PHILADELPHIA — Helmets may not be all that fashionable, but new findings from the University of Pennsylvania reinforce just how important it is to always protect one’s head. Scientists report any single head injury appears to be enough to significantly raise the risk of death.
Over the course of a 30 year period, participants who had suffered any head injury displayed two times the rate of mortality than those who did not have a head injury. Even worse, mortality rates among people with either moderate or severe head injuries were close to three times higher.
Head injuries are incredibly common in the USA; over 23 million adults aged 40 or older have a history of head injury accompanied by loss of consciousness. These accidents, of course, can happen for any number of reasons: sports, unintentional falls, or car accidents. Moreover, it’s hardly a secret anymore just how dangerous these injuries can be in both the short and long-term. Research conducted in recent decades has linked head injuries to stroke, dementia, CTE, disability, and late-onset epilepsy.
Other studies have suggested an increased short-term mortality associated with head injuries, but primarily among hospitalized patients. This latest work analyzed 30 years worth of data from over 13,000 community-dwelling subjects (not hospitalized or living in a nursing home). Researchers’ main aim was to determine if head injury has an impact on mortality rates in adults over longer periods of time.
Ultimately, study authors discovered 18.4 percent of studied subjects reported one or more head injuries during the study period, with 12.4 percent of those injuries being moderate or severe. The average length of time between a head injury and death was just under five years (4.7 years).
‘Head injury associated with increased death rates even long-term’
Death from all causes was seen among 64.6 percent of subjects who suffered a head injury, and in 54.6 percent of those without any head injury. Notably, after considering subjects’ characteristics, investigators also found that the mortality rate from all-causes among those with a head injury was 2.21 times greater than the mortality rate among others with no head injury. The mortality rate for people with more severe head injuries was 2.87 times the mortality rate among those with no head incidents.
“Our data reveals that head injury is associated with increased mortality rates even long-term. This is particularly the case for individuals with multiple or severe head injuries,” explains the study’s lead author, Dr. Holly Elser, a neurology resident at Penn, in a media release. “This highlights the importance of safety measures, like wearing helmets and seatbelts, to prevent head injuries.”
The research team was also sure to analyze data pertaining to specific causes of death among subjects. All in all, the most common deaths included cancers, cardiovascular disease, and neurologic disorders (dementia, stroke, epilepsy, etc). Among those with head injuries, deaths were more frequently linked to neurologic disorders and unintentional injury or trauma (falls, for example).
Close to two-thirds of neurologic causes of death were attributed to neurodegenerative diseases, like Alzheimer’s and Parkinson’s disease, among participants with head injury. Those diseases made up a much greater proportion of overall deaths among those with head injury (14.2%) compared to those without (6.6%).
“Study data doesn’t explain why the cause of death in individuals with head injuries is more likely to be from neurodegenerative diseases, which underscores the need for further research into the relationship between these disorders, head injury, and death,” adds Andrea L.C. Schneider, MD, PhD, an assistant professor of Neurology at Penn.
The data used for this project was provided by the Atherosclerosis Risk in Communities (ARIC) Study, an ongoing community-based study of 15,792 participants ages 45 through 65 years old. Participants in the ARIC were recruited from Maryland, Minnesota, Mississippi, and North Carolina.
The study is published in JAMA Neurology.