title: Mechanisms of morbid hearing loss associated with tumors of the endolymphatic sac in von Hippel-Lindau disease.
abstract: BACKGROUND
  Endolymphatic sac tumors (ELSTs) are associated with von Hippel-Lindau disease and cause irreversible sensorineural hearing loss (SNHL) and vestibulopathy. The underlying mechanisms of audiovestibular morbidity remain unclear and optimal timing of treatment is not known.
  
  
  OBJECTIVE
  To define the mechanisms underlying audiovestibular pathophysiology associated with ELSTs.
  
  
  METHODS
  Prospective and serial evaluation of patients with von Hippel-Lindau disease and ELSTs at the National Institutes of Health between May 1990 and December 2006.
  
  
  METHODS
  Clinical findings and audiologic data were correlated with serial magnetic resonance imaging and computed tomography imaging studies to determine mechanisms underlying audiovestibular dysfunction.
  
  
  RESULTS
  Thirty-five patients with von Hippel-Lindau disease and ELSTs in 38 ears (3 bilateral ELSTs) were identified. Tumor invasion of the otic capsule was associated with larger tumors (P = .01) and occurred in 7 ears (18%) causing SNHL (100%). No evidence of otic capsule invasion was present in the remaining 31 ears (82%). SNHL developed in 27 of these 31 ears (87%) either suddenly (14 ears; 52%) or gradually (13 ears; 48%) and 4 ears had normal hearing. Intralabyrinthine hemorrhage was found in 11 of 14 ears with sudden SNHL (79%; P < .001) but occurred in none of the 17 ears with gradual SNHL or normal hearing. Tumor size was not related to SNHL (P = .23) or vestibulopathy (P = .83).
  
  
  CONCLUSIONS
  ELST-associated SNHL and vestibulopathy may occur suddenly due to tumor-associated intralabyrinthine hemorrhage, or insidiously, consistent with endolymphatic hydrops. Both of these pathophysiologic mechanisms occur with small tumors that are not associated with otic capsule invasion.
authors.affiliation: Diagnostic Radiology Department, The Clinical Center of the National Institutes of Health, Bethesda, MD 20892, USA. jbutman@nih.gov
authors.forename: John A
authors.initials: JA
authors.lastname: Butman
authors.forename: H Jeffrey
authors.initials: HJ
authors.lastname: Kim
authors.forename: Martin
authors.initials: M
authors.lastname: Baggenstos
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Ammerman
authors.forename: James
authors.initials: J
authors.lastname: Dambrosia
authors.forename: Athos
authors.initials: A
authors.lastname: Patsalides
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Patronas
authors.forename: Edward H
authors.initials: EH
authors.lastname: Oldfield
authors.forename: Russell R
authors.initials: RR
authors.lastname: Lonser
mesh_terms: D000293:Adolescent; D000328:Adult; D001299:Audiometry; D004428:Ear Neoplasms / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D004487:Edema; D004712:Endolymphatic Sac; D005260:Female; D034381:Hearing Loss / Q000209:etiology*; D006470:Hemorrhage; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D014057:Tomography, X-Ray Computed; D006623:von Hippel-Lindau Disease / Q000150:complications*