Executive dysfunction in COVID-19 patients

An immersive virtual reality-based object-location memory task reveals spatial long-term memory alterations in Long-COVID

Object-location memory (OLM) is a type of declarative memory for spatial information and consists of the individual's ability to establish accurate associations between objects and their spatial locations. Long-COVID describes the long-term effects of the COVID-19 disease. Long-COVID patients show medial temporal lobe dysfunction and neuropsychological alterations affecting memory. This study aimed to assess OLM in a group of Long-COVID patients, n=66, and a Control group of healthy individuals with similar age and sex composition, n=21, using an immersive virtual reality (iVR)-based OLM task. We also explored associations between the performance in the iVR-based OLM task and general cognitive function (MoCA), and both verbal (VSTM) and visuospatial (SSTM) span. The Long-COVID group showed fewer correct responses, made more task attempts, and invested more time in the iVR-based OLM task than the Control group. Delayed memory was more severely altered than immediate memory in Long-COVID participants. Better MoCA scores of the Long-COVID group were strongly associated with shorter times to complete the immediate recall of the iVR-based OLM task. Besides, the months elapsed since the COVID-19 infection were slightly associated with fewer correct responses in the immediate and 24-hour recalls. These results corroborate previous findings of memory alterations in the Long-COVID syndrome using an iVR-based OLM task, adding new evidence on spatial memory and long-term memory in this population. Implementing spatial iVR tasks to clinical research may improve our understanding of neuropsychological disorders.

Memory alterations after COVID-19 infection: a systematic review

SARS-CoV-2 infection has a wide range of both acute and long-term symptoms. Memory alterations have been frequently reported in studies that explore cognition. The main objective of the systematic review is to update and further analyze the existing evidence of objective memory impairments in long-COVID-19 considering sample and study design characteristics, as well as to explore associations between memory performance and their epidemiological, clinical, and pathological features. A total of 13 studies were identified by searching in PubMed, Web of Science, and PsycInfo databases up to May 6, 2022. Most studies evaluated verbal component of memory in the short-term and long-term recall up to 30 min and mainly performed a single assessment completed at 4-6 months after the infection. The samples mainly consisted of middle-aged adults that required hospitalization. Samples were not stratified by sex, age, and severity. Poor verbal learning was reported in most cases (6-58%), followed by deficits in long-term (4-58%) and short-term (4-37%) verbal memory. Visuospatial component of memory was studied less than verbal component, showing impairment of long-term retention of visual items (10-49%). COVID-19 severity in the acute stage was not systematically associated with poor memory performance. Verbal memory deficits were associated with anxiety and depression. The existing literature on objective memory assessment in long-COVID suggests further research is warranted to confirm memory dysfunction in association with epidemiological, pathological, and clinical factors, using both verbal and visuospatial tests, and exploring in deep long-term memory deficits.

Microstructural brain abnormalities, fatigue, and cognitive dysfunction after mild COVID-19

Although some studies have shown neuroimaging and neuropsychological alterations in post-COVID-19 patients, fewer combined neuroimaging and neuropsychology evaluations of individuals who presented a mild acute infection. Here we investigated cognitive dysfunction and brain changes in a group of mildly infected individuals. We conducted a cross-sectional study of 97 consecutive subjects (median age of 41 years) without current or history of psychiatric symptoms (including anxiety and depression) after a mild infection, with a median of 79 days (and mean of 97 days) after diagnosis of COVID-19. We performed semi-structured interviews, neurological examinations, 3T-MRI scans, and neuropsychological assessments. For MRI analyses, we included a group of non-infected 77 controls. The MRI study included white matter (WM) investigation with diffusion tensor images (DTI) and functional connectivity with resting-state functional MRI (RS-fMRI). The patients reported memory loss (36%), fatigue (31%) and headache (29%). The quantitative analyses confirmed symptoms of fatigue (83% of participants), excessive somnolence (35%), impaired phonemic verbal fluency (21%), impaired verbal categorical fluency (13%) and impaired logical memory immediate recall (16%). The WM analyses with DTI revealed higher axial diffusivity values in post-infected patients compared to controls. Compared to controls, there were no significant differences in the functional connectivity of the posterior cingulum cortex. There were no significant correlations between neuropsychological scores and neuroimaging features (including DTI and RS-fMRI). Our results suggest persistent cognitive impairment and subtle white matter abnormalities in individuals mildly infected without anxiety or depression symptoms. The longitudinal analyses will clarify whether these alterations are temporary or permanent.

The effect of donepezil hydrochloride on post-COVID memory impairment: A randomized controlled trial

BACKGROUND

Post-Coronavirus Disease (COVID-19) condition, known as "post-COVID syndrome," is associated with a range of complications persisting even after recovery. Among these complications, cognitive dysfunction, including memory impairment, has been relatively common observed, impacting executive function and quality of life. To date, no approved treatment exists for this specific complication. Therefore, the present clinical trial aimed to investigate the impact of Donepezil Hydrochloride on post-COVID memory impairment.

METHODS

A randomized, controlled trial (Approval ID: IRCT20210816052203N1) was conducted, enrolling 25 patients with post-COVID memory impairment. Participants with a history of hospitalization were randomly assigned to either the drug group (n = 10) or the control group (n = 15). Memory indices were assessed at baseline, one month, and three months later using the Wechsler Memory Scale-Revised test. SPSS software and appropriate statistical tests were employed for data analysis.

