Hemifacial spasm is a nervous system disorder in which the muscles on one side of your face twitch involuntarily. Hemifacial spasm is most often caused by a blood vessel touching a facial nerve, but it may be caused by a facial nerve injury or a tumor, or it may not have a cause.
Hemifacial spasms typically occur more often on the left side of your face and are not considered dangerous on their own. Most patients report that the ever-present ‘twitch’ in the face can be frustrating or uncomfortable. In severe cases, these spasms can limit function due to involuntary eye closing or the impact they have on speaking.
In the procedure called microvascular decompression, a neurosurgeon lifts a blood vessel off the nerve it’s compressing, then inserts a small pad between the vessel and the nerve to relieve the pressure. Surgery for hemifacial spasm is a procedure called microvascular decompression.