Neuropsychological deficits in patients with cognitive complaints after COVID-19

Cognitive Slowing, Dysfunction in Verbal Working Memory, Divided Attention and Response Inhibition in Post COVID-19 Condition in Young Adults

After COVID-19 infection, about 30% of people have clinically persisting symptoms, characterized as Post COVID-19 Condition (PCC). One of the most reported symptoms in PCC is cognitive dysfunction, yet there are only a few studies investigating long-term effects on different domains of cognitive function. A total of 107 young adults, university students aged 18-34 years, participated. In total, 68.2% had contracted SARS-CoV-2; 21.9% showed PCC. Three groups were compared: no-C19 (COVID-19-negative controls), C19 (COVID-19-recovered without PCC) and PCC. Attention and executive function were measured with the Vienna Test System (Schuhfried®, Mödling, Austria). In verbal working memory, the PCC group had a significantly lower performance with a moderate effect. The rate of below-average performance was higher in PCC (56.2%) compared to no-C19 (20.6%) and C19 (15.8%). In divided attention and response inhibition, PCC also showed lower performance, 62.5% and 37.5%, respectively, than no-C19 and C19. The co-occurrence of decreased cognitive functions was pronounced in PCC. The present study revealed significant long-lasting cognitive dysfunction in PCC in young adults, two years after COVID-19 infection. Verbal working memory was significantly impaired, and a lower performance was found in divided attention and response inhibition. In addition, there was an increased reaction time in most cognitive tasks, demonstrating cognitive slowing in young people with PCC.

Variables associated with cognitive alterations in a cohort of COVID-19 survivors at a third-level hospital in Mexico

BACKGROUND

Cognitive impairments are one of the most common, insidious, and disabling symptoms of post-COVID-19 syndrome (PC-19), which have been correlated with damage to different brain structures.

OBJECTIVE

To describe cognitive impairments in PC-19, identify associated variables, and compare the impact of mechanical ventilation on cognitive and neuroimaging outcomes.

METHODS

A cohort of COVID-19 survivors was evaluated with neuropsychological tests (NPT) and cranial magnetic resonance imaging (MRI) 12 weeks after hospital discharge. Patients were classified into two groups based on whether they required invasive mechanical ventilation (IMV) or non-invasive mechanical ventilation (NIMV).

RESULTS

60 patients completed the study, 41 received IMV and 19 NIMV, with an average age of 57.11 years. 66% scored below 26 points on the MoCA test and 83.3% reported everyday memory failures (EMF). 85% showed impairments in at least one NPT. When comparing results between groups, significant differences were observed in the total MoCA test score (p = 0.045) and EMF (p = 0.032). Significant relationships were observed between the Boston Naming Test (-0.287; p = 0.035), the Rey Figure Recall Test (-0.324; p = 0.017) with parietal atrophy, as well as phonological verbal fluency with frontal atrophy (-0.276; p = 0.042). The HVLT (learning trial) test was related to hippocampal hyperintensity (-0.266; p = 0.050) and cingulate hyperintensity (0.311; p = 0.021). The TMT-B test was related to white matter hyperintensity (0.345; p = 0.010). The presence of poor functional prognosis was correlated with anxiety (p < 0.001), depression (p < 0.001), elevated D-dimer levels (p = 0.002) and the increase in days of intubation (p = 0.005).

CONCLUSION

Our study suggests that COVID-19 survivors who had moderate-to-severe infection experience subjective complaints and cognitive impairments in executive function, attention, and memory, regardless of whether invasive mechanical ventilation was used during treatment. We found white matter lesions and cerebral atrophy in frontal and parietal regions that were associated with cognitive deficits. Our findings highlight the clinical need for longitudinal programmes capable of evaluating the real impact of SARS-CoV-2 infection on the central nervous system, particularly in the cognitive and emotional domains.

Persistent neuropsychological deficits in recovered COVID-19 patients: Correlations with disease biomarkers

OBJECTIVE

Cognitive impairment, including deficits in attention, memory, executive function, and processing speed, is common in post-COVID-19 conditions, though language performance remains less studied. The present study examined the long-term effects of COVID-19 condition on cognition and language - communication, and its associations with disease severity, Body Mass Index (BMI), inflammatory markers, and quality of life.

METHOD

Nighty eight Greek participants under 65 years of age were recruited for this study. Forty-seven participants were allocated in the COVID-19 group and 51 served as cognitively healthy controls. The COVID-19 group was categorized by disease severity and long COVID status. Assessments occurred 12 weeks post-infection, with 12 patients reevaluated after another 12 weeks. Neurocognitive tests included ABCD-II, verbal fluency, CCT, SDMT, and Euro QoL EQ-5D. Blood samples were analyzed for inflammatory markers.

RESULTS

Covid-19 survivors experienced significant cognitive deficits compared to healthy controls, particularly in processing speed, memory, and verbal fluency. Long COVID patients showed notably lower scores in processing speed and QoL, compared to those without Long COVID. However, no significant differences were observed between groups on episodic memory and executive functions tasks. Cognitive deficits were associated with biomarkers such as d-dimers and C-Reactive protein, with elevated d-dimers linked to poorer performance on generative drawing and cognitive flexibility. Higher education served as a protective factor, and was associated with higher scores in tasks such as story retelling, confrontation naming, generative drawing and reading comprehension. Older age and higher Body Mass Index were associated with poorer cognitive performance, especially on processing speed. Sex appears to influence language comprehension outcomes, with males exhibiting enhanced performance on the reading comprehension-sentence task. Disease severity negatively affected performance on the Symbol Digit Modalities Test and generative naming, indicating that greater severity was linked to poorer outcomes in these domains. Follow-up evaluations of recovered COVID-19 patients revealed significant improvements in processing speed and recall, suggesting partial recovery in these areas, although some deficits persisted over time.

CONCLUSION

The study supports findings that the prolonged effects of COVID-19 markedly impaired neurocognitive functions in recovering patients, especially those with severe or long COVID syndrome. Moreover, while several cognitive domains may improve over time, many other domains remain impaired and vulnerable.

Long-term cognitive functioning following COVID-19: Negligible neuropsychological changes over time

Objective: Objective cognitive impairment has been shown in a minority of hospitalized COVID-19 patients, and longitudinal studies with a relatively long follow-up duration are scarce. We sought to investigate the presence and long-term change of objective cognitive functioning. Method: Forty-six initially hospitalized (18 ± 19 days) COVID-19 survivors (male/female: 30/16; age: 61 ± 11) underwent extensive neuropsychological assessment (including performance validity) approximately 1 (T1) and 2.5 years (T2) post-infection. Cognitive domains assessed were: memory, attention, executive functioning, processing speed, and language (n = 14 (sub)tests). We used normative data to derive age, sex, and education-adjusted T-scores (T ≤ 35 [≤-1.5SD], deficit cut-off). Repeated measures AN(C)OVAs were used to investigate cognitive functioning over time. Results: Mean neuropsychological performance (n = 14 tests) was within normal range at both timepoints, and number of individuals with objective cognitive deficits ranged from 0-20% (T1), and 2-22% (T2). Number of subjective cognitive complaints remained unchanged. A minority (17%) showed objective cognitive deficits on ≥2 tests at both 1 and 2.5 years post-infection, but not consistently within one cognitive domain. Longitudinal analyses on the total sample showed improvement in performance over time on phonemic fluency (p<.001), but stable cognitive performance on all other tests, independent of prior comorbidities, subjective cognitive complaints, depressive symptoms, and ICU admission. Conclusions: There were no consistent objective cognitive deficits or major cognitive disorders years after SARS-CoV-2 infection in the majority of cases. Neuropsychological functioning remained essentially unchanged over time. Future larger longitudinal studies are necessary to unravel COVID-19-related cognitive phenotypes of persisting deficits and how these can be modulated.

