MRI Tracks Developing Brain

Using MRI to track infant brain growth could help clinicians identify and treat the earliest signs of neurodevelopmental disorders, according to an article published in JAMA Neurology.

Researchers from the University of California, San Diego School of Medicine and the University of Hawaii conducted a study to determine if MRI could be used in measuring early brain, assessing size, asymmetry and rate of growth to detect and treat neurodevelopmental disorders, such as autism or perinatal brain injury. The study followed the brain growth of full-term and premature babies with no neurological or major health issues.

"A better understanding of when and how neurodevelopmental disorders arise in the postnatal period may help assist in therapeutic development, while being able to quantify related changes in structure size would likely facilitate monitoring response to therapeutic intervention. Early intervention during a period of high neuroplasticity could mitigate the severity of the disorders in later years," first author Dominic Holland, PhD, said in a release.

The researchers found that newborn brains grew, on average, one percent each day immediately following birth until three months of age, when the growth slowed to 0.4 percent per day. The cerebellum grew at the highest rate among both boys and girls, more than doubling volume in 90 days. The hippocampus grew at the slowest rate, increasing in volume by only 47 percent in 90 days.

The researchers noted that a week of prematurity resulted in a brain that was 4 percent to 5 percent smaller than would be expected for a full-term baby, but that the brains of the premature babies grew faster than that of full-term ones.

 "At 90 days post-delivery, however, premature brains were still two percent smaller,” Holland said. “The brain's rapid growth rates near birth suggest that inducing early labor, if not clinically warranted, may have a negative effect on the infant's neurodevelopment."

The researchers also found that many asymmetries in the brain are already established in the early postnatal period, including the right hippocampus being larger than the left, which historically, has been suggested to occur in the early adolescent years. Cerebral asymmetry is associated with functions such as dexterity and language abilities.

"Our findings give us a deeper understanding of the relationship between brain structure and function when both are developing rapidly during the most dynamic postnatal growth phase for the human brain," Holland said.