Unfortunately there aren't really any effective treatments to address numbness caused by MS. It will either remit on its own, or it won't. I've have numbness in the same area, as well as my arms and hands, for years. I take meds for neuropathic pain caused by MS, but they have no effect on my numbness, nor have steroids ever relieved it. I've just learned to live with it, because there's no alternative.
You should keep your neurologist informed of any new symptoms, and perhaps consider have the problem assessed to rule out other non-MS causes (eg: compressed nerve).
I peeked back at some of your initial posts, and you do not mention a dx of MS.
It's important for you to call your jot this down, specifically, describe the numbness, i.e., If you lean on something do you not feel anything touching your skin? And, what happens with your arms when they "feel" numb. Describe those sensation in your notes.
There are clear distinctions between numbness (i.e., when you can't feel them), and feeling something on your skin when it is touched, pressed, hot and cold sensation, or none, etc.
Once you have it written down, you'll be able to better describe to the doctor exactly what you are experiencing.
There are things that can be done to reduce inflammation, for example, if this is a c-spine issue (oftentimes the culprit with what you describe), and even for those of us with MS, there are things that can try to do to reduce these sensations (meds, prednisone, etc), And, sometimes it's just good old fashion "time" unfortunately :( And, remember, permanency is not always the case.
Hope this helps.