Post-COVID-Syndrome Patients Might Overestimate Own Cognitive Impairment

BACKGROUND

After a COVID-19 infection, some patients experience long-term consequences known as Post-Covid Syndrome, which often includes cognitive impairment. We investigated the congruence between subjectively experienced and objectively measured cognitive deficits after a COVID-19 infection in an unselected, successively admitted cohort of 46 patients reporting subjective cognitive complaints (SCC).

METHODS

We employed a comprehensive neuropsychological test battery to assess objective cognitive impairment across various cognitive domains. Three different cut-off criteria were applied, commonly used in the literature to define objective neurocognitive disorder (NCD).

RESULTS

We observed a notably low congruence between SCC and NCD in Post-Covid Syndrome, regardless of the cut-off criterion. Depending on the cognitive domain, only 4% to maximally 40% of the SCC could be objectified.

CONCLUSIONS

One possible explanation for this discrepancy could be the high rate of depressive symptoms observed in the group of patients studied, which may negatively influence the perception of one's cognitive abilities. These findings emphasize the need for careful evaluation of SCC in Post-Covid Syndrome and suggest that treating depressive symptoms may also alleviate some of the perceived cognitive deficits.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Can Personality Traits Affect Sleep Quality in Post-COVID-19 Patients?

Objectives: In the present study, we aimed (i) to describe the personality traits of a cohort of post-COVID-19 condition (PCC) patients compared with a healthy control (HC) group, (ii) to evaluate the relationship between sleep quality and personality traits, and (iii) to investigate whether this relationship differs according to disease severity. Methods: We included 599 participants from the Nautilus Project (ClincalTrials.gov IDs: NCT05307549 and NCT05307575) with an age range from 20 to 65 years old. Of 599 participants, 280 were nonhospitalized (mild PCC), 87 were hospitalized (hospitalized PCC), 98 were in the PCC-ICU, and 134 were in the HC group. We assessed sleep quality with the Pittsburgh Sleep Quality Index (PSQI) and personality traits with the NEO Five-Factor Inventory (NEO FFI). Results: We found that mild-PCC patients had higher scores of neuroticism than HCs (p < 0.001) and ICU-PCC patients did (p = 0.020). The higher the neuroticism score was, the higher the total PSQI score (B 0.162; p < 0.001), the worse the sleep latency (B 0.049; p < 0.001), the greater the degree of sleep disturbance (B 0.060; p < 0.001), the greater the use of sleeping medication (B 0.035; p = 0.033), and the greater the incidence of daytime disturbances (B 0.065; p < 0.001) among the PCC patients. High neuroticism is also an indicator of worse sleep quality in mild-PCC (t = 3.269; p 0.001) and hospitalized-PCC (t = 6.401; p < 0.001) patients and HCs (t = 4.876; p < 0.001) but not in ICU-PCC patients. Conclusions: Although neuroticism affected sleep quality in both the PCC patients and HCs, the clinical implications and magnitude of the relationship were more significant in the PCC group. Specific and multidimensional interventions are needed to treat sleep problems in this population, and the influence of their personality traits should be considered.

Neuropsychiatric Manifestations of Long COVID-19: A Narrative Review of Clinical Aspects and Therapeutic Approaches

The COVID-19 (C-19) pandemic has highlighted the significance of understanding the long-term effects of this disease on the quality of life of those infected. Long COVID-19 (L-C19) presents as persistent symptoms that continue beyond the main illness period, usually lasting weeks to years. One of the lesser-known but significant aspects of L-C19 is its impact on neuropsychiatric manifestations, which can have a profound effect on an individual's quality of life. Research shows that L-C19 creates neuropsychiatric issues such as mental fog, emotional problems, and brain disease symptoms, along with sleep changes, extreme fatigue, severe head pain, tremors with seizures, and pain in nerves. People with cognitive problems plus fatigue and mood disorders experience great difficulty handling everyday activities, personal hygiene, and social interactions. Neuropsychiatric symptoms make people withdraw from social activity and hurt relationships, thus causing feelings of loneliness. The unpredictable state of L-C19 generates heavy psychological pressure through emotional suffering, including depression and anxiety. Neuropsychiatric changes such as cognitive impairment, fatigue, and mood swings make it hard for people to work or study effectively, which decreases their output at school or work and lowers their job contentment. The purpose of this narrative review is to summarize the clinical data present in the literature regarding the neuropsychiatric manifestations of L-C19, to identify current methods of diagnosis and treatment that lead to correct management of the condition, and to highlight the impact of these manifestations on patients' quality of life.

Cardiopulmonary rehabilitation's influence on cognitive functions, psychological state, and sleep quality in long COVID-19 patients: A randomized controlled trial

BACKGROUND

Cognitive impairment, brain fog, depressive symptoms, and sleep disturbance are prevalent symptoms among individuals with long COVID, for which there currently is no treatment.

AIM

To assess the effectiveness of an eight-week cardiopulmonary rehabilitation programme on cognition, psychological well-being, and sleep quality in individuals with long COVID-19.

METHODS

Forty participants diagnosed with long COVID-19 (26 female, 14 male participants; mean age 53 ± 11 years) were randomly assigned to a rehabilitation group or to a control group. The control group maintained their regular daily habits, while the rehabilitation group was prescribed an individualized clinical programme consisting of three sessions per week. Each session involved light to moderate aerobic exercise, resistance training, and respiratory exercises. Neuropsychological tests evaluating executive function, memory, and processing speed were administered at baseline and at study completion. Participants also completed questionnaires on their psychological state and sleep quality at both time points.

RESULTS

No difference between groups was observed for neuropsychological test performance, however significant group differences in perceived stress and depression were found post-intervention.

CONCLUSION

Cardiopulmonary rehabilitation was shown to be effective in individuals suffering from long COVID in terms of decreasing perceived stress and depression levels but not for neuropsychological test performance.ClinicalTrials.gov: NCT05035628.Trial registration: ClinicalTrials.gov identifier: NCT05035628..

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.

Executive function deficit in patients with long COVID syndrome: A systematic review

Background

Post-COVID-19 condition (Long COVID) refers to a condition in which patients endure persistent symptoms for more than 12 weeks, typically occurring at least 3 months after the onset of Coronavirus disease 2019 (COVID-19) infection. It occurs when a constellation of symptoms persists following the initial illness, and this may obstruct a daily routine and impose difficulty in life. Therefore, this study aimed to systematically review published articles assessing the neurocognitive profile of long COVID patients, with a specific emphasis on executive function (EF), and to determine the correlation between EF deficits and brain alterations through the utilisation of neuroimaging modalities.

Methods

A thorough search was conducted using the PubMed/MEDLINE and Web of Science online databases following the PICOS and PRISMA 2020 guidelines. All included studies were deemed to be of high quality according to the Newcastle-Ottawa Scale (NOS).

