eventually change there policy and maybe one day we can deploy if we are clinically okay.
Wish you all the best, and hope you are well.