Replying to @scotlycrue's post:
Hi Scott,
I think spasm can refer to any involuntary muscle contraction, so I'll just enumerate every kind I have and let you decide which (if any) are applicable to your situation. :)
I was diagnosed with MMN about nine months ago, with symptoms starting about nine months before that. Since then I have experienced twitches all over, including chest and stomach. These single, brief muscle contractions are not painful and only occur when the muscle is at rest. I don't know how common this is or even if it is MMN-related.
I also get fasciculations, which I experience as weak, brief, usually repeated contractions. I only get these in the extremities. They are quite common in MMN.
I am also prone to cramps in the extremities and, very occasionally, the side of my chest (feels like it is between ribs). These are painful and generally triggered by contracting an overexerted muscle. They may be normal as they started long before I had any MMN symptoms, though I think they have increased since.
As you may already know, not all cases of MMN respond to IVIg: the rate is usually estimated to be 80-90%. Unfortunately there is no definitive test for MMN.
I hope your next doctor can get to the bottom of your symptoms.
Best wishes,
CM