Results

A total of 31 out of 3268 articles were included in the present study. The main outcome is the proportion of individuals with cognitive deficits, particularly in the EF domain, as detected by neuropsychological assessments. The present study also revealed that EF deficits in long COVID patients are correlated with disruptions in the frontal and cerebellar regions, affecting processes such as nonverbal reasoning, executive aspects of language, and recall. This consistent disturbance also emphasised the correlation between EF deficits and brain alterations in patients with long COVID.

Conclusion

The present study highlights the importance of evaluating EF deficits in long COVID patients. This insight has the potential to improve future treatments and interventions.

Cognition and objective sleep quality in post-COVID-19 patients

In the current study, we aimed (i) to evaluate sleep quality via wrist actigraphy monitoring of nonhospitalized and hospitalized post-COVID-19 condition (PCC) participants; (ii) to correlate actigraphy measures with subjective measures of sleep quality, such as the Pittsburgh Sleep Quality Index (PSQI); and (iii) to investigate whether total sleep time or sleep efficiency could affect PCC cognitive performance. We included 49 individuals with PCC from the NAUTILUS Project (NCT05307549 and NCT05307575) who were monitored for 1 week via actigraphy and who were also assessed with a comprehensive neuropsychological battery and the PSQI. We found that there were significant differences between nonhospitalized PCCs and hospitalized PCCs in the number of awakenings. We also found a correlation between the total sleep time of both measures (actigraphy and PSQI), but we did not observe correlations between objective and subjective parameters of latency and sleep efficiency. Regarding cognition and actigraphy measures, there was a trend of statistical significance in the performance of immediate visual memory, attention span and social cognition according to sleep efficiency. In conclusion, results indicate that although the PSQI provides clinically relevant indicators of sleep, there are divergent results between self-reported and objective sleep measures (actigraphy). Furthermore, we found a tendency toward statistical significance in cognitive performance in PCC participants according to their sleep efficiency which could indicate that is more important for cognitive function of post-COVID-19 patients than total sleep time.

Factors Associated with Cognitive Impairment in Patients with Persisting Sequelae of COVID-19

OBJECTIVE

Quantify cognitive deficits in patients with postacute sequelae of COVID-19 (PASC) and identify key variables related to cognitive impairment in PASC.

METHOD

Patients with polymerase chain reaction-confirmed COVID-19 underwent a comprehensive neuropsychological evaluation. The comparison group included patients without neurological disorders determined by the neuropsychologist to be cognitively intact. Cognitive impairment was defined as impairment (Composite T ≤35) in 1 of 6 cognitive domains. The PASC group was split into impaired or intact based on the above criteria. Multivariable logistic regression models assessed predictors including demographics, COVID-19 severity, clinical characteristics, and mood.

RESULTS

There were 210 patients with PASC, predominantly female (73.3%, P < .001), without other demographic differences when compared with 369 normal controls. Patients with PASC were more likely to have cognitive impairment (odds ratio 3.61; 95% confidence interval, 2.36-5.54; P < .001) compared with controls, with significantly lower scores in domains of memory, language, processing speed, visuospatial function, executive function (P < .001), and higher depressive (P = .004) and anxiety symptoms (P = .003). Patients with PASC who demonstrated cognitive impairment (n = 93) had higher body mass index compared with those with PASC without cognitive impairment (n = 117), without differences in other predictors.

CONCLUSION

Patients with PASC are almost 4 times more likely to evidence cognitive dysfunction compared with normal controls. Forty-four percent of patients with PASC demonstrated cognitive deficits about 7 months from infection. Estimated premorbid intelligence significantly correlated with impairment. Higher body mass index was the only metric shown to differentiate those with PASC and cognitive impairment from those with PASC who were cognitively intact.

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.

Executive functioning in subjects post COVID-19 infection in Mexico

Over the past three years, conflicting evidence has emerged regarding the impact of COVID-19 on executive functions and the frontal lobe. In this study, we evaluated executive functions in individuals from the state of Jalisco who had contracted COVID-19. Sixty individuals with a history of mild COVID-19 were included and compared to historical controls from the Mexican population, who had been assessed prior to the pandemic during the validation of the Trail Making Test Form B, the Stroop Color and Word Test, and the Modified Wisconsin Card Sorting Test (M-WCST). The post-infection group exhibited lower scores only on the M-WCST. Therefore, we concluded that individuals who have recovered from mild COVID-19 do not display widespread impairments in executive functions, with the exception of deficits observed on the M-WCST. This suggests possible neurophysiological alterations in the prefrontal cortex during SARS-CoV-2 infection, given that cognitive flexibility is primarily mediated in this region. These findings contribute to the growing body of evidence indicating that even non-hospitalized COVID-19 patients can experience executive function deficits, providing a foundation for further neurophysiological research into the mechanisms underlying this phenomenon.

Comprehensive neuropsychological assessment and predictors of cognitive functioning at six months after COVID-19 in patients treated in the ICU, regular hospital ward, or isolated at home

Cognitive impairment in patients with COVID-19 has been reported, but findings are inconsistent. This study assessed cognitive functioning 6 months post-infection across three COVID-19 severity groups compared to non-COVID controls. Seventy-two ICU-treated, 49 ward-treated, and 44 home-isolated patients with COVID-19, along with 48 controls, underwent neuropsychological evaluation and assessment of subjective cognitive symptoms, depressive symptoms, and fatigue. Cognitive test scores were compared using ANCOVA. Associations between cognitive functioning and variables including demographics, illness severity, comorbidities, depressive symptoms, fatigue, and ICU-related factors were examined with hierarchical linear regression models. Results showed no significant differences in cognitive test performance of impairment frequencies between COVID-19 groups and controls. However, patients with COVID-19 reported higher levels of subjective cognitive symptoms, depressive symptoms, and fatigue compared to controls. Predictors of cognitive functioning included age, education, and, to a lesser extent, comorbidities. COVID-19 severity, depression, fatigue, or ICU-related variables did not significantly impact performance. These findings suggest that while individual cognitive impairments may exist, overall cognitive functioning in patients with COVID-19 was comparable to controls.

Neurocognitive Impairment in Long COVID: A Systematic Review

OBJECTIVE

Although Coronavirus disease 2019 (COVID-19) is primarily a respiratory infectious disease, it has also been associated with a wide range of other clinical manifestations. It is widely accepted in the scientific community that many patients after recovery continue to experience COVID-19-related symptoms, including cognitive impairment. The aim of this systematic review was to investigate the cognitive profile of patients with long-COVID syndrome.

METHODS

A systematic search of empirical studies was conducted through the PubMed/Medline and Scopus electronic databases. Cross-sectional and longitudinal studies published between 2020 and 2023 were included.

RESULTS

Of the 516 studies assessed for eligibility, 36 studies met the inclusion criteria. All included studies support the presence of persistent cognitive changes after COVID-19 disease. Executive function, memory, attention, and processing speed appear to be the cognitive domains that are predominantly associated with long-COVID syndrome, whereas language is an area that has not been sufficiently investigated.

CONCLUSIONS

In this review, the high frequency of cognitive impairment after COVID-19 is evident. If we consider that cognitive functioning affects our ability to live independently and is a key determinant of our quality of life, it is imperative to precisely define those factors that may induce cognitive impairment in COVID-19 survivors, with the ultimate goal of early diagnosis of cognitive changes and, consequently, the development of targeted rehabilitation interventions to address them.

