Just when medical experts thought they had already identified all of the symptoms of COVID-19, a new study comes along, claiming that some patients suffer from a condition known as “face blindness.”

The bizarre symptom that makes one unable to recognize familiar faces, including loved ones, is rare but alarming. Scientifically called prosopagnosia, face blindness impairs the ability to discern one face from another, according to US News & World Report.

Marie-Luise Kieseler, a researcher at the Dartmouth College Social Perception Lab in Hanover, New Hampshire, told the outlet that the condition typically arises when there is damage to the brain’s face-processing network following a stroke or head injury.

But Kieseler and her colleague, Brad Duchaine, have identified the first case of face blindness related to COVID-19 infection.

In a single case report published in Cortex, the duo described the case of a 28-year-old woman named Annie, who contracted the novel coronavirus in March 2020.

Annie had a rough experience when she contracted the virus, suffering a high fever, diarrhea, coughing spells and shortness of breath. She also fainted from lack of oxygen at times. After three weeks, she recovered from the initial infection only to start experiencing feelings of disorientation several weeks later. She also realized something was off when she could not perceive faces correctly.

In June 2020, a shocking incident happened when she decided to meet with her family for dinner for the first time since she battled the disease. At the restaurant, she walked right past her loved ones since she could not recognize their faces.

When a man called Annie’s name, she turned to the familiar voice only to be stunned that it was from a face she could not recognize. “It was as if my dad’s voice came out of a stranger’s face,” she said.

Upon evaluation by the Dartmouth team, all evidence pointed to a deficit in face memory processing. But in addition to prosopagnosia, Annie also had difficulty navigating once-familiar places. She even has to rely on the Google Map pin function to remember where she had parked her car.

“The combination of prosopagnosia and navigational deficits that Annie had is something that caught our attention because the two deficits often go hand in hand after somebody either has had brain damage or developmental deficits,” Duchaine said, as per Daily Star.

“It's been known that there are broad cognitive problems that can be caused by COVID-19, but here we're seeing severe and highly selective problems in Annie, and that suggests there might be a lot of other people who have quite severe and selective deficits following COVID,” he added.

It’s unclear how a respiratory infection could lead to persistent neurological issues for some people even after their bout with the disease. It’s also unknown if the issue improves or resolves on its own. Kieseler noted that there is no cure for prosopagnosia at present; patients learn to compensate. In Annie’s case, she identifies her loved ones through their voices.

Trying to Understand Face-Blindness: A Mystery of Neuroscience
Individuals with face-blindness remember people by things other than their face, such as the clothes they wear. Wikimedia Commons (CC BY-SA 2.