RESULTS

The statistical analysis revealed no significant difference in WMS-R subtest and index scores between the drug and control groups at the 4-week and 12-week follow-up periods. However, within the drug group, there was a notable increase in the visual reproduction I and verbal paired associates II subtests during the specified time intervals.

CONCLUSION

While donepezil 5 mg did not exhibit a significant overall increase in memory scales compared to the control group over time, our findings suggest that this medication may exert a positive effect on specific memory subtests. Further research and exploration are warranted to better understand the potential benefits of donepezil in managing post-COVID-related memory impairment.

TRIAL REGISTRATION

The study was approved by the Research Ethics Committee of Aja University of Medical Sciences (Approval ID: IR.AJAUMS.REC.1400.125) and registered in the Iranian Registry of Clinical Trials (IRCT) (Approval ID: IRCT20210816052203N1).

Psychophysical assessment of olfactory and gustatory function in post-mild COVID-19 patients: A matched case-control study with 2-year follow-up

BACKGROUND

The aim of this study was to psychophysically evaluate the prevalence of smell and taste dysfunction 2 years after mildly symptomatic severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection compared to that observed at 1-year follow-up and while considering the background of chemosensory dysfunction in the no-coronavirus disease 2019 (COVID-19) population.

METHOD

This is a prospective case-control study on 93 patients with polymerase chain reaction (PCR)-positive SARS-CoV-2 infection and 93 matched controls. Self-reported olfactory and gustatory dysfunction was assessed by 22-item Sino-Nasal-Outcome Test (SNOT-22), item "Sense of smell or taste." Psychophysical orthonasal and retronasal olfactory function and gustatory performance were estimated using the extended Sniffin' Sticks test battery, 20 powdered tasteless aromas, and taste strips test, respectively. Nasal trigeminal sensitivity was assessed by sniffing a 70% solution of acetic acid.

RESULTS

The two psychophysical assessments of chemosensory function took place after a median of 409 days (range, 366-461 days) and 765 days (range, 739-800 days) from the first SARS-CoV-2-positive swab, respectively. At 2-year follow-up, cases exhibited a decrease in the prevalence of olfactory (27.9% vs. 42.0%; absolute difference, -14.0%; 95% confidence interval [CI], -21.8% to -2.6%; p = 0.016) and gustatory dysfunction (14.0% vs. 25.8%; absolute difference, -11.8%; 95% CI, -24.2% to 0.6%; p = 0.098). Subjects with prior COVID-19 were more likely than controls to have an olfactory dysfunction (27.9% vs. 10.8 %; absolute difference, 17.2%; 95% CI, 5.2% to 28.8%) but not gustatory dysfunction (14.0% vs. 9.7%; absolute difference, 4.3%; 95% CI, -5.8% to 14.4% p = 0.496) still 2 years after the infection. Overall, 3.2% of cases were still anosmic 2 years after the infection.

CONCLUSIONS

Although a proportion of subjects recovered from long-lasting smell/taste dysfunction more than 1 year after COVID-19, cases still exhibited a significant excess of olfactory dysfunction 2 years after SARS-CoV-2 infection when compared to matched controls.

Cognition in COVID-19 infected patients undergoing invasive ventilation: results from a multicenter retrospective study

A growing number of scientific contributions suggest that COVID-19 infection can lead to impairment of cognition, mainly in executive functions and memory domains, even in the absence of frank neurological pathologies.The primary objective of this retrospective study is to evaluate the frequency and type of inefficiencies in a selection of cognitive tests administered to a sample of subjects who, following infection, required invasive assisted ventilation and were admitted to rehabilitation wards for the treatment of functional impairment.Fifty-seven subjects were enrolled. The recruited patients undergone an assessment of verbal and visuospatial memory and executive functions, upon entry into the rehabilitation department, after discharge from intensive care. The following tests were administered: Rey Auditory Verbal Learning Test (AVLT) (immediate and delayed recall), Rey-Osterrieth Complex Figure Test (ROCFT) (copy and delayed recall), Stroop Color-Word Test, and Trail Making Test (TMT, A and B).Deficient scores, in beyond 25% of subjects, were found in the copy of the ROCFT (32.1% of subjects), and in the delayed recall of ROCFT (27.2%). Between 10 and 20% of patients presented an abnormal result in delayed recall of AVLT (16.07%), and Stroop Test (time, 15.6%, error, 11.5%). Less than 10% of the sample had abnormal performances on TMT (A, 3.5%, and B, 9.4%), and in AVLT immediate recall (8.9%). Correlations of the performances with age, sex, and education were also found.This paper highlights the high incidence of abnormal cognitive performances in this specific subpopulation of patients with COVID-19 infection.

Evaluation of cognitive functions in adult individuals with COVID-19

BACKGROUND AND PURPOSE

Cognitive deficits that are associated with coronavirus disease 2019 (COVID-19) and occur in the acute period are gaining importance. While most studies have focused on the elderly severely affected during acute infection, it remains unclear whether mild to moderate COVID-19 results in cognitive deficits in young patients. This study aims to evaluate the post-infection cognitive functions of young adults with mild to moderate symptoms of COVID-19.

METHODS

A total of 100 adults with similar age and educational background were included in the study. Half of those had been infected with COVID-19 in the last 60 days (N = 50), and the other half had not (N = 50). Global cognitive skills of the participants were evaluated through Montreal Cognitive Assessment Scale (MoCA) and Clock-Drawing Test; memory functions with Öktem Verbal Memory Processes Test (Ö-VMPT); attention span with Digit Span Test; executive functions with Fluency Tests, Stroop Test, and Trail Making Test; visual perceptual skills with Rey Osterrieth Complex Figure Test (ROCF); and neuropsychiatric status with Neuropsychiatric Inventory (NPI). Evaluations were performed in the experimental group for 21 to 60 days from the onset of the disease, and throughout the study, in the control group.

