COVER STORY
Study Shows Head Trauma May Activate Latent Viruses, Leading to Neurodegeneration
Concussions and repetitive head trauma in sports like football and boxing, once accepted as an unpleasant consequence of intense athletic competition, are now recognized as serious health threats. Of particular concern is the connection between head injuries and neurodegenerative diseases such as chronic traumatic encephalopathy, Alzheimer’ s disease, and Parkinson’ s disease, prompting sports governing bodies to adjust protective equipment and rules of play to minimize the risk.
Researchers at Tufts University and Oxford University have now uncovered mechanisms that may connect the dots between trauma event and the emergence of disease, pointing to latent viruses lurking in most of our brains that may be activated by the jolt, leading to inflammation and accumulating damage that can occur over the ensuing months and years. The results suggest the use of antiviral drugs as potential early preventive treatments post-head injury. The findings are published in a study in Science Signaling. 3
The microbiome— which includes many hundreds of bacterial species that inhabit our bodies— provides aid in digestion, immune system development, and protection against harmful pathogens. But the microbiome also includes dozens of viruses that swarm within our bodies at any given time. Some of these can be potentially harmful, but simply lie dormant within our cells. Herpes simplex virus 1( HSV-1), found in over 80 % of people, and varicella-zoster virus, found in 95 % of people, are known to make their way into the brain and sleep within our neurons and glial cells.
Dana Cairns, research associate in the Department of Biomedical Engineering at Tufts University and lead author of the study, had found evidence in earlier studies suggesting that activation of HSV-1 from its dormant state triggers the signature symptoms of Alzheimer’ s disease in lab models of brain tissue— amyloid plaques, neuronal loss, inflammations, and diminished neural network functionality.