A new study links the development of Alzheimer's disease with a specific history of concussions.
The research, led by study author Michelle Mielke of the Mayo Clinic, found a link between loss of consciousness in concussions and the build up of the plaque linked to the degenerative brain disease.
Alzheimer's is the most common form of dementia, and accounts for as many as 80,000 deaths annually in the United States.
Researchers performed brain scans on almost 600 participants over 70. A total of 448 showed no signs of having memory problems, while another 141 did show signs of having memory problems, known as mild cognitive impairment.
Participants also answered questions about their concussion history. They found a higher percentage of people with memory problems also reported having had a concussion that included loss of consciousness. That group was also found to have amyloid plaque levels associated with Alzheimer's that were about 18 percent higher than in those without a history of head trauma.
Says researcher Mielke:
Interestingly, in people with a history of concussion, a difference in the amount of brain plaques was found only in those with memory and thinking problems, not in those who were cognitively normal.
The research findings have been published in the journal Neurology.