RESULTS

It was found that global cognitive skills, verbal memory, visual memory, executive function, and neuropsychiatric status were affected during COVID-19 (p < 0.05).

CONCLUSION

When the cases were analyzed according to disease severity, no relationship was found between cognitive deficits and disease severity.

Anosmia in COVID-19 could be associated with long-term deficits in the consolidation of procedural and verbal declarative memories

Background and purpose

Long-COVID describes the long-term effects of the coronavirus disease 2019 (COVID-19). In long-COVID patients, neuropsychological alterations are frequently reported symptoms. Research points to medial temporal lobe dysfunction and its association with anosmia in long-COVID patients. This study aims to investigate the acquisition and consolidation of declarative and procedural memory in long-COVID patients and to explore whether anosmia is related to these dissociated memory functions.

Methods

Forty-two long-COVID participants and 30 controls (C) were recruited. The sample of long-COVID patients was divided into two groups based on the presence or absence of anosmia, group A and group NA, respectively. Objective performance in verbal declarative memory (Paired-Associate Learning, PAL), procedural memory (Mirror Tracing Test, MTT), general cognitive function (Montreal Cognitive Assessment scale), psychomotor speed, and incidental learning (Digit Symbol Substitution Test) were assessed and compared among the A, NA, and C groups. Long-term retention of PAL and MTT were assessed 24 h after acquisition.

Results

Lower scores in general cognition, psychomotor speed, and sustained attention were found in A and NA compared with C. However, incidental learning, both cue-guided and free-recalled, was diminished in group A compared with C, with no differences with group NA. General cognition and incidental learning were related to declarative memory function exclusively in long-COVID groups. Long-COVID groups presented lower long-term retention of verbal declarative memory than controls in recall tests but no differences in recognition tests. No group differences were found in the acquisition of procedural memory. However, long-term retention of this memory was worse in group A as compared to the NA and C groups, respectively, when errors and time of execution were considered.

Conclusion

Findings support that consolidation of both procedural and declarative memories is more affected than the acquisition of these memories in long-COVID patients, who are also more vulnerable to deficits in delayed recall than in recognition of declarative memories. Deficits in the consolidation of procedural memory and immediate recall of declarative information are especially relevant in long-COVID participants with anosmia. This indicates that anosmia in COVID-19 could be associated with a long-term dysfunction of the limbic system.

Post-Acute Sequelae of SARS-CoV-2 Infection: A Descriptive Clinical Study

OBJECTIVE

The investigators aimed to describe the clinical experience of a single center reporting on neuropsychiatric findings among patients experiencing persistent symptoms as part of post-acute sequelae of SARS-CoV-2 (PASC) infection.

METHODS

Data were collected retrospectively (between February 2020 and May 2021) from a cohort (N=100) within a COVID-19 survivors study of patients with persistent symptoms enrolled after a short inpatient stay or who had been outpatients never hospitalized. Patients without confirmatory positive PCR or antibody diagnostic test results were grouped separately as presumptive cases (N=13).

RESULTS

Of the 87 patients with confirmed SARS-CoV-2, 63 (72.4%) were female, and 65 (74.7%) were White. The mean age was 49.2 years (SD=14.9). The most prevalent symptoms after COVID-19 infection were fatigue, "brain fog," headache, anxiety, and sleep issues. Attention and executive function were frequently impaired. The mean Montreal Cognitive Assessment score was 26.0 (SD=2.8). Concentration and attention as well as memory issues were both significantly correlated with the complaint of brain fog.

CONCLUSIONS

These preliminary findings suggest that post-acute sequelae of SARS-CoV-2 vary in frequency and duration with relation to premorbid history and that these conditions affect functional domains and patients' ability to return to work. Longitudinal research with larger cohorts is needed to characterize PASC and to optimize care, especially for vulnerable populations.

Association of Anxiety and Depression with Objective and Subjective Cognitive Decline in Outpatient Healthcare Consumers with COVID-19: А Cross-Sectional Study

BACKGROUND: In addition to the neurological complications affecting people infected with COVID-19, cognitive impairment symptoms and symptoms of anxiety and depression remain a frequent cause of complaints. The specificity of cognitive impairment in patients with COVID-19 is still poorly understood. AIM: An exploratory study of factors that may be associated with cognitive decline during the COVID-19 pandemic. METHODS: The cross-sectional multicentre observational study was conducted in a polyclinic unit in Saint Petersburg and in the regions of the North-Western Federal Region. During the study, socio-demographic parameters and information about the somatic condition of patients who applied for primary health care was collected. Emotional and cognitive state were investigated using the Hospital Anxiety and Depression Scale (HADS) and Montreal Cognitive Assessment (MoCA). Mathematical and statistical data processing was carried out using SPSS and RStudio statistical programs. RESULTS: The study included 515 participants, 60% (n=310) of which were women. The sample was divided into those who did (28.5%, n=147) and did not (71.4%, n=368) complain of cognitive decline. Patients with complaints of cognitive decline were significantly older, had lower levels of education and higher levels of depression and anxiety according to HADS (p 0.05). Patients with complaints of cognitive decline underwent the MoCA test (24.3%, n=125). The median MoCA test scores were within the normal range (Median=27, Q1=25, Q3=28), and cognitive decline (MoCA less than 26 points) was detected in 40% (n=50) of patients with complaints of cognitive decline. No significant correlations were found between the MoCA scores and the levels of anxiety and depression according to the HADS (p 0.05). Patients with mild severity of the COVID-19 course were more successful with MoCA subtests than patients with moderate and severe courses. CONCLUSION: We found no linear association between objective cognitive deficit and the affective state of respondents. Patients subjective complaints about cognitive dysfunction were mostly caused by their emotional state than an objective decrease of their cognitive functions. Therefore, in case of subjective complaints on cognitive decline, it is necessary to assess not only the cognitive but also the affective state of the patient. The severity of the COVID-19 course affects the functions of the cognitive sphere, including attention, regulatory functions and speech fluency. Mild and moderate severity of the COVID-19 correlates with clinically determined depression. The absence of this relationship with the severe course of the disease is probably explained by the significant somatic decompensation of patients.

