Study finds an increased risk of dementia from decades-old head injuries

Head injury in the United States is common, with over 23 million adults age 40 or older reporting a history of head injury with loss of consciousness. Many head injuries can be caused by a host of different situations—from car and motorcycle accidents to sports injuries. What’s more, it has become increasingly recognized that the effects from head injuries are long-lasting. New research led by the Perelman School of Medicine shows that a single head injury could lead to dementia later in life. This risk further increases as the number of head injuries sustained by an individual increases. The findings also suggest stronger associations of head injury with risk of dementia among women compared to men, and among white as compared to Black populations.

 Gloved hand holding a scan of four brains

The researchers, whose findings were published in Alzheimer’s & Dementia: The Journal of the Alzheimer's Association, conducted the investigation using data from the Atherosclerosis Risk in Communities (ARIC) Study, which aimed to uncover associations between head injury and dementia over the span of 25 years in a diverse population in the United States. Previously, data on traumatic brain injury has been limited to select populations, such as military and medical claims databases. These are among the first findings to specifically investigate head injury and dementia risk in both Black and white populations, as well as among both males and females, in a community-based setting.

“Head injury is a significant risk factor for dementia, but it’s one that can be prevented. Our findings show that the number of head injuries matter—more head injuries are associated with greater risk for dementia,” says lead investigator, Andrea L.C. Schneider, an assistant professor of neurology at Penn. “The dose-dependence of this association suggests that prevention of head injury could mitigate some risk of dementia later in life. While head injury is not the only risk factor for dementia, it is one risk factor for dementia that is modifiable by behavior changes such as wearing helmets and seat belts.”

This story is by Kelsey Odorczyk. Read more at Penn Medicine News.