Subtle cognitive impairments in memory, attention, and executive functioning in patients with post-COVID syndrome and their relationships with clinical variables and subjective complaints

Background and objectives Cognitive symptoms persisting beyond three months following COVID-19 present a considerable disease burden. We aimed to establish a domain-specific cognitive profile of post-COVID syndrome (PCS) and relationships with subjective cognitive complaints and clinical variables to provide relevant information for the understanding of cognitive dysfunction and its predictors in a clinical cohort with PCS. Methods In this cross-sectional study, we compared cognitive performance on the clinically viable Oxford Cognitive Screen-Plus between a large post-COVID cohort ( n = 282) and a socio-demographically matched healthy control group ( n = 52). We assessed group differences in terms of fatigue and depression as well as relationships between cognitive dysfunction and clinical and patient-reported outcomes. Results On a group-level, patients scored significantly lower on delayed verbal memory (non-parametric effect size r = .13), attention ( r = .1), and executive functioning ( r =.1) than healthy controls. In each of these domains, 10-20% of patients performed more than 1.5 SD below the healthy control mean. Delayed Memory was particularly affected and a small proportion of its variance was explained by hospitalisation ( β = -.72, p < .01) and age ( β = -.03, p < .05; R 2 adj. = .08). Attention scores were significantly predicted by hospitalisation ( β = -.78, p < .01) and fatigue ( β = -.04, p < .05; R 2 adj. = .06). Discussion PCS is associated with long-term cognitive dysfunction, particularly in delayed verbal memory, attention, and executive functioning. Deficits in delayed memory performance seem to be of particular relevance to patients’ subjective experience of impairment. Initial disease severity, current level of fatigue, and age seem to predict cognitive performance, while time since infection, depression, and pre-existing conditions do not. Longitudinal data are needed to map long-term course of cognitive dysfunction in PCS.