Postcovid Syndrome – The New Reality

The second year of the COVID-19 pandemic has demonstrated the need for detection and assessment of the long-term consequences SARS-CoV-2 infection, including adequate cognitive functioning. This review addresses our current understanding of the direct and indirect mechanisms of nervous system infection in COVID-19, paying special attention to cause-effect relationships between SARS-CoV-2 infection and long-term neuropsychological disorders. Understanding the pathogenesis of neurological impairments in COVID-19 is important for studies of the long-term sequelae of the disease and for identifying preventive and therapeutic possibilities in relation to brain damage. Further studies of nervous system lesions in COVID-19 are clearly needed to expand existing knowledge. Early initiation of therapeutic measures for emerging disorders will probably have decisive importance for improving quality of life for many COVID-19 survivors.

Sleep alterations following COVID-19 are associated with both neuroinflammation and psychological disorders, although at different times

Introduction

By the end of 2019, severe acute respiratory syndrome coronavirus 2 rapidly spread all over the world impacting mental health and sleep habits. Insomnia, impaired sleep quality, and circadian rhythm alterations were all observed during the pandemic, especially among healthcare workers and in patients with acute and post-acute COVID-19. Sleep disruption may induce a pro-inflammatory state associated with an impairment of immune system function.

Objective

We investigated the relationship between sleep alterations, psychological disorders, and inflammatory blood biomarkers in patients with post-acute COVID-19.

Methods

We enrolled 47 subjects diagnosed with COVID-19 pneumonia at Santa Maria della Misericordia University Hospital (Udine, Italy) between March and May 2020. Selected patients were evaluated at 2 months (T1) and 10 months (T2) after discharge. Each time, we collected clinical interviews, neurological examinations, and self-administered questionnaires to assess sleep and life quality, anxiety, depression, and post-traumatic stress disorder. Blood biomarkers of endothelial activation, neuroinflammation, and inflammatory cytokines were also measured at each follow-up. Collected variables were analyzed using comparisons between groups and linear regression models.

Results

Prevalence of insomnia increased from 10.6% up to 27.3% after COVID-19. Poor sleep quality was found in 41.5% of patients at both study visits. At T1 follow-up, poor sleepers showed higher levels of neurofilament light chain, vascular cell adhesion molecule 1, and interleukin 10; no significant associations were found between sleep quality and psychological disorders. At T2 follow-up, lower sleep quality was associated with higher levels of vascular cell adhesion molecule 1 and interleukin 8, but also with higher scores for anxiety, depression, and post-traumatic stress disorder.

Conclusion

Our results suggest an association of poor sleep quality with both psychological disorders and neuroinflammation, although at different times, in previously hospitalized patients with moderate-to-critical COVID-19.

Mechanisms of coronavirus infectious disease 2019-related neurologic diseases

PURPOSE OF REVIEW

As of January 8, 2022, a global pandemic caused by infection with severe acute respiratory syndrome coronavirus (SARS-CoV)-2, a new RNA virus, has resulted in 304,896,785 cases in over 222 countries and regions, with over 5,500,683 deaths (www.worldometers.info/coronavirus/). Reports of neurological and psychiatric symptoms in the context of coronavirus infectious disease 2019 (COVID-19) range from headache, anosmia, and dysgeusia, to depression, fatigue, psychosis, seizures, delirium, suicide, meningitis, encephalitis, inflammatory demyelination, infarction, and acute hemorrhagic necrotizing encephalopathy. Moreover, 30-50% of COVID-19 survivors develop long-lasting neurologic symptoms, including a dysexecutive syndrome, with inattention and disorientation, and/or poor movement coordination. Detection of SARS-CoV-2 RNA within the central nervous system (CNS) of patients is rare, and mechanisms of neurological damage and ongoing neurologic diseases in COVID-19 patients are unknown. However, studies demonstrating viral glycoprotein effects on coagulation and cerebral vasculature, and hypoxia- and cytokine-mediated coagulopathy and CNS immunopathology suggest both virus-specific and neuroimmune responses may be involved. This review explores potential mechanistic insights that could contribute to COVID-19-related neurologic disease.

RECENT FINDINGS

While the development of neurologic diseases during acute COVID-19 is rarely associated with evidence of viral neuroinvasion, new evidence suggests SARS-CoV-2 Spike (S) protein exhibits direct inflammatory and pro-coagulation effects. This, in conjunction with immune dysregulation resulting in cytokine release syndrome (CRS) may result in acute cerebrovascular or neuroinflammatory diseases. Additionally, CRS-mediated loss of blood-brain barrier integrity in specific brain regions may contribute to the expression of proinflammatory mediators by neural cells that may impact brain function long after resolution of acute infection. Importantly, host co-morbid diseases that affect vascular, pulmonary, or CNS function may contribute to the type of neurologic disease triggered by SARS-COV-2 infection.

