Alzheimer Protein May Help Diagnose Traumatic Brain Injury in Athletes

A protein typically associated with Alzheimer’s disease may serve as a biomarker to detect chronic traumatic encephalopathy (CTE) in living patients, according to research reported by Science News on July 31, 2026. This finding suggests that tests designed for other neurodegenerative conditions could be adapted to identify the brain trauma often linked to contact sports.

CTE is a progressive brain condition found in people with a history of repetitive head impacts. Until now, a definitive diagnosis of CTE has required a post-mortem examination of brain tissue to identify specific patterns of tau protein accumulation.

The research indicates that the same protein hallmarks used to identify Alzheimer’s may also signal the presence of CTE. By targeting these proteins, clinicians may eventually be able to diagnose the condition in living individuals rather than relying on autopsy results.

This development centers on the behavior of tau, a protein that stabilizes microtubules in neurons. In both Alzheimer’s and CTE, tau malfunctions and forms clumps called neurofibrillary tangles. These tangles disrupt cell communication and eventually lead to cell death.

While both diseases involve tau, the distribution and shape of the protein aggregates differ. Alzheimer’s typically shows a widespread distribution of tangles throughout the neocortex, whereas CTE is characterized by tau clusters that concentrate in the depths of the cortical sulci, according to the scientific data cited by Science News.

The ability to identify these proteins through living tests—such as PET scans or cerebrospinal fluid analysis—would allow for earlier intervention and a better understanding of how the disease progresses in athletes and military veterans.

Current diagnostic challenges for CTE include the lack of a validated clinical test that can distinguish it from other forms of dementia or tauopathies while the patient is alive. The overlap in protein signatures between Alzheimer’s and CTE is what makes the existing Alzheimer’s testing framework a potential starting point for CTE detection.

Medical researchers are exploring whether specific ligands—molecules that bind to the tau protein—can be engineered to differentiate between the specific “folds” of tau found in CTE versus those found in Alzheimer’s. If these ligands can be delivered via imaging agents, doctors could potentially map the disease in a living brain.

The findings remain early. The transition from identifying a protein hallmark to a clinically approved diagnostic test requires extensive validation across diverse patient groups to ensure the test does not produce false positives by misidentifying other forms of brain degeneration.