You do not have to be a professional soccer player to have a solid shell on your head. By an estimate of medical researchers, more than 27 million people all over the world suffer a traumatic brain injury every year. Some are from car accidents, others are from falls, or take a header on the football field. But a growing body of evidence shows that even light hits to the head can cause long-term damage and increase the risk of neurological disease.
The brain is soft and usually cushioned from our skulls by cerebrospinal fluid. But when something hits the head hard enough, our brains jostle and can crash into that hard bone, causing swelling or bleeding. This can lead to concussion symptoms like short-term memory loss or confusion. (Not all concussions cause fainting or nausea or dizziness.)
A new study published this month in the journal Alzheimer’s and dementia draws from a large pool of tracking data from Americans whose health outcomes have been reported over the past 25 years. The authors find that even mild head injuries are associated with a long-term increased risk of dementia. The study also found that the more head injuries people have, the higher the risk of developing dementia.
Dementia is a general term for memory and cognitive loss caused by changes in the brain. The most common type is Alzheimer’s disease, a progressive and irreversible disease in which tangles of proteins interrupt the communication of neurons with each other. But there are other types of dementia, including vascular dementia, which occurs when there is not enough blood flow to provide oxygen to the brain, and frontotemporal dementia, which is caused by loss of blood. cells in the front and side regions of the brain that can drastically alter personality and behavior.
The researchers hope this new information will help raise awareness of the implications of head injuries and the importance of preventing them. “This really is one of the most important take-home messages from this study, because head injuries are preventable to some extent,” says Andrea Schneider, neurologist at the University of Pennsylvania and lead author of the article. “You can do practical things like wear bicycle helmets or wear your seat belt.”
Previous studies have demonstrated a similar relationship between head trauma and dementia, but most have focused on specialized populations such as military veterans. Schneider says this study is one of the first to examine the relationship in a general and community population, which may be more representative of the average person.
Schneider and colleagues at the University of Pennsylvania analyzed data from more than 14,000 participants in the Atherosclerosis in Communities study, an ongoing effort that followed people aged 45 to 65 in Minnesota, Maryland, La North Carolina and Mississippi since 1987. The study aimed to track environmental and genetic conditions that may contribute to heart disease, but the researchers also collected medical records and asked participants to self-report any injuries to heart disease. the head.
When researchers at the University of Pennsylvania analyzed data on traumatic brain injury, they found that people with a head injury were 25% more likely to develop dementia than those who did not. This risk doubled for those who suffered at least two head injuries.
Other health factors could also play a role. Genetic Make some people more prone to dementia; some forms are inherited or accompany other progressive disorders such as Parkinson’s and Huntington’s disease. Other risks include vascular problems such as Diabetes and arterial hypertension, environmental influences such as pollutionand lifestyle choices like smoking. But Schneider says head injuries are a big factor. “We were able to say that about 9.5% of all dementia cases in our study were attributable to head trauma,” she says.