Frequency of Abnormally Low Neuropsychological Scores in Post-COVID-19 Syndrome: the Geneva COVID-COG Cohort

Abstract

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.

Brain functional connectivity alterations associated with neuropsychological performance 6–9 months following SARS‐CoV‐2 infection

“…Therefore, we cannot exclude that the mild group also exhibits reduced neuropsychological scores in comparison to a control group as has been described in the literature. That said, a recent study by our group did not show a significant accumulation of deficits in the group of mild patients compared to a simulated normative population, while the moderate and severe groups presented a significantly greater accumulation of neuropsychological deficits (Voruz, Allali, et al, 2022 ; Voruz, Cionca, et al, 2022 ; Voruz, de Alcântara, et al, 2022 ). Moreover, our moderate and severe groups are potentially not representative of the population of hospitalized SARS‐CoV‐2 patients because of their lack of comorbidities.…”

“…The experimental design and tests used are comparable to those used in a previous published study (Voruz, Allali, et al, 2022 ; Voruz, Cionca, et al, 2022 ; Voruz, de Alcântara, et al, 2022 ).…”

The Impact of COVID-19 Lockdown Measures and COVID-19 Infection on Cognitive Functions: A Review in Healthy and Neurological Populations

“…A total of 27 out of 32 articles reported negative effects of COVID-19 infection during the medium period (5–8 months). As in the short period, most of the authors found a significant general cognitive decline [ 60 , 61 , 62 , 63 , 64 , 68 , 69 , 70 , 73 , 77 , 78 , 82 , 83 , 84 , 85 ], in particular, in memory [ 62 , 65 , 66 , 74 , 77 , 81 , 85 , 86 , 87 , 88 ], verbal fluency [ 62 , 65 , 66 , 71 , 72 , 88 ], executive functions [ 65 , 69 , 72 , 74 , 75 , 81 , 87 , 88 ] and attention tasks [ 65 , 72 , 76 , 89 ]. Three studies did not report significant effects on cognitive performance in hospitalized people that resulted positive in the SARS CoV-2 nasopharyngeal test compared to those with no history of the virus [ 37 , 38 , 79 ]; while, in the Pilotto et al [ 83 ] and Stallmach et al [ 84 ] study, a very low percentage of people with COVID-19 infection showed the presence of cognitive decline.…”

“…In the literature, this status is often referred to as ‘Long COVID’ [ 116 , 117 ], or ‘brain fog’ with accompanied clinical symptoms, such as low energy, insomnia, problems in concentration and spatial orientation and difficulty in finding the right words [ 118 ]. In particular, some studies reported a decrease in short-and-long term memory performance [ 62 , 65 , 66 , 74 , 77 , 81 , 85 , 86 , 87 , 88 ], in verbal fluency [ 62 , 65 , 66 , 71 , 72 , 88 ], in executive functions [ 65 , 69 , 72 , 74 , 75 , 81 , 87 , 88 ] and in selective attention tasks [ 65 , 72 , 76 , 89 ]. It is likely the case, as suggested by previous studies, that these cognitive deficits occurred as a consequence of respiratory symptoms severity due to the pandemic [ 119 , 120 ].…”

The economic burden of the post-COVID-19 condition: Underestimated long-term consequences of neuropsychological deficits

“…Therefore, direct and indirect costs of the post-COVID-19 condition have been recently estimated to range from US$140 to US$600 billion annually [ 4 ]. Moreover, one of the most prevalent and disabling symptoms of the post-COVID-19 condition is “brain fog”, reflecting the persistence of neurocognitive symptoms such as confusion, forgetfulness, a lack of focus and mental clarity, and fatigue [ 1 , 5 ]. Those were recently categorised as neuropsychological post-COVID-19 conditions, with 30%-40% of patients suffering or complaining of such symptoms [ 5 ], requiring exhaustive neuropsychological assessments from neuropsychologists.…”