It’s becoming known as Covid brain fog: troubling cognitive symptoms that can include memory loss, confusion, difficulty focusing, dizziness and grasping for everyday words. Increasingly, Covid survivors say brain fog is impairing their ability to work and function normally.
“There are thousands of people who have that,” said Dr. Igor Koralnik, chief of neuro-infectious disease at Northwestern Medicine in Chicago.
Scientists aren’t sure what causes brain fog, which varies widely and affects even people who became only mildly physically ill from Covid-19 and had no previous medical conditions. Leading theories are that it arises when the body’s immune response to the virus doesn’t shut down or from inflammation in blood vessels leading to the brain.
Confusion, delirium and other types of altered mental function, called encephalopathy, have occurred during hospitalization for Covid-19 respiratory problems, and a study found such patients needed longer hospitalizations, had higher mortality rates and often couldn’t manage daily activities right after hospitalization.
But research on long-lasting brain fog is just beginning. A French report in August on 120 patients who had been hospitalized found that 34 percent had memory loss and 27 percent had concentration problems months later.
“People say in a disparaging way ‘It’s all in their head,’” [neurologist and COVID survivor Dr. Kim Murphy] said. “In this case it is literally in our heads, and it is very real.”