Further research into the effects of long COVID-19 has revealed that in addition to the myriad neurological symptoms that have been linked to the disease, face blindness may also be one of them.
The long COVID study published in the journal Cortex, surveyed 54 patients and a majority told experts at Dartmouth College in Hanover, N.H., they have had difficulty identifying faces since their infection. The research on face blindness, also called prosopagnosia, following a long COVID-19 infection is reported to be the first of its kind.
Face blindness is a neurological impairment that individuals are typically born with or acquire after a stroke or brain injury, USA Today reports. Acquiring the impairment from another source later in life is often also associated with navigation and object-recognition difficulties.
Dartmouth researchers focused on the details from one of the patient's cases, Annie, 28, who had normal facial recognition abilities prior to her COVID-19 infection and said two months after the onset of it she experienced symptom relapses and challenges with face recognition.
Researchers set up four tests to analyze Annie's facial recognition capabilities. After undergoing evaluation of both familiar face recognition and unfamiliar face recognition, there were clear signs of impairment, researchers reported. However, her scores for other tests including assessing face detection, face identity perception, object recognition, scene recognition and non-visual memory were normal.
"In June 2020, Annie spent time with her family for the first time since becoming ill with COVID-19 and noticed that she was unable to recognize her father or visually distinguish him from her uncle," researchers wrote. "Annie reports that she is now relying heavily on people's voices for identification purposes."
Months later in November 2020, Annie also began experiencing migraines and balance issues in addition to fatigue and brain fog.
"At the most extreme, some with the condition can't even recognize themselves, apologizing for bumping into a person in the mirror," according to USA Today. "Others can't identify familiar people if they're in an unexpected context or wearing a hat. Some can't follow television plot lines because the characters look too much alike."
The findings point to more severe long-term neurological effects of COVID-19. Other, previously studied symptoms including memory deficits and attention and concentration impairments can also impair an individual's daily functioning. This research highlights that "in addition to the well-known broad impairments, COVID-19 sometimes causes severe selective impairments like prosopagnosia," researchers wrote. "Our findings suggest that there are a substantial number of individuals with PASC/long COVID who are experiencing selective visual deficits."
They underscored that future research should expand on these findings and additionally focus on what, if any, interventions may be helpful in lessening the severity of these impairments.