title: Chronological changes of hearing in pediatric patients with large vestibular aqueduct syndrome.
abstract: OBJECTIVE
  To describe the chronologic changes of hearing in patients with large vestibular aqueduct syndrome (LVAS) and identify the prognostic factors.
  
  
  METHODS
  A retrospective chart-review study.
  
  
  METHODS
  Twelve consecutive patients with LVAS were recruited at Taipei Veterans General Hospital between July 1986 and July 2000. The records of serial pure-tone audiogram and high-resolution computer tomography were collected. The chronologic figures of pure-tone average (PTA) were sketched. The investigated variables included sex, laterality and type of hearing loss (HL), size of vestibular aqueduct, and the chronologic changes and configurations of hearing. Data were analyzed statistically.
  
  
  RESULTS
  The degree of HL in early childhood was from moderate to profound. The worst hearing could be estimated by the hearing level in early childhood. Sixteen of 24 ears were stable. Bilateral, chronologically stepwise-downhill hearing occurred in only one patient (1/12) during the follow-up period. Chronologically, high-tone hearings were worse than those of low-tone, but fluctuations of high-tone hearing were smaller than those of low-tone. The sizes of vestibular aqueduct were predictive of the density of major depression and its depth.
  
  
  CONCLUSIONS
  LVAS, a congenital disease, is characterized by fluctuating sensorineural HL. Most hearing at PTA remained stable at least in one ear chronologically. The standard deviation of hearing at 500 Hz was the only prognostic factor for the progression of PTA. An enlarged vestibular aqueduct affects fluctuations of hearing, but the pathogenesis of HL still remains unclear and deserves further investigations.
authors.affiliation: Department of Otolaryngology, National Yang-Ming University, Taipei, Taiwan, Republic of China.
authors.forename: Chien-Chung
authors.initials: CC
authors.lastname: Lai
authors.forename: An-Suey
authors.initials: AS
authors.lastname: Shiao
mesh_terms: D000158:Acoustic Impedance Tests / Q000379:methods; D000293:Adolescent; D001301:Audiometry, Pure-Tone; D002648:Child; D002675:Child, Preschool; D002909:Chronobiology Phenomena / Q000502:physiology; D004432:Ear, Middle / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000209:etiology*; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013577:Syndrome; D014723:Vestibular Aqueduct / Q000503:physiopathology*; D015837:Vestibular Diseases / Q000150:complications* / Q000503:physiopathology