Research

Study Reveals Link Between Playing Contact Sports, Parkinsonism in Individuals with Chronic Traumatic Encephalopathy 

The largest chronic traumatic encephalopathy (CTE) study to date has found a new link between playing contact sports and the development of a movement disorder known as parkinsonism. 

The study of 481 deceased athletes by researchers at the school and VA Boston Healthcare, published in JAMA Neurology, reveals that most individuals with CTE developed parkinsonism, and CTE pathology appears to drive the parkinsonism symptoms in most cases. 

Parkinsonism is a condition characterized by symptoms similar to Parkinson’s disease such as tremors, abnormal slowness of movements, or abnormal stiffness of one’s arms or legs. It long has been associated with traumatic brain injury and CTE in boxers. However, the specific pathologies underlying these symptoms in CTE were unknown. 

Parkinson’s disease is classically associated with the buildup of proteins called Lewy bodies in brain cells, but researchers found that 76% of individuals with CTE and parkinsonism did not have Lewy body pathology. 

Subjects of the study had donated their brain to the Understanding Neurologic Injury and Traumatic Encephalopathy (UNITE) brain bank at the BU CTE Center. Those with parkinsonism were compared to those without to identify the types of pathologies that may explain why some individuals with CTE develop these symptoms and to examine relationships with duration of contact sports play. 

This study underscores the importance of understanding the long-term effects of repetitive head impacts and the need for preventive measures in contact sports to mitigate the risk of neurodegenerative diseases like CTE and parkinsonism. 

“We were surprised to find that most individuals with CTE and parkinsonism did not have Lewy body pathology,” says Thor Stein, MD, PhD, associate professor of pathology & laboratory medicine at BU and VA Boston Healthcare, and one of the corresponding authors of the study. “Rather, subjects with parkinsonism were more likely to have more severe CTE-related brain cell death in a region of the brainstem important for controlling movement.”