Spasticity is a common MS symptom that manifests itself an uncommon ways. For example, I experience a band of tightness around my rib cage most every night. It's as if someone took a belt and pulled it as tightly as possible. I can actually feel the difference between the muscles in spasm and the normal ones surrounding it.
My neurologists theorize that the problem is caused by thoracic lesions on my spinal cord that are too small to show up on an MRI. From my perspective, I don't care as much about why it happens as I do about how to remedy the situation. The good thing is that it seldom happens all day. I notice it most when I'm trying to fall asleep at night. My approach is to combine traditional and alternative medicine to help make me comfortable. I take 20 mg of an anti-spasmodic medication called Baclofen along with 50 mg of an older, anti-depressant called amitriptyline that reduces neuropathic pain. On top of this, I add deep breathing and relaxation techniques. By trying to slowly expand and contract my rib cage, I can get my muscles to stop contracting as hard.
General books on MS that I've come across describe this phenomenon as the "MS hug." I can assure you that it doesn't feel like any hug I've ever had. I am thankful that mine is lower than where the bottom of my bra sits. Other women have told me how awful that is. They avoid wearing their boulder holders unless they're out in public. It's bad enough to have MS, but who wants to explain that your boobs are saggy because wearing a bra is far too painful. That reminds me that I had a mammogram yesterday, but that's a whole other story.