Neuropsychological outcome of indoor rehabilitation in post-COVID-19 condition-results of the PoCoRe study

Background

Post COVID-19 condition (PCC) is increasingly recognized as a debilitating condition characterized by persistent symptoms following SARS-CoV-2 infection. Neuropsychological deficits, including cognitive impairments and fatigue, are prevalent in individuals with PCC. The PoCoRe study aimed to evaluate the burden of neuropsychological deficits in PCC patients undergoing multidisciplinary indoor rehabilitation and to describe possible changes in this symptomatology.

Methods

The PoCoRe study, a prospective, non-randomized, controlled longitudinal study, recruited PCC patients from six German indoor rehabilitation centers. Eligible participants underwent comprehensive neuropsychological assessments at admission and discharge. Various measures were employed, including the fatigue scale for motor functioning and cognition (FSMC), the Test Battery for Attention (TAP) and the Montreal Cognitive Assessment (MoCA).

Results

Out of the 1,086 recruited participants, a total of N = 701 participants were included in the main data analysis. The prevalence of fatigue on admission was high (84.6%) and decreased significantly by discharge (77.4%), with a mild effect size. Reaction times on the alertness subtest were abnormal in 70% of patients on admission and 50% on discharge. Sustained attention was abnormal in 55% of patients on admission, decreasing to 43% on discharge. These differences were significant with mild effect sizes. Furthermore, of the 27% of participants with pathological MoCA scores at admission, 63% improved to normative levels during rehabilitation, indicating a significant treatment effect (p ≤ 0.001). However, the MoCA demonstrated limited sensitivity in detecting attention deficits.

Conclusion

The PoCoRe study highlights the high prevalence of neuropsychological deficits and fatigue in PCC patients, with notable improvements observed following multidisciplinary rehabilitation. Challenges remain in accurately identifying and addressing these deficits, underscoring the importance of comprehensive neuropsychological assessment and tailored rehabilitation interventions. Further research is warranted to optimize screening tools and enhance neuropsychological care for PCC patients in both rehabilitation and outpatient settings.

The neuropsychological impacts of coronavirus disease 2019 in nonhospitalized patients with long coronavirus disease and brain fog

BACKGROUND

Coronavirus disease 2019 (COVID-19) causes persistent symptoms, including brain fog. Based on limited research on the long-term consequences of mild COVID-19, which has yielded inconsistent results, we investigated which cognitive functions were most affected by COVID-19 in nonhospitalized Asian patients with long-term COVID and subjective cognitive complaints.

METHODS

Fifty-five nonhospitalized patients with subjective cognitive complaints after COVID infection (24 males and 31 females, mean age: 45.6 ± 14.6 years, mean duration of education: 14.4 ± 3.0 years) finished the study. Neuropsychological assessments included screening tests for overall cognition, and comprehensive tests for memory, executive function, processing speed, and subjective emotional and disease symptoms. Cognitive test scores were converted into Z -scores. Moreover, principal component analysis (PCA) was used to define cognitive domains across subtest scores.

RESULTS

Comprehensive assessments revealed cognitive impairment in 69.1% of patients (<1.5 SD in at least one test). The processing speed (27.3%), memory recall (21.8%), memory learning (20.0%), and inhibitory control (18.2%) were the most affected areas. Self-reported anxiety and depression were observed in 35% and 33% of patients, respectively. Furthermore, the degree of anxiety was predictive of learning performance.

CONCLUSION

Nearly 70% of patients with subjective cognitive complaints and long COVID had objective cognitive impairments. A comprehensive evaluation is essential for these patients, even when they present with mild symptoms.

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

BACKGROUND AND PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Neuropsychiatric Manifestations of COVID-19 Disease and Post COVID Syndrome: The Role of N-acetylcysteine and Acetyl-L-carnitine

COVID-19 is associated with neuropsychiatric symptoms, such as anosmia, anxiety, depression, stress-related reactions, and psychoses. The illness can cause persistent cognitive impairment and "brain fog", suggesting chronic brain involvement. Clinical entities of ongoing symptomatic COVID-19 and Post COVID Syndrome (PCS) mainly present neuropsychiatric symptoms such as dysgeusia, headache, fatigue, anxiety, depression, sleep disturbances, and post-traumatic stress disorder. The pathophysiology of COVID-19-related brain damage is unclear, but it is linked to various mechanisms such as inflammation, oxidative stress, immune dysregulation, impaired glutamate homeostasis, glial and glymphatic damage, and hippocampal degeneration. Noteworthy is that the metabotropic receptor mGluR2 was discovered as a mechanism of internalisation of SARS-CoV-2 in Central Nervous System (CNS) cells. N-acetylcysteine (NAC) and acetyl-L-carnitine (ALC) are two supplements that have already been found effective in treating psychiatric conditions. Furthermore, NAC showed evidence in relieving cognitive symptomatology in PCS, and ALC was found effective in treating depressive symptomatology of PCS. The overlapping effects on the glutamatergic system of ALC and NAC could help treat COVID-19 psychiatric symptoms and PCS, acting through different mechanisms on the xc-mGluR2 network, with potentially synergistic effects on chronic pain and neuro-astrocyte protection. This paper aims to summarise the current evidence on the potential therapeutic role of NAC and ALC, providing an overview of the underlying molecular mechanisms and pathophysiology. It proposes a pathophysiological model explaining the effectiveness of NAC and ALC in treating COVID-19-related neuropsychiatric symptoms.

Unraveling brain fog in post-COVID syndrome: Relationship between subjective cognitive complaints and cognitive function, fatigue, and neuropsychiatric symptoms

BACKGROUND AND PURPOSE

"Brain fog" is a frequent and disabling symptom that can occur after SARS-CoV-2 infection. However, its clinical characteristics and the relationships among brain fog and objective cognitive function, fatigue, and neuropsychiatric symptoms (depression, anxiety) are still unclear. In this study, we aimed to examine the characteristics of brain fog and to understand how fatigue, cognitive performance, and neuropsychiatric symptoms and the mutual relationships among these variables influence subjective cognitive complaints.

METHODS

A total of 170 patients with cognitive complaints in the context of post-COVID syndrome were evaluated using a comprehensive neuropsychological protocol. The FLEI scale was used to characterize subjective cognitive complaints. Correlation analysis, regression machine-learning algorithms, and mediation analysis were calculated.

RESULTS

Cognitive complaints were mainly attention and episodic memory symptoms, while executive functions (planning) issues were less often reported. The FLEI scale, a mental ability questionnaire, showed high correlations with a fatigue scale and moderate correlations with the Stroop test, and anxiety and depressive symptoms. Random forest algorithms showed an R2 value of 0.409 for the prediction of FLEI score, with several cognitive tests, fatigue and depression being the best variables used in the prediction. Mediation analysis showed that fatigue was the main mediator between objective and subjective cognition, while the effect of depression was indirect and mediated through fatigue.

CONCLUSIONS

Brain fog associated with COVID-19 is mainly characterized by attention and episodic memory, and fatigue, which is the main mediator between objective and subjective cognition. Our findings contribute to understanding the pathophysiology of brain fog and emphasize the need to unravel the main mechanisms underlying brain fog, considering several aspects.

