Traumatic Brain Injury Could Reactivate Herpes Virus, Which Could Lead to Neurodegeneration

A new study suggests that mild traumatic brain injuries (TBI), like those from concussions, could reactivate the dormant herpes simplex virus type 1 (HSV-1) in the brain, potentially contributing to Alzheimer’s disease (AD).

Researchers used a 3D model of human brain tissue to show that a physical jolt could wake up HSV-1, leading to the production of amyloid beta and phosphorylated tau (p-tau), hallmarks of AD.

The brain model, made from silk protein and collagen, mimics real brain tissue. It showed that repeated mechanical blows could reactivate HSV-1, resulting in neuroinflammation, gliosis, and other changes associated with neurodegeneration. These effects were more severe with repeated injuries but didn’t appear in brain tissue without the virus.

Lead investigator Dr. Dana Cairns from Tufts University highlighted that this finding raises the question of whether early treatment with antiviral or anti-inflammatory drugs after head trauma could prevent HSV-1 reactivation and lower AD risk.

However, experts advise caution, MedScape reports. Dr. Tara Spires-Jones from the UK Dementia Research Institute points out that the study’s brain changes don’t exactly match what’s seen in actual Alzheimer’s cases. The experiments, she says, were done in controlled lab conditions and lack factors like age or blood vessel changes that are important in real life.

Dr. Robert Howard from University College London reminds us that finding an association doesn’t prove HSV-1 causes AD. More research is needed before these findings can be taken as a serious link between TBI, HSV-1, and Alzheimer’s.

Dr. Jennifer Pocock from UCL’s Institute of Neurology also noted that the study didn’t address the role of microglia, which are key in brain inflammation after TBIs. She suggests that the absence of microglia in the study might make the results less applicable to real-world cases.

This research hints at a possible connection between TBI, HSV-1, and Alzheimer’s, but many questions remain. For now, avoiding head injuries, especially in contact sports, remains a recommended way to protect the brain.

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