SUMMARY

Distinct effects of SARS-CoV-2 S protein and CNS compartment- and region-specific responses to CRS may underlie acute and chronic neuroinflammatory diseases associated with COVID-19.

Cognitive impairment in people with previous COVID-19 infection: A scoping review

Severe acute respiratory syndrome coronavirus 2 is a worldwide public health issue. Almost 2 years into the pandemic, the persistence of symptoms after the acute phase is a well-recognized phenomenon. We conducted a scoping review to map cognitive domain impairments, their frequency, and associated psycho-affective disorders in people with a previous COVID-19 infection. We searched PubMed/MEDLINE, Scopus, and PsycInfo to identify relevant reports published between December 1, 2019 and February 21, 2022. We followed the PRISMA (Preferred-Reporting-Items-for-Systematic-Reviews-and-Meta-Analyses) extension for scoping review guidelines. Three independent reviewers selected and charted 25 records out of 922. Memory, attention, and executive functions appeared to be the most affected domains. Delayed recall and learning were the most impaired domains of memory. Among the executive functions, abstraction, inhibition, set shifting, and sustained and selective attention were most commonly impaired. Language and visuo-spatial abilities were rarely affected, although this finding might be biased by the scarcity of reports. Neurological and respiratory conditions were often reported in association with cognitive deficits. Results on psycho-affective conditions were inconclusive due to the low frequency of reported data. Admission to an intensive care unit is not related to cognitive deficits. This review highlighted a potential effect of a previous post-COVID-19 infection on a pattern of memory, attention, and executive functions impairments. These findings need to be confirmed on larger cohorts with comprehensive neuropsychological batteries and correlated to neurophysiological and neurobiological substrates.

Neurological and Psychiatric Symptoms of COVID-19: A Narrative Review

Recently dubbed Long COVID or Long-Haul COVID, those recovering from the initial COVID-19 infection may maintain clinical signs for longer than two or more weeks following the initial onset of the infection. The virus can gain entry into the CNS through axonal transport mediated through the olfactory nerve or hematogenous spread and can also cross the blood–brain barrier to access the temporal lobe and the brainstem. The neurologic and neuropsychiatric symptoms associated with COVID-19 patients are becoming a highly studied area due to the increased frequency of reported cases. Multiple hospital case series and observational studies have found a headache to be a common symptom among patients who are symptomatic with the SARS-CoV-2 virus. The headache described by many of these patients is similar to new daily persistent headache (NDPH). NDPH potentially develops in response to pro-inflammatory cytokines during a persistent systemic or CNS inflammation, mostly due to the initial infection. The treatments investigated were high-dose steroids, tetracycline derivatives, onabotulinum toxin type A, and long-term multidrug regimens. Among the identified symptoms of post-COVID-19 viral illness, fatigue appears to be the most ubiquitous. High-dose vitamin C is currently a suggested therapy proposed for its antioxidant, anti-inflammatory, and immunomodulatory properties. The mental health consequences of this diagnosis are being identified among large portions of COVID-19 survivors. Among these consequences, cases of major depressive disorder (MDD) and anxiety are being reported and closely examined. The aim of this narrative review is to highlight the neurological and psychiatric symptoms that have been associated with Long-Haul COVID and their possible treatments.

Significant cognitive impairment likely associated with COVID-19 infection with relatively nonsevere symptoms

COVID-19 infection may involve the nervous system and has been associated with a number of neuropsychiatric complications, including impairment of cognition and dementia. Such complications are more likely to occur in (but are not limited to) patients with severe COVID-19 infections and those with concomitant risk factors. In this case report, the authors describe a normally functioning 51-year-old woman who developed cognitive impairment of a degree that rendered her unable to care for herself most likely related to a relatively nonsevere infection with COVID-19 about 2 months earlier. A detailed report of her deficits of different areas of cognitive functioning is provided. This report aims to make clinicians more aware of the potential for cognitive impairment in patients who have suffered from COVID-19, including those with infections that were not severe.

Evidence mapping and review of long-COVID and its underlying pathophysiological mechanism

PURPOSE

Apart from the global disease burden of acute COVID-19 disease, the health complications arising after recovery have been recognized as a long-COVID or post-COVID-19 syndrome. Evidences of long-COVID symptoms involving various organ systems are rapidly growing in literature. The objective was to perform a rapid review and evidence mapping of systemic complications and symptoms of long-COVID and underlying pathophysiological mechanisms.

METHODS

Publications reporting clinical trials, observational cohort studies, case-control studies, case-series, meta-analysis, and systematic reviews, focusing on the squeal of the disease, consequences of COVID-19 treatment/hospitalization, long-COVID, chronic COVID syndrome, and post acute COVID-19 were reviewed in detail for the narrative synthesis of frequency, duration, risk factors, and pathophysiology.

RESULTS

The review highlights that pulmonary, neuro-psychological, and cardiovascular complications are major findings in most epidemiological studies. However, dysfunctional gastrointestinal, endocrine, and metabolic health are recent findings for which underlying pathophysiological mechanisms are poorly understood. Analysis of the clinical trial landscape suggests that more than 50% of the industry-sponsored trials are focused on pulmonary symptoms. In contrast to the epidemiological trends and academic trials, cardiovascular complications are not a focus of industry-sponsored trials, suggestive of the gaps in the research efforts.

