title: Prognostic factors of hemifacial spasm after microvascular decompression.
abstract: OBJECTIVE
  The factors that influence the prognosis of patients with hemifacial spasm (HFS) treated by microvascular decompression (MVD) have not been definitely established. We report a prospective study evaluating the prognostic factors in patients undergoing MVD for HFS.
  
  
  METHODS
  From January 2004 to September 2006, the authors prospectively studied a series of 293 patients who underwent MVD for HFS. We prospectively analyzed a number of variables in order to evaluate the predictive value of independent variables for the prognosis of patients undergoing MVD. The patients were followed-up at regular intervals and divided into as cured and unsatisfactory groups based on symptom relief. Uni- and multivariate analyses were performed using logistic regression models.
  
  
  RESULTS
  A total 273 of 293 (94.2%) patients achieved symptom relief within one year after the operation. Intraoperatively, the indentation of the root exit zone was observed in 259 (88.5%) patients. Uni- and multivariate analyses revealed that the symptoms at postoperative 3 months (p<0.001) and indentation of the root exit zone (p=0.036) were associated with good outcomes.
  
  
  CONCLUSIONS
  The intraoperative finding of root exit zone indentation will help physicians determine the prognosis in patients with HFS. To predict the prognosis of HFS, a regular follow-up period of at least 3 months following MVD should be required.
authors.affiliation: Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hong Rae
authors.initials: HR
authors.lastname: Kim
authors.forename: Deok-Joo
authors.initials: DJ
authors.lastname: Rhee
authors.forename: Doo-Sik
authors.initials: DS
authors.lastname: Kong
authors.forename: Kwan
authors.initials: K
authors.lastname: Park