title: Frequency and prognosis of delayed facial palsy after microvascular decompression for hemifacial spasm.
abstract: BACKGROUND
  Microvascular decompression (MVD) for hemifacial spasm (HFS) provides a long-term cure rate. Delayed facial palsy (DFP) is not an unusual complication, but it has only been sporadically described in the literature. The purpose of this report is to evaluate the incidence of delayed facial palsy after MVD and its clinical course and final results.
  
  
  METHODS
  From January, 1998 to April, 2004, 410 patients underwent microvascular decompression for hemifacial spasm at our Institute. During this time, 21 patients (5.4%) developed delayed facial weakness; eighteen of them were given steroid medication and they were followed up in the out-patient clinic.
  
  
  RESULTS
  Twenty-one patients developed DFP after microvascular decompression an incidence of 5.4%. There were seventeen women (81.0%) among the 21 patients with DFP who were included in this study. In twenty of them, the symptoms of HFS improved completely after the operation, but the spasm remained with one of them. The onset of palsy occurred between postoperative day 7 and 23 (average: 12.1 days). The palsy was at least Grade II or worse on the House-Brackmann (HB) scale. The time to recovery averaged 5.7 weeks (range: 25 days-17 weeks); 20 patients improved to complete recovery and 1 patient remained with minimal weakness, as Grade II on the HB scale, at the follow-up examination.
  
  
  CONCLUSIONS
  Our findings demonstrated that the incidence of DFP was not so low as has been reported the literature, and it did not have any striking predisposing factors. Even though the degree of facial palsy was variable, almost all patients exhibited a complete recovery without any further special treatment. The etiology of DFP and its association with herpes infection should be further clarified.
authors.affiliation: Deparment of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: D J
authors.initials: DJ
authors.lastname: Rhee
authors.forename: D S
authors.initials: DS
authors.lastname: Kong
authors.forename: K
authors.initials: K
authors.lastname: Park
authors.forename: J A
authors.initials: JA
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D001488:Basilar Artery / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D015984:Causality; D019299:Decompression, Surgical / Q000009:adverse effects*; D005154:Facial Nerve / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology*; D005155:Facial Nerve Diseases / Q000150:complications / Q000503:physiopathology / Q000821:virology; D020220:Facial Nerve Injuries / Q000209:etiology* / Q000503:physiopathology; D005158:Facial Paralysis / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D019569:Hemifacial Spasm / Q000150:complications* / Q000503:physiopathology / Q000601:surgery; D016697:Herpes Zoster Oticus / Q000150:complications / Q000503:physiopathology; D006801:Humans; D008297:Male; D008866:Microsurgery / Q000009:adverse effects; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D011379:Prognosis; D013997:Time Factors; D014656:Vascular Surgical Procedures / Q000009:adverse effects*