CONCLUSION

The gap in epidemiological trends and academic trials, particularly concerning cardiovascular complications not being a focus of industry-sponsored trials is suggestive of the gaps in research efforts and longer follow-up durations would help identify other long-COVID-related health issues such as reproductive health and fertility.

[Postcovid syndrome - a new reality]

The second year of the COVID-19 (Coronavirus Disease 2019) pandemic has seen the need to identify and assess the long-term consequences of a SARS-CoV-2 (Severe acute respiratory syndrome coronavirus-2) infection on an individual's, including adequate cognitive functioning. This review is attempting to highlight the current understanding of the various direct and indirect mechanisms of nervous system damage, describing the causality of similar symptoms following SARS-CoV-2 infection. This understanding is essential to establish the long-term consequences from the disease (including the potential for increased risk of dementia in some cases) and to identify means of preventing or ameliorating the brain damage. There is urgent need for research to better understand the pathogenesis of neurological disturbances in COVID-19, some of which have probably been covert and the prevalence of which may be considerably underestimated. Neuropsychiatric monitoring follow-up of COVID-19 patients will be important in determining the extent and prevalence of long-term neurological and psychiatric consequences of COVID-19. Early intervention for emerging these problems will be critical for improving quality of life for many COVID-19 survivors.

Post-acute sequelae of COVID-19: Evidence of mood & cognitive impairment

Acute health consequences associated with coronavirus disease 2019 (COVID-19) infection have been thoroughly characterized; however, long-term impacts are not yet understood. Post-acute sequelae of COVID-19 (PASC), also known as Long COVID syndrome, is the persistence of COVID-19 symptoms long after viral infection. In addition to physical symptoms, those with PASC experience changes in mental health, but few studies have empirically examined these effects. The current study investigated mood and cognitive functioning in individuals who have recovered from COVID-19 infection. We recruited 100 male and female adults (M ​= ​30 years old) with no history of mood or cognitive impairment prior to the COVID-19 pandemic (Jan. 2020). Half of the subjects were healthy controls (i.e., no prior COVID-19 infection) and half had received a past COVID-19 diagnosis (ascertained by PCR or antibody test) but were no longer infectious. Participants completed self-reported measures of stress, depression, and anhedonia, as well as the Attention Network Test (ANT), a behavioural measure of attentional alerting, orienting and executive functioning. Relative to controls, depression and anhedonia were significantly higher in the past-COVID group. Selective impairment in attention was observed in the past-COVID group, marked by deficits in executive functioning while alerting and orienting abilities remained intact. Effects were most pronounced among individuals diagnosed 1-4 months prior to assessment. There were no group differences in pandemic-related experiences with respect to social interaction, social distancing, or isolation. The past-COVID group scored significantly higher on perceived stress; however, this did not moderate any effects observed on mood or cognition. These findings implicate a protracted reaction to the virus, possibly via prolonged inflammation, contributing to sustained mood dysregulation and cognitive impairment. Future research should examine the neural and physiological underpinnings of PASC, particularly mechanisms that promote psychiatric sequelae 1-4 months following diagnosis.

COVID-19 induces neuroinflammation and loss of hippocampal neurogenesis

Infection with the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is associated with onset of neurological and psychiatric symptoms during and after the acute phase of illness 1-4 . Acute SARS-CoV-2 disease (COVID-19) presents with deficits of memory, attention, movement coordination, and mood. The mechanisms of these central nervous system symptoms remain largely unknown.In an established hamster model of intranasal infection with SARS-CoV-2 5 , and patients deceased from COVID-19, we report a lack of viral neuroinvasion despite aberrant BBB permeability, microglial activation, and brain expression of interleukin (IL)-1β and IL-6, especially within the hippocampus and the inferior olivary nucleus of the medulla, when compared with non-COVID control hamsters and humans who died from other infections, cardiovascular disease, uremia or trauma. In the hippocampus dentate gyrus of both COVID-19 hamsters and humans, fewer cells expressed doublecortin, a marker of neuroblasts and immature neurons.Despite absence of viral neurotropism, we find SARS-CoV-2-induced inflammation, and hypoxia in humans, affect brain regions essential for fine motor function, learning, memory, and emotional responses, and result in loss of adult hippocampal neurogenesis. Neuroinflammation could affect cognition and behaviour via disruption of brain vasculature integrity, neurotransmission, and neurogenesis, acute effects that may persist in COVID-19 survivors with long-COVID symptoms.

Neuropsychological and psychological dysfunctions associated with coronavirus disease 2019: a case report

Background

Patient’s account of personal experiences of having lived through coronavirus disease 2019 is important for understanding the magnitude of the debilitating impact of the infection. There is increasing recognition that the infection impedes multiple functional domains, but to date the evidence remains scarce. Moreover, to the author’s knowledge, there are no documented cases reporting on research data derived from self-reflective first-person experience.

Case presentation

The patient was a 59-year-old female psychologist of White self-ascribed ethnicity who had coronavirus disease 2019. She had no history of medical, neurological, or psychiatric conditions and works in a neurosurgery clinic at a large hospital as a psychologist, specializing in neuropsychology. Using the introspective method, she captured the occurrence of neuropsychological and psychological dysfunctions she experienced in the acute stage of the illness, which took place in December 2020 and lasted for 17 days. Treatment of coronavirus disease 2019 was conducted in the home environment under medical supervision and followed a standardized protocol adopted at the time in the country.

