Ann McKee is the director of BU’s CTE Center. Credit: Asia Kepka
Key points:
- A new study shows some individuals with high-stage CTE had surprisingly low levels of tau pathology in their neocortex.
- This led researchers to identifying a new subtype of CTE, called cortical-sparing CTE.
- The finding could have important implications for the diagnosis and treatment of CTE.
The foremost experts from Boston University say they have identified a new subtype of chronic traumatic encephalopathy (CTE), according to a study published Monday.
All previous studies have suggested CTE begins in the outermost layer of the frontal lobe, the neocortex, where it then spreads to connected brain regions. Later, in high-stage disease, there is involvement of deeper regions of the brain, like the medial temporal lobe and brainstem, and typically significant neocortical disease.
But in the new study, researchers found 1 in 6 individuals with high-stage CTE had surprisingly low levels of tau pathology in their neocortex. This newly identified form of CTE, called cortical-sparing CTE (CSCTE), instead showed a higher concentration of tau pathology in the individuals’ medial temporal lobe and brainstem regions.
The team found that individuals with CSCTE were also less likely to have dementia and had less severe cognitive impairment compared with those with typical CTE. However, they did tend to have earlier onset of behavioral and movement symptoms.
"This pattern of tau pathology suggests that CSCTE may be a distinct subtype of CTE with a different underlying biology," said first author Abigail Alexander, MD, who performed the research while a resident affiliated from the Warren Alpert Medical School at Brown University.
The researchers say further studies are needed to confirm the existence of CSCTE and to understand its clinical implications.
"If CSCTE is confirmed to be a distinct subtype of CTE, it may be necessary to develop new diagnostic tools and treatment approaches that are specifically tailored to this form of the disease," said corresponding author Thor Stein, MD, a neuropathologist at VA Boston and Bedford Healthcare Systems. “This could help us understand why people with CTE can have different symptoms and ultimately lead to improved outcomes."