Changes in cognitive functioning after COVID-19: A systematic review and meta-analysis

Machine learning algorithms to predict mild cognitive impairment in older adults in China: A cross-sectional study

OBJECTIVE

This study aimed to explore the predictive value of machine learning (ML) in mild cognitive impairment (MCI) among older adults in China and to identify important factors causing MCI.

METHODS

In this study, 6434 older adults were selected based on the data of the China Health and Elderly Care Longitudinal Survey (CHARLS) in 2020, and the dataset was subsequently divided into the training set and the test set, with a ratio of 6:4. To construct a prediction model for MCI in older adults, six ML algorithms were used, including logistic regression, KNN, SVM, decision tree (DT), LightGBM, and random forest (RF). The Delong test was used to compare the differences of ROC curves of different models, while decision curve analysis (DCA) was used to evaluate the model performance. The important contributions of the prediction results were then used to explain the model by the SHAP value.The Matthews correlation coefficient (MCC) was calculated to evaluate the performance of the models on imbalanced datasets. Additionally, causal analysis and counterfactual analysis were conducted to understand the feature importance and variable effects.

RESULTS

The area under the ROC curve of each model range from 0.71 to 0.77, indicating significant difference (P < 0.01). The DCA results show that the net benefits of LightGBM is the largest within various probability thresholds. Among all the models, the LightGBM model demonstrated the highest performance and stability. The five most important characteristics for predicting MCI were educational level, social events, gender, relationship with children, and age. Causal analysis revealed that these variables had a significant impact on MCI, with an average treatment effect of -0.144. Counterfactual analysis further validated these findings by simulating different scenarios, such as improving educational level, increasing age, and increasing social events.

CONCLUSION

The ML algorithm can effectively predict the MCI of older adults in China and identify the important factors causing MCI.

Characterization of Change in Cognition Before and After COVID-19 Infection in Essential Workers at Midlife

Background

Research into COVID-19-related cognitive decline has focused on individuals who are cognitively impaired following hospitalization for COVID-19. Our objective was to determine whether cognitive decline emerged after the onset of COVID-19 and was more pronounced in patients with postacute sequelae of SARS-CoV-2 infection (PASC).

Methods

We analyzed longitudinal cognitive data collected during a cohort study of essential workers at midlife that continued through the COVID-19 pandemic. We used longitudinal discontinuity models, a form of causal modeling, to examine the change in cognitive performance among 276 participants with COVID-19 in comparison to contemporaneously-collected information from 217 participants who did not have COVID-19. Cognitive performance across four domains was measured before and after the pandemic. Eligible study participants were those with validated COVID-19 diagnoses who were observed before having a verified COVID-19 infection who survived their initial infection, and for whom post-COVID-19 information was also available.

Results

The mean age of the COVID-19 group was 56.0 ± 6.6 years old, while the control group was 58.1 ± 7.3 years old. Longitudinal models indicated a significant decline in cognitive throughput (β = -0.168, P = .001) following COVID-19, after adjustment for pre-COVID-19 functioning, demographics, and medical factors. Associations were larger in those with more severe COVID-19 and those who reported PASC. Observed changes in throughput were equivalent to 10.6 years of normal aging.

Conclusion

Findings from this longitudinal causal modeling study revealed that COVID-19 and PASC appeared to cause clincially relevant cognitive deterioration.

Translating insights into therapies for Long Covid

Long Covid is defined by a wide range of symptoms that persist after the acute phase of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Commonly reported symptoms include fatigue, weakness, postexertional malaise, and cognitive dysfunction, with many other symptoms reported. Symptom range, duration, and severity are highly variable and partially overlap with symptoms of myalgic encephalomyelitis/chronic fatigue syndrome and other post-acute infectious syndromes, highlighting opportunities to define shared mechanisms of pathogenesis. Potential mechanisms of Long Covid are diverse, including persistence of viral reservoirs, dysregulated immune responses, direct viral damage of tissues targeted by SARS-CoV-2, inflammation driven by reactivation of latent viral infections, vascular endothelium activation or dysfunction, and subsequent thromboinflammation, autoimmunity, metabolic derangements, microglial activation, and microbiota dysbiosis. The heterogeneity of symptoms and baseline characteristics of people with Long Covid, as well as the varying states of immunity and therapies given at the time of acute infection, have made etiologies of Long Covid difficult to determine. Here, we examine progress on preclinical models for Long Covid and review progress being made in clinical trials, highlighting the need for large human studies and further development of models to better understand Long Covid. Such studies will inform clinical trials that will define treatments to benefit those living with this condition.

Neurological, psychological, psychosocial complications of long-COVID and their management

Since it first appeared, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has had a significant and lasting negative impact on the health and economies of millions of individuals all over the globe. At the level of individual health too, many patients are not recovering fully and experiencing a long-term condition now commonly termed 'long-COVID'. Long-COVID is a collection of symptoms which must last more than 12 weeks following initial COVID infection, and which cannot be adequately explained by alternate diagnoses. The neurological and psychosocial impact of long-COVID is itself now a global health crisis and therefore preventing, diagnosing, and managing these patients is of paramount importance. This review focuses primarily on: neurological functioning deficits; mental health impacts; long-term mood problems; and associated psychosocial issues, among patients suffering from long-COVID with an eye towards the neurological basis of these symptoms. A concise account of the clinical relevance of the neurological and psychosocial impacts of long-COVID, the effects on long-term morbidity, and varied approaches in managing patients with significant chronic neurological symptoms and conditions was extracted from the literature, analysed and reported. A comprehensive account of plausible pathophysiological mechanisms involved in the development of long-COVID, its management, and future research needs have been discussed.

Acute and long-term effects of COVID-19 on brain and mental health: A narrative review

BACKGROUND

COVID infection has been associated with long term sequalae (Long COVID) which include neurological and behavioral effects in thousands of patients, but the etiology and scope of symptoms is not well understood. This paper reviews long term sequelae of COVID on brain and mental health in patients with the Long COVID syndrome.

METHODS

This was a literature review which queried databases for Pubmed, Psychinfo, and Medline for the following topics for January 1, 2020-July 15, 2023: Long COVID, PASC, brain, brain imaging, neurological, neurobiology, mental health, anxiety, depression.

RESULTS

Tens of thousands of patients have developed Long COVID, with the most common neurobehavioral symptoms anosmia (loss of smell) and fatigue. Anxiety and mood disorders are elevated and seen in about 25% of Long COVID patients. Neuropsychological testing studies show a correlation between symptom severity and cognitive dysfunction, while brain imaging studies show global decreases in gray matter and alterations in olfactory and other brain areas.

CONCLUSIONS

Studies to date show an increase in neurobehavioral disturbances in patients with Long COVID. Future research is needed to determine mechanisms.

Executive deficits after SARS-CoV-2 infection: A cross-sectional population study

Importance

Despite the major implications of executive deficits in day-to-day functioning, few studies have investigated this in post-acute sequelae of SARS-CoV-2 infection using standardized measures that differentiate between aspects of executive function.

Objective

Examine whether SARS-CoV-2 infection is associated with deficits in executive functions and if so, investigate the duration of this association.

Design Setting and Participants

The present research has a cross-sectional design and uses data from the Norwegian Covid-19 Cohort study. The current cohort (n = 8102) completed the Behavior Rating Inventory of Executive Function- Adult Version (BRIEF-A) electronically between April 2021 and September 2021. During the assessment, 4183 of the included participants had a prior positive polymerase chain reaction test (PCR) for SARS-CoV-2 and 3919 were untested or had a confirmed negative PCR test.

Exposure

Laboratory-confirmed SARS-CoV-2 infection.

Main outcomes and measures

Executive functions were measured using the BRIEF-A, a self-report questionnaire comprising 75 items within nine theoretically and empirically distinct clinical scales. All participants self-reported on demographical variables and comorbidity. Information on sex and age was derived from the personal identification number, and vaccination status was obtained from the Norwegian Immunization Registry (SYSVAK).

Results

Participants with a positive SARS-CoV-2 status reported executive deficits in everyday life above the clinical threshold (T-score ≥65) more often than non-infected controls (383 vs. 225). Specifically, the SARS-CoV-2 positive status group indicated significantly more deficits related to metacognition, with the greatest difference demonstrated for working memory. This difference remained when adjusting for various demographic factors and comorbidities, with significantly greater odds of reporting above the clinical threshold following SARS-CoV-2 infection, as observed on the global executive composite score 6-12 months after infection (OR 1.97; 95% CI 1.51 to 2.55).

Conclusions

Our study confirms more perceived executive deficits following SARS-CoV-2 infection compared to non-infected controls, with metacognitive aspects being the most affected. These findings shed light on the potential functional difficulties that individuals may encounter during the post-acute phase of SARS-CoV-2 infection and may guide further development of targeted interventions addressing metacognitive domains of executive functioning.

Cognitive and Functional Capacity Assessment of Individuals Who Were Admitted to the Intensive Care Unit Due to COVID-19: A Prospective Cohort Study

AIM

The goal of this study was to identify changes in cognitive and functional capacity after hospital discharge in those infected with COVID-19 who were admitted to the ICU.

METHODS

This is a prospective cohort study carried out with individuals who were admitted to a hospital, from July 2021 to May 2022. The evaluations happened in three moments: at hospital discharge, 30 days after discharge and 90 days after discharge. The instruments applied are the following: handgrip dynamometer, Montreal Cognitive Assessment Basic questionnaire (MoCA-B), Barthel Index (BI), timed up and go test (TUG), hospital anxiety and depressive scale (HADS) and 36-Item Short Form Health Survey questionary (SF-36).