Conclusions

The data derived from the first-person experience indicated that among the most salient cognitive functions impacted by the disease were: executive control, working memory, attention, concentration, and processing speed.

Furthermore, emotional instability; mood swings; racing, repetitive, or intrusive thoughts; uncontrolled associations; dizziness; fatigue; disbalance; and sleep disturbances featured consistently throughout the illness. The overall profile of these dysfunctions suggests disruption in the overall operation of the brain and particularly in the functioning of the frontal lobes. Although less tangible than the physical symptoms, the neuropsychological and psychological dysfunctions associated with coronavirus disease 2019 form a distinct cluster that has a highly debilitating impact on a person’s well-being.

Dementia and COVID-19, a Bidirectional Liaison: Risk Factors, Biomarkers, and Optimal Health Care

Cognitive impairment following SARS-CoV-2 infection is being increasingly recognized as an acute and possibly also long-term sequela of the disease. Direct viral entry as well as systemic mechanisms such as cytokine storm are thought to contribute to neuroinflammation in these patients. Biomarkers of COVID-19-induced cognitive impairment are currently lacking, but there is some limited evidence that SARS-CoV-2 could preferentially target the frontal lobes, as suggested by behavioral and dysexecutive symptoms, fronto-temporal hypoperfusion on MRI, EEG slowing in frontal regions, and frontal hypometabolism on 18F-FDG-PET. Possible confounders include cognitive impairment due to hypoxia and mechanical ventilation and post-traumatic stress disorder. Conversely, patients already suffering from dementia, as well as their caregivers, have been greatly impacted by the disruption of their care caused by COVID-19. Patients with dementia have experienced worsening of cognitive, behavioral, and psychological symptoms, and the rate of COVID-19-related deaths is disproportionately high among cognitively impaired people. Multiple factors, such as difficulties in remembering and executing safeguarding procedures, age, comorbidities, residing in care homes, and poorer access to hospital standard of care play a role in the increased morbidity and mortality. Non-pharmacological interventions and new technologies have shown a potential for the management of patients with dementia, and for the support of their caregivers.

SARS-CoV-2 and the Brain: What Do We Know about the Causality of 'Cognitive COVID?

The second year of the COVID-19 (coronavirus disease) pandemic has seen the need to identify and assess the long-term consequences of a SARS-CoV-2 infection on an individual's overall wellbeing, including adequate cognitive functioning. 'Cognitive COVID' is an informal term coined to interchangeably refer to acute changes in cognition during COVID-19 and/or cognitive sequelae with various deficits following the infection. These may manifest as altered levels of consciousness, encephalopathy-like symptoms, delirium, and loss of various memory domains. Dysexecutive syndrome is a peculiar manifestation of 'Cognitive COVID' as well. In the previous major outbreaks of viruses like SARS-CoV, MERS-CoV and Influenza. There have been attempts to understand the underlying mechanisms describing the causality of similar symptoms following SARS-CoV-2 infection. This review, therefore, is attempting to highlight the current understanding of the various direct and indirect mechanisms, focusing on the role of neurotropism of SARS-CoV-2, the general pro-inflammatory state, and the pandemic-associated psychosocial stressors in the causality of 'Cognitive COVID.' Neurotropism is associated with various mechanisms including retrograde neuronal transmission via olfactory pathway, a general hematogenous spread, and the virus using immune cells as vectors. The high amounts of inflammation caused by COVID-19, compounded with potential intubation, are associated with a deleterious effect on the cognition as well. Finally, the pandemic's unique psychosocial impact has raised alarm due to its possible effect on cognition. Furthermore, with surfacing reports of post-COVID-vaccination cognitive impairments after vaccines containing mRNA encoding for spike glycoprotein of SARS-CoV-2, we hypothesize their causality and ways to mitigate the risk. The potential impact on the quality of life of an individual and the fact that even a minor proportion of COVID-19 cases developing cognitive impairment could be a significant burden on already overwhelmed healthcare systems across the world make it vital to gather further evidence regarding the prevalence, presentation, correlations, and causality of these events and reevaluate our approach to accommodate early identification, management, and rehabilitation of patients exhibiting cognitive symptoms.

Impact of SARS-CoV-2 on neuropsychiatric disorders

Evolving data show a variable expression of clinical neurological manifestations in patients suffering with coronavirus disease 2019 (COVID-19) from early disease onset. The most frequent symptoms and signs are fatigue, dizziness, impaired consciousness, ageusia, anosmia, radicular pain, and headache, as well as others. Based on the high number of series of cases reported, there is evidence for the implication of the immune system in the pathological mechanism of COVID-19. Although the exact role of the immunological mechanism is not elucidated, two main mechanisms are suggested which implicate the direct effect of severe acute respiratory syndrome coronavirus 2 infection in the central nervous system and neuroinflammation. In the context of neurological manifestations associated with COVID-19, neuropsychiatric disorders show an exacerbation and are described by symptoms and signs such as depression, anxiety, mood alterations, psychosis, post-traumatic stress disorder, delirium, and cognitive impairment, which appear to be common in COVID-19 survivors. A worsened score on psychopathological measures is seen in those with a history of psychiatric comorbidities. We review the neuropsychiatric manifestations associated with COVID-19 and some critical aspects of the innate and adaptive immune system involved in mental health disorders occurring in COVID-19.

