Thursday, October 22, 2015

Prematurity and autism, ADHD and emotional disorders

Infants born premature are at an increased risk of developing autism, ADHD, and emotional disorders, as well as having difficulties with cognition and motor skills. Research presented at Neuroscience 2015 indicates that these deficits may be the result of weakened connections in brain networks associated with attention, communications, and emotional processing.

Researchers from the Washington University School of Medicine in St. Louis used multimodal imaging techniques to compare structural and functional connectivity in very preterm infants (gestational age <30 weeks, n=76) and healthy, full-term infants (gestational age >37 weeks; n=58).

"The brain is particularly 'plastic' very early in life and potentially could be modified by early intervention," said investigator Cynthia Rogers, MD, assistant professor of child psychiatry, in a news release. "We usually can't begin interventions until after symptoms develop, but what we're trying to do is develop objective measures of brain development in preemies that can indicate whether a child is likely to have later problems so that we can then intervene with extra support and therapy early on to try to improve outcomes."

All infants who participated in the study underwent MRI at term-equivalent age (36-42 weeks postmenstrual age), including diffusion tensor imaging (DTI) and resting state-MRI (rs-MRI). DTI was analyzed using tract based spatial statistics (TBSS) to assess differences in fractional anisotropy (FA), while rs-MRI data was analyzed to determine correlation and covariance within and between seven canonical resting state networks (RSNs).

Imaging data indicate that very preterm infants have widespread reductions in white matter tracts compared to full-term infants, as well as reduced correlation and covariance within and between all RSNs. The researchers noted that the default mode and frontoparietal networks, which are involved with attention, social-communicative, and affective processing, were strongly affected. White matter tracts connecting hubs of these RSNs, including the cingulum and anterior limb internal capsule, showed some of the greatest between-group differences.

The results ultimately suggest that preterm birth disrupts functional and structural connectivity in regions linked to psychiatric disorders that often occur in preterm children. While the current results could mean changes to screening and therapy for preterm children, the researchers are continuing to follow the children through childhood in order to form a more complete picture of how preterm birth affects child development.

"We're analyzing the data we've already gathered, but we want to bring the children back when they are 9 or 10 and continue to follow their development," said Dr. Rogers. "We want to look at the evolution of brain development in full-term versus preterm babies, and we want to know how that may affect who is impaired and who is not."


  1. Rogers C et al. Abstract 349.08. Impact of preterm birth on structural and functional connectivity in neonates. Presented at: Neuroscience 2015. Oct. 17-21; Chicago

1 comment:

  1. Infants born premature have reduced brain connectivity in regions linked to cognitive functioning, researchers from King's College London found. They are also at higher risk of cerebral palsy, autism, ADHD, and other developmental conditions.

    Preterm birth is the leading cause of neurological disability among children in the U.S., however there previously was little information available on why preterm babies have a higher risk of developing these neurodevelopmental problems.

    Using fMRI, researchers sought to investigate the connectivity between the thalamus and cortex — which develops rapidly while preemies are in the care of neonatal units — of 66 infants, 47 of whom were born prior to 33 weeks (preterm) and 19 born between 37 and 42 weeks (full term).

    Infants born at full term showed very similar brain structure to adults in the thalamus and cortex regions, confirming prior evidence that brain connectivity is fairly mature at time of birth. Conversely, infants born preterm had less connectivity between areas of the thalamus and regions of the cortex associated with cognitive functions. However, these preterm infants also showed greater connectivity between the thalamus and an area of the primary sensory cortex involved in processing signals from the face, lips, jaw, tongue, and throat.

    “Notably, more extreme prematurity was associated with increased functional connectivity between thalamus and lateral primary sensory cortex but reduced connectivity between thalamus and cortex in the prefrontal, insular and anterior cingulate regions,” the authors wrote in the study, published in the Proceedings of the National Academy of Sciences. “This work suggests that, in early infancy, functional integration through thalamocortical connections depends on significant functional overlap in the topographic organization of the thalamus and that the experience of premature extrauterine life modulates network development, altering the maturation of networks thought to support salience, executive, integrative, and cognitive functions.”

    The researchers suggested that the greater connectivity identified between the thalamus and primary sensory cortex is a result of the infants' exposure to breast and bottlefeeding, while the lack of connectivity in other regions is attributable to a child's developmental difficulties observed as they go through childhood.

    “The next stage of our work will be to understand how these findings relate to the learning, concentration and social difficulties which many of these children experience as they grow older,” said study author Hilary Toulmin, MD, of the Centre for the Developing Brain at King's College London.

    1.Toulmin H et al. PNAS. 2015; doi:10.1073/pnas.1422638112