Amplitude-Integrated Electroencephalogram and Cerebral Injury
Lena Hellström-Westas, MD, PhDDepartment of Paediatrics, University Hospital, SE-221 85 Lund, Sweden
Ingmar Rosén, MD, PhD
Department of Clinical Neurophysiology, University Hospital, SE-221 85 Lund, Sweden
Gorm Greisen, MD, PhD
Department of Neonatology, Rigshospitalet, Copenhagen, Denmark
To the Editor.—
We have, with interest, read the study by Inder et al.1 The findings in the study support previous studies that neurophysiologic measurements are sensitive for early evaluation of cerebral injury in preterm infants. The newly presented method, spectral edge frequency (SEF), seems to be very promising in this respect. We were, however, astonished when Inder et al in their paper first stated (about amplitude-integrated electroencephologram [aEEG]) that "no published data exist on its utility in evaluation of cerebral injury in the premature infant" and later that "There have been no published studies of use of the aEEG in the premature infant." This is not correct; there are several published studies on aEEG/CFM (cerebral function monitor) in preterm infants. The studies include investigations of early aEEG in relation to cranial ultrasound abnormalities and outcome, to cerebral blood flow, and to cerebral responses to medications and care procedures.2–12 The predictive ability agrees with EEG studies, eg, by Cornell et al who used tape-recorded 2-channel EEG to investigate cerebral injury in preterm infants.13,14 Thornberg and Thiringer15 published a study on normal CFM in full-term and preterm infants (from 30–31 weeks) in 1990. A review of aEEG for clinical and research purposes was recently published.16 Apparently, Inder et al did not consider the difference between the measure of EEG amplitude used in their study and that used by the CFM. The CFM gives more weight to higher frequencies and hence may have some of the qualities of SEF. Furthermore, the CFM gives a possibility of evaluating the degree of background discontinuity, a quality that directly correlates with severity of intraventricular hemorrhage in preterm infants. During the last few years there has been an encouraging development of new methods for monitoring of electrocortical activity in newborn infants. We hope that the new methods will be compared and evaluated together in the future, with the aim of developing methods that are optimal for early detection of cerebral injury in newborn infants.
REFERENCES
- Inder TE, Buckland L, Williams CE, et al. Lowered electroencephalographic spectral edge frequency predicts the rpesence of cerebral white matter injury in preterm infants.
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[Abstract/Free Full Text] - Thornberg E, Thiringer K. Normal patterns of cerebral function monitor traces in term and preterm neonates. Acta Paediatr Scand.1990; 79 :20 –25[Web of Science][Medline]
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Terrie E. Inder, MD, FRACP, MBChB
Royal Women’s and Royal Children’s Hospitals, Murdoch Children’s Research Institute, Melbourne, Australia
In Reply.—
In response to the letter from Drs Hellström-Westas, Rosén, and Greisen, I would first like to acknowledge the important contribution that these clinical investigators have made to the field of investigation of the aEEG in the newborn infant brain, as is reflected by their authorship of the cited articles in their letter. They have correctly highlighted that our manuscript has not cited the studies of aEEG in the premature newborn, and we are grateful for their highlighting this omission in the article for the general reader. Our study and article were highly focused on the relationship between these EEG measures and the presence of cerebral white matter injury, and thus have inadequately reflected the broader literature. Our introductory statement should have read that there is no published data that exist on aEEG in evaluation of cerebral "white matter" injury in the premature infant. This would have been a more correct statement, as highlighted by this response. Indeed, each EEG tool presents slightly unique information and may well complement each other in the assessment of both the premature and the term infant with cerebral injury. As suggested by these investigators, we are now undertaking a comparative analysis of these 2 tools in both the premature and the term infant and look forward to presenting that data in the near future.
PEDIATRICS (ISSN 1098-4275). ©2003 by the American Academy of Pediatrics
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