Lack of awareness of cognitive impairment (i.e. anosognosia) could be a key factor for distinguishing between neuropsychological post-COVID-19 condition phenotypes. In this context, the 2-fold aim of the present study was to (i) establish the prevalence of anosognosia for memory impairment, according to the severity of the infection in the acute phase and (ii) determine whether anosognosic patients with post-COVID syndrome have a different cognitive and psychiatric profile from nosognosic patients, with associated differences in brain functional connectivity. A battery of neuropsychological, psychiatric, olfactory, dyspnoea, fatigue and quality-of-life tests was administered 227.07 ± 42.69 days post-SARS-CoV-2 infection to 102 patients (mean age: 56.35 years, 65 men, no history of neurological, psychiatric, neuro-oncological or neurodevelopmental disorder prior to infection) who had experienced either a mild (not hospitalized; n = 45), moderate (conventional hospitalization; n = 34) or severe (hospitalization with intensive care unit stay and mechanical ventilation; n = 23) presentation in the acute phase. Patients were first divided into two groups according to the presence or absence of anosognosia for memory deficits (26 anosognosic patients and 76 nosognosic patients). Of these, 49 patients underwent an MRI. Structural images were visually analysed, and statistical intergroup analyses were then performed on behavioural and functional connectivity measures. Only 15.6% of patients who presented mild disease displayed anosognosia for memory dysfunction, compared with 32.4% of patients with moderate presentation and 34.8% of patients with severe disease. Compared with nosognosic patients, those with anosognosia for memory dysfunction performed significantly more poorly on objective cognitive and olfactory measures. By contrast, they gave significantly more positive subjective assessments of their quality of life, psychiatric status and fatigue. Interestingly, the proportion of patients exhibiting a lack of consciousness of olfactory deficits was significantly higher in the anosognosic group. Functional connectivity analyses revealed a significant decrease in connectivity, in the anosognosic group as compared with the nosognosic group, within and between the following networks: the left default mode, the bilateral somatosensory motor, the right executive control, the right salient ventral attention and the bilateral dorsal attention networks, as well as the right Lobules IV and V of the cerebellum. Lack of awareness of cognitive disorders and, to a broader extent, impairment of the self-monitoring brain system, may be a key factor for distinguishing between the clinical phenotypes of post-COVID syndrome with neuropsychological deficits.

Neuropsychological deficits and brain damage following SARS‐CoV‐2 infection are not well understood. Then, 116 patients, with either severe, moderate, or mild disease in the acute phase underwent neuropsychological and olfactory tests, as well as completed psychiatric and respiratory questionnaires at 223 ± 42 days postinfection. Additionally, a subgroup of 50 patients underwent functional magnetic resonance imaging. Patients in the severe group displayed poorer verbal episodic memory performances, and moderate patients had reduced mental flexibility. Neuroimaging revealed patterns of hypofunctional and hyperfunctional connectivities in severe patients, while only hyperconnectivity patterns were observed for moderate. The default mode, somatosensory, dorsal attention, subcortical, and cerebellar networks were implicated. Partial least squares correlations analysis confirmed specific association between memory, executive functions performances and brain functional connectivity. The severity of the infection in the acute phase is a predictor of neuropsychological performance 6–9 months following SARS‐CoV‐2 infection. SARS‐CoV‐2 infection causes long‐term memory and executive dysfunctions, related to large‐scale functional brain connectivity alterations.

There is growing awareness that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, even in its mild or moderate respiratory forms, can include long-term neuropsychological deficits. Standardized neuropsychological, psychiatric, neurological, and olfactory tests were administered to 45 patients 236.51 ± 22.54 days after hospital discharge following severe, moderate, or mild respiratory severity from SARS-CoV-2 infection (severe = intensive care unit hospitalization, moderate = conventional hospitalization, mild = no hospitalization). Deficits were found in all domains of cognition, and the prevalence of psychiatric symptoms was relatively high in the three groups. The severe infection group performed more poorly on long-term episodic memory tests and exhibited greater anosognosia than did the other two groups. Those with moderate infection had poorer emotion recognition, which was positively correlated with persistent olfactory dysfunction. Individuals with mild infection were more stressed, anxious, and depressed. The data support the hypothesis that the virus targets the central nervous system (notably the limbic system) and the notion that there are different neuropsychological phenotypes.

An increasing number of observational studies suggest that 10%-35% of people who contract coronavirus (COVID-19) may go on to experience persisting symptoms over many months [1]. The post-COVID-19 condition (long COVID) leads to functional impairment and low productivity at work [1]. A recent 2021 Swiss survey conducted by the Federal Social Insurance Office [2] found […]

Objective: Several studies have reported poor long-term neuropsychological performances in patients following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, but none has yet considered the effect of administering multiple intercorrelated neuropsychological tests and assessed the frequency of cognitive deficits in a normative population. Our aim was therefore to assess the presence of cumulative neuropsychological deficits in an actual post-coronavirus disease of 2019 (COVID-19) comparison group versus one simulated using Monte-Carlo methods. Method: Validated neuropsychological Monte-Carlo simulation methods were applied to scores from a battery of neuropsychological tests (memory, executive, attentional, perceptual, logical reasoning, language, and ideomotor praxis) administered to 121 patients who had had mild, moderate, or severe COVID-19 (mean age: 56.70 years; 32% women), 222 ± 43 days post-infection. The cumulative percentages of the three severity subgroups were compared with the results of a false discovery rate-corrected probability analysis based on normative data. Results: The cumulative percentages of deficits in memory and executive functions among the severe and moderate patients were significantly higher than those estimated for the normative population. Moderate patients also had significantly more deficits in perception and logical reasoning. In contrast, the mild group did not have significantly more cumulative deficits. Conclusions: Moderate and severe forms of COVID-19 cause greater long-term neuropsychological deficits than those that would be found in a normative population, reinforcing the hypothesis of long-term effects of SARS-CoV-2 on cognitive function, independent of the severity of the initial infection.

Alterations of the limbic system may be present in the chronic phase of SARS-CoV-2 infection. Our aim was to study the long-term impact of this disease on limbic system-related behaviour and its associated brain functional connectivity, according to the severity of respiratory symptoms in the acute phase. To this end, we investigated the multimodal emotion recognition abilities of 105 patients from the Geneva COVID-COG cohort 223 days on average after SARS-CoV-2 infection (diagnosed between March 2020 and May 2021), dividing them into three groups (severe, moderate, or mild) according to respiratory symptom severity in the acute phase. We used multiple regressions and partial least squares correlation analyses to investigate the relationships between emotion recognition, olfaction, cognition, neuropsychiatric symptoms, and functional brain networks. Six to 9 months following SARS-CoV-2 infection, moderate patients exhibited poorer recognition abilities than mild patients for expressions of fear (p = .03 corrected), as did severe patients for disgust (p = .04 corrected) and irritation (p < .01 corrected). In the whole cohort, these performances were associated with decreased episodic memory and anosmia, but not with depressive symptoms, anxiety or posttraumatic stress disorder. Neuroimaging revealed a positive contribution of functional connectivity, notably between the cerebellum and the default mode, somatosensory motor and salience/ventral attention networks. These results highlight the long-term consequences of SARS-Cov-2 infection on the limbic system at both the behavioural and neuroimaging levels.