title: Is it always necessary to apply botulinum toxin into the lower facial muscles in hemifacial spasm?: a randomized, single-blind, crossover trial.
abstract: BACKGROUND
  Botulinum toxin (BTX) injections are accepted as safe and efficacious in the treatment of hemifacial spasm (HFS), but it is still debated whether BTX treatment of lower facial muscles should be performed or not.
  
  
  OBJECTIVE
  The study aims to evaluate the necessity of BTX administration into lower facial muscles in patients with HFS.
  
  
  METHODS
  A randomized, single-blind, crossover, clinical trial was conducted. Twenty-three HFS patients were randomly allocated to two different application methods. The patients were administered BTX type A into both the orbicularis oculi and perioral muscles in the first method and BTX type A into the orbicularis oculi but placebo into the perioral muscles in the second method. Subjects were crossed over to the alternate method when they needed BTX injection with a minimum of 3 months' duration. All the patients underwent both methods with no change in the total dose of BTX.
  
  
  RESULTS
  All the patients benefited from BTX treatment regardless of the methods. However, in the patients with severe lower facial muscle involvement, the application of BTX into both orbicularis oculi and lower facial muscles led to better results.
  
  
  CONCLUSIONS
  Our data suggest that BTX application to lower facial muscles might not be necessary in patients with mild lower facial involvement.
authors.affiliation: Department of Neurology, Dokuz Eylül University, Medical School, Izmir, Turkey. berril.donmez @ deu.edu.tr
authors.forename: Beril Donmez
authors.initials: BD
authors.lastname: Colakoglu
authors.forename: Raif
authors.initials: R
authors.lastname: Cakmur
authors.forename: Fatma
authors.initials: F
authors.lastname: Uzunel
mesh_terms: D000368:Aged; D019274:Botulinum Toxins, Type A / Q000627:therapeutic use*; D018592:Cross-Over Studies; D005152:Facial Muscles / Q000187:drug effects* / Q000502:physiology*; D005260:Female; D019569:Hemifacial Spasm / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009465:Neuromuscular Agents / Q000627:therapeutic use*; D010147:Pain Measurement; D016037:Single-Blind Method
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A