First Known Case of CTE Found in Patient Without History of Head Trauma

Summary: Researchers report evidence of chronic traumatic encephalopathy (CTE) in the brain of a patient who had no documented history of head trauma or concussion.

Source: University Health Network

Researchers at Toronto Western Hospital’s Canadian Concussion Centre (CCC) have identified CTE pathology in the brain of a deceased patient with no known history of traumatic brain injury or concussion — the first reported case of its kind.

This unexpected finding is detailed in a case study published in the International Journal of Pathology and Research and was presented at the CCC’s 5th annual symposium on Research on the Concussion Spectrum of Disorders. The brain was examined after autopsy for a patient who had a seven-year clinical diagnosis of amyotrophic lateral sclerosis (ALS) and motor neuron disease (MND). According to family members, the individual had no history of head trauma, no participation in activities commonly associated with concussion risk, and no signs of dementia or cognitive decline; he remained mentally high-functioning until his death.

Dr. Lili-Naz Hazrati, neuropathologist with the CCC research team who conducted the autopsy, commented that finding CTE in someone without known head trauma challenges current assumptions about the disease’s origins. She emphasized that while repetitive head injury has been strongly linked to CTE in many cases, this single observation suggests the causes and risk factors may be more complex and merit further investigation.

Dr. Charles Tator, Director of the CCC and a co-author of the case study, said the discovery broadens the scope of questions researchers must address. He noted that if CTE can occur in individuals without a history of concussion, the condition may affect a wider range of people than previously thought. Better understanding of who develops CTE and why is essential for developing treatments and prevention strategies.

Autopsy studies of brains from people who reported repeated concussions have produced varied results. Some show no neuropathological changes, while others reveal CTE, CTE combined with another neurodegenerative disorder, or an entirely different neurodegenerative disease. The CCC and other centers have most often received brain donations from individuals who exhibited concerning symptoms such as unexplained cognitive impairment during life. That referral pattern can bias the sample toward people who already show signs of neurological disease, and therefore may not represent the broader population.

Dr. Hazrati stressed caution in attributing CTE exclusively to head trauma. She pointed out that the presence of CTE in some people with no documented concussions, alongside cases of multiple concussions without CTE identified at autopsy, indicates a more nuanced relationship. Factors such as genetics, environmental exposures, coexisting neurological conditions, or unknown mechanisms might also play roles. These possibilities highlight the need for more comprehensive research to clarify causation, risk factors, and the biological pathways that produce CTE-like changes in brain tissue.

The Canadian Concussion Centre is a multidisciplinary group of clinicians and basic scientists that studies the full spectrum of concussion-related disorders, from acute injury to chronic illness and brain degeneration. The CCC team brings together expertise in brain injury, imaging, genetics, neuropsychology, neurology, neurosurgery, neuropathology and clinical care to improve understanding, diagnosis and management of concussions and their long-term effects.

The case study was presented at the 5th Annual Symposium: Research on the Concussion Spectrum of Disorders and published in the International Journal of Pathology and Research.

Source: University Health Network
Image Source: NeuroscienceNews.com image used for illustration.
Original presentation: 5th Annual Symposium: Research on the Concussion Spectrum of Disorders.