[Referral Profile of Adult Patients Attended in the Neuropsychology Consultation at Hospital Universitario La Paz in Madrid from 2018 to 2023]

INTRODUCTION

Neuropsychology is an area of psychology that studies, through different methodologies, the relationship between the nervous system and behavior. This study aims to describe the profile of the patient who most frequently received a neuropsychological assessment at HULP between 2018 and 2023.

PATIENTS AND METHODS

This is a retrospective observational study of 394 clinical records of subjects aged 18 years or older who were attended in the neuropsychology consultation of HULP between 2018 and 2023. The data was recorded and anonymized in a database properly guarded. Frequency tables were extracted and χ2 tests were made. SPSS 26 was the programme used to make data analysis.

RESULTS

A total of 232 women (mean age of 46,47 years) and 162 men (mean age 43,31 years) were evaluated. The most frequent reason for consultation in both groups was suspicion of dementia (112 consultations for this reason in the female group; 76 in the male group). Regardless of the reason for consultation, there were more cases of patients who had studied up to the age of 18 years. Binomial analysis reveals a statistically significant relationship between being assessed in the neuropsychology consultation at HULP and having completed studies before the age of 18.

CONCLUSIONS

The profile of the patient who is most frequently attended at the neuropsychology consultation of HULP is a middle-aged woman with education up to 18 years of age, referred by the Mental Health Service for suspected dementia. The information obtained from this analysis will help to guide future planning of assessment strategies for patients with neuropsychological problems.

Six-month follow-up of multidomain cognitive impairment in non-hospitalized individuals with post-COVID-19 syndrome

Some people infected with SARS-CoV-2 report persisting symptoms following acute infection. If these persist for over three months, they are classified as post-COVID-19 syndrome (PCS). Although PCS is frequently reported, detailed longitudinal neuropsychological characterization remains scarce. We aimed to describe the trajectory of cognitive and neuropsychiatric PCS symptoms. 42 individuals with persisting cognitive deficits after asymptomatic to mild/moderate acute COVID-19 at study inclusion received neuropsychological assessment at baseline (BL) and follow-up (FU; six months after BL). Assessments included comprehensive testing of five neurocognitive domains, two cognitive screening tests, and questionnaires on depression, anxiety, sleep, fatigue, and health-related quality of life. Results showed high rates of subjective cognitive complaints at BL and FU (95.2% versus 88.1%) without significant change over time. However, objectively measured neurocognitive disorder (NCD) decreased (61.9% versus 42.9%). All cognitive domains were affected, yet most deficits were found in learning and memory, followed by executive functions, complex attention, language, and perceptual motor functions. In individuals with NCD, the first three domains mentioned improved significantly over time, while the last two domains remained unchanged. Cognitive screening tests did not prove valuable in detecting impairment. Neuropsychiatric symptoms remained constant except for quality of life, which improved. This study emphasizes the importance of comprehensive neuropsychological assessment in longitudinal research and provides valuable insights into the trajectory of long-term neuropsychological impairments in PCS. While cognitive performance significantly improved in many domains, neuropsychiatric symptoms remained unchanged.

Long-term follow-up of brain regional changes and the association with cognitive impairment in quarantined COVID-19 survivors

OBJECTIVE

This study aimed to evaluate the neuropsychiatric symptoms of quarantined COVID-19 survivors 15 months after discharge and explore its potential association with structural and functional brain changes and inflammation.

METHODS

A total of 51 quarantined COVID-19 survivors and 74 healthy controls were included in this study. Cognitive function was assessed using the THINC-integrated tool. Structural brain changes were examined through both surface- and volume-based analyses, and functional changes were assessed using resting-state amplitude low-frequency fluctuation (ALFF). Serum inflammatory markers were measured by a multiplexed flow cytometric assay.

RESULTS

COVID-19 survivors exhibited subjective cognitive decline compared to healthy controls, despite no significant differences in objective cognitive tasks. Structural analysis revealed significantly increased gray matter volume and cortical surface area in the left transverse temporal gyrus (Heschl's gyrus) in quarantined COVID-19 survivors. This enlargement was negatively correlated with cognitive impairment. The ALFF analysis showed decreased neural activity in multiple brain regions. Elevated levels of serum inflammatory markers were also found in COVID-19 survivors, including MIP-1a, MIP-1b, TNF-a, and IL-8, which correlated with functional abnormalities.

CONCLUSIONS

Our findings indicate a subjective cognitive decline in quarantined COVID-19 survivors 15 months after discharge, which is associated with brain structural alterations in the left Heschl's gyrus. The observed elevation of inflammatory markers suggests a potential mechanism involving inflammation-induced neurogenesis. These results contribute to our understanding of the possible mechanisms underlying long-term neuropsychiatric consequences of COVID-19 and highlight the need for further research to develop targeted interventions.

A multidisciplinary approach to assessment and management of long COVID cognitive concerns

Cognitive dysfunction is a commonly reported feature of Long COVID (LC). With the overlap of assessment and treatment for cognitive concerns across multiple disciplines, coupled with current guidelines supporting interdisciplinary care, the aim of this clinically focused article is to provide a review of current guidelines and research related to assessment and interventions to address LC-related cognitive concerns within clinical practice from a multidisciplinary perspective, incorporating best practices for collaboration among Clinical Neuropsychologists, Rehabilitation Psychologists, and Speech-Language Pathologists. Current guidelines for assessment and interventions for cognitive functioning are provided, with clinical suggestions for best practices offered. Additional considerations related to diversity and variable patient presentations are identified. This article provides guidance based on current research and practice standards regarding the utilization of a multidisciplinary, collaborative approach to provide comprehensive assessment and treatment for individuals with LC-related cognitive concerns.

Memory complaints after COVID-19: a potential indicator of primary cognitive impairment or a correlate of psychiatric symptoms?

Cognitive impairment and symptoms of psychiatric disorders have been reported frequently as features of post-acute sequelae of SARS-CoV-2 infection. This study aims to investigate subjective memory complaints in COVID-19 survivors and determine if these are more strongly associated with objective cognitive impairment related to sequelae of SARS-CoV-2 infection or with symptoms of psychiatric conditions. A total of 608 COVID-19 survivors were evaluated in-person 6-11 months after hospitalization, with 377 patients assigned to a "no subjective memory complaint (SMC)" group and 231 patients assigned to an SMC group based on their Memory Complaint Scale scores. Follow-up evaluations included an objective cognitive battery and scale-based assessments of anxiety, depression, and post-traumatic stress symptoms. We found the perception of memory impairment in COVID-19 survivors to be more strongly associated to core symptoms of psychiatric conditions rather than to primary objective cognitive impairment. Univariate analysis indicated significant differences between the "no SMC" and SMC groups, both for the psychiatric symptom evaluations and for the cognitive evaluations (p < 0.05); however, the psychiatric symptoms all had large partial eta-squared values (ranging from 0.181 to 0.213), whereas the cognitive variables had small/medium partial eta-squared values (ranging from 0.002 to 0.024). Additionally, multiple regression analysis indicated that only female sex and depressive and post-traumatic stress symptoms were predictors of subjective memory complaints. These findings may help guide clinical evaluations for COVID-19 survivors presenting with memory complaints while also serving to expand our growing understanding of the relationship between COVID-19, subjective memory complaints, and the risk of cognitive decline.

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.

