The groundbreaking study from Boston University Chobanian and Avedisian School of Medicine and VA Boston Healthcare has shed new light on the relationship between playing contact sports, chronic traumatic encephalopathy (CTE), and the development of parkinsonism. This study, published in JAMA Neurology, is the largest of its kind, involving 481 deceased athletes and revealing a significant connection between CTE and parkinsonism.
Parkinsonism is a condition that shares symptoms with Parkinson’s disease, such as tremors, slow movements, and stiffness in limbs. While it has long been linked to traumatic brain injury and CTE in boxers, the exact underlying pathologies were previously unknown.
The study found that a striking 76% of individuals with CTE and parkinsonism did not exhibit the characteristic Lewy body pathology associated with Parkinson’s disease. Instead, researchers discovered that these individuals had more severe brain cell damage in a specific region of the brainstem that regulates movement.
“The absence of Lewy bodies in most individuals with CTE and parkinsonism was surprising to us,” stated Dr. Thor Stein, a lead researcher on the study. “Our findings suggest that the brain cell death in the brainstem may be driving the development of parkinsonism symptoms in these cases.”
CTE is a progressive brain disease caused by repetitive head impacts, commonly seen in contact sports. Previous research by the same team linked the duration of contact sports play to an increased risk of developing Lewy body disease. However, this current study is the first to establish a direct correlation between contact sports participation, brainstem pathology, and the development of parkinsonism in individuals with CTE.
According to Daniel Kirsch, a MD/PhD student involved in the study, the severity of CTE is directly associated with the length of time spent playing contact sports. In fact, the study found that every additional eight years of contact sport play led to a 50% increased risk of more severe brainstem disease affecting movement.
The study participants had generously donated their brains to the UNITE brain bank, enabling researchers to compare individuals with parkinsonism to those without, to identify the specific pathologies leading to these symptoms and examine the relationship with the duration of contact sports play.
This study highlights the urgent need for further research into the long-term consequences of repetitive head impacts, as well as the importance of implementing preventive measures in contact sports to reduce the risk of debilitating neurodegenerative diseases like CTE and parkinsonism.
