The OT assigned to me said they don't supply stairlifts to people with MS - so I told her its better that me crawling up and down the stairs (and less dangerous)! But she didn't budge and I didn't get one from them. So I bought one second hand off eBay and guess what even though I have MS I can use it! LOL. Its great and it gives me access to upstairs (although I now sleep downstairs).
I transfer from my wheelchair at the bottom and have a wheelchair at the top to get me around - its great.
The OT said I needed a through floor lift and yes I would have liked one but I'd have to pay for it and I don't have the money to cover that (even though I'm working) so the stairlift was really my only option.
I'd think stairlift are fine for people with MS as long as you can transfer.
Hope this helps, Mary xxx