Prevalence and prospective evaluation of cognitive dysfunctions after SARS due to SARS-CoV-2 virus. The COgnitiVID study

Long-term neuropsychological consequences of severe COVID-19 infection: the NEUROCOG-COVID study

BACKGROUND

Recent studies have confirmed the presence of cognitive disorders, which may be maintained over the long term and associated with psychological disorders following COVID-19 infection. The aim of our study was to characterize long-term cognitive and psychiatric disorders in patients younger than 65 years hospitalized for severe COVID-19 infection.

METHODS

All patients who were hospitalized between October 2020 and July 2021 for severe COVID-19 infection with a cognitive complaint according to the QPC questionnaire were selected. They underwent a systematic neuropsychological evaluation assessing cognitive functions, psychological processes, and quality of life (QOL).

RESULTS

The QPC was offered to 293 patients, 129 of whom had a cognitive complaint. A total of 74 (57% men) of these patients, aged approximately 55 years, had undergone a full neuropsychological evaluation 337.38 ± 25.11 days after hospital discharge. Seventy-three percent presented with cognitive disorders, including executive disorders (66%), memory disorders (31%), language disorders (19%), and other instrumental disorders (12%). Single-domain impairment was found in 54% of patients, with predominantly "dysexecutive syndrome" (83%) profile. There was no difference between the groups concerning psychological impairment. Patients with a "dysexecutive syndrome" profile reported poorer mental QOL than did the other patients (p < .05).

CONCLUSIONS

Cognitive disorders are common after severe COVID-19. The consideration of these factors is essential in the management of patients with long-term COVID-19, especially considering their impact on patients' QOL. Comprehensive neuropsychological assessment helps to identify the factors contributing to cognitive complaints to optimize multidisciplinary management, particularly when not related to cognitive disorders on testing.

Estimated prevalence of post-intensive care cognitive impairment at short-term and long-term follow-ups: a proportional meta-analysis of observational studies

OBJECTIVE

Evidence of the overall estimated prevalence of post-intensive care cognitive impairment among critically ill survivors discharged from intensive care units at short-term and long-term follow-ups is lacking. This study aimed to estimate the prevalence of the post-intensive care cognitive impairment at time to < 1 month, 1 to 3 month(s), 4 to 6 months, 7-12 months, and > 12 months discharged from intensive care units.

METHODS

Electronic databases including PubMed, Cochrane Library, EMBASE, CINAHL Plus, Web of Science, and PsycINFO via ProQuest were searched from inception through July 2024. Studies that reported on cognitive impairment among patients discharged from intensive care units with valid measures were included. Data extraction and risk of bias assessment were performed independently for all included studies according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guidelines. Newcastle-Ottawa Scale was used to measure risk of bias. Data on cognitive impairment prevalence were pooled using a random-effects model. The primary outcome was pooled estimated proportions of prevalence of the post-intensive care cognitive impairment.

RESULTS

In total, 58 studies involving 347,940 patients were included. The pooled post-intensive care cognitive impairment prevalence rates at the follow-up timepoints < 1 month, 1-3 month(s), 4-6 months, 7-12 months, > 12 months were 49.8% [95% Prediction Interval (PI), 39.9%-59.7%, n = 19], 45.1% (95% PI, 34.8%-55.5%, n = 23), 47.9% (95% PI, 35.9%-60.0%, n = 16), 28.3% (95% PI, 19.9%-37.6%, n = 19), and 30.4% (95% PI, 18.4%-43.9%, n = 7), respectively. Subgroup analysis showed that significant differences of the prevalence rates between continents and study designs were observed.

CONCLUSIONS

The prevalence rates of post-intensive care cognitive impairment differed at different follow-up timepoints. The rates were highest within the first three months of follow-up, with a pooled prevalence of 49.8% at less than one month, 45.1% at one to three months, and 47.9% at three to six months. No significant differences in prevalence rates between studies that only included coronavirus disease 2019 survivors. These fundings highlight the need for further research to develop targeted interventions to prevent or manage cognitive impairment at short-term and long-term follow-ups.

Cognitive domains affected post-COVID-19; a systematic review and meta-analysis

BACKGROUND AND PURPOSE

This review aims to characterize the pattern of post-COVID-19 cognitive impairment, allowing better prediction of impact on daily function to inform clinical management and rehabilitation.

METHODS

A systematic review and meta-analysis of neurocognitive sequelae following COVID-19 was conducted, following PRISMA-S guidelines. Studies were included if they reported domain-specific cognitive assessment in patients with COVID-19 at >4 weeks post-infection. Studies were deemed high-quality if they had >40 participants, utilized healthy controls, had low attrition rates and mitigated for confounders.

RESULTS

Five of the seven primary Diagnostic and Statistical Manual of Mental Disorders (DSM-5) cognitive domains were assessed by enough high-quality studies to facilitate meta-analysis. Medium effect sizes indicating impairment in patients post-COVID-19 versus controls were seen across executive function (standardised mean difference (SMD) -0.45), learning and memory (SMD -0.55), complex attention (SMD -0.54) and language (SMD -0.54), with perceptual motor function appearing to be impacted to a greater degree (SMD -0.70). A narrative synthesis of the 56 low-quality studies also suggested no obvious pattern of impairment.

