title: Vestibular Function After Cochlear Implantation: A Comparison of Three Types of Electrodes.
abstract: To investigate the vestibular function after cochlear implantation with different types of electrode arrays.
  
  
  
  Retrospective cohort study.
  
  
  
  Academic tertiary referral center.
  
  
  
  Forty three adults underwent first cochlear implantation. Three consecutive series of patients: Group 1 (n = 13) implanted with a precurved electrode, Group 2 (n = 15) implanted with a straight electrode, Group 3 (n = 15) implanted with a flexible electrode. Patient's vestibular functions were assessed with pre- and postoperative caloric testing using videonystagmography (VNG). The postoperative reduction of the maximum slow phase velocity (MSPV) in the implanted ear was evaluated. Medical charts were reviewed to evaluate the occurrence of late onset of postoperative vestibular symptoms.
  
  
  
  Mean reduction of MSPV was 7.6/s (standard deviation [SD] 8.0) in Group 1, 23.1/s (SD 16.6) in Group 2, and 0.1/s (SD 18.5) in Group 3. Significant difference was found between Group 1 and 2 (p < 0.030) and between Group 2 and 3 (p < 0.001). Group 2 showed a higher prevalence of late onset of clinical vertigo (28.6%) than Group 1 (7.7%) and 3 (6.7%).
  
  
  
  In this prospective study, significantly larger reductions of caloric responses were found in subjects implanted with a straight electrode compared with subjects implanted with a precurved or flexible electrode. These findings seem to correlate to a higher prevalence of postoperative vertigo.
authors.affiliation: *Department of Otorhinolaryngology in Linköping, Anaesthetics, Operations and Specialty Surgery Center, Region Östergötland†Division of Neuro and Inflammation Science, Department of Clinical and Experimental Medicine, Linköping University‡Linneaus Centre HEAD, Linköping University, Sweden.
authors.forename: Jonas
authors.initials: J
authors.lastname: Frodlund
authors.forename: Henrik
authors.initials: H
authors.lastname: Harder
authors.forename: Elina
authors.initials: E
authors.lastname: Mäki-Torkko
authors.forename: Torbjörn
authors.initials: T
authors.lastname: Ledin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003051:Cochlea / Q000503:physiopathology; D019929:Cochlear Implantation / Q000009:adverse effects*; D003054:Cochlear Implants / Q000009:adverse effects*; D005260:Female; D034381:Hearing Loss / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology; D012189:Retrospective Studies; D014717:Vertigo / Q000209:etiology* / Q000503:physiopathology; D014724:Vestibular Function Tests; D014722:Vestibule, Labyrinth / Q000503:physiopathology*