Alzheimer's-like signaling in brains of COVID-19 patients

A study from researchers at Columbia University Vagelos College of Physicians and Surgeons reports that the brains of a small sample of patients who died of COVID display some of the same molecular changes found in the brains of people with Alzheimer's disease.

Early reports of "brain fog" and persistent cardiac symptoms in COVID survivors prompted the Columbia researchers to investigate how certain molecules called ryanodine receptors were affected in this new disease.

Defective ryanodine receptors have been implicated in diverse pathogenic processes, ranging from heart and lung disease to the brain's response to stress and Alzheimer's disease, as reported in research led by Andrew Marks, MD, chair of the Department of Physiology & Cellular Biophysics at the Vagelos College of Physicians and Surgeons, who led the new study.

In the new study, the Columbia researchers found high levels of phosphorylated tau in the brains of the COVID patients in addition to defective ryanodine receptors.

Phosphorylated tau was found in areas where tau is typically located in Alzheimer's patients, as well as in areas where tau is not typically located in Alzheimer's patients. That suggests that phosphorylated tau in the COVID patients could be a sign of early-stage Alzheimer's and also contribute to other neurological symptoms observed in COVID-19 patients.

Increased levels of phosphorylated tau in the brain are believed to be linked to memory problems in Alzheimer's and could be causing similar issues in people with long COVID, Marks says