Cognitive Dysfunction - Update

Those with Long Covid frequently report symptoms of cognitive dysfunction - often referred to colloquially as ‘brain fog’ - in the months following COVID-19 infection.

There have been two FURTHER papers to support this. These papers tally with the work of Hannah Davis et al in "Characterizing long COVID in an international cohort: 7 months of symptoms and their impact" a previously discussed Long COVID survey which showed that 88% of 3,762 respondents reported memory problems and cognitive dysfunction.

Paper 1

A large scale Oxford University study "Incidence, co-occurrence, and evolution of long-COVID features: a 6-month retrospective cohort study of 273,618 survivors of COVID-19" by Maxime Taquet et al revealed that cognitive problems were among the most commonly reported Long COVID symptoms.

Why was this study done?

  • Long-COVID has been described in recent studies. But we do not know the risk of developing features of this condition and how it is affected by factors such as age, sex, or severity of infection.

  • We do not know if the risk of having features of long-COVID is more likely after Coronavirus Disease 2019 (COVID-19) than after influenza.

  • We do not know about the extent to which different features of long-COVID co-occur.

What did the researchers do and find?

  • This research used data from electronic health records of 273,618 patients diagnosed with COVID-19 and estimated the risk of having long-COVID features in the 6 months after a diagnosis of COVID-19. It compared the risk of long-COVID features in different groups within the population and also compared the risk to that after influenza.

  • The research found that over 1 in 3 patients had one or more features of long-COVID recorded between 3 and 6 months after a diagnosis of COVID-19. This was significantly higher than after influenza.

  • For 2 in 5 of the patients who had long-COVID features in the 3- to 6-month period, they had no record of any such feature in the previous 3 months.

  • The risk of long-COVID features was higher in patients who had more severe COVID-19 illness, and slightly higher among females and young adults. White and non-white patients were equally affected.

What do these findings mean?

  • Knowing the risk of long-COVID features helps in planning the relevant healthcare service provision.

  • The fact that the risk is higher after COVID-19 than after influenza suggests that their origin might, in part, directly involve infection with SARS-CoV-2 and is not just a general consequence of viral infection. This might help in developing effective treatments against long-COVID.

  • The findings in the subgroups, and the fact that the majority of patients who have features of long-COVID in the 3- to 6-month period already had symptoms in the first 3 months, may help in identifying those at greatest risk.

Paper 2

A recent study "Assessment of Cognitive Function in Patients After COVID-19 Infection" published in the JAMA Network Open journal strengthens the link between COVID-19 and ongoing cognitive problems and also suggests that brain fog may have a wider societal and economic impact as it will likely affect long-haulers’ ability to work effectively.

Why was the study done?

  • People who have survived COVID-19 frequently complain of cognitive dysfunction, which has been described as brain fog.

  • The prevalence of post–COVID-19 cognitive impairment and the association with disease severity are not well characterized.

  • Previous studies on the topic have been limited by small sample sizes and suboptimal measurement of cognitive functioning.

What did the researchers do and find?

  • We investigated rates of cognitive impairment in survivors of COVID-19 who were treated in outpatient, emergency department (ED), or inpatient hospital settings.

  • We tested cognition for attention, working memory, processing speed and executive functioning, phonemic and category fluency (language), and memory encoding, recall, and recognition

  • The mean age of 740 participants was 49 (38-59) years, 63% were women, and the mean time from COVID-19 diagnosis was 7.6 months.

  • The most prominent deficits were in processing speed, executive functioning, phonemic fluency and category fluency, memory encoding and memory recall.

  • Hospitalized patients were more likely to have impairments in attention executive functioning, category fluency, memory encoding , and memory recall than those in the outpatient group.

  • Patients treated in the ED were more likely to have impaired category fluency and memory encodingthan those treated in the outpatient setting. No significant differences in impairments in other domains were observed between groups.

What do these findings mean?

  • We found a relatively high frequency of cognitive impairment several months after patients contracted COVID-19.

  • Impairments in executive functioning, processing speed, category fluency, memory encoding, and recall were predominant among hospitalized patients. The relative sparing of memory recognition in the context of impaired encoding and recall suggests an executive pattern.

  • This pattern is consistent with early reports describing a dysexecutive syndrome after COVID-19 and has considerable implications for occupational, psychological, and functional outcomes.

  • It is well known that certain populations (eg, older adults) may be particularly susceptible to cognitive impairment after critical illness; however, in the relatively young cohort in the present study, a substantial proportion exhibited cognitive dysfunction several months after recovering from COVID-19.

The authors conclude that if an acute Covid-19 infection is leading to executive dysfunction in both non - hospitalised and hospitalised patients then it raises key questions in the LONG TERM management and treatment of these patients.

Given that on the NHS it is impossible to get cognitive testing (even in a Long Covid Clinic which as part of NICE guidelines are supposed to offer this). If we are not even being identified as having cognitive and executive dysfunction HOW are we going to be able to be rehabilitated for it?


What is executive dysfunction?

Incidence, co-occurrence, and evolution of long-COVID features: a 6-month retrospective cohort study of 273,618 survivors of COVID-19

Characterizing long COVID in an international cohort: 7 months of symptoms and their impact

Assessment of Cognitive Function in Patients After COVID-19 Infection

79 views0 comments

Recent Posts

See All