title: Hemifacial spasm caused by vertebral artery dolichoectasia.
abstract: OBJECTIVE
  To display the characteristic magnetic resonance imaging (MRI) abnormalities associated with hemifacial spasm caused by compression of the seventh cranial nerve by a dolichoectatic vertebral artery.
  
  
  METHODS
  Interventional case report.
  
  
  METHODS
  Correlation of imaging and clinical findings.
  
  
  RESULTS
  In a 36-year-old man with mild left hemifacial spasm, MRI showed an enlarged (dolichoectatic) vertebral artery that compressed the seventh cranial nerve at its exit from the caudal pons. Manifestations of hemifacial spasm were relieved with periocular botulinum toxin injections.
  
  
  CONCLUSIONS
  In hemifacial spasm, MRI may show compression of the ipsilateral seventh cranial nerve or other structural abnormalities. Relief of hemifacial spasm may occur with botulinum toxin injection or with neurosurgical intervention designed to relieve the compression.
authors.affiliation: Department of Ophthalmology, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Ersalan A
authors.initials: EA
authors.lastname: Rahman
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Trobe
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Gebarski
mesh_terms: D000328:Adult; D019274:Botulinum Toxins, Type A / Q000627:therapeutic use; D005155:Facial Nerve Diseases / Q000175:diagnosis / Q000209:etiology; D019569:Hemifacial Spasm / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology*; D006801:Humans; D007267:Injections; D008279:Magnetic Resonance Imaging; D008297:Male; D009408:Nerve Compression Syndromes / Q000175:diagnosis / Q000209:etiology; D009465:Neuromuscular Agents / Q000627:therapeutic use; D014715:Vertebrobasilar Insufficiency / Q000150:complications* / Q000175:diagnosis
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A