Issue 32.3 study were members of Kaiser Permanente Washington in the Seattle area who were randomly selected to be invited to participate . To qualify , they had to be 65 or older , living in the community and not have dementia .
At the time of enrollment and every two years thereafter , the participants underwent detailed health and cognitive assessments until they either died , developed dementia or dropped out . As part of their assessments , information was gathered from the participants , their medical records and , in the event of their death or the onset of dementia , from interviews with family and friends about the participant ’ s history of head trauma , including whether it was accompanied by loss of consciousness which can occur with more severe head trauma .
Examination of the participants ’ donated brains did not find more of the changes seen with Alzheimer ’ s disease and related dementias , such as amyloid plaques , in those who had brain injury with loss of consciousness . But they did find that those who had experienced head trauma with loss of consciousness were more likely to have brain atrophy .
The increase in risk for brain atrophy was small , or about 22 %, ” but it was statistically significant , so it ’ s likely real ,” noted C . Dirk Keene , the Nancy and Buster Alvord Endowed Chair in Neuropathology and professor of laboratory medicine and pathology at the UW School of Medicine , whose team examined the brains . The cause of brain atrophy in these individuals is unknown , Keene said .
“ We typically see atrophy as the downstream consequence of many other forms of neuropathology ,” said Keene . “ Strokes can cause atrophy , Alzheimer ’ s-type neuropathological changes like amyloid plaques can cause atrophy , and so on . But we looked for everything else and did not find any other clear associations with TBI — just atrophy itself . Atrophy is also a consequence of the diffuse injury to axons commonly seen after brain injury , so this finding supports axonal injury as a contributor to post-traumatic neurodegeneration . We still have a lot to figure out .” g
Computed tomography ( CT scan ) of the brain , showing brain atrophy of bilateral frontal lobes .
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