Creatine, Glutamine plus Glutamate, and Macromolecules Are Decreased in the Central White Matter of Premature Neonates around Term

PLoS One. 2016 Aug 22;11(8):e0160990. doi: 10.1371/journal.pone.0160990. eCollection 2016.

Abstract

Preterm birth represents a high risk of neurodevelopmental disabilities when associated with white-matter damage. Recent studies have reported cognitive deficits in children born preterm without brain injury on MRI at term-equivalent age. Understanding the microstructural and metabolic underpinnings of these deficits is essential for their early detection. Here, we used diffusion-weighted imaging and single-voxel 1H magnetic resonance spectroscopy (MRS) to compare brain maturation at term-equivalent age in premature neonates with no evidence of white matter injury on conventional MRI except diffuse excessive high-signal intensity, and normal term neonates. Thirty-two infants, 16 term neonates (mean post-conceptional age at scan: 39.8±1 weeks) and 16 premature neonates (mean gestational age at birth: 29.1±2 weeks, mean post-conceptional age at scan: 39.2±1 weeks) were investigated. The MRI/MRS protocol performed at 1.5T involved diffusion-weighted MRI and localized 1H-MRS with the Point RESolved Spectroscopy (PRESS) sequence. Preterm neonates showed significantly higher ADC values in the temporal white matter (P<0.05), the occipital white matter (P<0.005) and the thalamus (P<0.05). The proton spectrum of the centrum semiovale was characterized by significantly lower taurine/H2O and macromolecules/H2O ratios (P<0.05) at a TE of 30 ms, and reduced (creatine+phosphocreatine)/H2O and (glutamine+glutamate)/H2O ratios (P<0.05) at a TE of 135 ms in the preterm neonates than in full-term neonates. Our findings indicate that premature neonates with normal conventional MRI present a delay in brain maturation affecting the white matter and the thalamus. Their brain metabolic profile is characterized by lower levels of creatine, glutamine plus glutamate, and macromolecules in the centrum semiovale, a finding suggesting altered energy metabolism and protein synthesis.

MeSH terms

  • Cognitive Dysfunction / diagnostic imaging
  • Cognitive Dysfunction / metabolism*
  • Cognitive Dysfunction / physiopathology
  • Creatine / metabolism
  • Diffusion Magnetic Resonance Imaging
  • Female
  • Glutamic Acid / metabolism
  • Glutamine / metabolism
  • Humans
  • Infant
  • Infant, Newborn
  • Infant, Premature*
  • Infant, Very Low Birth Weight
  • Male
  • Occipital Lobe / diagnostic imaging
  • Occipital Lobe / metabolism*
  • Occipital Lobe / physiopathology
  • Proton Magnetic Resonance Spectroscopy
  • Retrospective Studies
  • Taurine / metabolism
  • Temporal Lobe / diagnostic imaging
  • Temporal Lobe / metabolism*
  • Temporal Lobe / physiopathology
  • Term Birth
  • Thalamus / diagnostic imaging
  • Thalamus / metabolism*
  • Thalamus / physiopathology
  • White Matter / diagnostic imaging
  • White Matter / metabolism*
  • White Matter / physiopathology

Substances

  • Glutamine
  • Taurine
  • Glutamic Acid
  • Creatine

Grant support

The author(s) received no specific funding for this work.