Chronic traumatic encephalopathy (CTE), a degenerative brain disorder seen in football players and other individuals exposed to repeated head impacts, should be recognized as an independent cause of dementia, according to a study issued yesterday by Alzheimer’s and Dementia.Analyzing hundreds of post-mortem brain samples, researchers found that individuals with advanced CTE were significantly more likely to have had dementia during their lifetime than those without CTE—even in the absence of other neurodegenerative biomarkers.
Why It’s Relevant
CTE is currently diagnosed postmortem and there remains disagreement about the degree to which CTE neuropathology contributes to clinical symptoms like memory loss. Notably, many people with suspected CTE also had evidence of other dementia-associated conditions like Alzheimer’s disease or Lewy body dementia.
By the Numbers
-
The researchers assessed 366 donated brains with diagnosed CTE and 248 without CTE; all donors had experienced repeated head impacts during their lifetimes. The researchers excluded brains with disease such as Alzheimer’s, Lewy body, or frontotemporal lobar degeneration to avoid confounding that was problematic in other studies.
- Compared with individuals with no CTE, those with stage III or IV CTE were 2.1 and 4.5 times more likely, respectively, to have been diagnosed with dementia during their lifetime.
- Stage I and II CTE were not associated with cognitive symptoms or dementia.
- CTE neuropathology of any stage was not associated with mood and behavioral symptoms.
What’s More
- Among those with CTE who received a dementia diagnosis during their lifetime, 40% had been misdiagnosed as having Alzheimer’s disease—but showed no evidence at autopsy. An additional 38% were told the causes of their dementia were “unknown” or could not be specified.
The Other Side
The findings may be affected by selection bias, as individuals who experienced significant impairment are more likely to donate their brains. Symptoms were also reported by the next of kin, which is subject to recall bias. Prospective studies will be needed to validate the associations between CTE neuropathology and objectively measured symptoms.
Takeaway Message
“Establishing that cognitive symptoms and dementia are outcomes of CTE moves us closer to being able to accurately detect and diagnose CTE during life, which is urgently needed,” senior author Michael Alosco, Ph.D., of Boston University Chobanian & Avedisian School of Medicine, said in a news release.
Related Information
Source
Rachel M. Layden, et al. CTE neuropathology alone is associated with dementia and cognitive symptoms. Alzheimer’s & Dementia. Published January 27, 2026. doi: doi.org/10.1002/alz.71032
(Image: Getty Images/iStock/skynesher)