RESULTS

74 individuals were eligible to participate in the study, 25 of which were followed for 90 days. Based on the results of the MoCA-b, there were no relevant cognitive changes after 3 months. According to the Barthel Index applied to each of the evaluations, the percentage of subjects that were classified as independent or minimally dependent was 48%, 92% then 96%, respectively, demonstrating that individuals can achieve a good degree of functional independence after 3 months. Despite that, the SF-36 demonstrated a score below the South Brazilian normal in some domains.

CONCLUSION

The individuals studied did not present persistent cognitive changes after 3 months and functional capacity showed significant improvement during this period. However, when the assessment is about the self-perceived quality of life, the majority of domain values are still below expectations, deserving attention by the health professionals involved.

Clinical usefulness of the serum levels of neuroinflammatory and lung fibrosis biomarkers in the assessment of cognitive dysfunction in post-COVID19 patients

A growing body of evidence indicates there is an increasing incidence of cognitive dysfunction in patients after coronavirus disease 2019 (COVID-19) infection. However, still lack diagnostic tools, which allow us to predict prognosis in such cases and improve the stratification of the disease. This study aims to evaluate the usefulness of the biomarkers that could allow to predict the severity and progression of COVID-19 in patients with post-COVID syndrome and cognitive problems. Data regarding clinical history, pre-existing conditions, chest CT scan, and therapy (remdesivir, steroids) were acquired. A total of 44 patients with hospitalized COVID-19, and healthy controls were enrolled in the investigation, and serum blood was obtained. After 6 months of observations, patients with COVID-19 were divided into two groups: first - without post-COVID syndrome and memory complaints, and second - with post-COVID and cognitive problems. Measurements of YKL-40 and MR-pro-ADM were taken in the serum with enzyme immunoassay kits at the time of admission (visit 1) and 6 months after discharge from the hospital (visit 2). Significantly higher concentrations of YKL-40 were found in patients with COVID-19 as compared to healthy individuals (p = 0.016). Moreover, YKL-40 ratio allowed to differentiate patients with and without post-COVID syndrome (median: 0.94 vs. 1.55, p = 0.004). Additionally, COVID-19 patients with dyspnea presented significantly elevated levels of MR-pro-ADM as compared to the group of COVID-19 survivors without dyspnea (p = 0.015). In the group of patients without post-COVID syndrome, the concentrations of YKL-40 and MR-pro-ADM decreased after treatment as compared to levels before therapy (77 vs. 36 ng/ml and 607 vs. 456 pmol/L). However, in patients with post-COVID syndrome and cognitive problems, the levels of both markers did not alter 6 months after hospital discharge in comparison to basal levels. Furthermore, after dexamethasone treatment the YKL-40 concentrations declined significantly (p = 0.003) in patients with COVID-19. This study demonstrated the predictive usefulness of YKL-40 as an indicator of successful treatment in patients with COVID-19 infection allowing risk stratification of hospitalized patients. It seems that indicators of neuroinflammation might have the potential to track development of cognitive complaints, however, it requires further investigations.

COVID-19: a multi-organ perspective

In this mini review, we explore the complex network of inflammatory reactions incited by SARS-CoV-2 infection, which extends its reach well beyond the respiratory domain to influence various organ systems. Synthesizing existing literature, it elucidates how the hyperinflammation observed in COVID-19 patients affects multiple organ systems leading to physiological impairments that can persist over long after the resolution of infection. By exploring the systemic manifestations of this inflammatory cascade, from acute respiratory distress syndrome (ARDS) to renal impairment and neurological sequelae, the review highlights the profound interplay between inflammation and organ dysfunction. By synthesizing recent research and clinical observations, this mini review aims to provide an overview of the systemic interactions and complications associated with COVID-19, underscoring the need for an integrated approach to treatment and management. Understanding these systemic effects is crucial for improving patient outcomes and preparing for future public health challenges.

Exploring the effects of COVID-19 on verbal memory function in schizophrenia: Multiple case study and brief literature review

Individuals recovering from COVID-19 may experience persistent impairment in verbal memory performance, potentially due to illness-related hippocampal injury. Although verbal memory dysfunction is central to schizophrenia, the interactions between this vulnerability and COVID-19 remain unclear, with no imaging studies addressing the issue to-date. To explore this gap and generate hypotheses for future research, we adopted a multiple case study approach. Two pairs of individuals with an ICD-10 diagnosis of schizophrenia were selected, each consisting of one case with a positive COVID-19 anamnesis and one without. We calculated the Reliable Change Index to estimate the clinical significance of verbal memory performance changes, with annualized change rates in hippocampal volumes assessed against normative data. Compared to their matches, COVID-19 positive cases did not show mutually consistent changes in verbal memory performance: one case experienced a significant decline in verbal memory and learning, while the other showed a general normalization of test scores. Left hippocampal volumes showed a comparatively slowed increase, while the right hippocampi decreased in volume, although these atrophy rates did not exceed those expected in general population samples. Based on these findings, we hypothesize that COVID-19 alone does not lead to verbal memory decline in schizophrenia. Instead, the relationship between the diseases may depend on additional factors. Our case pairs differed in body mass index, systolic blood pressure, sex, phase of illness, and whole grey matter volume trajectories, leading us to hypothesize that these variables represent additional predictors or moderators of this relationship.

Functioning of post-COVID-19 patients: a cross-sectional study at the outpatient clinic for long-term effects

BACKGROUND

After COVID-19 infection, long-term impacts on functioning may occur. We studied the functioning of patients with post-COVID-19 condition (PCC) and compared them to controls without PCC.

METHODS

This cross-sectional study consisted of 442 patients with PCC referred to rehabilitation at the Helsinki University Hospital (HUS) Outpatient Clinic for the Long-Term Effects of COVID-19, and 198 controls without PCC. Functioning was assessed with a questionnaire including WHODAS 2.0. Patients underwent physical testing including a hand grip strength test (HGST) and a 6-minute walking test (6MWT). Lifestyle was assessed by questionnaire and comorbidities were collected as ICD-10 codes from the HUS Data Lake on the HUS Acamedic platform.

RESULTS

The WHODAS 2.0 average total score was 34 (SD 18) (moderate functional limitation) for patients with PCC and 6 (SD 8) (normal or mild limitation) for the controls. The disability was higher in all aspects of WHODAS 2.0 in patients with PCC. Bivariate binomial and multivariable regression analyses showed that the presence of comorbidities, anxiety, depression, and smoking predicted a WHODAS 2.0 score of 24 (moderate functional limitation) or above in the PCC group. The average 6MWT distance was 435 m (SD 98 m) in patients with PCC and 627 m (SD 70 m) in controls. HGST measurements showed no significant differences from controls.

CONCLUSIONS

In conclusion, patients with PCC had significantly reduced functioning based on WHODAS 2.0 scores and the 6MWT results. Comorbidities, anxiety, depression, and smoking were associated with moderate or severe limitations in functioning. Findings support that PCC is multifactorial and requires a holistic approach to rehabilitation.

COVID-19 related cognitive, structural and functional brain changes among Italian adolescents and young adults: a multimodal longitudinal case-control study

Coronavirus disease 2019 (COVID-19) has been associated with brain functional, structural, and cognitive changes that persist months after infection. Most studies of the neurologic outcomes related to COVID-19 focus on severe infection and aging populations. Here, we investigated the neural activities underlying COVID-19 related outcomes in a case-control study of mildly infected youth enrolled in a longitudinal study in Lombardy, Italy, a global hotspot of COVID-19. All participants (13 cases, 27 controls, mean age 24 years) completed resting-state functional (fMRI), structural MRI, cognitive assessments (CANTAB spatial working memory) at baseline (pre-COVID) and follow-up (post-COVID). Using graph theory eigenvector centrality (EC) and data-driven statistical methods, we examined differences in ECdelta (i.e., the difference in EC values pre- and post-COVID-19) and Volumetricdelta (i.e., the difference in cortical volume of cortical and subcortical areas pre- and post-COVID) between COVID-19 cases and controls. We found that ECdelta significantly between COVID-19 and healthy participants in five brain regions; right intracalcarine cortex, right lingual gyrus, left hippocampus, left amygdala, left frontal orbital cortex. The left hippocampus showed a significant decrease in Volumetricdelta between groups (p = 0.041). The reduced ECdelta in the left amygdala associated with COVID-19 status mediated the association between COVID-19 and disrupted spatial working memory. Our results show persistent structural, functional and cognitive brain changes in key brain areas associated with olfaction and cognition. These results may guide treatment efforts to assess the longevity, reversibility and impact of the observed brain and cognitive changes following COVID-19.

High Somatization Rates, Frequent Spontaneous Recovery, and a Lack of Organic Biomarkers in Post-Covid-19 Condition

INTRODUCTION

Many patients report neuropsychiatric symptoms after SARS-CoV-2 infection. Data on prevalence of post-COVID-19 condition (PCC) vary due to the lack of specific diagnostic criteria, the report of unspecific symptoms, and reliable biomarkers.

METHODS

PCC patients seen in a neurological outpatient department were followed for up to 18 months. Neurological examination, SARS-CoV-2 antibodies, Epstein-Barr virus antibodies, and cortisol levels as possible biomarkers, questionnaires to evaluate neuropsychiatric symptoms and somatization (Patient Health Questionnaires D [PHQ-D]), cognition deficits (Montreal Cognitive Assessment [MoCA]), sleep disorders (ISS, Epworth Sleepiness Scale [ESS]), and fatigue (FSS) were included.

