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

Abstract

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 = .045) and EMF (P = .032). Significant relationships were observed between the Boston Naming Test (−0.287; P = .035), the Rey Figure Recall Test (−0.324; P = .017) with parietal atrophy, as well as phonological verbal fluency with frontal atrophy (−0.276; P = .042). The HVLT (learning trial) test was related to hippocampal hyperintensity (−0.266; P = .050) and cingulate hyperintensity (0.311; P = .021). The TMT-B test was related to white matter hyperintensity (0.345; P= .010). The presence of poor functional prognosis was correlated with anxiety (P < .001), depression (P < .001), elevated D-dimer levels (P = .002) and the increase in days of intubation (P = .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.