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Brain charts map the size of the human brain over a lifetime

Researchers found a way to track the size of the human brain over a person’s lifetime, allowing them to compare brain growth and decline in a manner similar to how pediatricians use growth charts to measure a child’s development.

(CN) — Brain charts could allow doctors to compare the size and relative function of individual sections of a person’s brain with those of their peers across every age group, providing clinicians a powerful new tool to detect problems in the brain sooner.

These charts detail how a person’s brain expands rapidly in youth and slowly begins to shrink as they age. By comparing brain size and function in this way, experts can determine if a person may be developing Alzheimer’s or other cognitive issues at a stage when more treatments may be available.

Researchers from the University of Cambridge in the United Kingdom published their findings in a study Wednesday in the journal Nature. The authors assembled the largest neuroimaging dataset ever compiled, aggregated from nearly 125,000 brain scans taken from more than 100 individual studies.

These brain charts have not yet been approved for clinical use, but the authors hope one day in the near future they will become a routine clinical tool, similar in the way that pediatric growth charts have been used for two centuries to measure the physical development of children.

“We’re still at an extremely early stage with our Brain Charts, showing that it is possible to create these tools by bringing together huge datasets,” co-author Dr. Richard Bethlehem, from the Department of Psychiatry at the University of Cambridge, explained in a related statement. “The charts are already beginning to provide interesting insights into brain development, and our ambition is that in future, as we integrate more datasets and refine the charts, they could eventually become part of routine clinical practice.

You could imagine them being used to help evaluate patients screened for conditions such as Alzheimer’s, for example, allowing doctors to spot signs of neurodegeneration by comparing how rapidly a patient’s brain volume has changed compared to their peers.”

Until now no one had developed a standardized reference chart for the human brain, meaning it’s been difficult for doctors to compare changes in a person’s brain relative to others in their age group. Pediatricians rely on growth charts to determine of a child’s height, weight and other metrics of healthy growth fall within an average range for their age group, and the authors hope that brain maps can fill a similar role.

Unlike pediatric growth charts, however, brain charts map the growth and decline of a person’s brain across their entire lifespan — from development in the womb through old age. The goal is to create a common language among practitioners to record normal and abnormal variations in the human brain as it ages. The authors recently released an open-access tool called BrainChart, allowing other scientists and medical professionals to upload their own neuroimaging data and compare it with the existing dataset. But they caution the tool is currently intended for research purposes only and hasn’t been approved for clinical use.

“One of the things we’ve been able to do, through a very concerted global effort, is to stitch together data across the whole life span,” Bethlehem said in a related statement. “It’s allowed us to measure the very early, rapid changes that are happening in the brain, and the long, slow decline as we age.”

This novel tool allowed the authors to confirm certain development milestones for the first time ever, such as at which age certain regions of the brain attain maturity and when specific classes of brain tissue reach their peak volume.

They discovered that grey matter, or brain cells, peaks shortly before the age of six, then slowly declines as a person ages. White matter, which connects various brain tissue, increases through early childhood and peaks shortly before the age of 29, before also beginning to decline, speeding up after a person turns 50. Grey matter, responsible for controlling basic behavior and bodily functions, peaks around the age of 14-and-a-half.

“With brain imaging data, things are a bit more complicated than just taking out a measuring tape and measuring someone's height, or head circumference,” co-author Dr. Jakob Seidlitz, from the Lifespan Brain Institute at Children’s Hospital of Philadelphia, said in a related statement. “There were significant challenges to deal with, including logistic and administrative hurdles as well as the huge methodological variability we find between brain imaging datasets.”

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Categories / Health, Science

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