RESULTS

A total of 175 consecutive patients (78% females, median age 42 years) were seen between May 2021 and February 2023. Fatigue, subjective stress intolerance, and subjective cognitive deficits were the most common symptoms. Specific scores were positive for fatigue, insomnia, and sleepiness and were present in 95%, 62.1%, and 44.0%, respectively. Cognitive deficits were found in 2.3%. Signs of somatization were identified in 61%, who also had an average of two symptoms more than patients without somatization. Overall, 28% had a psychiatric disorder, including depression and anxiety. At the second visit (n = 92), fatigue (67.3%) and insomnia (45.5%) had decreased. At visit three (n = 43), symptom load had decreased in 76.8%; overall, 51.2% of patients were symptom-free. Biomarker testing did not confirm an anti-EBV response. SARS-CoV-2-specific immune reactions increased over time, and cortisol levels were within the physiological range.

CONCLUSION

Despite high initial symptom load, 76.8% improved over time. The prevalence of somatization and psychiatric disorders was high. Our data do not confirm the role of previously suggested biomarkers in PCC patients.

Oculomotor Behaviour in Individuals with Long COVID-19

OBJECTIVE

To determine, the impact of long COVID-19 on oculomotor behaviour.

DESIGN

A case-control study.

SETTING

Spanish Association of Persistent COVID.

PARTICIPANT

Participants were 75 cases (64 women, 11 men, mean age 46.4 years ±8.9) and 42 controls (22 women, 20 men, mean age 53.5 years ±13.13).

INTERVENTION

An eye-tracking test based on visual search paradigm and the Adult Developmental Eye Movement Test were used to evaluate the participants.

MAIN MEASURES

The primary outcomes in the Adult Developmental Eye Movement Test were horizontal reading time, vertical reading time, and their ratio. And for the eye-tracking test the time to find the target, the duration, and the number of eye fixations.

RESULTS

In cases and controls, eye movement test results were horizontal(Hadj) reading time 74.2 ± 22.7 s vs 52.0 ± 6.1 s (p < .0001); vertical(Vadj) reading time 67.6 ± 17.8 s vs 50.4 ± 6.9 s (p < .0001); Hadj/Vadj ratio 0.9 ± 0.1 vs 1.0 ± 0 (p = .0032), respectively; and eye-tracking test results were fixation number 11.3 ± 3.07 vs 3.51 ± 2.57 (p < .0001); fixation duration 2.01 ± 0.79 s vs 1.5 ± 0.4 s (p = .0013), and time to find target 24.5 ± 8.0 vs 18 ± 9.4 (p = .0034), respectively.

CONCLUSIONS

Data showed a lower performance in oculomotor behaviour in people with long COVID-19, compared to healthy individuals. It cannot be affirmed an ocular musculature dysfunction; the differentiated behaviour could be associated to cognitive alterations affected in these people. Both tests used could be an useful tool for the clinical assessment of these participants. Further studies are needed to explore the utility of these procedures.

Research evidence on the management of the cognitive impairment component of the post-COVID condition: a qualitative systematic review

BACKGROUND

Cognitive impairment (CI) is one of the most prevalent and burdensome consequences of COVID-19 infection, which can persist up to months or even years after remission of the infection. Current guidelines on post-COVID CI are based on available knowledge on treatments used for improving CI in other conditions. The current review aims to provide an updated overview of the existing evidence on the efficacy of treatments for post-COVID CI.

METHODS

A systematic literature search was conducted for studies published up to December 2023 using three databases (PubMed-Scopus-ProQuest). Controlled and noncontrolled trials, cohort studies, case series, and reports testing interventions on subjects with CI following COVID-19 infection were included.

RESULTS

After screening 7790 articles, 29 studies were included. Multidisciplinary approaches, particularly those combining cognitive remediation interventions, physical exercise, and dietary and sleep support, may improve CI and address the different needs of individuals with post-COVID-19 condition. Cognitive remediation interventions can provide a safe, cost-effective option and may be tailored to deficits in specific cognitive domains. Noninvasive brain stimulation techniques and hyperbaric oxygen therapy showed mixed and preliminary results. Evidence for other interventions, including pharmacological ones, remains sparse. Challenges in interpreting existing evidence include heterogeneity in study designs, assessment tools, and recruitment criteria; lack of long-term follow-up; and under-characterization of samples in relation to confounding factors.

CONCLUSIONS

Further research, grounded on shared definitions of the post-COVID condition and on the accurate assessment of COVID-related CI, in well-defined study samples and with longer follow-ups, is crucial to address this significant unmet need.

Deep into Cognition: The Neuropsychological Identikit of Younger and Older Individuals after COVID-19 Infection

The literature on COVID-19 continues to increase daily. Cognitive sequelae associated with COVID-19 infection still draw the attention of the scientific community given the lack of consensus about their existence, etiology, characterization and reversibility. The aim of this study is to provide a neuropsychological identikit for younger (<65 years) and older (≥65 years) individuals diagnosed with COVID-19 infection, at baseline and after 3 and 6 months. In total, 226 individuals took part in a retrospective observational study and their cognitive performance was compared across groups (younger adults vs. older adults) and time (T0, T1, T2). The results highlighted differences between younger and older adults in the Montreal Cognitive Assessment (MoCA) global score, as expected in consideration of the different physiological conditions of the two populations. However, memory performance highlighted the two groups as characterized by a difference in patterns of recall that may move beyond a physiological explanation and provide information about COVID-19 cognitive sequelae. This study suggests that cognitive deficits observed in COVID-19 survivors may reflect a difficulty in attention and concentration that interferes mainly with retrieval processes. This result fits well with the concept of "brain fog" typical of post-COVID-19 syndrome and may also reflect the stress experienced while facing the pandemic.

How Mild Is the Mild Long COVID? A Comprehensive Neuropsychological Assessment of Patients with Cognitive Complaints

The global impact of the Coronavirus Disease (COVID-19) pandemic has extended beyond physical health, leading to widespread mental health issues. Beyond respiratory symptoms, there is a growing concern about long-term cognitive effects, particularly in individuals who experienced mild cases of the infection. We aimed to investigate the neuropsychological aspects of long-term COVID-19 in non-hospitalized adults compared with a control group. This cross-sectional study included 42 participants, 22 individuals with a history of mild COVID, and 20 healthy controls. The participants were recruited from the community and underwent a comprehensive neuropsychological assessment. Participants from the mild COVID group reported cognitive symptoms persisting for an average of 203.86 days and presented a higher frequency of psychological treatment history (81.8%) compared with the control group (25.0%). History of anxiety disorders was more prevalent in the mild COVID group (63.6%) than in the control group (20.0%). Significant reductions in verbal working memory were observed in the mild COVID group. Levels of anxiety were found to have a significant impact on difficulties with visual recognition memory. This study reveals important neuropsychological alterations in individuals following mild COVID-19, emphasizing executive functions deficits. Our findings underscore the persistence of these deficits even in non-hospitalized cases, suggesting potential inflammatory mechanisms in the central nervous system. The study highlights the need for comprehensive assessments and targeted interventions to address the diverse cognitive impacts on individuals recovering from COVID-19.

Averting older adults' memory function decline via meaningful activities: a follow-up longitudinal study

PURPOSE

The purpose of the study was to investigate the effects of satisfaction with meaningful activities and their performance on the memory function among community-dwelling older adults 3 years later.

METHODS

A longitudinal analysis was conducted on 288 community-dwelling older adults aged 65 years and more who had completed the survey in 2019 and 2022 as participants in the Tarumizu Study. Meaningful activities were assessed in 2019 using the Aid for Decision-Making in Occupation Choice for activities. Satisfaction with and performance of meaningful activities were assessed, and the bottom 25% were classified into two groups: low satisfaction and low performance. Memory function was assessed using the National Center for Geriatrics and Gerontology-Functional Assessment Tool in 2019 and 2022. Changes in memory function over 3 years were analyzed by satisfaction and performance of meaningful activities.

RESULTS

Two-way analysis of variance with group (satisfaction with and performance of meaningful activities) and time (2019 and 2022) as factors showed no statistically significant group-time interaction for memory in the satisfaction with meaningful activities group (F = 1.4, p = 0.24). Meanwhile, a statistically significant group-time interaction was observed for memory in the meaningful activity performance group, indicating that high performance of meaningful activities may play a protective role against memory decline (F = 7.4, p = 0.007).

CONCLUSION

Higher performance of meaningful activities may protect against age-related changes in memory. A careful assessment of meaningful activities, and engagement that enhances performance may be useful in designing health support against memory decline.

Dissecting the causal relationship between moderate to vigorous physical activity levels and cognitive performance: a bidirectional two-sample Mendelian randomization study

Introduction

Recent studies increasingly suggest that moderate-to-vigorous physical activity (MVPA) impacts cognitive risk. However, the bidirectional nature of this relationship warrants further exploration. To address this, we employed a Mendelian randomization (MR) approach, analyzing two distinct samples.