Implications of the COVID-19 Pandemic on the Mental Health and Professional Psychomotor Skills of Dental Students

Purpose

To estimate dental students’ self-perception of mental well-being (MWB) and its effects on their clinical psychomotor skills (CPS) once they (or their family members) get infected with COVID-19.

Materials and Methods

This is a cross-sectional (n =268) study from a public dental college in Riyadh. We collected data on MWB and CPS. An 18-item online survey was used to collect the responses from the participants. The inter-rater reliability for the finalised survey came out to be 0.86.

Results

The participants (54.3%) who were infected with COVID-19 recorded that their CPS were significantly affected (almost 4 times higher) as compared to others (OR= 4.02; P=0.0004). However, 42.2% reported infection control measures at clinics resulted in bringing significant (OR=2.22, P=0.04) psychological upsets, for those who were infected with COVID-19. Participants (45.1%) also reported that they have difficulty in recalling old memories or information due to the COVID-19 pandemic; among them, 46.7% were the ones who (and/or any family member) were exposed to COVID-19.

Conclusion

The study spotlighted the extent of dental students’ MWB and its significant effect on their CPS once (themselves or a family member) infected with COVID-19. Moreover, levels of infection control measures at clinics resulted in psychological upsets for dental students.

Clinical Significance

The issue is fundamental as participants enter the clinical workforce and face the ever-increasing demands of dental practice.

Neuropsychological Pattern in a Series of Post-Acute COVID-19 Patients in a Rehabilitation Unit: Retrospective Analysis and Correlation with Functional Outcomes

Intensive Care Unit delirium, insomnia, anxiety, and frontal/dysexecutive disorders have been described following COVID-19 infection. The aim of this case study was to re-evaluate the neuropsychological pattern in a series of patients with COVID-19 outcomes. We retrospectively evaluated 294 patients admitted to the Istituti Clinici Scientifici Maugeri of Lumezzane (Brescia) (May-September 2020). Neuropsychological assessment was available for 12 patients. We extracted clinical, functional data (FIM and Barthel Index score) and neuropsychological tests (MMSE, Trail making a-b, verbal fluency test, digit span, prose memory test, Frontal Assessment Battery, clock drawing test, Rey-Osterrieth complex figure, Tower of London test). The results were analyzed by Spearman (rho) correlation. Six patients presented dysexecutive alterations even in the presence of normal overall cognitive functioning. Forward digit span score was directly correlated to FIM value at admission (p = 0.015) and inversely correlated to delta FIM (p = 0.030) and delta Barthel Index (p = 0.025). In our experience, subclinical cognitive alterations were present in 4% of patients recovering from COVID-19 pneumonia. The possible correlation between verbal memory and frontal functions, and the degree of functional impairment at admission and its subsequent improvement, underscores the importance of an adequate cognitive evaluation and rehabilitation.

Cognitive assessment in asymptomatic COVID-19 subjects

Neurological features of COVID-19 have been reported in addition to the respiratory manifestations, but cognitive dysfunction has been scarcely described. And cognitive assessment has not been studied in asymptomatic subjects. We compared the cognitive assessment scores between asymptomatic SARS-CoV-2 infected subjects with that of controls to detect mild cognitive impairment by the Montreal Cognitive Assessment test. Asymptomatic COVID-19 subjects secured lower scores in certain domains of the MoCA in comparison with the controls. The domains were visuoperception (2.4 ± 0.7 vs2.8 ± 0.7, p = 0.032), naming (3.6 ± 0.5 vs3.9 ± 0.2, p = 0.016) and fluency (0.9 ± 0.6 vs1.6 ± 0.7, p =  < 0.001). Also, older aged COVID-19 positive subjects scored lower in the MoCA when compared to the younger people. Our study shows that even otherwise asymptomatic COVID-19 subjects have cognitive deficits in certain subdomains and suggests the need for a detailed psychometric assessment especially in the elderly population.

SUPPLEMENTARY INFORMATION

The online version of this article (10.1007/s13337-021-00663-w).

Neurological symptoms, manifestations, and complications associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and coronavirus disease 19 (COVID-19)

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus, is responsible for the outbreak of coronavirus disease 19 (COVID-19) and was first identified in Wuhan, China in December 2019. It is evident that the COVID-19 pandemic has become a challenging world issue. Although most COVID-19 patients primarily develop respiratory symptoms, an increasing number of neurological symptoms and manifestations associated with COVID-19 have been observed. In this narrative review, we elaborate on proposed neurotropic mechanisms and various neurological symptoms, manifestations, and complications of COVID-19 reported in the present literature. For this purpose, a review of all current published literature (studies, case reports, case series, reviews, editorials, and other articles) was conducted and neurological sequelae of COVID-19 were summarized. Essential and common neurological symptoms including gustatory and olfactory dysfunctions, myalgia, headache, altered mental status, confusion, delirium, and dizziness are presented separately in sections. Moreover, neurological manifestations and complications that are of great concern such as stroke, cerebral (sinus) venous thrombosis, seizures, meningoencephalitis, Guillain-Barré syndrome, Miller Fisher syndrome, acute myelitis, and posterior reversible encephalopathy syndrome (PRES) are also addressed systematically. Future studies that examine the impact of neurological symptoms and manifestations on the course of the disease are needed to further clarify and assess the link between neurological complications and the clinical outcome of patients with COVID-19. To limit long-term consequences, it is crucial that healthcare professionals can early detect possible neurological symptoms and are well versed in the increasingly common neurological manifestations and complications of COVID-19.