title: Vascular compression of the cochlear nerve and tinnitus: a pathophysiological investigation.
abstract: OBJECTIVE
  Chronic microvascular compressions of the eighth nerve induce a slowing down of signal transmission in the auditory nerve, electrophysiologically characterized by IPL I-III prolongation.
  
  
  METHODS
  The authors hypothesize this is compensated by an active slowing down of signal transmission of the contralateral input at the level of the brainstem, characterized by contralateral IPL III-V prolongation.
  
  
  RESULTS
  Differences between ipsilateral and contralateral IPL I-III and IPL III-V are analyzed before and after microvascular decompression. ABR diagnostic criteria for microvascular compression are ipsilateral IPL I-III prolongation or ipsilateral peak II decrease + ipsilateral IPL I-III prolongation. With IPL I-III as diagnostic criterion, unlike preoperatively the difference between the ipsi- and contralateral IPL I-III is significant postoperatively. When using the stricter diagnostic criterion of IPL I-III + peak II, there is a preoperative significant difference between ipsi- and contralateral IPL I-III, but postoperatively the difference between the ipsi- and contralateral IPL I-III is not significant.
  
  
  CONCLUSIONS
  Preoperatively, there is a marginal significant difference between the ipsi- and contralateral IPL III-V, which disappears postoperatively.
authors.affiliation: TRI Tinnitus Clinic, BRAI2N & Department of Neurosurgery, University Hospital Antwerp, Edegem, Belgium.
authors.forename: Dirk
authors.initials: D
authors.lastname: De Ridder
authors.forename: Sven
authors.initials: S
authors.lastname: Vanneste
authors.forename: Ine
authors.initials: I
authors.lastname: Adriaensens
authors.forename: Alison Po Kee
authors.initials: AP
authors.lastname: Lee
authors.forename: Paul
authors.initials: P
authors.lastname: van de Heyning
authors.forename: Aage
authors.initials: A
authors.lastname: Möller
mesh_terms: D000328:Adult; D000368:Aged; D001933:Brain Stem / Q000503:physiopathology / Q000601:surgery; D003056:Cochlear Nerve / Q000503:physiopathology* / Q000601:surgery; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D006801:Humans; D008297:Male; D061145:Microvascular Decompression Surgery; D008875:Middle Aged; D014012:Tinnitus / Q000503:physiopathology* / Q000601:surgery