Methods

These analyses utilized published genome-wide association study (GWAS) summary statistics for MVPA (n = 377,234) and cognitive performance (n = 257,841). Our primary method was the inverse variance weighted (IVW) model with random effects, aiming to deduce potential causal links. Additionally, we employed supplementary methods, including MR Egger regression, Weighted median, Weighted mode, and Simple mode. For sensitivity analysis, tools like the MR Egger test, Cochran's Q, MR PRESSO, and leave-one-out (LOO) were utilized.

Results

Our findings indicate a decrease in cognitive risk with increased MVPA (Odds Ratio [OR] = 0.577, 95% Confidence Interval [CI]: 0.460-0.723, p = 1.930 × 10-6). Furthermore, enhanced cognitive levels corresponded to a reduced risk of inadequate MVPA (OR = 0.866, 95% CI: 0.839-0.895, p = 1.200 × 10-18).

Discussion

In summary, our study demonstrates that MVPA lowers cognitive risk, while poor cognitive health may impede participation in MVPA. Overall, these findings provide valuable insights for developing personalized prevention and intervention strategies in health and sports sciences.

Exploring cognitive impairments and the efficacy of phosphatidylcholine and computer-assisted cognitive training in post-acute COVID-19 and post-acute COVID-19 Vaccination Syndrome

Purpose

The COVID-19 pandemic has led to millions of confirmed cases worldwide, resulting in numerous deaths and hospitalizations. Long-term symptoms after infection or vaccination, known as Post-acute COVID-19 Syndrome (PACS) or Post-acute COVID-19 Vaccination Syndrome (PACVS), present a challenge for the healthcare system. Among the various neurological symptoms, cognitive impairments are frequently observed in PACS/PACVS patients. This study aimed to understand cognitive deficits in PACS/PACVS patients and evaluated potential treatment options, including phosphatidylcholine and computer-assisted cognitive training (CCT).

Methods

The Neuro-COVID Outpatient Clinic at Evangelic Hospital Vienna evaluated n = 29 PACS/PACVS patients from May 2023 to October 2023. Enrolled patients were divided into three therapy schemes: Group A received phosphatidylcholine, B received phosphatidylcholine plus access to a computer-assisted cognitive training program, and C (divided into two subgroups) served as a control group. Cognitive impairments were evaluated in multiple assessments (initial and during therapy) using the COGBAT test. Simultaneously, an assessment of the quality of life was conducted using the WHOQOL-BREF.

Results

Primary cognitive impairments, especially attentional deficits were notably evident compared to the general population. While all treatment groups showed cognitive improvement (significant or with a positive trend, but without reaching the level of statistical significance) after therapy, no significant interaction was found between assessment time points and treatment schemes for overall cognitive performance, attention, memory, and executive functions, suggesting consistency across the groups. The WHOQOL-BREF primarily demonstrated deficits in the domains of physical health and psychological well-being.

Conclusion

This study examined the impact of PACS/PACVS on cognitive performance and evaluated phosphatidylcholine and CCT as potential treatment options. Patients with PACS/PACVS showed notable cognitive deficits, especially in the domain attention. While the effectiveness of phosphatidylcholine and CCT in treating cognitive deficits was inconclusive, the study indicated the possibility of spontaneous remission of cognitive deficits in PACS/PACVS.

Brain fog assessment in patients recovered from COVID-19 in China: a development and validation study

BACKGROUND

Post coronavirus disease 2019 (COVID-19) pandemic, the widespread emergence and persistence of brain fog has led to a decline in people's productivity and quality of life. However, the clinical characteristics of COVID-19-associated brain fog are unclear, and standardized assessments are lacking. This study aims to develop a scale for brain fog assessment and support clinical practice and research.

METHODS

The 17-item Brain Fog Assessment (BFA) scale was developed using a standardized methodology, including literature review, focus group discussions (FGDs), expert evaluation, and psychometric validation. Eighteen potential items were generated following the literature review. These items were subsequently refined during FGDs, which included input from patients, caregivers, and multidisciplinary experts in neurology, cognitive neuroscience, and psychology. After thorough deliberation and expert evaluation, the item pool was finalized into a 17-item scale. We recruited 1,325 patients recovered from COVID-19 from Chinese communities. Psychometric properties were assessed by reliability and validity analysis.

RESULTS

Exploratory factor analysis of the BFA scale revealed a three-factor mode comprising 'cognitive decline' (nine items), 'confusion - disorientation' (five items), and 'fatigue' (three items). The internal consistency of each factor was strong (Cronbach's α: 0.82-0.92). Confirmatory factor analysis showed that the model fit, convergent validity, and discriminant validity of the scale were satisfactory. The test-retest reliability was strong (intraclass correlation coefficient = 0.84). Criterion-related validity analysis showed a strong correlation to the Wood Mental Fatigue Inventory (r = 0.70, p < 0.001). Individuals with a higher BFA score tended to score lower on the Montreal Cognitive Assessment (r = -0.23, p = 0.015).

CONCLUSIONS

We established a novel BFA scale to quantify multiple clinical aspects of COVID-19-associated brain fog. Using the BFA scale, fatigue and declining performance in memory, attention, and thought were identified as the main symptoms of COVID-19-associated brain fog. This scale has potential implications for disease monitoring and therapy development for individuals with COVID-19-associated brain fog.

COVID-19 is associated with changes in brain function and structure: A multimodal meta-analysis of neuroimaging studies

The actual role of coronavirus disease 2019 (COVID-19) in brain damage has been increasingly reported, necessitating a meta-analysis to collate and summarize the inconsistent findings from functional imaging and voxel-based morphometry (VBM) studies. A comprehensive voxel-wise meta-analysis of the whole brain was conducted to identify alterations in functional activity and gray matter volume (GMV) between COVID-19 patients and healthy controls (HCs) by using Seed-based d Mapping software. We included 15 functional imaging studies (484 patients with COVID-19, 534 HCs) and 9 VBM studies (449 patients with COVID-19, 388 HCs) in the analysis. Overall, patients with COVID-19 exhibited decreased functional activity in the right superior temporal gyrus (STG) (extending to the right middle and inferior temporal gyrus, insula, and temporal pole [TP]), left insula, right orbitofrontal cortex (OFC) (extending to the right olfactory cortex), and left cerebellum compared to HCs. For VBM, patients with COVID-19, relative to HCs, showed decreased GMV in the bilateral anterior cingulate cortex/medial prefrontal cortex (extending to the bilateral OFC), and left cerebellum, and increased GMV in the bilateral amygdala (extending to the bilateral hippocampus, STG, TP, MTG, and right striatum). Moreover, overlapping analysis revealed that patients with COVID-19 exhibited both decreased functional activity and increased GMV in the right TP (extending to the right STG). The multimodal meta-analysis suggests that brain changes of function and structure in the temporal lobe, OFC and cerebellum, and functional or structural alterations in the insula and the limbic system in COVID-19. These findings contribute to a better understanding of the pathophysiology of brain alterations in COVID-19. SIGNIFICANCE STATEMENT: This first large-scale multimodal meta-analysis collates existing neuroimaging studies and provides voxel-wise functional and structural whole-brain abnormalities in COVID-19. Findings of this meta-analysis provide valuable insights into the dynamic brain changes (from infection to recovery) and offer further explanations for the pathophysiological basis of brain alterations in COVID-19.

Objective and subjective cognitive outcomes one year after COVID-19

OBJECTIVE

This study aimed to evaluate subjective cognitive, physical, and mental health symptoms as well as objective cognitive deficits in COVID-19 patients 1 year after infection.

METHODS

This was a cross-sectional study. Seventy-four patients, who contracted a SARS-CoV-2 infection in 2020, underwent an in-person neuropsychological assessment in 2021. This included standardized tests of memory, attention, and executive functions. In addition, participants also responded to scales on subjective attention deficits, mental health symptoms, and fatigue. Patients' scores were compared to published norms.

RESULTS

Patients (N = 74) had a median age of 56 years (42% female). According to the initial disease severity, they were classified as mild (outpatients, 32%), moderate (hospitalized, non-ICU-admitted, 45%), or severe (ICU-admitted, 23%). Hospitalized patients were more often affected than outpatients. In general, deficits were most common in attention (23%), followed by memory (15%) and executive functions (3%). Patients reported increased levels of fatigue (51%), anxiety (30%), distractibility in everyday situations (20%), and depression (15%). An additional analysis suggested an association between lower scores in an attention task and hyperferritinemia. As indicated by a hierarchical regression analysis, subjective distractibility was significantly predicted by current anxiety and fatigue symptoms but not by objective attention performance (final model, adj-R 2 = 0.588, P < 0.001).

INTERPRETATION

One year after infection, COVID-19 patients can have frequent attention deficits and can complain about symptoms such as fatigue, anxiety, and distractibility. Anxiety and fatigue, more than objective cognitive deficits, have an impact on the patients' experienced impairments in everyday life.

Subjective and objective measures of cognitive function are correlated in persons with Post-COVID-19 Condition: a secondary analysis of a Randomized Controlled Trial

BACKGROUND

It remains unclear whether subjective and objective measures of cognitive function in Post COVID-19 Condition (PCC) are correlated. The extent of correlation has mechanistic and clinical implications.

METHODS

This post-hoc analysis of a randomized, double-blind, placebo-controlled clinical trial contains baseline data of subjective and objective measures of cognition in a rigorously characterized cohort living with PCC. Herein, we evaluated the association between subjective and objective condition function, as measured by the Perceived Deficits Questionnaire, 20-item (PDQ-20) and the Digit Symbol Substitution Test (DSST) and Trails Making Test (TMT)-A/B, respectively.

