Head growth in infants with hypoxic-ischemic encephalopathy: Correlation with neonatal magnetic resonance imaging

Objectives. The aims of the study were to establish the relationship betwee n head growth in the first year of life with the pattern on injury on neona tal magnetic resonance imaging (MRI) in infants with hypoxic-ischemic encep halopathy (HIE) and to relate these to the neurodevelopmental outcome. Methods. Fifty-two term infants who presented at birth with a neonatal ence phalopathy consistent with HIE and who had neonatal brain MRI were entered into the study. Head circumference charts were evaluated retrospectively an d the head growth over the first year of life compared with the pattern of brain lesions on MRI and with the neurodevelopmental outcome at 1 year of a ge. Suboptimal head growth was classified as a drop of >2 standard deviatio ns across the percentiles with or without the development of microcephaly, which was classified as a head circumference below the third percentile. Results. There was no statistical difference between the neonatal head circ umferences of the infants presenting with HIE and control infants. At 12 mo nths, microcephaly was present in 48% of the infants with HIE, compared wit h 3% of the controls. Suboptimal head growth was documented in 53% of the i nfants with HIE, compared with 3% of the controls. Suboptimal head growth w as significantly associated with the pattern of brain lesions, in particula r to involvement of severe white matter and to severe basal ganglia and tha lamic lesions. Suboptimal head growth predicted abnormal neurodevelopmental outcome with a sensitivity of 79% and a specificity of 78%, compared with the presence of microcephaly at 1 year of age, which had a sensitivity of o nly 65% and a specificity of 73%. The exceptions were explained by infants with only moderate white matter abnormalities who had suboptimal head growt h but normal outcome at 1 year of age and by infants with moderate basal ga nglia and thalamic lesions only who had normal head growth but significant motor abnormality.