title: Abnormalities in auditory evoked potentials of 75 patients with Arnold-Chiari malformations types I and II.
abstract: OBJECTIVE
  To evaluate the frequency and degree of severity of abnormalities in the auditory pathways in patients with Chiari malformations type I and II.
  
  
  METHODS
  This is a series-of-case descriptive study in which the possible presence of auditory pathways abnormalities in 75 patients (48 children and 27 adults) with Chiari malformation types I and II were analyzed by means of auditory evoked potentials evaluation. The analysis was based on the determination of intervals among potentials peak values, absolute latency and amplitude ratio among potentials V and I.
  
  
  RESULTS
  Among the 75 patients studied, 27 (36%) disclosed Arnold-Chiari malformations type I and 48 (64%) showed Arnold-Chiari malformations type II. Fifty-three (71%) of these patients showed some degree of auditory evoked potential abnormalities. Tests were normal in the remaining 22 (29%) patients.
  
  
  CONCLUSIONS
  Auditory evoked potentials testing can be considered a valuable instrument for diagnosis and evaluation of brain stem functional abnormalities in patients with Arnold-Chiari malformations type I and II. The determination of the presence and degree of severity of these abnormalities can be contributory to the prevention of further handicaps in these patients either through physical therapy or by means of precocious corrective surgical intervention.
authors.affiliation: Neurophysiology Department, International Center of Neural Science and Rehabilitation, North Lake SARAH Hospital, University of Brasilia School of Medicine Pos-Graduation Program, DF, Brazil. pazeredo@linkexpress.com.br
authors.forename: Paulo Sergio A
authors.initials: PS
authors.lastname: Henriques Filho
authors.forename: Riccardo
authors.initials: R
authors.lastname: Pratesi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001139:Arnold-Chiari Malformation / Q000145:classification / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D006801:Humans; D007223:Infant; D008875:Middle Aged; D011930:Reaction Time / Q000502:physiology; D012720:Severity of Illness Index