RESULTS

A total of 152 participants comprised the baseline sample. Due to missing data, our statistical analyses included 150 for self-reported PDQ-20, 147 individuals for combined DSST-measured cognitive function (composite z-score of the Pen/Paper plus Online CogState Version, NcombinedDSST), 71 for in-person DSST-measured cognitive function (Pen/Paper Version), 70 for TMT-A-measured cognitive function, and 70 for TMT-B-measured cognitive function. After adjusting for age, sex, and education, PDQ-20 was significantly correlated with pen-and-paper DSST (β = -0.003, p = 0.002) and TMT-B (β = 0.003, p = 0.008) scores, but not with TMT-A scores (β = -0.001, p = 0.751).

CONCLUSIONS

Overall, a statistically significant correlation was observed between subjective and objective cognitive functions. Clinicians providing care for individuals with PCC who have subjective cognitive function complaints may consider taking a measurement-based approach to cognition at the point of care that focuses exclusively on patient-reported measures.

Neuropsychology practice guidance for the neuropsychiatric aspects of Long COVID

Objective: The coronavirus disease-2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has had a profound global impact on individual health and well-being in adults and children. While most fully recover from COVID-19, a relatively large subgroup continues to experience persistent physical, cognitive, and emotional/behavioral symptoms beyond the initial infection period. The World Health Organization has termed this phenomenon "Post-COVID-19 Condition" (PCC), better known as "Long COVID." Due to the cognitive and psychosocial symptoms, neuropsychologists often assess and recommend treatment for individuals with Long COVID. However, guidance for neuropsychologists' involvement in clinical care, policy-making, and research has not yet been developed. The authors of this manuscript convened to address this critical gap and develop guidance for clinical neuropsychologists working with patients presenting with Long COVID. Method: Authors include pediatric and adult neuropsychologists with expertise in Long COVID and behavioral health. All authors have been engaged in clinical and research efforts examining the impact of COVID-19. Authors summarized the literature-to-date pertinent to the neuropsychiatric sequelae of Long COVID and developed guidance for neuropsychologists working with individuals with Long COVID. Conclusions: Research findings regarding neuropsychiatric symptoms associated with Long COVID are mixed and limited by methodological differences. As they practice and conduct research, neuropsychologists should remain mindful of the evolving and tenuous nature of the literature.

A review of the roles of pathogens in Alzheimer's disease

Alzheimer's disease (AD) is one of the leading causes of dementia and is characterized by memory loss, mental and behavioral abnormalities, and impaired ability to perform daily activities. Even as a global disease that threatens human health, effective treatments to slow the progression of AD have not been found, despite intensive research and significant investment. In recent years, the role of infections in the etiology of AD has sparked intense debate. Pathogens invade the central nervous system through a damaged blood-brain barrier or nerve trunk and disrupt the neuronal structure and function as well as homeostasis of the brain microenvironment through a series of molecular biological events. In this review, we summarize the various pathogens involved in AD pathology, discuss potential interactions between pathogens and AD, and provide an overview of the promising future of anti-pathogenic therapies for AD.

Effects of intraoperative body temperature, blood pressure, cerebral tissue oxygenation, and anesthesia type on postoperative cognitive functions in geriatric arthroplasty surgery for hip fracture

OBJECTIVES

This study aimed to explore the effects of cerebral oxygenation, body temperature, hemodynamic changes, and anesthesia type on postoperative cognitive dysfunction (POCD) in geriatric patients undergoing hip fracture surgery.

PATIENTS AND METHODS

One hundred five elderly patients (59 males, 46 females; mean age: 76.7±8.8 years; range, 65 to 95 years) who were scheduled for hip fracture surgery under general or spinal anesthesia between March 2021 and March 2023 were enrolled in the prospective observational study. The cognitive functions were evaluated using the Mini-Mental State Examination (MMSE). Postoperative MMSE values <24 were considered indicative of POCD. Cerebral oxygenation was evaluated before and during the operation using near-infrared spectroscopy (NIRS), and body temperature was measured using a tympanic thermometer, with values <36℃ considered hypothermia. The relationship between decreases in blood pressure ≥30% and POCD was investigated. The relationship between decreases in NIRS of 25% and POCD was also investigated.

RESULTS

Postoperative cognitive dysfunction was observed in 29 (27.25%) of the 105 patients. The MMSE value was 24 in 67.06% of 29 patients, and all these patients developed POCD. The incidence of POCD in patients with a preoperative MMSE1 score of 30 was 12.30% (p=0.001). No relationship was identified between MMSE changes and anesthesia type, hypotension, and decreases in the NIRS (p=0.439, p=0.399). Hypothermia was found to be significantly related to POCD (p=0.013). The degree of hypothermia decreased the postoperative MMSE value at different rates. A 1°C body temperature decrease caused a 16.7%, 44.4%, and 50% decrease in MMSE scores of one, one, and two patients, respectively.

CONCLUSION

Hypothermia was found to be significantly related to POCD. The same degree of hypothermia caused different MMSE changes. Since the number of patients with POCD was very low, the effect of amounts of body temperature changes on clinically significant MMSE changes could not be supported by logistic regression. The preoperative MMSE values, MMSE change rates, and age were found to be effective in POCD. Maintaining the body temperature throughout the operation will ensure the preservation of postoperative cognitive functions.

Assessment of visuospatial functions in post-Covid 19 patients: Beyond the traditional paradigm

Several studies indicate that some cognitive changes occur after COVID-19. Visuospatial alterations have been reported in 24-40 %. These alterations may be useful as early biomarkers of neurodegenerative disease. Thus, we can emphasize the importance of visuospatial processes in cognition through quantitative and qualitative analysis of performance on the Clock Test (CDT) and the Rey-Osterrieth Complex Figure (FCRO). Our objective was to describe the performance of post COVID 19 patients in visuospatial tests, with different degrees of respiratory impairment and to perform a qualitative analysis of the performance to check its relationship with alterations in attention and executive functions. This will allow highlighting the executive component of the performance of the CDT and ROCF and differentiate patients with possible cognitive impairment. 77 patients with SARS-CoV-2 infection were evaluated (3 months post-infection) with a complete neuropsychological battery and MRI. Overall, there is a significant difference between FCRO and CDT, with FCRO having only 9 % change and CDT having 51.9 % change. Regarding the correlations observed between groups (VM Inv, VM non I and non hospitalized) the highest correlations were observed between Boston with FCRO copy (r=0.497; p=0.001) and with FCRO memory (r=0.429; p=0.001). Comparing the performance between groups by severity, significant differences were observed only in the TMT A (13.706 p=0.001) and B (9.583 p=0.008) tests and in the phonological fluency letter A (13.445 p=0.001), we observed that the group of non-hospitalized patients had a better performance. Neuropsychological deficits often have a direct impact on daily life by affecting the ability to learn and adapt. Thus, a useful strategy for the neuropsychological characterization of post-COVID-19 patients is the qualitative analysis of visuospatial abilities in conjunction with executive functions that cannot be analyzed in isolation.

Cognitive performance in adults with post-COVID syndrome: Results from a German case-control study

Numerous studies on post-COVID syndrome (PCS) describe persisting symptoms of cognitive impairment. Previous studies, however, often investigated small samples or did not assess covariates possibly linked to cognitive performance. We aimed to describe 1) global and domain-specific cognitive performance in adults with PCS, controls with previous SARS-CoV-2 infection and healthy controls, 2) associations of sociodemographics, depressive symptoms, anxiety, fatigue, somatic symptoms and stress with cognitive performance and subjective cognitive decline (SCD), using data of the LIFE-Long-COVID-Study from Leipzig, Germany. Group differences in cognitive performance and associations with sociodemographic and neuropsychiatric covariates were assessed using multivariable regression analyses. Our study included n = 561 adults (Mage: 48.8, SD: 12.7; % female: 70.6). Adults with PCS (n = 410) performed worse in tests on episodic memory (b = -1.07, 95 % CI: -1.66, -0.48) and visuospatial abilities (b = -3.92, 95 % CI: -6.01, -1.83) compared to healthy controls (n = 64). No impairments were detected for executive function, verbal fluency, and global cognitive performance. Odds of SCD were not higher in PCS. A previous SARS-CoV-2 infection without PCS (n = 87) was not linked to cognitive impairment. Higher age and higher levels of stress and fatigue were linked to worse performance in several cognitive domains. Routine administration of tests for episodic memory and visuospatial abilities might aid in the identification of individuals at risk for cognitive impairment when reporting symptoms of PCS. Low numbers of participants with severe COVID-19 infections possibly limit generalizability of our findings.

Acute and Preventive Treatment of COVID-19-Related Headache: A Series of 100 Patients

To describe the need and effectiveness of acute and preventive medications in a series of 100 consecutive patients referred due to COVID-19-related headaches. Patients were aged 48.0 (standard deviation (SD): 12.4), 84% were female, and 56% had a prior history of headache. The most common headache phenotype was holocranial (63%), frontal (48%), pressing (75%), of moderate intensity (7 out of 10), and accompanied by photophobia (58%). Acute medication was required by 93%, with paracetamol (46%) being the most frequently used drug, followed by ibuprofen (44%). The drugs with the highest proportion of a 2 h pain-freedom response were dexketoprofen (58.8%), triptans (57.7%), and ibuprofen (54.3%). Preventive treatment was required by 75% of patients. The most frequently used drugs were amitriptyline (66%), anesthetic blockades (18%), and onabotulinumtoxinA (11%). The drugs with the highest 50% responder rate were amitriptyline (45.5%), mirtazapine (50%), and anesthetic blockades (38.9%). The highest 75% responder rate was experienced following onabotulinumtoxinA (18.2%). In conclusion, most patients required acute medication, with triptans and non-steroidal anti-inflammatory drugs achieving the best responses. Three-quarters of patients required preventive medication. The most frequently used drug was amitriptyline, which obtained the best results. In some treatment-resistant patients, anesthetic blockades and onabotulinumtoxinA were also beneficial.

