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

Cognitive reserve, depressive symptoms, obesity, and change in employment status predict mental processing speed and executive function after COVID-19

The risk factors for post-COVID-19 cognitive impairment have been poorly described. This study aimed to identify the sociodemographic, clinical, and lifestyle characteristics that characterize a group of post-COVID-19 condition (PCC) participants with neuropsychological impairment. The study sample included 426 participants with PCC who underwent a neurobehavioral evaluation. We selected seven mental speed processing and executive function variables to obtain a data-driven partition. Clustering algorithms were applied, including K-means, bisecting K-means, and Gaussian mixture models. Different machine learning algorithms were then used to obtain a classifier able to separate the two clusters according to the demographic, clinical, emotional, and lifestyle variables, including logistic regression with least absolute shrinkage and selection operator (LASSO) (L1) and Ridge (L2) regularization, support vector machines (linear/quadratic/radial basis function kernels), and decision tree ensembles (random forest/gradient boosting trees). All clustering quality measures were in agreement in detecting only two clusters in the data based solely on cognitive performance. A model with four variables (cognitive reserve, depressive symptoms, obesity, and change in work situation) obtained with logistic regression with LASSO regularization was able to classify between good and poor cognitive performers with an accuracy and a weighted averaged precision of 72%, a recall of 73%, and an area under the curve of 0.72. PCC individuals with a lower cognitive reserve, more depressive symptoms, obesity, and a change in employment status were at greater risk for poor performance on tasks requiring mental processing speed and executive function. Study registration: www.ClinicalTrials.gov , identifier NCT05307575.

ASSESSMENT AND CHARACTERIZATION OF COVID-19 RELATED COGNITIVE DECLINE: RESULTS FROM A NATURAL EXPERIMENT

Background

Cognitive impairment is the most common and disabling manifestation of post-acute sequelae of SARS-CoV-2. There is an urgent need for the application of more stringent methods for evaluating cognitive outcomes in research studies.

Objective

To determine whether cognitive decline emerges with the onset of COVID-19 and whether it is more pronounced in patients with Post-Acute Sequelae of SARS-CoV-2 or severe COVID-19.

Methods

This longitudinal cohort study compared the cognitive performance of 276 patients with COVID-19 to that of 217 controls across four neuroinflammation or vascular disease-sensitive domains of cognition using data collected both before and after the pandemic starting in 2015.

Results

The mean age of the COVID-19 group was 56.04±6.6 years, while that of the control group was 58.1±7.3 years. Longitudinal models indicated a significant decline in cognitive throughput ((β=-0.168, P=.001) following COVID-19, after adjustment for pre-COVID-19 functioning, demographics, and medical factors. The effect sizes were large; the observed changes in throughput were equivalent to 10.6 years of normal aging and a 59.8% increase in the burden of mild cognitive impairment. Cognitive decline worsened with coronavirus disease 2019 severity and was concentrated in participants reporting post-acute sequelae of SARS-CoV-2.

Conclusion

COVID-19 was most likely associated with the observed cognitive decline, which was worse among patients with PASC or severe COVID-19. Monitoring patients with post-acute sequelae of SARS-CoV-2 for declines in the domains of processing speed and visual working memory and determining the long-term prognosis of this decline are therefore warranted.