Agreeing with Girlie - any symptom improvements is significant, as someone with true ALS would not be seeing any symptom improvements.
I also agree that it's part of Lyme - it's well known to attack joints, particularly if they have injuries, or in your mom's case, just that much 'wear and tear' on her joints after making it this many years in life.
You can try using ice packs to lower the specific inflammation in the joints, or if that makes them more painful, try heat. For some, ice helps and other heat may help. I use both, depending on just what's going on.
Keep looking for ways to incorporate more detoxing in her schedule that you can manage while she's in the nursing home. Something that's not talked about
a lot is Jernigan's detox tinctures. It's something else that does help many. There are three different types, but they are all called NeruoAntitox II. Just pick one to target detoxing in that area.
hansacenter.com/shop/page/3/