Hemifacial spasm (HS) is another neurologic disease that causes involuntary contraction of specific muscles in the face. The spasms begin as infrequent, random movements which later become generalized and constant. These involuntary movements are only present on one side of the face, hence the term hemifacial (hemi means half). The spasms may be a manifestation of a vessel in the brainstem compressing the facial nerve or the presence of a tumor in that area. Therefore, it is important to perform an MRI in these patients. If the MRI is normal, the symptoms of the disease can be treated without surgery.

Hemifacial spasm responds very well to treatment with botulinum toxin injections. This is done in the office every two to four months, depending on the product used and the response to treatment. Botulinum toxin helps to relax the muscles and make the spasms disappear or improve significantly. The doses that are necessary to reduce the spasms are much larger than those utilized for aesthetic purposes.