It sounds like a seventh cranial nerve palsy which is unrelated to MS. Unknown etiology.
Diabetics are prone to this, but it sometimes comes on after flu, infection or herpes. They usually get worse over two to four days, then stabilize, and remain that way for one to three months. Treatment is anti-inflamatories. Prednisone for starters (for a few days), then NSAIDS daily. It's goof to get the nerve swelling down ASAP because the nerve has a warm ischemic time.