Since MS is a disease of the central nervous system, it does not directly cause
muscle pain. MS can cause neuropathic
pain, or it can cause spasticity that can cause muscle pain.
Ibuprofen is an anti-inflammatory and while it may address the pain due to inflammation, it does nothing for the "cause" and like ALL NSAIDs, it may increase cardiac risks (like the COX-2 inhibitors.) All drugs have side effects.