Although dementia is typically seen as a problem of the elderly, a new Finnish study shows that traumatic brain injuries may set off processes that can lead to dementia well before old age.
Researchers at the University of Helsinki and Helsinki University Hospital have found that traumatic brain injury (TBI) is tied to a greater risk for dementia in working-age adults. However, they found no such link between TBI and later onset of Parkinson’s disease or amyotrophic lateral sclerosis (ALS/ Lou Gehrig’s disease).
The researchers believe the findings may have strong implications regarding the rehabilitation and long-term monitoring of TBI patients.
Degenerative brain diseases include memory disorders such as Alzheimer’s disease as well as Parkinson’s disease and ALS. While previous research has suggested a link between TBI and degenerative brain diseases, this is the first comprehensive study to determine the impact of TBI on degenerative brain diseases in working age adults.
The study combined several nationwide registers in Finland to monitor more than 40,000 working-age adults, who survived the initial TBI, for ten years. Each person’s level of education and socioeconomic status were accounted for.
“It seems that the risk for developing dementia after TBI is the highest among middle-aged men. The more severe the TBI, the higher the risk for subsequent dementia,” said Dr. Rahul Raj, docent of experimental neurosurgery and one of the primary authors of the study.
“While previous studies have identified good education and high socioeconomic status as protective factors against dementia, we did not discover a similar effect among TBI survivors.”
A significant discovery is that the risk of dementia among TBI survivors who have seemingly recovered well remains high for years after the injury. Raj points out that TBI patients may occasionally be incorrectly diagnosed with dementia due to the damage caused by the TBI itself, but such possible errors were considered in the study.
“These results are significant for the rehabilitation and monitoring of TBI patients. Such a reliable study of the long-term impact of TBI has previously been impossible,” said Professor Jaakko Kaprio, a member of the research group.
Traumatic brain injuries are among the top causes of death and disability, particularly among the young and middle aged. Approximately one in three that suffer from moderate-to-severe TBI die, and about half of the survivors will suffer from lifelong disabilities.
TBI will become a leading cause of death and long-term illness throughout the next ten years, according to the World Health Organization (WHO). Already one percent of the population in the United States suffers from a long-term disability caused by TBI. In Western countries, the aging of the population and age-related accidents increase the number of TBIs, while in Asia, TBIs due to traffic accidents are on the rise.
“It is a tragedy when an adult of working age develops dementia after recovering from a brain injury, not just for the patient and their families, but it also negatively impacts the whole society. In the future, it will be increasingly important to prevent TBIs and to develop rehabilitation and long-term monitoring for TBI patients,” Raj said.
The study is published in the journal PLOS Medicine.
Source: University of Helsinki