Predictive value of the intracarotid amobarbital test in bihemispheric seizure onset

The intracarotid amobarbital test (IAT) is used to lateralize language func tion and assess hemispheric memory. In this study 23 non-lesional epileptic patients were evaluated. The magnitude of the difference in IAT scores bet ween the two hemispheres was significantly greater in the patients whose se izures lateralized on scalp or intracranial EEG than in patients with bihem ispheric seizure onset. This suggests that the IAT is useful not only in pr edicting lateralized seizure focus, but bihemispheric onset as well.