In my experience, multiple sclerosis does not produce facial drooping or facial sagging.
Left sided facial droop is generally the result of mental and physical trauma to the nerves that control the facial muscles, like extreme anger and a CVA (cerebrovascular accident).
Multiple sclerosis affects mainly the sciatic nerves, rendering a person incapacitated, unable to stand, unable to walk, unable to raise the legs, unable to stretch, and there is mid and lower back pain associated with multiple sclerosis.
It took me four years to rehabilitate a German lady in her late 30s. She came to me in crutches. Even into her third year of rehabilitation, she would be on the floor unable to get up and she would call me at night. I would drive 30 miles at night to help her with rehabilitation exercises just so she could get up again. Each of those sessions would take about 4 hours for her to be able to stand up again. It took at least 45 minutes to drive to her place and I would usually arrive at around 9:30 or 10:00 p.m and leave around 3:00 a.m. in the morning.