title: Prediction of long-term facial nerve outcomes with intraoperative nerve monitoring.
abstract: OBJECTIVE
  Evaluate the utility of a statistical equation using two independent intraoperative monitoring parameters in predicting long-term facial nerve function.
  
  
  METHODS
  Retrospective case review.
  
  
  METHODS
  Tertiary care hospital.
  
  
  METHODS
  Sixty patients undergoing resection of vestibular schwannomas with intraoperative facial nerve monitoring at a single institution.
  
  
  METHODS
  All patients underwent microsurgical resection of vestibular schwannomas with the use of intraoperative cranial nerve monitoring.
  
  
  METHODS
  Final facial nerve outcome measured using the House-Brackmann scale at least 6 months after microsurgical resection.
  
  
  RESULTS
  Five out of 60 (8.3%) patients demonstrated significant long-term weakness (i.e., House-Brackmann grade III or worse). Intraoperative monitoring parameters (proximal stimulation threshold, proximal-to-distal response amplitude ratio) were accurate in predicting increased risk of long-term facial nerve dysfunction when used in a logistic regression model. A Student's t test confirmed the equation result was statistically significant in differentiating long-term facial nerve outcomes.
  
  
  CONCLUSIONS
  Patients with immediate weakness are at higher risk of having long-term poor facial nerve function. The use of intraoperative monitoring parameters was reliable in predicting facial nerve outcomes. Patients with permanent facial nerve dysfunction often require rehabilitative procedures. The ability to predict facial nerve outcomes with intraoperative monitoring may allow early rehabilitative procedures to improve quality of life and prevent ocular complications.
authors.affiliation: University of Michigan Hospitals, Department of Otolaryngology-Head and Neck Surgery, Ann Arbor, Michigan, USA.
authors.forename: Brandon
authors.initials: B
authors.lastname: Isaacson
authors.forename: Paul R
authors.initials: PR
authors.lastname: Kileny
authors.forename: Hussam K
authors.initials: HK
authors.lastname: El-Kashlan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D004558:Electric Stimulation; D004568:Electrodiagnosis / Q000295:instrumentation*; D005154:Facial Nerve / Q000503:physiopathology*; D020220:Facial Nerve Injuries / Q000175:diagnosis / Q000503:physiopathology / Q000517:prevention & control; D005158:Facial Paralysis / Q000175:diagnosis / Q000503:physiopathology / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D016343:Monitoring, Intraoperative / Q000295:instrumentation*; D009464:Neuroma, Acoustic / Q000601:surgery*; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data; D011183:Postoperative Complications / Q000175:diagnosis / Q000503:physiopathology / Q000517:prevention & control*; D011237:Predictive Value of Tests; D011336:Probability; D011379:Prognosis; D012189:Retrospective Studies; D012306:Risk; D012684:Sensory Thresholds / Q000502:physiology