title: Reduced thalamic volume in preterm infants is associated with abnormal white matter metabolism independent of injury.
abstract: BACKGROUND
  Altered thalamocortical development is hypothesized to be a key substrate underlying neurodevelopmental disabilities in preterm infants. However, the pathogenesis of this abnormality is not well-understood. We combined magnetic resonance spectroscopy of the parietal white matter and morphometric analyses of the thalamus to investigate the association between white matter metabolism and thalamic volume and tested the hypothesis that thalamic volume would be associated with diminished N-acetyl-aspartate (NAA), a measure of neuronal/axonal maturation, independent of white matter injury.
  
  
  METHODS
  Data from 106 preterm infants (mean gestational age at birth: 31.0 weeks ± 4.3; range 23-36 weeks) who underwent MR examinations under clinical indications were included in this study.
  
  
  RESULTS
  Linear regression analyses demonstrated a significant association between parietal white matter NAA concentration and thalamic volume. This effect was above and beyond the effect of white matter injury and age at MRI and remained significant even when preterm infants with punctate white matter lesions (pWMLs) were excluded from the analysis. Furthermore, choline, and among the preterm infants without pWMLs, lactate concentrations were also associated with thalamic volume. Of note, the associations between NAA and choline concentration and thalamic volume remained significant even when the sample was restricted to neonates who were term-equivalent age or older.
  
  
  CONCLUSIONS
  These observations provide convergent evidence of a neuroimaging phenotype characterized by widespread abnormal thalamocortical development and suggest that the pathogenesis may involve impaired axonal maturation.
authors: Department of Radiology, Children's Hospital Los Angeles, 4650 Sunset Blvd., MS #81, Los Angeles, CA, 90027, USA, wisnowski@college.usc.edu.
authors: Jessica L
authors: JL
authors: Wisnowski
authors: Rafael C
authors: RC
authors: Ceschin
authors: So Young
authors: SY
authors: Choi
authors: Vincent J
authors: VJ
authors: Schmithorst
authors: Michael J
authors: MJ
authors: Painter
authors: Marvin D
authors: MD
authors: Nelson
authors: Stefan
authors: S
authors: Blüml
authors: Ashok
authors: A
authors: Panigrahy
mesh_terms: D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D009929:Organ Size; D012189:Retrospective Studies; D013788:Thalamus / Q000473:pathology*; D066127:White Matter / Q000378:metabolism*