Researchers have found differences in the brain pathology of paediatric and adult patients that might explain the sometimes “catastrophic outcomes” seen in children following a traumatic brain injury.

The study, led by the University of Glasgow, found that the pattern of damage to blood vessels after a severe brain injury appears to be age-dependent.

In adult brains, vessels showing signs of damage after trauma were often medium or larger sized.

However in paediatric patients, it was typically the smallest sized vessels, or capillaries, that were damaged.

This research has considerable implications in terms of understanding TBI in younger people

Researchers said that traumatic brain injury (TBI) represents the leading cause of death and permanent disability in young children and adolescents.

The study was led by consultant neuropathologist Professor Willie Stewart, who authored the FIELD Study on football and neurodegenerative disease risks.

Commenting on the latest study, he said: “This research has considerable implications in terms of understanding TBI in younger people.

“In contrast to adults, paediatric patients appear especially vulnerable to catastrophic outcomes, which can arise following all injury severities, including mild TBI or concussion. Given this, further research in this area is needed.

“In the meantime, these findings reinforce the reasoning behind our, ‘If in doubt, sit them out’ approach to concussion management, especially with younger players and in sports like rugby.”

For the study, the researchers studied post-mortem brain tissue samples from 81 paediatric patients (aged three-18 years) and 62 (aged 19 or over) adults who died shortly after sustaining a traumatic brain injury.

The researchers found that severe brain swelling was far more common among the paediatric cases examined, which they suggest might be a result of the differences in blood vessel damage seen after trauma.

Previous research from Professor Stewart and collaborators found that former international rugby players had an approximately two and a half times higher risk of neurodegenerative disease than expected, with risk of disease varying by subtype, but not by player position.

The research on rugby came after the 2019 FIELD study found that former professional footballers had an approximately three and a half times higher rate of death due to neurodegenerative disease than expected.

The paper, Paediatric traumatic brain injury and microvascular blood-brain barrier pathology, is published in the journal JAMA Network Open.

The study was supported by the Glasgow Children’s Hospital Charity grant; the National Institutes of Health (NIH); the Department of Defence; and an NHS Research Scotland Senior Fellowship.