NEW YORK  (Dispatches)  --   A small  number  of  patients who died of COVID  indicate some of the same molecular changes found in the brains of people with Alzheimer’s disease.
Previous  reports of “brain fog” and persistent cardiac symptoms in COVID survivors prompted the researchers at Columbia University Vagelos College of Physicians and Surgeons to investigate how certain molecules called ryanodine receptors were affected in this new disease.
Researchers found high levels of phosphorylated tau in the brains of the COVID patients in addition to defective ryanodine receptors.
Inside neurons, defective ryanodine receptors have previously been linked to an increase in phosphorylated tau, a well-known hallmark of Alzheimer’s.
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” , said  Andrew Marks, MD, chair of the Department of Physiology & Cellular Biophysics at the Vagelos College of Physicians and Surgeons, who led the study.