Brain and cognitive changes in patients with long COVID compared with infection-recovered control subjects

Between 2.5% and 28% of people infected with SARS-CoV-2 suffer long COVID or persistence of symptoms for months after acute illness. Many symptoms are neurological, but the brain changes underlying the neuropsychological impairments remain unclear. This study aimed to provide a detailed description of the cognitive profile, the pattern of brain alterations in long COVID and the potential association between them. To address these objectives, 83 patients with persistent neurological symptoms after COVID-19 were recruited, and 22 now healthy control subjects chosen because they had suffered COVID-19 but did not experience persistent neurological symptoms. Patients and controls were matched for age, sex and educational level. All participants were assessed by clinical interview, comprehensive standardized neuropsychological tests and structural MRI. The mean global cognitive function of patients with long COVID assessed by Addenbrooke's Cognitive Examination-III screening test [overall cognitive level (OCLz) = -0.39 ± 0.12] was significantly below the infection recovered-controls (OCLz = +0.32 ± 0.16, P < 0.01). We observed that 48% of patients with long COVID had episodic memory deficit, with 27% also with impaired overall cognitive function, especially attention, working memory, processing speed and verbal fluency. The MRI examination included grey matter morphometry and whole brain structural connectivity analysis. Compared to infection recovered controls, patients had thinner cortex in a specific cluster centred on the left posterior superior temporal gyrus. In addition, lower fractional anisotropy and higher radial diffusivity were observed in widespread areas of the patients' cerebral white matter relative to these controls. Correlations between cognitive status and brain abnormalities revealed a relationship between altered connectivity of white matter regions and impairments of episodic memory, overall cognitive function, attention and verbal fluency. This study shows that patients with neurological long COVID suffer brain changes, especially in several white matter areas, and these are associated with impairments of specific cognitive functions.

Neural basis of fatigue in post-COVID syndrome and relationships with cognitive complaints and cognition

The main objective was to evaluate structural and functional connectivity correlates of fatigue in post-COVID syndrome, and to investigate the relationships with an objective measure of mental fatigue and with subjective cognitive complaints. One-hundred and twenty-nine patients were recruited after 14.79 ± 7.17 months. Patients were evaluated with fatigue, neuropsychological, and subjective cognitive complaints assessments. Structural and functional magnetic resonance imaging were acquired, and functional connectivity, white matter diffusivity and grey matter volume were evaluated. Fatigue was present in 86 % of patients, and was highly correlated to subjective cognitive complaints. Fatigue was associated with structural and functional connectivity mostly in frontal areas but also temporal, and cerebellar areas, showing mental fatigue different pattern of functional connectivity correlates compared to physical fatigue. White matter diffusivity correlates were similar in fatigue and subjective cognitive complaints, located in the forceps minor, anterior corona radiata and anterior cingulum. Findings confirm that fatigue in post-COVID syndrome is related to cerebral connectivity patterns, evidencing its brain substrates. Moreover, results highlight the relationship between fatigue and subjective cognitive complaints. These findings point out the relevance of the multidisciplinary assessment of post-COVID syndrome patients with subjective cognitive complaints, in order to unravel the symptomatology beneath the patient's complaints.

Structural and functional brain markers of cognitive impairment in healthcare workers following mild SARS-CoV-2 infection during the original stream

Severe acute respiratory syndrome coronavirus 2 infection often involves the nervous system, leading to cognitive dysfunctions, fatigue and many other neurological signs that are becoming increasingly recognized. Despite mild forms of the disease accounting for most cases worldwide, research on the pathophysiology driving mild coronavirus disease 2019 (COVID-19) has received little attention. In this respect, recent evidence has pointed out that around 30-40% of non-critical, mild-to-moderate severity COVID-19 survivors may display cognitive disturbances several months post-illness. Hence, the impact of COVID-19 on the brain structure and function, through potential neuropathological mechanisms underpinning cognitive alterations in post-mild COVID-19 infections, remains largely unexplored. This retrospective multicentre observational cohort study, entirely based on a healthcare worker sample (n = 65; 55% females, aged 21-61), investigated the cognitive status and the structural and functional brain integrity among non-hospitalized individuals who developed mild COVID-19 symptoms during the occurrence of severe acute respiratory syndrome coronavirus 2 variants Alpha to Delta, compared with healthy controls tested before the pandemic onset. All evaluations were performed at an average of 9-month follow-up post-infection period. Participants completed a comprehensive neuropsychological assessment and structural and functional MRI exams. Radiological inspection sought to detect the presence of white matter hyperintensities on axial fluid-attenuated inversion recovery images. Global and regional grey matter integrity assessment, analysing changes in grey matter volumes and cortical thinning, and functional connectivity alterations of resting-state brain networks were also conducted. Regression analyses tested the relationships between the presence of specific cognitive impairments and potential structural and functional brain findings. Our results revealed that clinical, cognitive screening and neuropsychological examinations were average between both groups, except for specific impairments related to executive functions in the mild COVID-19. Compared to healthy controls, mild COVID-19 subjects exhibited increased juxtacortical white matter hyperintensities, thalamic and occipital volume loss and diminished resting-state functional connectivity involving the left precuneus and cuneus in default-mode network and affecting the right angular gyrus and left precuneus in the dorsal attentional network. Reduced thalamic volume was the only variable selected in the final model explaining the observed executive function impairment in mild COVID-19. The presence of cognitive, structural and functional brain abnormalities over time suggests that the action of widespread neurovascular and inflammatory phenomena on the nervous system might also occur in mild forms following COVID-19 infection rather than permanent brain damage linked to the direct or indirect action of the virus. Our findings emphasize the need to pay attention to the long-term brain-related consequences of mild COVID-19 infections during the original stream.

Multimodal neuroimaging in Long-COVID and its correlates with cognition 1.8 years after SARS-CoV-2 infection: a cross-sectional study of the Aliança ProHEpiC-19 Cognitiu

Introduction

There is a growing interest in the effect of Long-COVID (LC) on cognition, and neuroimaging allows us to gain insight into the structural and functional changes underlying cognitive impairment in LC. We used multimodal neuroimaging data in combination with neuropsychological evaluations to study cognitive complaints in a cohort of LC patients with mild to moderate severity symptoms.

Methods

We conducted a 3T brain magnetic resonance imaging (MRI) study with diffusion tensor imaging (DTI) and functional MRI (fMRI) sequences on 53 LC patients 1.8 years after acute COVID-19 onset. We administered neuropsychological tests to evaluate cognitive domains and examined correlations with Tract-Based Spatial Statistics (TBSS) and resting state.

Results

We included 53 participants with LC (mean age, 48.23 years; 88.7% females). According to the Frascati criteria, more than half of the participants had deficits in the executive (59%) and attentional (55%) domains, while 40% had impairments in the memory domain. Only one participant (1.89%) showed problems in the visuospatial and visuoconstructive domain. We observed that increased radial diffusivity in different white matter tracts was negatively correlated with the memory domain. Our results showed that higher resting state activity in the fronto-parietal network was associated with lower memory performance. Moreover, we detected increased functional connectivity among the bilateral hippocampus, the right hippocampus and the left amygdala, and the right hippocampus and the left middle temporal gyrus. These connectivity patterns were inversely related to memory and did not survive false discovery rate (FDR) correction.

Discussion

People with LC exhibit cognitive impairments linked to long-lasting changes in brain structure and function, which justify the cognitive alterations detected.

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.

