Brain concussions may lead to dementia later in life

Two studies, one of veterans and the other of former professional football players, provide new evidence that head injuries such as concussions are linked to dementia later in life and may make the brain more vulnerable to the development of symptoms characteristic of Alzheimer's disease, according to Wall Street Journal.

Veterans who had been diagnosed with a brain injury, anything from a concussion to a severe head wound, were more than twice as likely to develop dementia compared to those with no injury to the brain, researchers reported today at the Alzheimer's Association' International Conference in Paris.

The results were even more striking in a study of retired football players: 35 percent of the former National Football League players had signs of dementia, which compares to a 13 percent Alzheimer's rate in the general population.

For the veterans study, researchers reviewed the medical records of 281,540 military personnel age 55 and older who received care at Veterans Administration hospitals from 1997 to 2000 and who had at least one follow-up visit from 2001 to 2007. None of the veterans in the study were diagnosed with dementia at the beginning of the seven year study, says msnbc.com.

TBI survivors showed a high density and wide distribution of neurofibrillary tau tangles and amyloid-beta plaque pathology far beyond what was found in controls.

Specifically, about a third of the cases showed tangle pathology years after a single TBI, similar in appearance to the tangles found after repetitive TBI and in neurodegenerative diseases such as Alzheimer's disease.

Moreover, the amyloid-beta plaques were not only found years after TBI, but the majority of cases displayed diffuse as well as "neuritic" plaques with the same character as "senile" plaques also found in Alzheimer's disease. This suggests that years after a single TBI, amyloid-beta plaques may return and become neuritic, informs Times of India.