It's usually one-sided. The earlier it goes, the more complete the recovery will be. It is suspected to be caused by the HSV-1 virus, which is already present in the facial nerve. Surgery activates it, and after 7-10 days, it's reached a point where it affects the nerve. Three to four weeks later, it subsides, and the Bells Palsy is relieved.
Most people call it botox.
It is very expensive. The diagnostic used to monitor cranial nerves, especially the 7th, during surgery to determine if it is injured. The diagnostic test which confirms HFS as opposed to other problems causing spasms. It usually starts around the eye and slowly progresses down the face. The muscles in the forehead and the neck are usually the last affected.