title: Effects of aminoglycoside administration on cochlear elements in human temporal bones.
abstract: OBJECTIVE
  Although there have been numerous reports on the relationship between the period of aminoglycoside administration and cochlear damage in animals, to date there have been no such studies in humans. The purpose of this study is to observe the early and late cochlear effects of aminoglycoside administration on hair cells, spiral ganglion cells, stria vascularis, and spiral ligament.
  
  
  METHODS
  Specimens were divided into three groups. Group I included "normal" temporal bones with no histopathologic findings of otitis media and no history of otologic or ototoxic drug administration. Group II consisted of temporal bones that received aminoglycosides within 2 weeks before death and group III of temporal bones that had aminoglycosides from 2 weeks to 6 months prior to death. Patients in groups II and III received gentamycin, kanamycin or tobramycin. Temporal bones were excluded from groups II and III if patients had a history of otologic disease or other ototoxic drugs. All temporal bones were examined under light microscopy. Standard cytocochleograms and spiral ganglion cell reconstructions were done on all temporal bones. Morphometric measurements of areas of stria vascularis were made in all turns of the cochlea on mid-modiolar sections. Spiral ligament was divided into four segments according to the locations of different types of fibrocytes. The mean loss of fibrocytes in each segment was estimated.
  
  
  RESULTS
  The percentages of intact outer hair cells in the basal turn were significantly greater in group I compared to groups II and III. The mean area of the stria vascularis in the apical turn was significantly less in groups II and III compared to group I.
  
  
  CONCLUSIONS
  This study demonstrates that in a short period (within 2 weeks) after aminoglycoside administration, a decrease in hair cells and in the area of the stria vascularis occurred.
authors.affiliation: International Hearing Foundation, Minneapolis, MN, USA.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kusunoki
authors.forename: Sebahattin
authors.initials: S
authors.lastname: Cureoglu
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Schachern
authors.forename: Andre
authors.initials: A
authors.lastname: Sampaio
authors.forename: Hisaki
authors.initials: H
authors.lastname: Fukushima
authors.forename: Mehmet F
authors.initials: MF
authors.lastname: Oktay
authors.forename: Michael M
authors.initials: MM
authors.lastname: Paparella
mesh_terms: D000287:Administration, Topical; D000293:Adolescent; D000328:Adult; D000368:Aged; D000617:Aminoglycosides / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D002648:Child; D003051:Cochlea / Q000187:drug effects* / Q000473:pathology; D005839:Gentamicins / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology; D018072:Hair Cells, Auditory, Outer / Q000187:drug effects / Q000473:pathology; D006801:Humans; D007612:Kanamycin / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology; D008875:Middle Aged; D013136:Spiral Ganglion / Q000187:drug effects / Q000473:pathology; D013316:Stria Vascularis / Q000187:drug effects / Q000473:pathology; D013701:Temporal Bone / Q000187:drug effects* / Q000473:pathology; D014031:Tobramycin / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D005839:Gentamicins; D007612:Kanamycin; D014031:Tobramycin