Cognitive Outcomes After Neonatal Encephalopathy

Abstract

OBJECTIVES: To describe the spectrum of cognitive outcomes of children with and without cerebral palsy (CP) after neonatal encephalopathy, evaluate the prognostic value of early developmental testing and report on school services and additional therapies. METHODS:The participants of this study are the school-aged survivors of the National Institute of Child Health and Human Development Neonatal Research Network randomized controlled trial of whole-body hypothermia. Children underwent neurologic examinations and neurodevelopmental and cognitive testing with the Bayley Scales of Infant Development-II at 18 to 22 months and the Wechsler intelligence scales and the Neuropsychological Assessment-Developmental Neuropsychological Assessment at 6 to 7 years. Parents were interviewed about functional status and receipt of school and support services. We explored predictors of cognitive outcome by using multiple regression models.RESULTS: Subnormal IQ scores were identified in more than a quarter of the children: 96% of survivors with CP had an IQ ,70, 9% of children without CP had an IQ ,70, and 31% had an IQ of 70 to 84. Children with a mental developmental index ,70 at 18 months had, on average, an adjusted IQ at 6 to 7 years that was 42 points lower than that of those with a mental developmental index .84 (95% confidence interval, 249.3 to 235.0; P , .001). Twenty percent of children with normal IQ and 28% of those with IQ scores of 70 to 84 received special educational support services or were held back $1 grade level. CONCLUSIONS:Cognitive impairment remains an important concern for all children with neonatal encephalopathy. WHAT'S KNOWN ON THIS SUBJECT:Surviving infants with neonatal encephalopathy treated with hypothermia have lower rates of moderate to severe cerebral palsy and cognitive impairment at 18 to 24 months. Limited data exist on the association between cognitive functioning and neuromotor, behavioral, and school outcomes.WHAT THIS STUDY ADDS: Although the incidence of death or IQ ,55 is reduced after therapeutic hypothermia, survivors of neonatal encephalopathy with and without cerebral palsy are at elevated risk for subnormal IQ and the need for specialized educational services at 6 to 7 years. Dr Pappas conceptualized and designed the study, participated in data acquisition and interpretation, and drafted the initial manuscript; Dr Shankaran participated in the conceptualization and study design, data acquisition and interpretation, and review and revision of the manuscript; Mr McDonald and Dr Das participated in the study design and data interpretation, carried out the data analysis, and reviewed and revised the manuscript; Drs Vohr, Hintz, Ehrenkranz, Tyson, Yolton, Hammond, and Higgins and Ms Bara participated in the study design, data acquisition and interpretation, and review and revision of the manuscript; and all authors approved the final manuscript as submitted. (CP) proposed that an acute intrapartum event could not result in isolated cognitive deficits. 13 Yet early human studie...

Hypothermia for neonatal hypoxic–ischemic encephalopathy: NICHD Neonatal Research Network contribution to the field

“…All children with IQ < 70, 20% of children with normal IQ and 28% of those with IQ 70 to 84 received special educational support services or were held back ≥1 grade level. These data suggested that assessment and intervention for cognitive impairment should be undertaken in all children with neonatal encephalopathy, regardless of motor impairment 39 .…”

Hyperglycaemia in infants with hypoxic–ischaemic encephalopathy is associated with improved outcomes after therapeutic hypothermia: a post hoc analysis of the CoolCap Study

“…In the absence of a sentinel event, however, the timing, duration and chronicity of fetal hypoxia–ischaemia remain uncertain. Universal application of therapeutic hypothermia, without consideration for the heterogeneous pathophysiological mechanisms of injury, may be suboptimal, as many treated infants with moderate-to-severe HIE still die or survive with severe neurodevelopmental and cognitive impairment 7. This emphasises the importance of investigating whether laboratory and clinical parameters can be identified early after birth, to predict the response to hypothermia treatment and perhaps to guide the choice of individualised adjuvant neuroprotective therapies based on specific underlying pathophysiology among this heterogeneous population.…”

Outcomes in childhood following therapeutic hypothermia for neonatal hypoxic-ischemic encephalopathy (HIE)

“…The NICHD trial reported detailed cognitive outcomes in a secondary study of all children followed at 18 to 22 months and at school age 17 . 30 children were lost to follow-up (12 in the hypothermia group and 18 in the normothermia group).…”