June 11, 2021 – A new Cleveland Clinic-led study has identified mechanisms by which COVID-19 can lead to Alzheimer’s disease-like dementia. The findings indicate an overlap between COVID-19 and brain changes common in patients with Alzheimer’s.
Cleveland Clinic says the findings may help inform risk management and therapeutic strategies for COVID-19-associated cognitive impairment.
Reports of neurological complications in COVID-19 patients and “long-hauler” patients whose symptoms persist after the infection clears are becoming more common, suggesting that SARS-CoV-2 may have lasting effects on brain function, but it is not yet well understood how the virus leads to neurological issues.
Researchers found little evidence that the virus targets the brain directly, but they did discover close network relationships between the virus and genes/proteins associated with several neurological diseases, pointing to pathways by which COVID-19 could lead to Alzheimer’s disease-like dementia.
To explore this further, they investigated potential associations between COVID-19 and neuroinflammation and brain microvascular injury, which are both hallmarks of Alzheimer’s.
“We discovered that SARS-CoV-2 infection significantly altered Alzheimer’s markers implicated in brain inflammation and that certain viral entry factors are highly expressed in cells in the blood-brain barrier,” explained Dr. Cheng. “These findings indicate that the virus may impact several genes or pathways involved in neuroinflammation and brain microvascular injury, which could lead to Alzehimer’s disease-like cognitive impairment.”
The researchers also found that individuals with the greatest genetic risk factor for Alzheimer’s had decreased ability to naturally fight viral infections, which could make these patients more susceptible to COVID-19.