What Causes Recurring Drooping Of Eye Lids?

I have been having on and off drooping of my right upper eye lid for the past 3-4 months. the episodes occur for about 3-4 days in which the drooping can occur a dozen + times in the course of a day. My eye lid droops for about 15-20 seconds and then returns to normal. No vision changes are noticed. No other facial drooping or other stroke like symptoms have been noted. I have been referred to a neurologist but don t have an appointment for a month. I had a Ct scan of my head done in July after an episode of labrynthitis which resulted in some right facial numbness, which did resolve on it own after a few days. That CT scan was deemed normal at that time.