A new study suggests that brain fog from a COVID-19 infection could linger for months for both inpatients and outpatients.
The study was published Friday in the journal JAMA Network Open by researchers with the Mount Sinai Health System in New York.
"People who have survived COVID-19 frequently complain of cognitive dysfunction, which has been described as brain fog," the study read.
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Researchers conducted a survey of 740 Mount Sinai COVID-19 patients from April 2020 to May 2021. The average age was 49 years old.
They concluded that hospitalized COVID-19 patients had a higher rate of impairment in attention, executive functioning, memory recall and other cognitive functions compared to COVID-19 outpatients.
Some patients reported having trouble with their memory nearly eight months after a COVID-19 infection.
Researchers found that 15% of respondents had problems with phonemic fluency in their speaking. Sixteen percent had issues in executive functioning. Eighteen percent showed impairment in their cognitive processing speed. Twenty percent showed slowed ability to process categories or lists. Twenty-three percent had problems in memory recall and 24% had issues in memory encoding, among other cognitive impairments.
"In this study, we found a relatively high frequency of cognitive impairment several months after patients contracted COVID-19," the study’s authors said. "Impairments in executive functioning, processing speed, category fluency, memory encoding, and recall were predominant among hospitalized patients."
Researchers said further studies are needed to understand the underlying risks and treatments for COVID-19 brain fog.
It’s not the first study to examine the length of the COVID-19 symptom.
In March, researchers from the University of California, San Francisco published their findings after examining 100 patients who were recovering from mild cases of COVID-19. Fourteen non-hospitalized patients reported having cognitive issues that lasted at a median of 98 days.
Researchers highlighted two patients involved in the study. One 33-year-old woman said a week after her COVID-19 diagnosis, she had difficulty focusing, remembering and keeping track of information. After 149 days, tests indicated that her mental condition had improved, but she had difficulty recalling events in a timely fashion.
A 56-year-old woman also had difficulty focusing when she was diagnosed with a mild case of COVID-19. She reported that her symptoms lasted for 72 days after the initial onset.
Researchers have been studying the long-term effects of the coronavirus since reports surfaced of people experiencing an array of symptoms not listed on the U.S. Centers for Disease Control and Prevention’s website, lasting months.
A study led by Adam Hampshire, a doctor at Imperial College London, found that people recovering from COVID-19 may suffer long-lasting impaired brain function.
"[Cognitive deficits] were of substantial effect size for people who had been hospitalized, but also for mild but biologically confirmed cases who reported no breathing difficulty," the researchers wrote in a post published on MedRxiv. "Finer grained analyses of performance support the hypothesis that COVID-19 has a multi-system impact on human cognition."
FOX News and Austin Williams contributed to this report. This story was reported from Los Angeles.