Neuropsychological rehabilitation for post-COVID-19 syndrome: results of a clinical programme and six-month follow up

INTRODUCTION

Patients with post-COVID-19 syndrome may present cognitive and emotional symptomatology. This study aims to analyse the results of an outpatient neuropsychological intervention programme for post-COVID-19 syndrome.

METHOD

In June 2020 Institut Guttmann started an outpatient post-COVID-19 neurorehabilitation programme, including respiratory therapy, physiotherapy, and neuropsychological rehabilitation. Before and after the programme, the cognitive-emotional state of all participants is assessed. Six months after treatment, a follow-up assessment is administered (which includes a collection of information on various aspects of daily life).

RESULTS

The sample analysed consisted of 123 patients (mean age: 51 years, SD: 12.41). Seventy-four per cent (n = 91) had cognitive impairment and underwent cognitive treatment (experimental group); the remaining 26% (n = 32) constituted the control group. After the intervention, the experimental group improved in working memory, verbal memory (learning, recall and recognition), verbal fluency and anxious-depressive symptomatology. The control group showed changes in immediate memory, verbal memory (learning and recognition) and depressive symptomatology, although the effect size in the latter two was smaller than in the experimental group. Six months after treatment, 44.9% of the patients were unable to perform their pre-COVID-19 work activity, and 81.2% reported difficulties in their activities of daily living.

CONCLUSIONS

Neuropsychological rehabilitation is an effective tool to treat the cognitive-emotional deficits present in post-COVID-19 syndrome. However, months after the end of treatment, not all patients recover their pre-COVID-19 functional level.

Long Neurocognitive and Neuropsychiatric Sequelae in Participants with Post-COVID-19 Infection: A Longitudinal Study

OBJECTIVE

To evaluate and characterize the cognitive changes in COVID-19 participants at 6-month follow-up, and to explore a possible association with clinical symptoms, emotional disturbance and disease severity.

METHODS

This single-center longitudinal cohort study included participants aged 20 and 60 years old to exclude cognitive impairment age-associated with confirmed COVID-19 infection. The initial evaluation occurred 10 to 30 days after hospital or ambulatory discharge, with a subsequent follow-up at 6 months. Patients who had a history of cognitive impairment, neurological conditions, or serious psychiatric disorders were not included. Information on demographics and laboratory results was gathered from medical records. Cognitive outcomes were assessed with a neuropsychological battery including attention, verbal and visual memory, language and executive function tests.

RESULTS

A total of 200 participants were included in the study, and 108 completed the follow-up visit. At the 6-month follow-up, comparing the means from baseline with those of the follow-up evaluation, significant overall improvement was observed in verbal and visual memory subtests (p = 0.001), processing speed (p = 0.001), executive function (p = 0.028; p = 0.016) and naming (p = 0.001), independently of disease severity and cognitive complaints. Anxiety and depression were significantly higher in groups with Subjective Cognitive Complaints (SCC) compared to those without (p < 0.01 for both).

CONCLUSIONS

Persistent symptoms are common regardless of disease severity and are often linked to cognitive complaints. Six months after COVID-19, the most frequently reported symptoms included headache, dyspnea, fatigue, cognitive complaints, anxiety, and depression. No cognitive impairment was found to be associated with the severity of COVID-19. Overall, neuropsychological and psychopathological improvement was observed at 6 months regardless of disease severity and cognitive complaints.

Medium- and Long-Term Effects of COVID-19 in a Population of Patients Admitted to the Intensive Care Unit: Cognitive and Psychological Sequelae and Quality of Life Six Months and One Year after Discharge

Most researchers have assessed cognitive functions in post-COVID-19 patients by means of screening tools and found cognitive sequelae in addition to anxiety, stress, depression, and a reduced quality of life (QoL). This study was aimed at investigating cognitive and psychological sequelae in patients admitted to the intensive care unit (ICU) six months (t6) and one year (t12) after discharge from the hospital, the impact of critical illness on well-being and QoL, and the protective role of cognitive reserve (CR). Twenty-three ICU patients underwent an extensive neuropsychological test battery at t6 and t12; a healthy control group underwent the same evaluation. Patient scores were compared with control scores: patients reported significantly lower scores in visual-spatial functions, both at t6 (U = 122; p = 0.033) and at t12 (U = 70; p = 0.003), and higher levels of anxiety (U = 126; p = 0.043) and depression (U = 97; p = 0.005) at t6; the levels of anxiety decreased at t12, while only depression symptoms persisted (U = 99.5; p = 0.025). Regarding the QoL, patients obtained lower scores in the physical component of QoL, both at t6 (U = 72; p = 0.008) and at t12 (U = 56.5; p = 0.005). Few and moderate correlations emerged between isolated cognitive functions and CR and the length of hospital stay. The results suggest a prevalent visual-spatial involvement, the medium- and long-term persistence of psychological sequelae, and a reduced QoL in ICU patients.

Evolving trends in neuropsychological profiles of post COVID-19 condition: A 1-year follow-up in individuals with cognitive complaints

Cognitive difficulties are reported as lasting sequelae within post COVID-19 condition. However, the chronicity of these difficulties and related factors of fatigue, mood, and perceived health have yet to be fully determined. To address this, the current longitudinal study aimed to clarify the trends of cognitive test performance and cognitive domain impairment following COVID-19 onset, and whether hospitalization influences outcomes. 57 participants who reported subjective cognitive difficulties after confirmed COVID-19 infection were assessed at baseline (~6 months post COVID-19) and follow-up (~15 months later) visits. Assessments included measures across multiple cognitive domains and self-report questionnaires of fatigue, mood, and overall health. Analyses were conducted in three stages: at the test score level (raw and adjusted scores), at the cognitive domain level, and stratified by hospitalization status during infection. Results at the test-score level indicate that cognitive performance remains relatively stable across assessments at the group level, with no significant improvements in any adjusted test scores at follow-up. Cognitive domain analyses indicate significant reductions in attention and executive functioning impairment, while memory impairment is slower to resolve. On self-report measures, there was a significant improvement in overall health ratings at follow-up. Finally, those hospitalized during infection performed worse on timed cognitive measures across visits and accounted for a larger proportion of cases with short-term and working memory impairment at follow-up. Overall, our findings indicate that cognitive difficulties persist both at test score and cognitive domain levels in many cases of post COVID-19 condition, but evidence suggests some improvement in global measures of attention, executive functioning and overall self-rated health. Furthermore, an effect of hospitalization on cognitive symptoms post COVID-19 may be more discernible over time.

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.

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.

Long COVID: cognitive, balance, and retina manifestations

Background

The neurological symptoms of Long COVID (LC) and the impact of neuropsychological manifestations on people's daily lives have been extensively described. Although a large body of literature describes symptoms, validating this with objective measures is important. This study aims to identify and describe the effects of Long COVID on cognition, balance, and the retinal fundus, and determine whether the duration of symptoms influences cognitive impairment.

Methods

This cross-sectional study involved LC volunteers with cognitive complaint from public health centers in northern Barcelona who participated between January 2022 and March 2023. This study collected sociodemographic characteristics, information on substance use, comorbidities, and clinical data related to COVID-19. We measured five cognitive domains using a battery of neuropsychological tests. Balance was assessed through posturography and retinal vascular involvement by retinography.

