Focal burst-suppression induced by thiopental

Five patients were subjected to a thiopental fast activation test, recording with implanted depth electrodes in two patients and at electrocorticography in 3 patients. A burst-suppression pattern was seen focally in each patient, while adjacent regions in that hemisphere and in the contralateral hemisphere had continuous activity. Although detected in depth electrodes, this pattern was not seen with simultaneous scalp electrode recording. This focal pattern correlated with the presence of a pathological abnormality on histologic examination in all patients. It is postulated that the appearance of a focal burst-suppression pattern during a thiopental fast activation test implies the presence of underlying structural abnormality.