The beta-amyloid protein that accumulates in the form of plaques and tangles in the brain is related to the appearance of cognitive impairment and the development of Alzheimer’s and other neurodegenerative diseases. Some studies have suggested that the buildup of this toxic substance could be linked to severe or repeated traumatic brain injuries, and now new research has identified an early buildup of amyloid in the brain in healthy men who had been exposed to repetitive subconcussive traumatic events.
Head injury can be caused by direct head trauma, such as a fall or contact sports such as boxing or soccer (by hitting the head with the ball), but it can also result from exposure to indirect forces. , like shock waves from explosions on the battlefield, violently shaking the brain in the skull. In fact, previous studies in which autopsies were performed only a few hours after the deceased suffered a severe brain injury showed the presence of amyloid plaques in this organ.
Researchers at the University of Missouri School of Medicine in Columbia, Missouri used positron emission tomography (PET) to identify and quantify beta-amyloid in the brains of 18 men: nine military grenade instructors or breacher at the Fort Leonard Wood military base in Fort Leonard, Missouri from January 2020 to December 2021 and nine civilians who acted as a control group.
“PET could be used to identify the accumulation of beta-amyloid in people or professionals exposed to traumatic brain injuries, such as the military, police, firefighters, soccer players…”
Grenade and breacher instructors are military officers who train recruits to learn how to use hand grenades and explosives or other mechanical methods to force open doors. All of the participants were men in their early 30s – which is an age when amyloid buildup is not expected – and none of them had previously suffered a concussion.
The researchers tested the 18 participants twice. The first assessment allowed a baseline to be established and the second was carried out after the blast exposure, approximately five months after the baseline examination. Military instructors filled out a digital log detailing the number of blast exposures, including gunshots, and control group participants were tested at similar times.
All participants underwent a head PET scan to assess and quantify amyloid changes, and analysis software was used to segment six brain regions commonly associated with Alzheimer’s disease and traumatic brain injury.
Six of the nine military personnel exposed to blasts had an abnormal buildup of amyloid in their brains. Three of the participants had one brain region with increased amyloid accumulation, two participants had two regions, and one participant had three regions with abnormal accumulation. In contrast, none of the healthy participants in the control group showed abnormal amyloid accumulation. The findings have been published in Radiology.
“Amyloid-beta is a molecule that is not normally found in the brain of young patients,” explained study author Carlos Leiva-Salinas, an associate professor of radiology at the University of Missouri School of Medicine. “Non-invasive positron emission tomography, or PET, could be used to identify early-stage beta-amyloid accumulation in people or professionals exposed to traumatic brain injuries, such as military, police, firefighters, soccer players, etc.,” he says. .
“More research is needed to establish the relationship between the frequency and severity of traumatic brain injuries and the degree of amyloid changes in the brain, the natural course of observed accumulation, and other potential biologic risk factors for amyloid plaque deposition. and the development of cognitive impairment”, concludes Leiva-Salinas.
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