title: Postural stability of preoperative acoustic neuroma patients assessed by sway magnetometry: are they unsteady?
abstract: OBJECTIVE
  The objective was to evaluate the preoperative postural stability of acoustic neuroma patients using sway magnetometry.
  
  
  METHODS
  Prospective two-center study.
  
  
  METHODS
  Fifty-one patients (mean age, 53 years) diagnosed with unilateral acoustic neuroma on magnetic resonance imaging at two tertiary referral centers were studied. Preoperatively, each patient had sway patterns (with eyes open and with eyes closed, and standing on foam) recorded for 120 seconds by sway magnetometry. Path length for 30 seconds was calculated. The Romberg coefficient (path length with eyes open divided by path length with eyes closed) was calculated.
  
  
  RESULTS
  Forty-four percent of patients had abnormal path lengths with eyes open, and 49% with eyes closed. The Romberg coefficients were significantly lower than normal (P <.001; 95% CI, 0.19-0.87). Mean Romberg coefficient was 0.59 (normal value = 0.73), and all patients had a coefficient of less than 1.
  
  
  CONCLUSIONS
  Half of preoperative acoustic neuroma patients are unsteady, exhibiting abnormal sway patterns based on path length measurements. The increase in sway path length demonstrable in normal subjects with eyes closed was significantly exaggerated in patients with acoustic neuroma.
authors.affiliation: Department of Otolaryngology, Freeman Hospital, Newcastle-upon-Tyne, UK. melaniemcollins@hotmail.com
authors.forename: Melanie M
authors.initials: MM
authors.lastname: Collins
authors.forename: Ian J M
authors.initials: IJ
authors.lastname: Johnson
authors.forename: Elaine
authors.initials: E
authors.lastname: Clifford
authors.forename: John P
authors.initials: JP
authors.lastname: Birchall
authors.forename: Gerald M
authors.initials: GM
authors.lastname: O'Donoghue
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008280:Magnetics / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000473:pathology / Q000601:surgery*; D011187:Posture / Q000502:physiology*; D011300:Preoperative Care; D011446:Prospective Studies; D011795:Surveys and Questionnaires