Suffered a head injury in the past and had a momentary loss of consciousness? You could be at greater risk of Alzheimer's disease later in life.
The symptoms of concussion -- a short loss of normal brain function in response to a head injury -- may lead to the build-up of brain plaques related to Alzheimer's disease, says a new study.
The results, published in the journal Neurology, suggest a potential link between a history of head trauma and later cognitive decline.
"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," said study author Michelle Mielke who is working with Mayo Clinic in Rochester, Minnasota.
For the study, 448 people without any signs of memory problems and 141 people with memory and thinking problems -- called mild cognitive impairment -- were selected.
Of the 448 without any thinking or memory problems, 17 percent reported a brain injury and 18 percent of 141 people with memory and thinking difficulties reported a concussion or head trauma.
People with memory and thinking impairments with a history of head trauma had higher levels of amyloids, a kind of fibrous protein, than those with no head trauma history.
"Our results add merit to the idea that concussion and Alzheimer's disease may be linked," said Mielke.
"However, the fact that we did not find a relationship in those without memory and thinking problems suggests that any association between head trauma and amyloids is complex," he added.
Researchers suggested that higher amyloid levels could be a response to a higher level of damage to the myelin coating of the axons of neurons - the brain's white matter.