Cognitive impairments four months after COVID-19 hospital discharge: Pattern, severity and association with illness variables

Abstract

The ongoing Coronavirus Disease 2019 (COVID-19) pandemic has affected more than 100 million people and clinics are being established for diagnosing and treating lingering symptoms, so called long-COVID. A key concern are neurological and long-term cognitive complications. At the same time, the prevalence and nature of the cognitive sequalae of COVID-19 are unclear. The present study aimed to investigate the frequency, pattern and severity of cognitive impairments 3-4 months after COVID-19 hospital discharge, their relation to subjective cognitive complaints, quality of life and illness variables. We recruited patients at their follow-up visit at the respiratory outpatient clinic, Copenhagen University Hospital, Bispebjerg, approximately four months after hospitalisation with COVID-19. Patients underwent pulmonary, functional and cognitive assessments. Twenty-nine patients were included. The percentage of patients with clinically significant cognitive impairment ranged from 59-65% depending on the applied cut-off for clinical relevance of cognitive impairment, with verbal learning and executive functions being most affected. Objective cognitive impairment scaled with subjective cognitive complaints, lower work function and poorer quality of life. Cognitive impairments were associated with d-dimer levels during acute illness and residual pulmonary dysfunction. In conclusion, these findings provide new evidence for frequent cognitive sequelae of COVID-19 and indicate an association with the severity of the lung affection and potentially restricted cerebral oxygen delivery. Further, the associations with quality of life and functioning call for systematic cognitive screening of patients after recovery from severe COVID-19 illness and implementation of targeted treatments for patients with persistent cognitive impairments.

Rapid vigilance and episodic memory decrements in COVID-19 survivors

“…Our findings are consistent with the most prevalent complaints concerning post-COVID cognitive issues, including poor concentration and/or impaired memory in 18-50% of patients post-recovery. 8,32,33 However, in contrast with previous reports of long-COVID patients [6][7][8]12,13,16 , here we found no difference in short-term attention (performance over the first few minutes of a vigilance test; overall performance in tasks measuring executive function and response speed, Table 2) or working memory (performance in the immediate object or word memory tests, Table 2 and…”

“…In the present study, COVID-19 survivors began with apparently normal behavioural performance followed by a gradual decline away from age-matched controls, suggesting impaired ability to attentively track and maintain information over time. The inconsistency with previous reports might be due to the fact that patients featured in those studies had severe COVID-19 symptoms 3,4,6,12 , clinically significant cognitive impairment 16 , or at least reported persistent cognitive symptoms 7,8,13 , while our participants were mostly nonhospitalised and devoid of self-reported abnormality.…”

Long-Term Outcomes of Patients with Coronavirus Disease 2019 at One Year after Hospital Discharge

“…Cognitive impairment in patients with previous Alzheimer's disease or other previously acquired cognitive impairment or dementia was documented in half of the patients we assessed. The literature has described similar proportions of cognitive decline in COVID-19 survivors with dementia [62]; these data can be explained not only by a direct involvement with the central nervous system, but also by the social consequences of the pandemic-such as a greater level of stress, and the loneliness and isolation experienced by people with dementia during this period [63].…”

Psychiatric and neuropsychiatric sequelae of COVID-19 – A systematic review

“…Stress-related symptoms were associated with neurocognitive impairment. Miskowiak et al, 2021 (Denmark) To investigate frequency, pattern and severity of cognitive impairments 3–4 months after COVID-19 Cohort study SCIP-D; TMT; CFQ 29 17 (59%) 56 3–4 months Hospitalized COVID-19 survivors Language barriers; preexisting neurological comorbidity 59–65% of the patients suffered from clinically significant cognitive impairments. This was associated with d-dimer levels during acute illness and residual pulmonary dysfunction indicating an association with severity of lung function and potentially restricted cerebral oxygen delivery Monti et al, 2021 (Italy) To assess QoL of invasively ventilated COVID-19 ARDS survivors Cohort study EQ-5D-3L, HADS, 39 35 (90%) 56 61 days after ICU discharge Adult previously ICU admitted COVID-19 ARDS patients Not reported 1 patient (2.6%) experienced cognitive decline.…”