CONCLUSIONS

This review found moderate impairments across multiple domains of cognition in patients post-COVID-19, with no specific pattern. The reported literature was significantly heterogeneous, with a wide variety of cognitive tasks, small sample sizes and disparate initial disease severities limiting interpretability. The finding of consistent impairment across a range of cognitive tasks suggests broad, as opposed to domain-specific, brain dysfunction. Future studies should utilize a harmonized test battery to facilitate inter-study comparisons, whilst also accounting for the interactions between COVID-19, neurological sequelae and mental health, the interplay between which might explain cognitive impairment.

Measuring subjective cognitive complaints with covid-19 brain fog using the subjective scale to investigate cognition (SSTICS)

The term "brain fog" has emerged from the observations of neuropsychiatric conditions present in post-COVID-19 infections. This is characterized by concentration and memory problems, selective attention disorders and difficulties in executive functions, yet it is unclear how long these deficits may persist and which cognitive functions are most vulnerable. Therefore, there is a need to properly evaluate these cognitive complaints using an assessment tool that specifies their intensity and nature. Our primary objective was to explore subjective perceptions of cognitive functioning in COVID-19-associated with brain fog using a tool that was previously validated for assessing subjective cognitive complaints. A total of 68 participants were recruited and the Subjective Scale to Investigate Cognition (SSTICS) was used to assess cognitive complaints. This was the first time that the SSTICS was used for this purpose in subjects with COVID-19. In addition, participants were administered a questionnaire assessing for the presence of various symptoms, as well as COVID-19 clinical parameters. The neuropsychological basis for the construct of the SSTICS was related to the cognitive complaints expressed by participants. A reliability analysis of our sample indicated a high degree of internal consistency (Cronbach's alpha= 0.951). Associations between various SSTICS scores and COVID-related symptomatology and the differences between group of participants who reported cognitive complaints ("complainers") and those who did not were assessed. We performed an exploratory factorial analysis based on Principal Component Analysis (PCA). Based on their distribution, participants were grouped into: "good functioning" - scores 0-9 (35.3%); "medium functioning" - scores 14-23 (25%); and "poor functioning" - scores 26-71 (39.7%). The mean SSTICS score was 20.59 (SD 16.61) and correlated with the quarantine duration and loss of smell. Complainers differed significantly from non-complainers in the total number of symptoms, the quarantine duration and the presence/absence of specific symptoms, such as loss of smell, tiredness and aches/pains. Our study showed that >10% of patients reported subjective cognitive complaints following COVID-19, with most reporting mild or serious cognitive complaints, mostly within the domains of memory, attention, language, executive functioning or praxis.

Neurocognitive and Neuropsychiatric Sequelae in Long COVID-19 Infection

Objective: To characterize the cognitive profile of long COVID-19 subjects and its possible association with clinical symptoms, emotional disturbance, biomarkers, and disease severity. Methods: We performed a single-center cross-sectional cohort study. Subjects between 20 and 60 years old with confirmed COVID-19 infection were included. The assessment was performed 6 months following hospital or ambulatory discharge. Excluded were those with prior neurocognitive impairment and severe neurological/neuropsychiatric disorders. Demographic and laboratory data were extracted from medical records. Results: Altogether, 108 participants were included, 64 were male (59.25%), and the mean age was 49.10 years. The patients were classified into four groups: non-hospitalized (NH, n = 10), hospitalized without Intensive Care Unit (ICU) or oxygen therapy (HOSPI, n = 21), hospitalized without ICU but with oxygen therapy (OXY, n = 56), and ICU (ICU, n = 21) patients. In total, 38 (35.18%) reported Subjective Cognitive Complaints (SCC). No differences were found considering illness severity between groups. Females had more persistent clinical symptoms and SCC than males. Persistent dyspnea and headache were associated with higher scores in anxiety and depression. Persistent fatigue, anxiety, and depression were associated with worse overall cognition. Conclusions: No cognitive impairment was found regarding the severity of post-COVID-19 infection. SCC was not associated with a worse cognitive performance, but with higher anxiety and depression. Persistent clinical symptoms were frequent independent of illness severity. Fatigue, anxiety, and depression were linked to poorer cognitive function. Tests for attention, processing speed, and executive function were the most sensitive in detecting cognitive changes in these patients.

