A new Cleveland clinic-led study has identified mechanisms by which COVID-19 can lead to Alzheimer's disease-like dementia. The findings, published in Alzheimer's Research and Therapy, indicate an overlap between COVID-19 and brain changes common in Alzheimer and may help inform risk management and therapeutic strategies for COVID-19-associated cognitive impairment. Reports of neurological complications in COVID-19 patients and 'long haulier' patients whose symptoms persist after the infection clears are becoming more common, suggesting that SARS-CoV-2 (the virus that causes COVID-19) may have lasting effects on brain function. However, it is not yet well understood how the virus leads to neurological issues. The researchers also analyzed the genetic factors that enabled SARS-COV-2 to infect brain tissues and cells. Researchers found little evidence that the virus targets the brain directly, they discovered close network relationships between the virus and genes/proteins associated with several neurological diseases, most notably Alzheimer's, 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. The researchers also found that individuals with the allele APOE E4/E4, the greatest genetic risk factor for Alzheimer's, had decreased expression of antiviral defence genes, which could make these patients more susceptible to COVID-19.