A new symptom associated with COVID-19, ‘face blindness’

The list of symptoms that can befall long-term COVID patients just got longer and a little more mysterious: Researchers are reporting “face blindness” associated with the syndrome.

The condition, medically known as prosopagnosia, causes a very specific disorder: difficulty distinguishing faces from others. Even the once-familiar face of a loved one may just as well be the face of a stranger.

Typically, face blindness results from damage to the brain’s face-processing network, such as after a head injury or stroke, said Marie-Luise Kieseler, a researcher at Dartmouth College’s Social Perception Laboratory in Hanover, NH.

Now, he and colleague Brad Duchaine have identified the first case of face blindness linked to long-distance COVID.

Reported in the journal Cortex, they describe the case of 28-year-old Annie, who contracted COVID in March 2020. She had a rather rough time, with high fever, shortness of breath, diarrhea and cough. sometimes bad that he passed out from lack of oxygen.

After three weeks, Annie finally felt well enough to return to work (from home). But several weeks later, he began to notice feelings of confusion and that “something was wrong” with his ability to perceive faces.

Things came to a head when, in June 2020, he met his family for dinner for the first time since his illness. When he arrived at the restaurant, he walked past them because he didn’t recognize them.

Annie said when her father called out, she turned to the familiar voice to see a face she didn’t recognize.

As Annie described it, “It was like my father’s voice coming from a stranger’s face.”

Annie was eventually evaluated by the Dartmouth team, who asked her to perform a series of standard tests to get to the bottom of it.

It turned out that Annie performed “flawlessly” on certain tests, including tests that asked her to learn and remember pictures of cars and landscapes, as well as audio recordings. He ran into trouble against facial recognition.

For example, one test presents people with pictures of six male faces for memory. They must then distinguish these learned faces from images of unfamiliar faces. On average, test takers get it right about 80% of the time. However, Annie was right 56% of the time.

It all pointed to a specific deficit in face memory processing, Kieseler said.

Faces weren’t Annie’s only challenge, however. He also had trouble navigating places he once knew – for example, he got confused at the grocery store and had no idea where he parked his car. (He now uses Google’s map pin function to track his car.)

Kieseler said navigation problems are known to occur commonly with face blindness — probably because certain brain regions critical for processing faces and “scenes” are close together. (Annie’s navigation problems don’t seem to be visual, the researchers said. Instead, the problem seems to be with her use of a “cognitive map” — which helps people figure out where another place is relative to where they are.)

Dr. William Schaffner is a professor at Vanderbilt University Medical Center in Nashville, Tenn., and a spokesman for the Infectious Diseases Society of America.

He said the case adds to the list of neurological symptoms known to plague many long-term COVID patients — from loss of taste and smell to memory and attention deficits and chronic pain.

One of the big questions, however, is why the respiratory infection becomes a persistent neurological problem for some people — including young people who have had mild bouts of COVID.

In general, many researchers believe that it is related to abnormal activation of the immune system. For reasons that are unclear, Schaffner said, “there appears to be a chronic, smoldering inflammatory response” that continues long after the initial infection.

As for face blindness, it is not clear how common (or rare) it may be. The Dartmouth researchers surveyed 86 people who had contracted COVID—32 of whom had fully recovered and 54 who had had prolonged symptoms of COVID for at least 12 weeks.

No one in the long COVID group reported symptoms of face blindness, Kieseler said. But navigation problems were common: a third said they had sometimes gotten lost while traveling, and almost half said once-familiar streets now felt unfamiliar. Few said they had these problems before COVID.

“This can really interfere with everyday life,” Kieseler said. “If you get lost on your way to the grocery store, that’s a big problem.”

Another looming question: How often do such neurological problems improve or resolve?

Kieseler said there is currently no cure for face blindness. Instead, people learn to compensate. For example, Annie relies on voices to recognize people she knows.

According to Schaffner, some other neurological manifestations of long-term COVID, such as loss of taste and smell, often seem to improve. He recommended that people who have lingering symptoms in the weeks or months after a COVID infection talk to their primary care doctor.

Those with more severe symptoms, such as debilitating fatigue and persistent problems with memory and thinking, may end up at a long-term COVID clinic — which many major U.S. medical centers now have, Schaffner said.

Kieseler said people who think they may be suffering from face blindness or other long-term visual impairments related to COVID-19 are welcome to contact the research team at faceblind.org.

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