A new study by researchers at Boston University’s Alzheimer’s Disease and CTE Center is helping to solve the mystery of why the brain shrinks in a unique pattern, known as atrophy, in chronic traumatic encephalopathy (CTE). Published in Neuropathological ActThis research provides novel evidence that cumulative and repetitive impacts to the head are driving specific patterns of brain degeneration found at the base of the brain’s surface folds, known as the cortical sulcus.
CTE, a progressive neurodegenerative disease often linked to contact sports, has long been characterized by the accumulation of tau protein in the brain, and computer models have suggested that the base of the cortex folds experiences the greatest tension when the human brain rotates rapidly. This study is the first to measure patterns of brain degeneration in CTE and shows that repetitive impacts to the head are linked to cell loss, shrinkage, and the accumulation of tau pathology within the folds of the brain. Regional brain atrophy is also prominent in the frontal, hippocampal, hypothalamic, mammillary body, and thalamic areas of the brain.
The study analyzed brain samples from 185 athletes with a history of contact sports and 52 non-athlete controls. Additional key findings include:
• Significant cortical thinning and reduced neuronal density in the brain folds within the frontal cortex, especially in advanced stages of CTE.
• A strong association between duration of exposure to contact sports and cortical thinning, indicating a possible cumulative effect of head impacts.
• Evidence that neuronal loss is mediated by tau protein accumulation, while cortical thinning also involves tau-independent mechanisms.
• Changes in synaptic proteins suggest a dynamic process of damage and repair in brains affected by CTE.
“The cortical sulcus appears especially vulnerable to head impacts, with pronounced neurodegenerative changes occurring in these regions,” said corresponding author Thor Stein, MD, PhD, neuropathologist at VA and Bedford Healthcare Systems and associate professor of pathology and medicine. laboratory at school. . “These findings have important implications for understanding how CTE progresses and identifying potential biomarkers for early detection.”
This research highlights the need for protective measures in contact sports and offers new insights into the role of neurodegeneration in the cognitive and behavioral symptoms of CTE.