title: Application of envelope trend to analyze early EEG changes in the frontal regions during intracarotid amobarbital procedure in children.
abstract: BACKGROUND
  Intracarotid amobarbital procedure (IAP) is acknowledged as the gold standard test for language lateralization. EEG is performed routinely during IAP to monitor the anesthetization of a brain hemisphere. Here, we studied the correlation between the early EEG changes using envelope trend and the clinical outcome of IAP.
  
  
  METHODS
  Fifty consecutive patients underwent IAP at Texas Children's Hospital (2004-2009). Intracarotid amobarbital procedure was considered "complete" or "incomplete" based on the outcome if the procedure was completed or aborted due to behavior changes. Envelope trend was used to calculate the median EEG amplitude changes within the first 60s of IAP. Statistical analysis was performed to determine the role of EEG changes and clinical features on the procedure outcome.
  
  
  RESULTS
  Only 30 IAP-EEG files were available for review. Amobarbital was administered at the dose of 60-150mg (mean: 110±20). The intracarotid amobarbital procedure was recorded as complete in 23 patients and incomplete in 7 patients. EEG changes occurred within the first few seconds following amobarbital injection. Following amobarbital injection, focal slowing was present in the ipsilateral frontal region or both ipsilateral and contralateral frontal regions. Elapsed time to the first EEG change or duration and change in median EEG amplitude in the ipsilateral frontal regions were indifferent between the complete and incomplete groups (p>0.05). However, the median amplitude changes between the ipsilateral and contralateral frontal regions within each group were found significant only in the complete group (p<0.05), suggesting ipsilateral without contralateral frontal slowing. Other than age at the time of IAP (p=0.03), none of the other clinical features correlated with the clinical outcome of IAP (p>0.05).
  
  
  CONCLUSIONS
  Early EEG changes during IAP using envelope trend may predict successful completion of the IAP test. Younger children are at risk of behavioral changes during IAP.
authors.affiliation: Division of Pediatric Neurology, Texas Children's Hospital, Houston, TX, USA; Division of Pediatric Neurology, Clinical Neurophysiology, Texas Children's Hospital, Houston, TX, USA. Electronic address: cia11@columbia.edu.
authors.forename: Cigdem I
authors.initials: CI
authors.lastname: Akman
authors.affiliation: Division of Pediatric Neurology, Texas Children's Hospital, Houston, TX, USA.
authors.forename: Vesna
authors.initials: V
authors.lastname: Micic
authors.affiliation: Division of Pediatric Neurology, Texas Children's Hospital, Houston, TX, USA; Division of Pediatric Neurology, Clinical Neurophysiology, Texas Children's Hospital, Houston, TX, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Quach
authors.affiliation: Division of Pediatric Neurology, Texas Children's Hospital, Houston, TX, USA.
authors.forename: Angus A
authors.initials: AA
authors.lastname: Wilfong
authors.affiliation: Division of Pediatric Neurology, Texas Children's Hospital, Houston, TX, USA.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Schultz
authors.affiliation: Division of Pediatric Neurology, Texas Children's Hospital, Houston, TX, USA; Division of Pediatric Neurology, Clinical Neurophysiology, Texas Children's Hospital, Houston, TX, USA.
authors.forename: James J
authors.initials: JJ
authors.lastname: Riviello
authors.affiliation: Division of Pediatric Neurology, Texas Children's Hospital, Houston, TX, USA.
authors.forename: Mary L
authors.initials: ML
authors.lastname: Chapieski
mesh_terms: D000293:Adolescent; D000654:Amobarbital / Q000008:administration & dosage; D002339:Carotid Arteries; D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography / Q000187:drug effects*; D004827:Epilepsy / Q000175:diagnosis* / Q000523:psychology*; D005260:Female; D005625:Frontal Lobe / Q000187:drug effects*; D007839:Functional Laterality; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage; D007261:Infusions, Intra-Arterial; D007802:Language; D008297:Male; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D006993:Hypnotics and Sedatives; D000654:Amobarbital
keywords: Children; EEG; Epilepsy; Neuropsychology; The intracarotid amobarbital procedure; Wada test