A recent study has identified a new association between participating in contact sports, chronic traumatic encephalopathy (CTE), and the onset of a movement disorder called parkinsonism.
A team of researchers from Boston University Chobanian and Avedisian School of Medicine and VA Boston Healthcare conducted the largest CTE study to date involving 481 deceased athletes. Their findings, published in JAMA Neurology, reveal that a majority of individuals with CTE also developed parkinsonism, with CTE pathology playing a significant role in causing parkinsonism symptoms in most cases.
Parkinsonism shares similarities with Parkinson’s disease, showcasing symptoms like tremors, slowed movements, and muscle stiffness. This condition has long been linked to traumatic brain injuries (TBI) and CTE in boxers, although the specific pathological mechanisms in CTE were previously unknown.
While Parkinson’s disease is commonly associated with the accumulation of Lewy bodies in brain cells, the study discovered that 76% of CTE individuals with parkinsonism did not exhibit Lewy body pathology.
Dr. Thor Stein, an associate professor at BU and VA Boston Healthcare and one of the study’s authors, expressed surprise at this finding. Instead of Lewy bodies, individuals with parkinsonism showed more severe CTE-related brain cell damage in a brainstem area critical for movement control.
CTE is a degenerative brain condition caused by repetitive head impacts, commonly seen in contact sports. A prior study in 2018 by the same team revealed a correlation between years of contact sports play and increased odds of developing Lewy body disease. However, this recent study is the first to establish a relationship between contact sports participation, brainstem pathology, and parkinsonism in CTE.
Daniel Kirsch, an MD/PhD student at BU and study co-author, highlighted the association between prolonged contact sports play and greater CTE severity. Each additional eight years of contact sports play raised the risk of more severe brainstem disease related to movement control by 50%.
The research subjects had donated their brains to the Understanding Neurologic Injury and Traumatic Encephalopathy (UNITE) brain bank. By comparing individuals with parkinsonism to those without, the study aimed to uncover the pathological factors contributing to parkinsonism development in CTE and its connection to the duration of contact sports play.
This study emphasizes the significance of comprehending the lasting impacts of repetitive head injuries and underscores the necessity for preventive strategies in contact sports to reduce the risk of neurodegenerative conditions like CTE and parkinsonism.
