title: FMRI reveals functional cortex in a case of inconclusive Wada testing.
abstract: OBJECTIVE
  The intracarotid amobarbital test (Wada test) currently represents the gold standard for preoperative lateralization of hemispheric dominance. Here, we report an epileptic patient with a longstanding extended lesion of the left hemisphere showing absence of motor and speech dysfunction with left carotid amobarbital injection, but tetraplegia and speech arrest with right carotid injection interpreted as a neuroplastic shift of motor and language functions to the right hemisphere. In contrast to the Wada results, motor functional magnetic resonance imaging (fMRI) showed a strong left hemispheric activation with right hand movements.
  
  
  METHODS
  Right and left hand motor fMRI was performed. FMRI results and neurophysiological information obtained by motor and sensory evoked potential measurements were compared with the Wada test results.
  
  
  RESULTS
  Initial interpretation of neuroplastic shifts of intrinsic left hemisphere functions to the right brain was revised after fMRI results which were confirmed by motor and sensory evoked potentials.
  
  
  CONCLUSIONS
  As motor inactivation usually is thought to be the most robust feature of the Wada test, this case demonstrates that fMRI may reveal residual functional cortex in cases of inconclusive Wada results.
authors.affiliation: Study Group Clinical fMRI at the Department of Neurology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
authors.forename: Rupert
authors.initials: R
authors.lastname: Lanzenberger
authors.forename: Gerald
authors.initials: G
authors.lastname: Wiest
authors.forename: Alexander
authors.initials: A
authors.lastname: Geissler
authors.forename: Markus
authors.initials: M
authors.lastname: Barth
authors.forename: Helmut
authors.initials: H
authors.lastname: Ringl
authors.forename: Christian
authors.initials: C
authors.lastname: Wöber
authors.forename: Andreas
authors.initials: A
authors.lastname: Gartus
authors.forename: Christoph
authors.initials: C
authors.lastname: Baumgartner
authors.forename: Roland
authors.initials: R
authors.lastname: Beisteiner
mesh_terms: D000328:Adult; D000654:Amobarbital / Q000494:pharmacology; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000187:drug effects / Q000503:physiopathology*; D004292:Dominance, Cerebral / Q000502:physiology*; D004828:Epilepsies, Partial / Q000503:physiopathology; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D008279:Magnetic Resonance Imaging
chemical_list: D006993:Hypnotics and Sedatives; D000654:Amobarbital