title: Tumor growth and audiometric change in vestibular schwannomas managed conservatively.
abstract: OBJECTIVE
  To prospectively define the correlation between changes in tumor volume and audiometric function in vestibular schwannomas managed conservatively.
  
  
  METHODS
  Prospective longitudinal study.
  
  
  METHODS
  Twenty-one patients (age range, 15-84 y; mean age, 63.3 y) with newly diagnosed vestibular schwannomas were enrolled between 1994 and 1999 in a protocol at The Ohio State University Hospital (Columbus, OH) to evaluate the correlation between tumor volume and audiometric change during a period of observation. Patients were evaluated yearly by clinical examination, a standardized internal auditory canal magnetic resonance imaging scan with gadolinium contrast for volumetric analysis, and audiometric function testing. Demographic data, historical features, neurofibromatosis type 2 (NF2) status, initial testing results, and serial testing results were recorded.
  
  
  RESULTS
  An increase in tumor volume occurred in 14 of the 21 patients (66%). The pattern of volumetric change was found to be extremely variable. Multiple regression analysis revealed significant correlations of changes in tumor volume with changes in pure-tone average and speech discrimination score (P < .0001 and P = .0021, respectively). Change in tumor volume had greater effect on pure-tone average and speech discrimination score in patients initially with class D audiometric function when compared with those initially in class A (P = .0083 and P = .0245, respectively). The presence of NF2 had an independent protective effect against deterioration of the pure-tone average when compared with patients without NF2 (P = .0125).
  
  
  CONCLUSIONS
  This study demonstrated a significant correlation between a change in volume and auditory deterioration in vestibular schwannomas being managed with a trial of observation. A given change in tumor volume appeared to have a greater effect on pure-tone average and speech discrimination score as initial auditory classification declined.
authors.affiliation: Department of Otolaryngology, The Ohio State University, Columbus 43210, USA.
authors.forename: D D
authors.initials: DD
authors.lastname: Massick
authors.forename: D B
authors.initials: DB
authors.lastname: Welling
authors.forename: E E
authors.initials: EE
authors.lastname: Dodson
authors.forename: M
authors.initials: M
authors.lastname: Scholfield
authors.forename: H N
authors.initials: HN
authors.lastname: Nagaraja
authors.forename: P
authors.initials: P
authors.lastname: Schmalbrock
authors.forename: D W
authors.initials: DW
authors.lastname: Chakeres
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001299:Audiometry; D004428:Ear Neoplasms / Q000473:pathology* / Q000503:physiopathology* / Q000628:therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000473:pathology* / Q000503:physiopathology* / Q000628:therapy; D011446:Prospective Studies; D012044:Regression Analysis; D013067:Speech Perception; D014723:Vestibular Aqueduct