I knew someone who had MS. I found out through someone else. I kept my mouth shut. I only mentioned it when a medical emergency arose that may have been related - and then in only in confidence. I eventually told her that I knew, but her self-respect was something that I kept in mind throughout.
Don't publicize until you have had the chance to speak with the person, or in the case of a health crisis. When you have spoken honestly with the person, then offer. If they are paralyzed, it will be impossible to hide it forever, and at that point you can speak with the person and offer your help.
Thank you @ajdohmen, that's excellent advice. I have been trying very hard to refrain from taking action, knowing that it would cause offense and humiliation, and that eventually the situation would become more widely known anyway.
But it has been hard on me to exercise restraint in this scenario, though not usually something that is difficult, and so receiving counsel reaffirming my initial judgement renews my commitment to it as the best course of action.
Hopefully this person breaks their silence soon, the earlier that support, be it physiological, neurological, or social, can be brought to bear, the better the outcome.
I've friends and family that have worked with MS foundations, in direct care provision. It's a tough one, all degenerative conditions are. Maintaining the highest level of independent living and social/life participation are critically important to the affected individual, and efforts to those outcomes are usually highly appreciated them.
Thank you for your thoughtful reply.