Hi Deborah,
I feel for you. I have had those wretched spasms and the pain in the arm too. I don't know it's my MS or my neck or a combo. Could be a combo. I only know from MRIs that the disc herniates in the same area of my neck and the lesion is around the same area of my c-spine.
Does the pain sit at the top of your shoulder and then goes deep into to top outer part of you arm and goes into your elbow and forearm too? My gosh, it's so painful.
If it's from your neck, the only thing I can think of is taking an anti-flammatory and then trying to get into a position that takes the pressure off your neck. It's hard to find such a position but maybe someone will be willing to try with you using varying sized pillows, etc. Props work for me a little.
Also, because sitting makes it so much worse, try to press the tops of your shoulders downward if even with your hands at 1st to get the feel for it.
Not sure if this is what you are experiencing but if it is, I'm willing to share anything I've done to relieve it if even a little bit for your sanity.
(((hugs)))
shell
I have leg spasms. Aside from the muscle relaxers, I use local warmth (hot washcloth) and massage. It seems to take the edge off.
Are you staying hydrated? With your aforementioned bladder issues, I was wondering if you were cutting back on your fluid intake to avoid an accident. Dehydrated muscles are more irritable. You could try increasing your fluid intake.
I hope things improve soon for you.
Ren