Brain PET study suggests link between early amyloid accumulation and repetitive subconcussive trauma

Emerging research on brain positron emission tomography (PET) imaging suggests a link between repetitive subconcussive trauma and increased amyloid deposition in the brain in otherwise healthy men.

For the study, recently published in Radiologythe researchers used brain PET imaging to assess the impact of repeated blast exposure for nine military instructors (mean age 33) and compared them to nine age-matched healthy controls.

Five months after a military instructor was exposed to repeated blasts, the study authors noted a significant increase in amyloid deposition in the superior parietal lobule, precuneus, anterior cingulum, and inferomedial frontal lobe at the within this cohort. Of the nine military instructors, three men had increased amyloid uptake in one brain region, two men had abnormal amyloid deposition in two brain regions, and one study participant had abnormal amyloid increases in three brain regions, according to the ‘study.

Noting that amyloid accumulation is a pathological marker of Alzheimer’s disease (AD), the researchers pointed out that the increases in amyloid seen on PET imaging were in brain regions known for abnormalities related to the MA.

“(Head trauma) is a risk factor for the development of dementia or AD type encephalopathy. Several autopsy studies have shown that amyloid plaques were present in the brain as early as hours after the injury, persisting years later,” wrote the study’s lead author, Carlos Leiva-Salinas, MD, Ph.D., MBA, chief of neuroradiology and director of the Neuroradiology Fellowship Program at the medical school. from the University of Missouri, and colleagues.

The researchers also noted that their use of a voxel-based approach for parametric whole-brain mapping with PET could facilitate better recognition of patterns associated with abnormal increases in amyloid resulting from traumatic brain injury and put the table for future research efforts.

“Because amyloid (beta) can accumulate in pre-symptomatic individuals years before symptoms of neurodegeneration manifest, understanding the relationship between traumatic injury and amyloid (beta) accumulation could provide strategies to remove amyloid deposits. This ability may delay or even prevent neurodegeneration in military and civilian populations,” Leiva-Salinas and colleagues suggested.

(Editor’s note: For related content, see “Can the Keto Diet Affect Brain PET Imaging?” And “Researcher presents first non-invasive images of alpha-synuclein in the brain. »

In a accompanying editorialSven Haller, MD, MSc., noted that the study design’s emphasis on longitudinal evaluation of the same study participants with repeated brain PET scans may have contributed to the early detection of a deposit. abnormal amyloid that was not evident in previous studies.

“There is considerable interindividual variability in the accumulation of amyloid PET. Therefore, when comparing an individual case to a reference data set or when averaging individuals in a cross-sectional group analysis, Subtle changes may remain hidden in normal variation. However, the intra-individual longitudinal design implemented in this study avoids this inter-individual variability and could detect a subtle accumulation of individual amyloid PET over time,” noted Dr. Haller, neuroradiologist and medical director at the Center d’Imagerie Médicale de Cornavin in Geneva, Switzerland.

Regarding study limitations, the authors acknowledged that the small sample size may have thwarted possible ideas about associations between trauma burden and degree of amyloid (beta) deposition. Leiva-Salinas and colleagues also noted that multiple follow-up points as opposed to a five-month follow-up assessment in the study may have provided insight into the course of increased amyloid deposition. The absence of electronic ranging equipment prevented assessment of the severity of the explosion during amyloid deposition, according to the study authors.