Head Injuries Reactivate Alzheimer’s Viruses

A study using “miniature brains” from stem cells has shown that repeated brain injuries, whether from violent blows or mild concussions, contribute to activating dormant viruses in the brain, such as the herpes simplex-1 virus, which causes inflammation and long-term damage leading to Alzheimer’s disease.

Dana Kearns, a biomedical engineer at Tufts University, said: “We wondered what would happen if we subjected a brain tissue model to physical trauma, something like a concussion? Would the herpes simplex virus 1 reactivate and start a neurodegenerative process?”

A week after the injury, researchers observed the formation of plaques and protein tangles in brain tissue, a hallmark of neurodegenerative diseases like Alzheimer’s.

Some brain cells also showed damage consistent with neuroinflammation, and there was a significant increase in pro-inflammatory immune cells, according to Science Alert.

The site also mentioned that traumatic brain injuries, including chronic traumatic encephalopathy (CTE), have recently been identified as a major risk factor for neurodegenerative diseases, and preliminary research suggests that chronic inflammation resulting from mild concussions may play a role in cumulative damage.

In a 2008 study, researchers found that genes from the herpes simplex virus type 1 were present in 90% of protein plaques in the brains of Alzheimer’s patients after their death. The majority of this viral DNA was found inside the plaques.