Report from ISMRM: Parental nurturing in neonatal ICU units helps babies survive

May 16, 2005

Brain injuries associated with premature birth could be offset somewhat by neonatal therapies designed to help preemies survive and thrive, according to an Australian study using volumetric MR.

Brain injuries associated with premature birth could be offset somewhat by neonatal therapies designed to help preemies survive and thrive, according to an Australian study using volumetric MR.

Results from a study performed at Royal Children's Hospital in Melbourne indicate an emphasis on parental nurturing to reduce postpartum white matter injury and lower the babies' susceptibility to cognitive and motor diseases such as cerebral palsy. The study suggests that radiologists will play a role in predicting the outcomes of these cases, according to principal investigator Dr. Terrie Inder, an associate professor of pediatric medicine.

The results show that the stress of living the first days of one's life in a neonatal intensive care unit affects frontal brain regions, especially the extent and reversibility of white matter damage. Tender loving care in the form of more cuddling and other positive interactions with parents soon after birth improves the baby's behavior and brain structure, Inder said. Minimizing needle sticks and other negative encounters with staff helps as well.

Better treatment strategies for sepsis and blood pressure control, which appear to be the main direct causes of white matter injury, also need to be addressed, she said.

Volumetric MRI mapped the neuroanatomical characteristics of 202 preterm infants with a mean gestational age of 28 weeks as well as 36 full-term babies. Whole-brain volume was calculated, and regional comparisons were performed by dividing the brains into hemispheres and then into eight sectors.

Overall, the preterm infants had an average of 25 cc less total cerebral tissue than did the full-term babies, said Deanne K. Thompson, a research associate who presented the results at the International Society for Magnetic Resonance in Medicine meeting in Miami. The premature babies had significantly reduced basal ganglia or subcortical gray matter and less cerebrospinal fluid.

Perinatal factors contributing to reduced total brain tissue volume in preterm infants included the number of days on total parenteral nutrition and intrauterine growth restriction (IUGR). Increases in CSF volumes related to gestational age and the amount of white matter injury.

The presence and severity of cerebral white matter injury was a major predictor of preterm tissue volume, according to Thompson. Moderate to severe white matter injury resulted in a significant reduction in cortical gray matter in preterm infants compared with no or mild white matter injury.

The sensorimotor region displayed the largest changes in cortical gray matter. Gestational age, hours on positive pressure ventilation, and IUGR predicted how much cortical gray matter would be measured in this region.

The dorsal prefrontal region displayed changes in cortical gray matter, with IUGR as a contributor, but the unmyelinated white matter showed no clear perinatal correlates. The parieto-occipital area showed significant differences between preterm and full-term infants for cortical gray matter, but again with no clear perinatal correlates, she said. In contrast, the premotor area was reduced in unmyelinated white matter - male gender was a significant perinatal contributor.

Additional data, soon to be released by the Melbourne group, will show quantitative MRI can be used to predict the outcome of extremely premature neonatal patients, Inder said.

"Depending on what a radiologist says about what the brain looks like at term, the pediatrician will have the capability to predict the baby's developmental outcomes at two years of age," she said.

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