Long-Term Effects of the Multicomponent Program BrainProtect® on Cognitive Function: One-Year Follow-Up in Healthy Adults

Background

Age-related neuronal changes impact cognitive integrity, which is a major contributor to health and quality of life. The best strategy to prevent cognitive decline and Alzheimer's disease is still debated.

Objective

To investigate the long-term effects of the eight-week multicomponent training program BrainProtect® on cognitive abilities compared to general health counseling (GHC) in cognitively healthy adults in Germany.

Methods

Healthy adults (age ≥50 years) previously randomized to either GHC (n = 72) or BrainProtect (intervention group, IG, n = 60) for eight-weeks (once weekly, 90 minutes, group-based) underwent a comprehensive neuropsychological test battery and health-related quality of life (HRQoL) evaluation 3- and 12-months after intervention end.

Results

Dropout rates were n = 8 after 3 months and n = 19 after 12 months. No significant long-term effect of BrainProtect was observed for the primary endpoint Consortium to Establish a Registry for Alzheimer's Disease (CERAD-Plus) total score. Logical reasoning was significantly improved (p = 0.024) 12 months after completion of the training program in IG participants compared to the GHC group independent of sex, age, education, diet, and physical activity. In IG participants, thinking flexibility (p = 0.019) and confrontational naming (p = 0.010) were improved 3 months after completing the intervention compared to the GHC group, however, after conservative Bonferroni adjustment, significance was lost.

Conclusions

BrainProtect® independently improved logical reasoning compared to GHC up to 12 months after cognitive training's end in healthy adults. To uncover the long-term clinical significance of multicomponent cognitive training in healthy adults, studies with larger sample size and frequent follow up visits are necessary.

Impact of SARS-CoV-2 infection on the cognitive functioning of patients institutionalized in nursing homes

BACKGROUND

COVID-19 disease affected the cognitive level of institutionalized patients in nursing homes, especially in the older subjects regardless of gender. This study aims to assess cognitive impairment using the Mini-Mental State Examination (MMSE) before and after COVID-19 infection, and to determine whether these changes varied based on gender.

METHODS

A pre- and post-COVID-19 study was conducted, involving 68 geriatric patients (34 men and 34 women) from two nursing homes. Cognitive impairment was assessed using the MMSE.

RESULTS

COVID-19 infection had a notable impact on the cognitive health of older adults residing in nursing homes, primarily attributed to the social isolation they experienced. This effect was more pronounced in older individuals. A comparison of the MMSE results by gender before and after contracting COVID-19 revealed significant differences in attention and calculation, with women obtaining the worst score before the virus. However, following their recovery from the virus, men demonstrated significantly lower scores in time and space orientation and evocation.

CONCLUSION

COVID-19 has led to a decline in cognitive functioning, significantly worsening the mental state of older individuals, even after recovery from the virus. Consequently, it is crucial to implement proactive measures to prevent isolation and safeguard the cognitive well-being of this vulnerable population.

Neuropsychological functioning after COVID-19: minor differences between individuals with and without persistent complaints after SARS-CoV-2 infection

Objective: It is unclear how self-reported severe fatigue and difficulty concentrating after SARS-CoV-2 infection relate to objective neuropsychological functioning. The study aimed to compare neuropsychological functioning between individuals with and without these persistent subjective complaints. Method: Individuals with and without persistent severe fatigue (Checklist Individual Strength (CIS) fatigue ≥ 35) and difficulty concentrating (CIS concentration ≥ 18) at least 3 months after SARS-CoV-2 infection were included. Neuropsychological assessment was performed on overall cognitive functioning, attention, processing speed, executive functioning, memory, visuo-construction, and language (18 tests). T-scores -1.5 SD below population normative data (T ≤ 35) were classified as "impaired". Results: 230 participants were included in the study, of whom 22 were excluded from the analysis due to invalid performance. Of the participants included in the analysis, 111 reported persistent complaints of severe fatigue and difficulty concentrating and 97 did not. Median age was 54 years, 59% (n = 126) were female, and participants were assessed a median of 23 months after first infection (IQR: 16-28). With bivariate logistic regression, individuals with persistent complaints had an increased likelihood of slower information processing speed performance on the Stroop word reading (OR = 2.45, 95%CI = 1.02-5.84) compared to those without persistent complaints. Demographic or clinical covariates (e.g. hospitalization) did not influence this association. With linear regression techniques, persistent complaints were associated with lower t-scores on the D2 CP, TMT B, and TMT B|A. There were no differences in performance on the other neuropsychological tests. Conclusions: Individuals with subjective severe fatigue and difficulty concentrating after COVID-19 do not typically demonstrate cognitive impairment on extensive neuropsychological testing.

Lifetime History of Low Birth Weight Delivery and Cognitive Function in Middle-Aged Parous Women

BACKGROUND AND OBJECTIVES

Pregnancy outcomes such as low birth weight (LBW) delivery may reflect vascular or metabolic dysfunction in mothers and presage future cognitive impairment and dementia. However, the evidence is currently limited. Our objective was to examine the extent to which a lifetime history of LBW delivery was associated with cognitive function in parous middle-aged women.

METHODS

We studied participants from the Nurses' Health Study II, an ongoing longitudinal cohort of female nurses enrolled in 1989. In 2009, participants completed a reproductive history questionnaire. Participants who completed at least one of 2 post-traumatic stress disorder questionnaires were invited to participate in a cognition substudy with 2 waves of baseline data collection (2014 or 2018). We restricted the analysis to participants with one valid cognitive assessment who reported ≥1 birth at 18 years and older. We defined LBW delivery history as having delivered offspring with a birth weight <2,500 g (<5.5 lbs) in any pregnancy. The outcome was a single assessment of cognitive function evaluated with the self-administered Cogstate Brief Battery. The battery comprises 4 tasks, which we used to create 2 composite z-scores measuring psychomotor speed/attention and learning/working memory (higher z-scores = better cognitive function). We used multivariable linear regression models.

RESULTS

The analysis included 15,323 participants with a mean age of 62 (standard deviation: 4.9 years) at cognitive assessment. Among them, 1,224 (8%) had a history of LBW delivery. After adjusting for age at cognitive assessment, race, and ethnicity, participants' education, wave of baseline cognitive assessment, socioeconomic status, and prepregnancy characteristics, women with a history of LBW delivery had lower z-scores in the psychomotor speed/attention (β, -0.06; 95% CI -0.12 to -0.01) and learning/working memory (β, -0.05; 95% CI -0.09 to -0.01) composites than parous women without a history of LBW delivery. We observed a gradient of lower z-scores with an increasing number of LBW deliveries.

DISCUSSION

History of LBW delivery may be marker of future poorer cognition. If confirmed, our findings support future investigations into the value of early preventive efforts targeting women with a history of LBW delivery to reduce the burden of cognitive impairment in women.

Neuropsychological functioning and its correlates at 1 year follow-up of severe COVID-19

BACKGROUND

Short-term cognitive impairment is associated with SARS-CoV-2 infection but the long-term impact is yet to be examined in detail. We aim to study the evolution of these symptoms in severe COVID-19 patients admitted to the intensive care unit (ICU) between April and December 2020 1 year after hospital discharge and to analyze its clinical correlates.

METHOD

A total of 58 patients agreed to participate in the 6 months follow-up and 30 at 1 year after hospital discharge. Demographic, clinical and laboratory data were collected and a comprehensive neuropsychological battery including validated tests for the main cognitive domains was administered. To test the magnitude of neurocognitive sequelae, two standard deviations below normative group were considered. To compare the neuropsychological performance at 6 and 12 months follow-up we used repeated measures tests. Finally, regression analyses were performed to test the main effects of medical and psychological factors on multiple cognition.

RESULTS

Almost half of the sample continued to have impaired performance on neuropsychological tests at 12 months follow-up. In comparison with the results obtained at 6 months, significant improvements were found in immediate recall (d = 0.49), delayed recall (d = 0.45), and inhibitory control (d = 0.53). Medical variables predicted cognitive performance at 6 months but not at 12 months follow-up, while anxiety and depression predicted cognitive deficits in the long-term.

CONCLUSIONS

A generalised improvement was observed in severe COVID-19 patients at follow-up. This improvement was particularly notable in verbal memory and executive functioning. However, a considerable proportion of the sample continued to present deficits at 1 year follow-up.

Post-acute COVID-19 syndrome in previously hospitalized patients

INTRODUCTION

With the prolongation of the COVID-19 pandemic, more individuals are experiencing sequelae after COVID-19 infection, also known as post-acute COVID-19 syndrome (PCS). The aims of this study were to describe the prevalence and characteristics of PCS symptoms such as fatigue, anxiety, and depression and to compare these symptoms according to participant characteristics in patients who had been previously hospitalized due to COVID-19.

DESIGN

A descriptive cross-sectional study design was used.

