Last Updated: September 30, 2018
Hemifacial spasm (HFS) is a cranial nerve hyperactivity disorder most likely caused by neurovascular conflict (compression) as one of its underlying etiological phenomenon. It is typically characterized by unilateral involuntary intermittent twitching of the muscles of the face. The spasms usually start around the eye, involving the orbicularis oculi muscle, and later spread to other muscles of the face that are innervated by the facial nerve, including the platysma. The spasms are bilateral in about 2% of the patients with this disorder.
Hemifacial spasm has an estimated prevalence of 11 cases per 100000 individuals and is twice as common in females as males. Onset is mostly during the 4th and 5t...