In a recent study published in Neurological Sciences, researchers assessed the prevalence of cognitive complaints (CC) in patients with coronavirus disease 2019 (COVID-19) and explored factors associated with brain fog one year after diagnosis. of COVID-19.
Study: Predictors of ‘brain fog’ 1 year after COVID-19 illness. Image credit: Mary Long/Shutterstock
background
Studies have frequently reported cognitive symptoms among patients with COVID-19 ≤1 year after becoming infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), along with fatigue, anxiety, chest tightness, and myalgia . CC or brain fog includes difficulty paying attention, slow thinking, and confusion.
Recent imaging studies have also reported functional alterations in the brains of individuals with long-term symptoms of cognitive impairment following SARS-CoV-2 infection. Persistent brain fog has been reported even after ≥1 year of SARS-CoV-2 infection; however, the mechanisms underlying brain fog and the association of brain fog with the severity of COVID-19, long-term symptoms of COVID-19, and premorbid conditions need further investigation.
About the study
In the present study, researchers assessed the prevalence and factors associated with CC among patients infected with SARS-CoV-2 one year after diagnosis of COVID-19.
The study included patients hospitalized for lung complications associated with COVID-19 between March 1 and May 31. Participants were evaluated after one year of hospital discharge and comprehensive neurological, psychological and clinical examinations were performed. Assessments included the Impact of Events Scale-Revised (IES-R), the Montreal Cognitive Assessment (MoCA), the Zung Self-Assessment Anxiety Scale (SAS), the Fatigue Severity Scale (FSS) and the Zung Self-Rating Depression Scale (SDS).
Other assessments include the modified rating scale (mRS), rapid sequential assessment of organ failure (qSOFA), low-flow oxygen requirements, noninvasive ventilation requirements, and total duration of l oxygen therapy Individuals were excluded from the analysis if they had cognitive impairment, anamnestic depressive syndrome, or premorbid conditions such as dementia.
Logistic regression modeling was used to assess potential factors related to brain fog after adjusting for various covariates such as sex, age, Cumulative Illness Rating Scale (CIRS) scores ) for premorbid conditions, education level, and Brescia Respiratory Severity Scale-COVID (BCRSS) scores.
results
Of the 246 patients, only 132 patients were considered for the final analysis. Two patients with cognitive impairment or premorbid dementia and three patients with a history of depressive syndrome were excluded from the analysis. Only 22% (n = 25) of participants reported brain fog after one year of SARS-CoV-2 infection. The mean age of participants with CC was 68.5 years and most of them (72%, n=18) were male.
Participants with cognitive impairments showed lower MoCA scores (23 vs. 26) and higher IES-R scores (34 vs. 26), SDS scores (41 vs. 36), and FSS scores (34 vs. 24), compared to participants without CC. Of note, SDS scores were significantly correlated with brain fog after data adjustments for covariates and MoCA scores, indicating that depression was the best predictor of the development of cognitive impairments among long-term COVID patients, regardless of their MoCA scores. The findings are fascinating, especially since patients with psychological disorders and premorbid cognitive impairment were excluded from the analysis.
The team found no significant association between CC/brain fog and the severity of SARS-CoV-2 infections, indicating that multiple factors may affect the long-term sequelae of COVID-19. Further research with prospective study designs and assessment of glial and neuronal markers among post-COVID patients is required to improve understanding of factors associated with cognitive decline or post-acute improvement in the post-acute phase of COVID-19.
Conclusions
Overall, the study results showed that depression was the strongest predictor of persistent brain fog associated with COVID-19; however, longitudinal observational studies with larger sample sizes should be conducted to deepen the understanding of cognitive impairments among long-term patients with COVID.
The authors believe that the present study is the first of its kind to highlight the positive correlation between brain fog or cognitive complaints and depression one year after recovery from COVID-19, regardless of the severity of SARS infections -CoV-2 and the presence. of comorbid conditions.
Further research is warranted to elucidate the underlying mechanisms to guide the development of therapeutics and reduce the long-term neurological burden of COVID-19.