Original Articles

Serial Visual Evoked Potentials and Outcome in Term Birth Asphyxia Sarah C. Muttitt, MD*, Margot J. Taylor, PhD*, Jeffrey S. Kobayashi, MD~, Lynn MacMillan, RN*, and Hilary E. Whyte, MB*

Birth asphyxia is a major cause of neonatal mortality and morbidity. It remains difficult to predict accurately neurologic outcome among survivors, particularly infants with moderate hypoxic-ischemic encephalopathy. Visual evoked potential (VEP) is a reproducible measure of cortical function and reflects acute changes in central nervous system status secondary to asphyxial insult. We performed serial VEPs on 36 term infants with documented birth asphyxia to investigate the relationship between VEPs and neurodevelopmental outcome at 18 months of age. Fourteen infants were neurologically intact at subsequent examination; all had normal VEPs during the first week of life. Twenty-two infants had died or were significantly handicapped at 18 months of age; 20 had abnormal VEPs persisting beyond day 7 of life. Abnormal VEPs accurately predicted abnormal outcome (100%) and were both sensitive (91%) and specific (100%). In 20 infants who were classified as moderately asphyxiated according to the criteria of Sarnat and Sarnat, even greater accuracy, sensitivity, and specificity (all 100%) were observed. VEPs demonstrate good correlation with n e u r o d e v e l o p m e n t a l outcome in t e r m infants with birth asphyxia and provide accurate prognostic information useful in the clinical m a n a g e m e n t of these infants. Muttitt SC, Taylor M J, Kobayashi JS, MacMillan L, Whyte HE. Serial visual evoked potentials and outcome in term birth asphyxia. Pediatr Neurol 1991 ;7:86-90.

Introduction Despite advances in antenatal care, fetal monitoring techniques, obstetric intervention, and newborn resuscitation, the incidence of birth asphyxia among term infants has remained unchanged (2.9 - 9 per 1,000 live births) [16]. Birth asphyxia continues to be a major cause of neonatal mortality and is associated with an increased risk of chronic neurologic disability in childhood [4,7]. Prediction

From the *Divisions of Neonatology and Neurology; tHospital for Sick Children: University of Toronto: Toronto, Ontario, Canada.

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of neumlogic sequelae is accurate only among the most mildly or severely affected infants using clinical assessment, neuroimaging techniques, and electroencephalographic (EEG) monitoring. Prognosis for the moderately asphyxiated infant is more difficult and a simple, noninvasive means of reliably predicting significant handicap is not available. A number of studies have indicated that visual evoked potentials are sensitive to acute alterations in central nervous system (CNS) function during and following asphyxia and may provide information for long-term prognosis [8-101. In this study, we performed serial VEPs on term infants with perinatal asphyxia to investigate possible correlations between VEPs in the acute phase of birth asphyxia and long-tem~ neurodevelopmental outcome.

Methods The study population consisted of 36 term inlants with birth asphyxia admitted to the Neonatal Intensive Care Unit at the Hospital ff)r Sick Children, Toronto, Ontario, Canada. This population was entirely outhorn; all infants were _

Serial visual evoked potentials and outcome in term birth asphyxia.

Birth asphyxia is a major cause of neonatal mortality and morbidity. It remains difficult to predict accurately neurologic outcome among survivors, pa...
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