Normal brain growth curves for children developed childhood brain disorders, infections and injuries

In the United States, almost all pediatrician visits begin with three measurements: weight, height, and head circumference. Compared to the average child growth charts across the country, established in the 1970s, the number of a child can confirm typical development or provide a diagnostic baseline for assessing curve deviations. However, the brain, vital to the child’s development, can only be seen in these measures.

Head circumference may indicate a head growth problem, which could be investigated to determine if there is a problem with brain size an extra fluid. But now, in the age of non-invasive brain scanning like magnetic resonance imaging (MRI), could researchers develop normalized growth curve charts for the brain?

That was the question Steven Schiff, president of Brush’s engineering professor at Penn State, and his multi-institutional research team set out to answer. They have published their results today (July 9) in the Journal of Neurosurgery, Pediatrics.

“Research on brain size also has a very unfortunate history, as it was often used to try to scientifically prove that one gender or race or culture of people is better than another,” said Schiff, also a professor of scientific and mechanical engineering at the College of Engineering and Neurosurgery at the College of Medicine. “In this article, we discuss research that goes back about 150 years and then analyze what data from a contemporary cohort really tells us.”

The researchers analyzed 1,067 brain scans of 505 healthy children, aged between 13 days and 18 years, from the Repository of Pediatric Resonance of the National Institutes of Health (NIH). To ensure a representative sample population based on sex, race, socioeconomic status, and geographic location, MRI scans were performed sequentially over several years in hospitals and medical schools in California, Massachusetts, Missouri. , Ohio, Pennsylvania and Texas. To ensure calibrated results, one person was established as a control and scanned at each site.

“The study of brain size and growth has a long and controversial history, even in the era of MRI, studies that define normal patterns of brain volume growth often include small sample sizes, limited algorithm technology, incomplete coverage of the pediatric age range, and other problems, “said first author Mallory R. Peterson, a Penn State student pursuing a doctorate in science and mechanical engineering at the College of Pediatrics. Engineering and a degree in medicine from the College of Medicine. He earned a bachelor of science degree in biomedical engineering from Penn State in 2016. “These studies have not addressed the relationship between brain growth and cerebrospinal fluid in depth, either. In this paper, we solve these two problems. “

The first surprising discovery, according to Schiff and Peterson, was the difference in brain volume between children and women. Even after adjusting for body size, men showed greater overall brain volume, but specific brain structures did not differ in size between sexes, nor did cognitive ability.

“Clearly, gender-based differences don’t take intelligence into account; we’ve known this for a long time, and that doesn’t suggest otherwise,” Schiff said. “The important thing here is that there is a difference in how the brains of male and female children grow. When a child is diagnosed or treated, we need to know when a child’s brain does not grow normally.”

The second finding resulted from a striking similarity rather than differences.

“Regardless of the sex or size of the child, we unexpectedly found that the ratio between the size of the child’s brain and the volume of fluid in the head — cerebrospinal fluid — was universal,” Schiff said. “This fluid floats and protects the brain. , and performs various functions as it flows through the brain. Although we have not previously recognized this narrow normal proportion, this fluid-brain relationship is exactly what we try to regulate when we treat children. excess fluid under hydrocephalus conditions. “

Researchers plan to continue studying the proportion and its potential functions, as well as the underlying mechanisms, in children and throughout life.

“The apparent universal nature of the age-dependent brain-fluid ratio, regardless of sex or body size, suggests that the role of this ratio offers new ways to characterize conditions that affect children’s brains,” he said. dir Peterson.

The researchers also resolved a long-running controversy in terms of the temporal lobe, according to Schiff. After two years of age, the left side of this brain structure, where language function is usually located, was clearly larger than the right side throughout childhood. A portion of the temporal lobe called the hippocampus, which can cause epilepsy, was larger on the right than on the left as it grew during childhood.

“These normal growth curves for these critical structures often involved in epilepsy will help us determine when these structures are damaged and are smaller than normal for age,” Schiff said.

This approach to normal brain growth during childhood could help researchers understand normal and excessive volume loss during later life, according to Schiff.

“Brain volume reaches its peak at puberty,” Schiff said. “Then it decreases as we age and decreases more rapidly in people with certain types of dementia. If we can better understand both brain growth and the brain / fluid ratio at each age, we can not only improve the way we diagnose clinical conditions. , but also how we treat them “.