METHODS

We included 114 individuals who had been hospitalized for COVID-19 and were discharged from the hospital at least 4 weeks before. Symptoms were assessed using the Fatigue Severity Scale, the Hospital Anxiety-Depression Scale, and the PCS symptom questionnaire developed by the authors. We used descriptive statistics, the Student's t-test, the Wilcoxon rank-sum test, and the Kruskal-Wallis test for statistical analyses.

RESULTS

The most prevalent symptoms were anxiety (66.7%), fatigue (64.0%), headache (57.9%), and concentration or memory difficulties (57.9%). Concentration or memory difficulties and sleep disturbances had the highest mean frequency. Concentration or memory difficulties were rated with the highest mean severity, and cough, loss of taste, and muscle and joint pain had the highest mean distress scores. Female participants, individuals hospitalized for more than 2 weeks, individuals discharged more than 9 months ago, unvaccinated patients, and those who tried at least one symptom relief method reported higher symptom distress.

CONCLUSION

The findings of this investigation into the frequency, severity, and distress of symptoms shed light on the identification of post-COVID symptoms in detail. To objectively evaluate and comprehend the symptom trajectories of PCS, prospective studies about the development of symptom assessment tools and studies with a longitudinal design should be conducted.

CLINICAL RELEVANCE

A substantial number of respondents reported numerous symptoms and expressed symptom distress; therefore, the development of nursing interventions and treatments to alleviate PCS symptoms is crucial.

Cognitive functioning in patients with neuro-PASC: the role of fatigue, mood, and hospitalization status

This study sought to characterize cognitive functioning in patients with neurological post-acute sequelae of SARS-CoV-2 infection (Neuro-PASC) and investigate the association of subjective and objective functioning along with other relevant factors with prior hospitalization for COVID-19. Participants were 106 adult outpatients with Neuro-PASC referred for abbreviated neuropsychological assessment after scoring worse than one standard deviation below the mean on cognitive screening. Of these patients, 23 had been hospitalized and 83 had not been hospitalized for COVID-19. Subjective cognitive impairment was evaluated with the self-report cognition subscale from the Patient-Reported Outcome Measurement Information System. Objective cognitive performance was assessed using a composite score derived from multiple standardized cognitive measures. Other relevant factors, including fatigue and depression/mood symptoms, were assessed via the Patient-Reported Outcome Measurement Information System. Subjective cognitive impairment measures exceeded the minimal difficulties noted on objective tests and were associated with depression/mood symptoms as well as fatigue. However, fatigue independently explained the most variance (17.51%) in patients' subjective cognitive ratings. When adjusting for fatigue and time since onset of COVID-19 symptoms, neither objective nor subjective impairment were associated with prior hospitalization for COVID-19. Findings suggest that abbreviated neuropsychological assessment may not reveal objective difficulties beyond initial cognitive screening in patients with Neuro-PASC. However, subjective cognitive concerns may persist irrespective of hospitalization status, and are likely influenced by fatigue and depression/mood symptoms. The impact of concomitant management of fatigue and mood in patients with Neuro-PASC who report cognitive concerns deserve further study.

Exploring the impact of cognitive dysfunction, fatigue, and shortness of breath on activities of daily life after COVID-19 infection, until 1-year follow-up

OBJECTIVE

Despite expanding knowledge on COVID-19,  the long-term effects on daily-life activities remain unclear. The prevalence and changes in fatigue, cognitive dysfunction, and activity limitations in the first year after COVID-19 infection in hospitalized and non-hospitalized patients were explored.

SUBJECTS

A total of 122 patients were recruited from hospital care and 90 from primary care.

METHOD

Baseline data comprised the Montreal Cognitive Assessment and Trail Making Test. Participants were followed up at 3 and 12 months using these tests and a semi-structured interview to identify symptoms and how they affected participation in daily-life activities. Both within- and between-group analyses were performed to explore changes over time and compare groups.

RESULT

High levels of fatigue and cognitive dysfunction were found in both groups, which persisted for 12 months. A significant impact on daily-life activities was also observed, with marginal change at the 12-month follow-up. The hospital care group performed worse than the primary care group in the cognitive tests, although the primary care group perceived a higher level of fatigue and cognitive dysfunction. Activity limitations were higher in the primary care group than in the hospital care group.

CONCLUSION

These findings highlight the need for long-term follow-up and further investigation of the impact of persistent deficits on rehabilitation.

The impact of COVID-19 post-infection on the cognition of adults from Peru

Introduction

The COVID-19 pandemic, with over 83 million confirmed cases and 1.8 million deaths, has raised concerns about long-term cognitive issues, especially in populations facing disparities. Despite a few years since Peru's first COVID-19 wave, the cognitive effects on adults remain unclear. This study is the first in Peru to explore COVID-19's impact on general cognition and executive function.

Methods

A retrospective cross-sectional study compared individuals with COVID-19 history to controls, assessing general cognition, verbal fluency, attention, and executive function. Among 240 assessed, 154 met the study inclusion criteria, with about 60% female and an average age of 38.89 ± 16.001 years. Groups included controls (n = 42), acute phase (AP, n = 74) (1-14 days of symptoms), and hyperinflammatory phase (HP, n = 38) (>14 days of symptoms).

Results

Significant cognitive differences were observed. The HP group exhibited lower general cognitive performance (p = 0.02), working memory (p = 0.01), and executive function (planning; p < 0.001; flexibility; p = 0.03) than controls. Those with <14 days of illness (AP vs. HP) had deficits in general cognitive performance (p = 0.02), working memory (p = 0.02), and planning (p < 0.001), mainly during the hyperinflammatory phase, showing differences in working memory (p = 0.003) and planning (p = 0.01). Gender differences emerged, with males in the HP phase having poorer working memory (p = 0.003) and planning (p = 0.01).

Discussion

This study underscores COVID-19's negative impact on cognitive function, even in mild cases, with potential heightened effects in men during acute or hyperinflammatory phases. The findings provide Peru's first evidence, highlighting the vulnerability of populations facing socioeconomic disparities.

Neurocognitive and psychiatric outcomes associated with postacute COVID-19 infection without severe medical complication: a meta-analysis

BACKGROUND

Cognitive symptoms are often reported by those with a history of COVID-19 infection. No comprehensive meta-analysis of neurocognitive outcomes related to COVID-19 exists despite the influx of studies after the COVID-19 pandemic. This study meta-analysed observational research comparing cross-sectional neurocognitive outcomes in adults with COVID-19 (without severe medical/psychiatric comorbidity) to healthy controls (HCs) or norm-referenced data.

METHODS

Data were extracted from 54 studies published between January 2020 and June 2023. Hedges' g was used to index effect sizes, which were pooled using random-effects modelling. Moderating variables were investigated using meta-regression and subgroup analyses.

RESULTS

Omnibus meta-analysis of 696 effect sizes extracted across 54 studies (COVID-19 n=6676, HC/norm-reference n=12 986; average time since infection=~6 months) yielded a small but significant effect indicating patients with COVID-19 performed slightly worse than HCs on cognitive measures (g=-0.36; 95% CI=-0.45 to -0.28), with high heterogeneity (Q=242.30, p<0.001, τ=0.26). Significant within-domain effects was yielded by cognitive screener (g=-0.55; 95% CI=-0.75 to -0.36), processing speed (g=-0.44; 95% CI=-0.57 to -0.32), global cognition (g=-0.40; 95% CI=-0.71 to -0.09), simple/complex attention (g=-0.38; 95% CI=-0.46 to -0.29), learning/memory (g=-0.34; 95% CI=-0.46 to -0.22), language (g=-0.34; 95% CI=-0.45 to -0.24) and executive function (g=-0.32; 95% CI=-0.43 to -0.21); but not motor (g=-0.40; 95% CI=-0.89 to 0.10), visuospatial/construction (g=-0.09; 95% CI=-0.23 to 0.05) and orientation (g=-0.02; 95% CI=-0.17 to 0.14). COVID-19 samples with elevated depression, anxiety, fatigue and disease severity yielded larger effects.

CONCLUSION

Mild cognitive deficits are associated with COVID-19 infection, especially as detected by cognitive screeners and processing speed tasks. We failed to observe clinically meaningful cognitive impairments (as measured by standard neuropsychological instruments) in people with COVID-19 without severe medical or psychiatric comorbidities.

Effects of Pycnogenol® in people with post-COVID-19 condition (PYCNOVID): study protocol for a single-center, placebo controlled, quadruple-blind, randomized trial

BACKGROUND

A significant proportion of the global population has been infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at some point since the onset of the pandemic. Although most individuals who develop coronavirus disease 2019 (COVID-19) recover without complications, about 6% have persistent symptoms, referred to as post-COVID-19 condition (PCC). Intervention studies investigating treatments that potentially alleviate PCC-related symptoms and thus aim to mitigate the global public health burden and healthcare costs linked to PCC are desperately needed. The PYCNOVID trial investigates the effects of Pycnogenol®, a French maritime pine bark extract with anti-inflammatory and antioxidative properties, versus placebo on patient-reported health status in people with PCC.

METHODS

This is a single-center, placebo-controlled, quadruple blind, randomized trial. We aim to randomly assign 150 individuals with PCC (1:1 ratio) to receive either 200 mg Pycnogenol® or placebo daily for 12 weeks. Randomization is stratified for duration of PCC symptoms (≤ 6 months versus > 6 months) and presence of symptomatic chronic disease(s). The primary endpoint is perceived health status at 12 weeks (EuroQol-Visual Analogue Scale) adjusted for baseline values and stratification factors. Secondary endpoints include change in self-reported PCC symptoms, health-related quality of life, symptoms of depression and anxiety, cognitive function, functional exercise capacity, physical activity measured with accelerometry, and blood biomarkers for endothelial health, inflammation, coagulation, platelet function, and oxidative stress. Investigators, study participants, outcome assessors, and data analysts are blinded regarding the intervention assignment. Individuals with PCC were involved in the design of this study.

