Print OverviewHemifacial 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. CausesHemifacial spasm is most often caused by a blood vessel touching a facial nerve. It can also be caused by a facial nerve injury or a tumor. Sometimes there's no identifiable cause. By Mayo Clinic Staff Hemifacial spasm care at Mayo Clinic Request an Appointment at Mayo Clinic Diagnosis & treatment Dec. 20, 2018 Print Share on: FacebookTwitter Show references Daroff RB, et al. Parkinson disease and other movement disorders. In: Bradley's Neurology in Clinical Practice. 7th ed. Philadelphia, Pa.: Saunders Elsevier; 2016. https://www.clinicalkey.com. Accessed July 16, 2017. Chaudhry N, et al. Hemifacial spasm: The past, present and future. Journal of the Neurological Sciences. 2015;356:27. Hemifacial spasm. Merck Manual Professional Version. https://www.merckmanuals.com/professional/neurologic-disorders/neuro-ophthalmologic-and-cranial-nerve-disorders/hemifacial-spasm. Accessed July 16, 2017. Riggin EA. Allscripts EPSi. Mayo Clinic, Rochester, Minn. July 17, 2017. Hemifacial spasmSymptoms & causesDiagnosis & treatmentDoctors & departmentsCare at Mayo Clinic Advertisement Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission. Advertising & Sponsorship Policy Opportunities Ad Choices Mayo Clinic Marketplace Check out these best-sellers and special offers on books and newsletters from Mayo Clinic. NEW – Guide to FibromyalgiaInstant access – Mayo Clinic Health LetterDiabetes? This diet works …Stop osteoporosis in its tracksThe Mayo Clinic Diet Online CON-20373287 Patient Care & Health Information Diseases & Conditions Hemifacial spasm