Head injuries linked to double death rate in long run: Research

According to new research, adults who had any type of brain damage during a 30-year study period had double the rate of mortality as those who did not, while mortality rates among those with moderate or severe head injuries were nearly three times higher.

The study’s findings were reported in JAMA Neurology. Over 23 million persons aged 40 and over in the United States report a history of head injury with loss of consciousness. Head injuries can be caused by a variety of factors, including car accidents, inadvertent falls, and sports injuries. Furthermore, brain damage has been related to a variety of long-term health issues such as disability, late-onset epilepsy, dementia, and stroke.

Previous research has found an increase in short-term mortality related with head injuries, particularly among hospitalised patients. This 30-year study examined data from over 13,000 community-dwelling individuals (those who were not hospitalised or living in nursing home facilities) to see if a brain injury affects adult mortality rates in the long term. The researchers discovered that 18.4% of the individuals reported one or more head injuries throughout the study period, and 12.4% of those who sustained a head injury were classified as moderate or severe. The median interval between sustaining a head injury and dying was 4.7 years.

Death from any cause was documented in 64.6 percent of those who experienced a head injury and in 54.6 percent of those who did not suffer a head injury. After controlling for participant characteristics, researchers discovered that the mortality rate from all causes among people with a head injury was 2.21 times that of those without a head injury. Furthermore, the mortality rate for those with more severe head injuries was 2.87 times that of those without a head injury.

“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,” explained the study’s lead author, Holly Elser, MD, PhD, MPH a Neurology resident at Penn. “This highlights the importance of safety measures, like wearing helmets and seatbelts, to prevent head injuries.”

The data was also analysed for specific causes of death across all individuals by the investigators. Cancer, cardiovascular disease, and neurologic illnesses were the leading causes of mortality overall (which include dementia, epilepsy, and stroke). Deaths from neurologic illnesses and unintentional damage or trauma (such as falls) occurred more commonly among people with head injuries.

When researchers examined specific neurologic causes of mortality among participants with head injuries, they discovered that neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease accounted for approximately two-thirds of all neurologic causes of death. These diseases accounted for a higher proportion of overall mortality among people who had suffered a head injury (14.2%) than those who did not (6.6 per cent).

“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,” said Andrea L.C. Schneider, MD, PhD, an assistant professor of Neurology at Penn.