Issue 32.3 of radiology at the University of Missouri School of Medicine in Columbia , Missouri . “ Amyloid-beta accumulation in the brain is proposed to be an early event in the pathogenesis of Alzheimer ’ s disease , the most common type of dementia worldwide , impacting millions of people .”
TBI can be the result of direct head trauma , such as from a fall or from playing contact sports , but it can also result from indirect forces — such as shockwaves from battlefield explosions — that shake the brain violently in the skull .
Previous autopsy studies have shown the presence of amyloid plaques as early as hours after severe brain injury .
“ Non-invasive positron emission tomography , or PET , imaging could be used to identify early-stage amyloid-beta accumulation in individuals or professions exposed to traumatic brain injury such as military personnel , police officers , firefighters , football players , etc .,” Dr . Leiva-Salinas said .
For the study , researchers recruited nine military grenade or breacher instructors at Fort Leonard Wood Military Base in Fort Leonard , Missouri , from January 2020 to December 2021 . Grenade and breacher instructors are military officers who train recruits in the use of hand grenades and explosives or other mechanical methods to force open doors .
An additional nine civilians were included in the study as a healthy control group . All participants had no previous history of concussion , and they were all males in their early 30s , an age at which amyloid accumulation is not expected .
The 18 participants were evaluated twice . The first evaluation was to establish a baseline and the second occurred after blast exposure , approximately five months after the baseline
Alzheimer ' s disease : the amyloid-beta peptide accumulates to amyloid fibrils that build up dense amyloid plaques .
examination . The military instructors filled out a digital log with the number of exposures to explosions , including the firing of weapons . The control participants were evaluated at similar time points .
All participants underwent a PET scan of the head to evaluate and quantify amyloid changes . Analysis software was used to segment six brain regions that are usually associated with Alzheimer ’ s disease and TBI .
Abnormal amyloid accumulation was seen in six of the nine participants who were exposed to explosions . Three of the participants had one region of the brain with increased amyloid accumulation , two participants had two regions , and one participant had three regions with abnormal accumulation .
None of the healthy control participants showed any abnormal amyloid accumulation .
“ Further research needs to be done to establish the relationship between the frequency and the severity of traumatic brain injury and the degree of amyloid changes in the brain , the natural course of the observed accumulation , and other potential biologic risk factors for amyloid plaque deposition and the development of cognitive decline ,” Dr . Leiva-Salinas said . g
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