Hi scuba,
All I can say is it's happened to me too.
The left side of my face is swollen to the point that my glasses leave a dent or crease on my temple area. Also a slight drooping that increases at times of triggers.
I was told by my neurologist is it's a symptom of my CRSP condition.
With no any real explination all I know that it's common in some cases. Sucks don't it?
I wish you luck...