DISCUSSION

This is the first trial to investigate the effects of Pycnogenol® versus placebo on patient-reported health status in people with PCC. Should the trial proof clinical effectiveness, Pycnogenol® may serve as a therapeutic approach to mitigate symptoms associated with PCC.

TRIAL REGISTRATION

The study is registered at ClinicalTrials.gov. :NCT05890534, June 6, 2023.

Meta-analysis of Cognitive Function Following Non-severe SARS-CoV-2 Infection

To effectively diagnose and treat subjective cognitive symptoms in post-acute sequalae of COVID-19 (PASC), it is important to understand objective cognitive impairment across the range of acute COVID-19 severity. Despite the importance of this area of research, to our knowledge, there are no current meta-analyses of objective cognitive functioning following non-severe initial SARS-CoV-2 infection. The aim of this meta-analysis is to describe objective cognitive impairment in individuals with non-severe (mild or moderate) SARS-CoV-2 cases in the post-acute stage of infection. This meta-analysis was pre-registered with Prospero (CRD42021293124) and utilized the PRISMA checklist for reporting guidelines, with screening conducted by at least two independent reviewers for all aspects of the screening and data extraction process. Fifty-nine articles (total participants = 22,060) with three types of study designs met our full criteria. Individuals with non-severe (mild/moderate) initial SARS-CoV-2 infection demonstrated worse objective cognitive performance compared to healthy comparison participants. However, those with mild (nonhospitalized) initial SARS-CoV-2 infections had better objective cognitive performance than those with moderate (hospitalized but not requiring ICU care) or severe (hospitalized with ICU care) initial SARS-CoV-2 infections. For studies that used normative data comparisons instead of healthy comparison participants, there was a small and nearly significant effect when compared to normative data. There were high levels of heterogeneity (88.6 to 97.3%), likely reflecting small sample sizes and variations in primary study methodology. Individuals who have recovered from non-severe cases of SARS-CoV-2 infections may be at risk for cognitive decline or impairment and may benefit from cognitive health interventions.

The relationship between comprehensive geriatric assessment on the pneumonia prognosis of older adults: a cross-sectional study

BACKGROUND

The mortality of pneumonia in older adults surpasses that of other populations, especially with the prevalence of coronavirus disease 2019 (COVID-19). Under the influence of multiple factors, a series of geriatric syndromes brought on by age is one of the main reasons for the poor prognosis of pneumonia. This study attempts to analyze the impact of geriatric syndrome on the prognosis of pneumonia.

METHODS

This is a prospective cross-sectional study. Patients over 65 years old with COVID-19 and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-negative community-acquired pneumonia (SN-CAP) were included in the research. General characteristics, laboratory tests, length of stay (LOS), and comprehensive geriatric assessment (CGA) were collected. Multivariate regression analysis to determine the independent predictors of the severity, mortality, and LOS of COVID-19. At the same time, the enrolled subjects were divided into three categories by clustering analysis of 10 CGA indicators, and their clinical characteristics and prognoses were analyzed.

RESULTS

A total of 792 subjects were included in the study, including 204 subjects of SN-CAP (25.8%) and 588 subjects (74.2%) of COVID-19. There was no significant difference between non-severe COVID-19 and SN-CAP regarding mortality, LOS, and CGA (P > 0.05), while severe COVID-19 is significantly higher than both (P < 0.05). The Barthel Index used to assess the activities of daily living was an independent risk factor for the severity and mortality of COVID-19 and linearly correlated with the LOS (P < 0.05). The cluster analysis based on the CGA indicators divided the geriatric pneumonia patients into three groups: Cluster 1 (n = 276), named low ability group, with the worst CGA, laboratory tests, severity, mortality, and LOS; Cluster 3 (n = 228), called high ability group with the best above indicators; Cluster 2 (n = 288), named medium ability group, falls between the two.

CONCLUSION

The Barthel Index indicates that decreased activities of daily living are an independent risk factor for the severity, mortality, and LOS of geriatric COVID-19. Geriatric syndrome can help judge the prognosis of pneumonia in older adults.

Long COVID in Brain Health Research: A Call to Action

The COVID-19 pandemic has brought attention to the long-term consequences of the virus, particularly the persistent symptoms that characterize long COVID. This syndrome, which can last for months after the initial infection, includes a range of neurological and neuropsychiatric manifestations that have significant implications for brain health and dementia research. This review explores the current understanding of long COVID's cognitive, neurological, and psychiatric symptoms and their potential impact on brain stimulation and neuroimaging studies. It argues that researchers must adapt their study designs and screening processes to account for the confounding effects of long COVID and ensure the accuracy and reliability of their findings. To advance the understanding of this condition and its long-term effects on brain health, the review proposes a series of strategies, including the development of standardized screening tools, the investigation of underlying mechanisms, and the identification of risk factors and protective factors. It also emphasizes the importance of collaborative research efforts and international data sharing platforms in accelerating the pace of discovery and developing targeted interventions for individuals with long COVID. As the prevalence of this condition continues to grow, it is imperative that the neuroscience community comes together to address this challenge and support those affected by long COVID.

Attentional impairment and altered brain activity in healthcare workers after mild COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) is highly transmissible and pathogenic. Patients with mild cases account for the majority of those infected with coronavirus disease 2019 (COVID-19). Although there is evidence that many patients with COVID-19 have varying degrees of attentional impairment, little is known about how SARS-COV-2 affects attentional function. This study included a high-risk healthcare population divided into groups of healthcare workers (HCWs) with mild COVID-19 (patient group, n = 45) and matched healthy HCWs controls (HC group, n = 42), who completed general neuropsychological background tests and Attention Network Test (ANT), and underwent resting-state functional magnetic resonance imaging (rs-fMRI) using amplitude of low-frequency fluctuation (ALFF) to assess altered brain activity; Selective impairment occurred in orienting and executive control networks, but not in alert network, in the patient group, and widespread cognitive impairment encompassing general attention, memory, and executive dysfunction. Moreover, the patient group had significantly lower ALFF values in the left superior and left middle frontal gyri than the HC group. SARS-COV-2 infection may have led to reduced brain activity in the left superior and left middle frontal gyri, thus impairing attentional orienting and executive control networks, which may explain the development of attentional deficits after COVID-19.

Transcranial alternating current stimulation in affecting cognitive impairment in psychiatric disorders: a review

Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation method that, through its manipulation of endogenous oscillations, can affect cognition in healthy adults. Given the fact that both endogenous oscillations and cognition are impaired in various psychiatric diagnoses, tACS might represent a suitable intervention. We conducted a search of Pubmed and Web of Science databases and reviewed 27 studies where tACS is used in psychiatric diagnoses and cognition change is evaluated. TACS is a safe and well-tolerated intervention method, suitable for multiple-sessions protocols. It can be administered at home, individualized according to the patient''s anatomical and functional characteristics, or used as a marker of disease progression. The results are varying across diagnoses and applied protocols, with some protocols showing a long-term effect. However, the overall number of studies is small with a great variety of diagnoses and tACS parameters, such as electrode montage or used frequency. Precise mechanisms of tACS interaction with pathophysiological processes are only partially described and need further research. Currently, tACS seems to be a feasible method to alleviate cognitive impairment in psychiatric patients; however, a more robust confirmation of efficacy of potential protocols is needed to introduce it into clinical practise.

Longitudinal Associations Between Cannabis Use and Cognitive Impairment in a Clinical Sample of Middle-Aged Adults Using Cannabis for Medical Symptoms

Introduction: Cannabis use to alleviate medical symptoms is increasing in middle-aged and older adults. Cognitive impairment associated with cannabis use may be especially detrimental to these understudied age groups. We hypothesized that among middle-aged and older adults who used cannabis for 12 months, frequent (≥3 days/week) compared with nonfrequent (≤2 days/week) use will be associated with cognitive impairment. Materials and Methods: We performed secondary analysis on data from a clinical trial of cannabis use for medical symptoms. Participants (n=62) were ≥45 years, and completed a baseline and at least one postbaseline visit. Cognitive domains were assessed through the Cambridge Neuropsychological Test Automated Battery. Cannabis use was assessed prospectively through daily smartphone diaries. Frequency of cannabis use was a binary predictor in a mixed-effects logistic regression model predicting cognitive impairment adjusted for baseline cognitive functioning. Results: At baseline, participants were primarily nonfrequent cannabis users; however, in all other time periods, most participants were frequent users (range: 55-58%). Cognitive outcomes did not differ between frequent and nonfrequent cannabis users. However, in sensitivity analyses, respondents with problematic cannabis use scored significantly worse on one cognitive domain compared to those without problematic cannabis use. Conclusions: In a clinical sample of adults aged ≥45 years, no longitudinal associations were found between cannabis use and cognitive functioning. However, a few significant associations were observed between problematic use and cognitive functioning. Further research is needed to assess the impact of cannabis use on adults, particularly those aged ≥65 years, and to investigate potential subtler influences of cannabis use on cognition. ClinicalTrials.gov ID: NCT03224468.