title: Peripheral vestibular system in Down syndrome: quantitative assessment of vestibular histopathology.
abstract: OBJECTIVE
  To evaluate the maturity of the peripheral vestibular system in Down syndrome by examining the number of Scarpa's ganglion cells and the density of vestibular hair cells.
  
  
  METHODS
  Case-control study using human temporal bones.
  
  
  METHODS
  Tertiary academic center, otopathology laboratory.
  
  
  METHODS
  Sixteen temporal bones from 8 patients with Down syndrome and 15 control temporal bones from 8 individuals with no history of otologic disease were selected. Hypoplasia of the lateral semicircular canal (LSC) and vestibule was investigated by measuring the dimensions of the structures. Scarpa's ganglion cells were counted under light microscopy. The vestibular hair cells were counted in the LSC crista and the utricular and saccular maculae under differential interference contrast (Nomarski) microscopy and expressed as density.
  
  
  RESULTS
  The patients with Down syndrome were divided into 2 groups: with and without LSC hypoplasia. The number of Scarpa's ganglion cells and the density of vestibular hair cells were significantly smaller in both groups of patients with Down syndrome than in the control group. There was no significant difference in the number of Scarpa's ganglion cells or the density of vestibular hair cells between the groups with and without LSC hypoplasia.
  
  
  CONCLUSIONS
  The peripheral vestibular system, including Scarpa's ganglion cells and vestibular hair cells, is hypoplastic irrespective of the vestibular malformation in Down syndrome.
authors.affiliation: Department of Otolaryngology, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: Taro
authors.initials: T
authors.lastname: Inagaki
authors.forename: Norimasa
authors.initials: N
authors.lastname: Morita
authors.forename: Sebahattin
authors.initials: S
authors.lastname: Cureoglu
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Schachern
authors.forename: Shigenobu
authors.initials: S
authors.lastname: Nomiya
authors.forename: Rie
authors.initials: R
authors.lastname: Nomiya
authors.forename: Michael M
authors.initials: MM
authors.lastname: Paparella
mesh_terms: D000293:Adolescent; D002452:Cell Count; D002648:Child; D002675:Child, Preschool; D004314:Down Syndrome / Q000150:complications / Q000473:pathology*; D006198:Hair Cells, Auditory / Q000473:pathology*; D018069:Hair Cells, Vestibular / Q000473:pathology*; D006801:Humans; D007223:Infant; D012665:Semicircular Canals / Q000473:pathology; D015837:Vestibular Diseases / Q000150:complications / Q000473:pathology*; D014725:Vestibular Nerve / Q000473:pathology*; D014722:Vestibule, Labyrinth / Q000473:pathology*