Numerous individuals report memory loss, difficulty concentrating, lethargy, or sleeplessness when recovering from acute coronavirus sickness, according to research (COVID-19). Similar issues continue even a year later for critically ill patients, such as those with acute respiratory distress syndrome (ARDS). Fears of long-term neurocognitive problems following COVID-19 have arisen as a result, mostly as a result of cerebral hypoxia, viral encephalitis, metabolic abnormalities, immunological activation, or other processes.
Cognitive impairments, as well as impairments of verbal fluency, attention and executive function, and memory, were found to be quite common in a recent review that involved neuropsychological test data of people who had recently contracted the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It was anticipated that many patients would improve during the first six to twelve months. It is unknown, though, if the early evaluation of cognitive function is a reliable predictor of long-term effects.
Furthermore, despite the fact that they make up the majority of those with SARS-CoV-2 infection, nothing is known about the cognitive function of individuals who recovered without being admitted to a hospital. Furthermore, it is unclear if neurocognitive impairment is correlated with the severity of COVID-19. In two recent investigations, patients who were 2 to 8 months post-COVID-19 performed less well on cognitive tests than controls who had not previously been infected.
A recent study that was just released in the PLOS ONE journal examines cognitive abnormalities in non-hospitalized patients that occurred 8 to 13 months after COVID-19. In particular, it concentrated on the earliest symptoms that suggested a connection with the central nervous system (CNS) during the acute phase of infection. It also intended to study the factors that are related with neurocognitive impairments.
Concerning the study
Participants in the trial required to be at least 18 years old and had to have tested positive for the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) by polymerase chain reaction (PCR), but they did not need to be hospitalised. They were hired from the start of the outbreak through June 1st, 2020.
The participants were first asked to complete a paper-based questionnaire or a web-based questionnaire of a similar nature to gather data on background variables (demography, comorbidity, education, weight, height, smoking status, etc.), symptoms experienced during the acute phase of COVID-19, symptoms present at the time of the survey, and some other common questionnaires like the Chalder fatigue questionnaire (CFQ) and EQ-5D-5L health status questionnaire.
Participants gave blood samples and completed surveys between December 2020 and April 2021 during the follow-up phase. As a result of the participants’ prior reports of exhaustion, dyspnea, and weariness plus dyspnea, they were then split into three groups. Participants in the control group did not experience fatigue or dyspnea. After that, cognitive tests were administered to the groups with dyspnea and tiredness, fatigue, and no dyspnea or fatigue.
11 months after COVID-19, a battery of tasks from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were used to test cognitive performance using an iPad. Four tests, a motor screening test (MOT), one warm-up activity, and one were chosen. The four tests were the One-touch Stockings of Cambridge (OTS), which assessed executive functions, the Delayed Matching to Sample (DMS), which measured short-term memory, attention, and learning, the Rapid Visual Information Processing (RVP), which measured sustained attention, and the Spatial Working Memory (SWM), which measured strategy and memory. The RVP, DMS, OTS, and SWM tests should be taken after the MOT, according to the participants’ instructions.
The CANTAB cognitive test battery was completed by 233 participants, according to the results. Headaches, fevers, dyspnea, and a loss of smell were the most common COVID-19 symptoms recorded. Additionally, it was discovered that those who passed the CANTAB exam had a lower quality of life and more intense symptoms.
Participants 11 months after COVID-19 infection showed slight declines in cognitive scores relative to individuals who had not previously been infected. But over the entire sample, there was no evidence of a decline in executive function (OTS). At the follow-up, 29% of the participants reported cognitive impairment in at least one of the four tests, while 6% reported impairment in at least two of the four tests. Furthermore, no test demonstrated an association with symptoms related to the central nervous system (CNS), only the SWM test result was shown to be related to the initial number of COVID-19 symptoms. Additionally, only RVP was found to exhibit an age-related drop, but OTS and RVP both displayed better results with increased schooling.
Therefore, the current study found that among non-hospitalized patients 8 to 13 months after COVID-19, there was only a modest reduction in cognitive function. The findings imply that they experience less cognitive effects following infection in contrast to having a lot of symptoms during the acute period.
The study has several restrictions. The study’s sample size was small, to start. Second, there was no information on cognitive performance prior to infection. Third, there was no useful comparison group in the study. Finally, the study may include selection bias, which prevents it from being generalised.
Stavem, K. et al. (2022). Cognitive function in non-hospitalized patients 8–13 months after acute COVID-19 infection: A cohort study in Norway. PLOS ONE. doi: https://doi.org/10.1371/journal.pone.0273352. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0273352