title: White matter tract integrity and developmental outcome in newborn infants with hypoxic-ischemic encephalopathy treated with hypothermia.
abstract: OBJECTIVE
  To determine whether corpus callosum (CC) and corticospinal tract (CST) diffusion tensor imaging (DTI) measures relate to developmental outcome in encephalopathic newborn infants after therapeutic hypothermia.
  
  
  METHODS
  Encephalopathic newborn infants enrolled in a longitudinal study underwent DTI after hypothermia. Parametric maps were generated for fractional anisotropy, mean, radial, and axial diffusivity. CC and CST were segmented by DTI-based tractography. Multiple regression models were used to examine the association of DTI measures with Bayley-II Mental (MDI) and Psychomotor Developmental Index (PDI) at 15 months and 21 months of age.
  
  
  RESULTS
  Fifty-two infants (males n=32, females n=20) underwent DTI at median age of 8 days. Two were excluded because of poor magnetic resonance imaging quality. Outcomes were assessed in 42/50 (84%) children at 15 months and 35/50 (70%) at 21 months. Lower CC and CST fractional anisotropy were associated with lower MDI and PDI respectively, even after controlling for gestational age, birth weight, sex, and socio-economic status. There was also a direct relationship between CC axial diffusivity and MDI, while CST radial diffusivity was inversely related to PDI.
  
  
  CONCLUSIONS
  In encephalopathic newborn infants, impaired microstructural organization of the CC and CST predicts poorer cognitive and motor performance respectively. Tractography provides a reliable method for early assessment of perinatal brain injury.
authors.affiliation: Division of Neonatology, Children's National Medical Center, Washington, DC, USA; Department of Pediatrics, The George Washington University School of Medicine, Washington, DC, USA.
authors.forename: An N
authors.initials: AN
authors.lastname: Massaro
authors.forename: Iordanis
authors.initials: I
authors.lastname: Evangelou
authors.forename: Ali
authors.initials: A
authors.lastname: Fatemi
authors.forename: Gilbert
authors.initials: G
authors.lastname: Vezina
authors.forename: Robert
authors.initials: R
authors.lastname: Mccarter
authors.forename: Penny
authors.initials: P
authors.lastname: Glass
authors.forename: Catherine
authors.initials: C
authors.lastname: Limperopoulos
mesh_terms: D002657:Child Development / Q000502:physiology*; D003337:Corpus Callosum / Q000473:pathology* / Q000503:physiopathology; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced; D020925:Hypoxia-Ischemia, Brain / Q000473:pathology* / Q000503:physiopathology / Q000628:therapy; D007223:Infant; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000473:pathology* / Q000503:physiopathology; D008137:Longitudinal Studies; D008297:Male; D011712:Pyramidal Tracts / Q000473:pathology* / Q000503:physiopathology; D016037:Single-Blind Method; D066127:White Matter / Q000473:pathology / Q000503:physiopathology