A recent study published in the journal Lancet Psychiatry provides new evidence of a link between traumatic brain injuries (TBIs) and dementia, including Alzheimer's disease, in older adults. People who suffered TBIs were compared with people who suffered skull or spinal fractures that did not involve a TBI. Those who suffered TBIs had a higher risk of dementia and Alzheimer's.
The research was performed by University of Washington researchers using record from the national health system in Denmark. The Danish records were used because they have features which allow the exploration of connections between records.
The researchers pulled data on 2.79 million people who were known to be at risk of dementia. From those, they culled people who were living in Denmark on Jan. 1, 1995, and were at least 50 when asked for follow-up information between 1999 and 2013.
Of that group, 4.7 percent had suffered at least one traumatic brain injury between 1977 and 2013, while 4.5 percent had been diagnosed with incident dementia during the period between 1999 and 2013. The researchers then analyzed the data based on 1) the length of time between the TBI and the dementia diagnosis; 2) whether the patient suffered multiple TBIs; and 3) gender. These three analyses were to adjust the model for factors that might otherwise explain the dementia.
The study indicated that:
- Only about 5 percent of TBI sufferers were diagnosed with dementia.
- The risk of dementia is greatest within the first 6 months after a TBI.
- The younger the person is when sustaining a TBI, the greater the overall risk of dementia, when stratified by the time since they sustained it.
- The risk of dementia was greater among those who suffered multiple TBIs.
The Associated Press notes that this study is in alignment with a previous Swedish study this year which involved 3.3 million patients.
The University of Washington researchers closed their report with calls for increased TBI prevention and the identification of strategies to reduce the risk of subsequent dementia and Alzheimer's.