Concussions Linked to Alzheimer's Risk in Study 
 
 Brain scans found seniors with both poor memory and prior head injury have more plaque buildup 
 
 
 
 WebMD News from HealthDay 
 
 WebMD News Archive 
 
 By Kathleen Doheny 
 
 HealthDay Reporter 
 
 THURSDAY, Dec. 26, 2013 (HealthDay News) -- Older adults with memory problems and a history of concussion have more buildup of Alzheimer's disease-associated plaques in the brain than those who also had concussions but don't have memory problems, according to a new study. 
 
 ''What we think it suggests is, head trauma is associated with Alzheimer's-type dementia -- it's a risk factor," said study researcher Michelle Mielke, an associate professor of epidemiology and neurology at Mayo Clinic Rochester. "But it doesn't mean someone with head trauma is [automatically] going to develop Alzheimer's." 
 
 Her study is published online Dec. 26 and in the Jan. 7 print issue of the journal Neurology. 
 
 Previous studies looking at whether head trauma is a risk factor for Alzheimer's have come up with conflicting results, she noted. And Mielke stressed that she has found only a link or association, not a cause-and-effect relationship. 
 
 In the study, Mielke and her team evaluated 448 residents of Olmsted County, Minn., who had no signs of memory problems. They also evaluated another 141 residents with memory and thinking problems known as mild cognitive impairment. 
 
 More than 5 million Americans have Alzheimer's disease, according to the Alzheimer's Association. Plaques are deposits of a protein fragment known as beta-amyloid that can build up in between the brain's nerve cells. While most people develop some with age, those who develop Alzheimer's generally get many more, according to the Alzheimer's Association. They also tend to get them in a predictable pattern, starting in brain areas crucial for memory. 
 
 In the Mayo study, all participants were aged 70 or older. The participants reported if they ever had a brain injury that involved loss of consciousness or memory. 
 
 Of the 448 without any memory problems, 17 percent had reported a brain injury. Of the 141 with memory problems, 18 percent did. This suggests that the link between head trauma and the plaques is complex, Mielke said, as the proportion of people reporting concussion was the same in both groups. 
 
 Brain scans were done on all the participants. Those who had both concussion history and cognitive [mental] impairment had levels of amyloid plaques that were 18 percent higher than those with cognitive impairment but no head trauma history, the investigators found. ||||| Having a serious concussion could be a risk factor for developing Alzheimer's decades later – though not everyone with head trauma will lose their memory, a new study suggests. 
 
 PET scan of a brain in the early stages of Alzheimer's disease. (Photo: Gary Small, UCLA School of Medicine) Story Highlights Study shows link among those who had head injuries and later had memory problems 
 
 Scientists say more research needed to understand the relationship 
 
 Brain scans measure buildup of protein called beta amyloid 
 
 Having a serious concussion could be a risk factor for developing Alzheimer's decades later – though not everyone with head trauma will lose their memory, a new study suggests. 
 
 A team from the Mayo Clinic in Rochester Minn., conducted brain scans on 448 older Minnesotans who had no signs of memory problems and 141 who did. Roughly 17% in both groups had had a brain injury earlier in life involving some loss of consciousness or memory. 
 
 Those who had no signs of memory problems had normal brain scans, regardless of their history of brain injury. Scans of those with memory problems and a history of brain injury were five times more likely to show a buildup of a brain protein long associated with Alzheimer's Disease, says study author Michelle Mielke, an associate professor of epidemiology and neurology at the Mayo Clinic. 
 
 The study, published online today in the journal Neurology, examined people in their 70s and 80s who reported having an earlier head trauma – in most cases 50 or 60 years earlier when they were adolescents. In those days, only the sickest people went to the doctor, so the head injuries were probably quite significant, Mielke says. 
 
 This is one of the first studies to take advantage of new technology, allowing brain scans to measure the buildup of a protein called beta amyloid, long associated with Alzheimer's. Most previous studies of the connection between Alzheimer's and head injury had looked only at cadavers. 
 
 "In my view, these findings are consistent with the idea that traumatic brain injury may lead to amyloid accumulation and Alzheimer's disease," says Richard Lipton, director of the Division of Cognitive Aging and Dementia and the Montefiore Headache Center at Albert Einstein College Of Medicine in New York City. 
 
 More research is needed, he cautions, to help explain how one causes the other. "To more fully explore the causal links, we need not just brilliant snapshots but the movies which track brain changes and cognitive changes over time." 
 
 For people worried about their own head injuries, the study provides some comfort, Lipton says. Both groups of older adults – impaired and normal – had the same rate of head injury. So, clearly, not every head injury leads to Alzheimer's disease, he says. 
 
 Most head injuries are accidents and therefore unavoidable, though helmets and seat belts can make a difference in some cases. 
 
 Lipton says he hopes that learning more about the connection between head injury and Alzheimer's will lead to interventions to protect injured brains from long-term damage. "Drugs that block the development of amyloid or increase its removal from the brain may help protect persons with traumatic brain injury from Alzheimer's disease, though that has not been demonstrated," he says. 
 
 Until then, the best strategy is to minimize known risk factors for Alzheimer's – high blood pressure, diabetes and high cholesterol – by eating a healthy Mediterranean diet and exercising both mind and body, he says.
– If you've ever suffered a concussion, a new study suggests you may have a higher risk of developing Alzheimer's disease—or not. Mayo Clinic researchers performed brain scans on 141 people in their 70s and 80s who had memory problems and 448 who didn't. Some 18% and 17%, respectively, reported at one time suffering a brain injury in which they lost consciousness or memory. The latter group's scans came back normal, head injury or not. But the group with memory issues and a previous concussion were five times more likely to have an Alzheimer's-associated plaque buildup in the brain, the study author explains, per HealthDay News. Since both groups had the same rate of injury and only some showed a buildup of the protein beta amyloid, the findings show the link between head trauma and the plaque is complex and not all brain injuries lead to the disease. "If you do hit your head, it doesn't mean you are going to develop Alzheimer's," the study author says, but "it may increase your risk." A medical director agrees, and tells USA Today, "In my view, these findings are consistent with the idea that traumatic brain injury may lead to amyloid accumulation and Alzheimer's disease."