Results

A total of 166 people with LC and cognitive complaints participated, 80.72% were women and mean age was 49.28 ± 8.39 years. The most common self-reported symptoms were concentration and memory deficit (98.80%), brain fog (82.53%) and insomnia (71.17%). The 68.67% presented cognitive deficit in at least one domain, with executive functions being the most frequent (43.98%). The 51.52% of the participants exhibited a dysfunctional pattern in balance, and 9.2% showed some alteration in the retina. There were no statistically significant differences between cognitive impairment and symptom duration.

Conclusion

Our findings contribute to a more comprehensive understanding of the pathology associated with Long COVID. They highlight the diversity of self-reported symptoms, the presence of abnormal balance patterns, and some cognitive impairment. These findings underscore the necessity of addressing the clinical management of this condition in primary care through follow-up and the pursuit of multidisciplinary and comprehensive treatment.

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.

Neurocognitive and Neuropsychiatric Sequelae in Long COVID-19 Infection

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

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.

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.

Cognitive profile, neuroimaging and fluid biomarkers in post-acute COVID-19 syndrome

We aimed to characterize the cognitive profile of post-acute COVID-19 syndrome (PACS) patients with cognitive complaints, exploring the influence of biological and psychological factors. Participants with confirmed SARS-CoV-2 infection and cognitive complaints ≥ 8 weeks post-acute phase were included. A comprehensive neuropsychological battery (NPS) and health questionnaires were administered at inclusion and at 1, 3 and 6 months. Blood samples were collected at each visit, MRI scan at baseline and at 6 months, and, optionally, cerebrospinal fluid. Cognitive features were analyzed in relation to clinical, neuroimaging, and biochemical markers at inclusion and follow-up. Forty-nine participants, with a mean time from symptom onset of 10.4 months, showed attention-executive function (69%) and verbal memory (39%) impairment. Apathy (64%), moderate-severe anxiety (57%), and severe fatigue (35%) were prevalent. Visual memory (8%) correlated with total gray matter (GM) and subcortical GM volume. Neuronal damage and inflammation markers were within normal limits. Over time, cognitive test scores, depression, apathy, anxiety scores, MRI indexes, and fluid biomarkers remained stable, although fewer participants (50% vs. 75.5%; p = 0.012) exhibited abnormal cognitive evaluations at follow-up. Altered attention/executive and verbal memory, common in PACS, persisted in most subjects without association with structural abnormalities, elevated cytokines, or neuronal damage markers.

Poor sleep quality may trigger cognitive deficits after recovery from COVID-19

Objective

In the present study, we aimed to assess the cognition of post-COVID-19 condition (PCC) participants in relation to their subjective sleep quality (Pittsburgh Sleep Quality Index, PSQI) and to analyse possible moderators of this effect, such as quality of life (European Quality of Life-5 Dimensions, EQ-5D), fatigue (Chadler Fatigue Questionnaire, CFQ), cognitive reserve (Cognitive Reserve Questionnaire, CRC), and subjective cognitive complaints (Memory Failures of Everyday Questionnaire, MFE-30).

Methods

We included 373 individuals with PCC and 126 healthy controls (HCs) from the NAUTILUS Project (NCT05307549 and NCT05307575) who were assessed with a comprehensive neuropsychological battery and various questionnaires.

Results

We found that PCC participants with poor sleep quality had a 4.3% greater risk of immediate verbal memory deficits than those with good sleep quality, as indicated by the greater odds ratio (OR) of 1.043 and confidence interval (CI) of 1.023-1.063. Additionally, their risk of immediate verbal memory disorders was multiplied by 2.4 when their EQ-5D score was low (OR 0.33; CI 0.145-0.748), and they had a lower risk of delayed visual memory deficits with a greater CRC (OR 0.963; CI 0.929-0.999). With respect to processing speed, PCC participants with poor sleep quality had a 6.7% greater risk of deficits as the MFE increased (OR 1.059; CI 1.024-1.096), and the risk of slowed processing speed tripled with a lower EQ-5D (OR 0.021; CI 0.003-0.141).

Conclusion

These results indicate that poor subjective sleep quality is a potential trigger for cognitive deficits. Therapeutic strategies to maximize sleep quality could include reducing sleep disturbances and perhaps cognitive impairment in PCC individuals.

Reduced Cortical Thickness Correlates of Cognitive Dysfunction in Post-COVID-19 Condition: Insights from a Long-Term Follow-up

BACKGROUND AND PURPOSE

There is a paucity of data on long-term neuroimaging findings from individuals who have developed the post-coronavirus 2019 (COVID-19) condition. Only 2 studies have investigated the correlations between cognitive assessment results and structural MR imaging in this population. This study aimed to elucidate the long-term cognitive outcomes of participants with the post-COVID-19 condition and to correlate these cognitive findings with structural MR imaging data in the post-COVID-19 condition.

MATERIALS AND METHODS

A cohort of 53 participants with the post-COVID-19 condition underwent 3T brain MR imaging with T1 and FLAIR sequences obtained a median of 1.8 years after Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) infection. A comprehensive neuropsychological battery was used to assess several cognitive domains in the same individuals. Correlations between cognitive domains and whole-brain voxel-based morphometry were performed. Different ROIs from FreeSurfer were used to perform the same correlations with other neuroimaging features.

RESULTS

According to the Frascati criteria, more than one-half of the participants had deficits in the attentional (55%, n = 29) and executive (59%, n = 31) domains, while 40% (n = 21) had impairment in the memory domain. Only 1 participant (1.89%) showed problems in the visuospatial and visuoconstructive domains. We observed that reduced cortical thickness in the left parahippocampal region (t(48) = 2.28, P = .03) and the right caudal-middle-frontal region (t(48) = 2.20, P = .03) was positively correlated with the memory domain.

CONCLUSIONS

Our findings suggest that cognitive impairment in individuals with the post-COVID-19 condition is associated with long-term alterations in the structure of the brain. These macrostructural changes may provide insight into the nature of cognitive symptoms.

Outcomes and Management After COVID-19 Critical Illness

TOPIC IMPORTANCE

COVID-19 has caused > 7 million deaths worldwide since its onset in 2019. Although the severity of illness has varied throughout the pandemic, critical illness related to COVID-19 persists. Survivors of COVID-19 critical illness can be left with sequelae of both the SARS-CoV-2 virus and long-term effects of critical illness included within post-intensive care syndrome. Given the complexity and heterogeneity of COVID-19 critical illness, the biopsychosocial-ecological model can aid in evaluation and treatment of survivors, integrating interactions among physical, cognitive, and psychological domains, as well as social systems and environments.

REVIEW FINDINGS

Prolonged illness after COVID-19 critical illness generally can be classified into effects on physical, cognitive, and psychosocial function, with much interaction among the various effects, and includes a wide range of symptoms such as ICU-acquired weakness, prolonged respiratory symptoms, cognitive changes, post-traumatic stress disorder post-traumatic stress disorder, anxiety, and depression. Risk factors for COVID-19 critical illness developing are complex and include preexisting factors, disease course, and specifics of hospitalization in addition to psychological comorbidities and socioenvironmental factors. Recovery trajectories are not well defined, and management requires a comprehensive, interdisciplinary, and individualized approach to care.

SUMMARY

The onset of vaccinations, new therapeutics, and new strains of SARS-CoV-2 virus have decreased COVID-19 mortality; however, the number of survivors of COVID-19 critical illness remains high. A biopsychosocial-ecological approach is recommended to guide care of COVID-19 critical illness survivors.