The Link Between "Brain Fog" and Long COVID
Patients who perceived brain fog within 4 weeks of COVID-19 infection were twice as likely to report symptoms of long COVID than patients without cognitive deficits.
For COVID-19 patients, perceiving cognitive deficits or “brain fog” within the first 4 weeks of infection might be associated with long COVID, according to an original investigation published in JAMA Network Open.
Investigators from UCLA conducted a prospective cohort study of 766 patients with COVID-19 in order to describe the characteristics of patients with perceived cognitive deficits within the first 4 weeks post-COVID-19 infections and the links between those deficits and long COVID. Patients were enrolled in the study between April 2020 and February 2021 after laboratory-confirmed COVID-19 infection.
The study authors said such neuropsychiatric symptoms are common in acute COVID-19 and long COVID but the link between these deficits—so called “brain fog”— and long COVID are currently unknown. Brain fog has impacted all age groups, too, the study authors added, and neurocognitive symptoms can include memory problems, difficulty concentrating, trouble focusing, and PTSD.
The participants were followed up with using questionnaires administered by nurses via telephone after 30-, 60-, and 90-days post-hospital discharge (or in the case of non-hospitalized patients, from the date of the first positive COVID-19 test). The questionnaire asked participants if they felt their health had returned to normal, if they could complete vigorous activities (like running), moderate activities (like moving a table, climbing a flight of stairs, etc.), and bathe and dress independently.
The study authors noted that patients were also asked about symptoms in the previous 4 weeks such as: fever, chills, or night sweats; loss of smell or taste; fatigue; shortness of breath; chest pain; numbness or tingling; nausea, vomiting or diarrhea; muscle aches; and rash.
Finally, the questionnaire asked participants whether they had trouble keeping things organized, trouble concentrating on activities such as television or reading a book, and whether they forgot what they talked about during a phone conversation over the previous 4 weeks. The participants could respond “never,” “rarely,” “sometimes,” “often,” and “almost always.”
At baseline, the investigators observed that 23.5% of the participants reported being able to complete vigorous activities, and 48% reported being able to complete moderate activities.
Additionally, 64% of participants reported no perceived cognitive deficits on the 3 questionnaire items. About a third of the patients reported having trouble getting things organized, and a third reported trouble concentrating on activities, while a quarter reported forgetting what they had talked about during a phone call. The most common symptoms of acute COVID-19 during this time were fatigue, shortness of breath, and muscle aches, the study authors noted.
For long COVID patients, the study authors found that patients who reported cognitive defects were more likely to report long COVID symptoms at 60 and 90 days compared to those without perceived cognitive defects. There were 233 patients that reported long COVID symptoms at 60 and 90 days, and of those, half reported cognitive deficits at 30 days. To compare, of the 543 patients who did not report long COVID symptoms at 60 or 90 days, just 29% reported cognitive deficit at the 30-day survey.
“In a longitudinal cohort study of patients with COVID-19 in 1 health care system, we found an association between perceived cognitive deficits early in the disease and long COVID, which suggests direction for exploration of the underpinnings of long COVID,” the study authors concluded.
For further reading about COVID-19 and brain fog, check out a previous report from Contagion: “COVID-19 Infection Makes Dementia Worse.”