[Interaction of somatic findings and psychiatric symptoms in COVID-19. A scoping review]

An infection with SARS-CoV‑2 can affect the central nervous system, leading to neurological as well as psychiatric symptoms. In this respect, mechanisms of inflammation seem to be of much greater importance than the virus itself. This paper deals with the possible contributions of organic changes to psychiatric symptomatology and deals especially with delirium, cognitive symptoms, depression, anxiety, posttraumatic stress disorder and psychosis. Processes of neuroinflammation with infection of capillary endothelial cells and activation of microglia and astrocytes releasing high amounts of cytokines seem to be of key importance in all kinds of disturbances. They can lead to damage in grey and white matter, impairment of cerebral metabolism and loss of connectivity. Such neuroimmunological processes have been described as a organic basis for many psychiatric disorders, as affective disorders, psychoses and dementia. As the activation of the glia cells can persist for a long time after the offending agent has been cleared, this can contribute to long term sequalae of the infection.

Long-term outcomes, residual symptoms and quality of life in COVID-19 hospitalized patients: A 12-month longitudinal study

The long-term impact of the coronavirus disease 2019 (COVID-19) pandemic is a critical public health concern. The presence of residual symptoms in COVID-19 survivors has been investigated with various results; however, there is limited data documenting outcomes longer than 6 months post-hospitalization. We aimed to investigate the 12-month lasting effects of COVID-19 in hospitalized patients. From October 2020 through March 2021, 92 patients were enrolled. At admission and 1, 3, 6, and 12 months post-hospitalization, demographic, clinical, laboratory and imaging data, and echocardiography and spirometry test results were recorded. Possible cognitive and functional impairment, as well as the quality of life (QoL), were also assessed. In our cohort (median age: 61 years), 31.5% had severe disease at admission, which correlated with worse laboratory findings and a longer hospital stay (p < 0.001). Inflammatory markers were associated with severity initially, but reverted to normal after 3 months. In total, 55%, 37%, 19%, and 15.5% of patients reported at least one persistent symptom in months 1, 3, 6, and 12, respectively, while "brain fog" persisted up to 12 months in 10% of patients. Spirometry and echocardiography tests returned to normal in most patients during the evaluation, and no one had substantial residual disease. Our study provides insight into the long-term effects of COVID-19 on patients' physical and mental health. Despite the lack of significant residual disease or major complications after a year of thorough follow-up, COVID-19 survivors experienced lasting symptoms and a negative impact on their QoL.

Cognitive impairment in post-acute COVID-19 syndrome: a scoping review

Emerging studies indicate the persistence of symptoms beyond the acute phase of COVID-19. Cognitive impairment has been observed in certain individuals for months following infection. Currently, there is limited knowledge about the specific cognitive domains that undergo alterations during the post-acute COVID-19 syndrome and the potential impact of disease severity on cognition. The aim of this review is to examine studies that have reported cognitive impairment in post-acute COVID-19, categorizing them into subacute and chronic phases. The methodology proposed by JBI was followed in this study. The included studies were published between December 2019 and December 2022. The search was conducted in PubMed, PubMed PMC, BVS - BIREME, Embase, SCOPUS, Cochrane, Web of Science, Proquest, PsycInfo, and EBSCOHost. Data extraction included specific details about the population, concepts, context, and key findings or recommendations relevant to the review objectives. A total of 7,540 records were identified and examined, and 47 articles were included. The cognitive domains most frequently reported as altered 4 to 12 weeks after acute COVID-19 were language, episodic memory, and executive function, and after 12 weeks, the domains most affected were attention, episodic memory, and executive function. The results of this scoping review highlight that adults with post-acute COVID-19 syndrome may have impairment in specific cognitive domains.

Cognitive Impairment after Post-Acute COVID-19 Infection: A Systematic Review of the Literature

The present study aims to provide a critical overview of the literature on the relationships between post-acute COVID-19 infection and cognitive impairment, highlighting the limitations and confounding factors. A systematic search of articles published from 1 January 2020 to 1 July 2022 was performed in PubMed/Medline. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Only studies using validated instruments for the assessment of cognitive impairment were included. Out of 5515 screened records, 72 studies met the inclusion criteria. The available evidence revealed the presence of impairment in executive functions, speed of processing, attention and memory in subjects recovered from COVID-19. However, several limitations of the literature reviewed should be highlighted: most studies were performed on small samples, not stratified by severity of disease and age, used as a cross-sectional or a short-term longitudinal design and provided a limited assessment of the different cognitive domains. Few studies investigated the neurobiological correlates of cognitive deficits in individuals recovered from COVID-19. Further studies with an adequate methodological design are needed for an in-depth characterization of cognitive impairment in individuals recovered from COVID-19.

COVID-19 Encephalopathy: Delayed Onset in Unvaccinated Patients

COVID-19 infections have a broad spectrum of severity, with more severe symptoms observed in elderly patients, patients with underlying comorbidities, and patients with unvaccinated status. This case series aims to highlight two cases of unvaccinated patients who developed COVID-19 encephalopathy, contrasted with a vaccinated patient with similar risk factors. This article highlights the unique characteristics of COVID-19 encephalopathy to guide clinicians while approaching the broad diagnosis of acute encephalopathy or altered mental state in hospitalized patients. Current literature was reviewed and summarized the information available regarding encephalopathy separate from the more complex encephalitis and encephalomyelitis.