title: Is speech arrest during wada testing a valid method for determining hemispheric representation of language?
abstract: OBJECTIVE
  The intracarotid amobarbital procedure, or Wada test, is the method of choice to determine hemispheric representation of language, and is routinely used in the presurgical evaluation for intractable epilepsy. Some investigators perform comprehensive language assessments, but others base language lateralization solely on speech arrest. This study sought to determine whether speech arrest alone during Wada testing provides valid data regarding language lateralization.
  
  
  METHODS
  The subjects (previously reported) were 21 patients evaluated for intractable epilepsy, who underwent language lateralization by Wada testing and functional MRI (FMRI). For each patient, language representation was determined by calculating: (1) a Wada laterality index based exclusively on speech arrest; (2) a Wada laterality index based on comprehensive language assessment; and (3) an FMRI laterality quotient. Correlation coefficients and categorical classifications were analyzed.
  
  
  RESULTS
  There was no significant correlation between the Wada laterality quotient derived from duration of speech arrest and either the comprehensive Wada language laterality score (r =.35, p =.12) or FMRI language laterality score (r =.32, p =.16). Categorical classification as left, right or bilateral language also showed marked discordance between speech arrest and the other two methods.
  
  
  CONCLUSIONS
  Duration of speech arrest during Wada testing is not a valid measure of language dominance.
authors.affiliation: Department of Neurology, Cleveland Clinic Florida, Ft. Lauderdale, USA. benbads@cesmtp.ccf.org
authors.forename: S R
authors.initials: SR
authors.lastname: Benbadis
authors.forename: J R
authors.initials: JR
authors.lastname: Binder
authors.forename: S J
authors.initials: SJ
authors.lastname: Swanson
authors.forename: M
authors.initials: M
authors.lastname: Fischer
authors.forename: T A
authors.initials: TA
authors.lastname: Hammeke
authors.forename: G L
authors.initials: GL
authors.lastname: Morris
authors.forename: J A
authors.initials: JA
authors.lastname: Frost
authors.forename: J A
authors.initials: JA
authors.lastname: Springer
mesh_terms: D000654:Amobarbital; D001921:Brain / Q000187:drug effects*; D004827:Epilepsy; D007839:Functional Laterality; D018757:GABA Modulators; D006801:Humans; D013060:Speech / Q000502:physiology*
chemical_list: D018757:GABA Modulators; D000654:Amobarbital