Objective cognitive performance and subjective complaints in patients with chronic Q fever or Q fever fatigue syndrome

Profiles of objective and subjective cognitive function in Post-COVID Syndrome, COVID-19 recovered, and COVID-19 naïve individuals

Post-COVID Syndrome has emerged as a significant public health concern worldwide with increasing evidence to suggest that individuals who have had an acute COVID-19 infection report lingering memory and attention difficulties, even in individuals who have fully recovered and no longer experiencing symptoms of COVID-19. The present study sought to investigate the profile of objective and subjective cognitive difficulties in people who have Post-COVID Syndrome, people who have fully recovered from an acute COVID infection and people who have never had COVID-19. We further sought to explore the extent to which self-reported fatigue and stress are related to subjective and objective cognitive difficulties. 162 participants including 50 people living with Post-COVID Syndrome, 59 people who have had COVID-19 but have fully recovered and 53 people who have never experienced symptoms of COVID-19 and had never tested positive for COVID-19 were recruited from Academic Prolific to complete a series of online questionnaires and neurocognitive tasks. Subjective cognitive function was measured using the Cognitive Failures Questionnaire and objective cognitive function was measured using the Cognitron cognitive test battery. We found that objective and subjective measures of cognitive function were not significantly related, suggesting that self-reports of "brain fog" are not reflecting objectively measured cognitive dysfunction. A MANOVA revealed that subjective cognitive deficits were driven by heightened perceived stress and fatigue and not significantly related to COVID-19 status. Objective cognitive function, however, was significantly related to perceived stress and COVID status whereby we observed significant objective cognitive deficits in people who have been exposed to an acute COVID-19 infection regardless of whether they had Post-COVID Syndrome or had fully recovered, as compared to people who had never had COVID-19. This suggests that an acute infection can have long term effects on cognitive function, even without persistent COVID-19 symptoms. Encouragingly, objective cognitive function was significantly associated with time since initial infection showing that cognitive deficits improved over time for people who had recovered from COVID-19. However, we did not observe the same improvement in individuals with Post-COVID Syndrome and observed that cognitive dysfunction was significantly related to the number of neurological symptoms presently experienced. These results add to the accumulating literature that COVID-19 is associated with significant cognitive difficulties following a COVID-19 infection, which appear to improve over time for those who have recovered from COVID-19 yet persist in people living with Post-COVID Syndrome.

Systemic inflammation relates to neuroaxonal damage associated with long-term cognitive dysfunction in COVID-19 patients

BACKGROUND AND OBJECTIVES

Cognitive deficits are increasingly recognized as a long-term sequela of severe COVID-19. The underlying processes and molecular signatures associated with these long-term neurological sequalae of COVID-19 remain largely unclear, but may be related to systemic inflammation-induced effects on the brain. We studied the systemic inflammation-brain interplay and its relation to development of long-term cognitive impairment in patients who survived severe COVID-19. Trajectories of systemic inflammation and neuroaxonal damage blood biomarkers during ICU admission were analyzed and related to long-term cognitive outcomes.

METHODS

Prospective longitudinal cohort study of patients with severe COVID-19 surviving ICU admission. During admission, blood was sampled consecutively to assess levels of inflammatory cytokines and neurofilament light chain (NfL) using an ultrasensitive multiplex Luminex assay and single molecule array technique (Simoa). Cognitive functioning was evaluated using a comprehensive neuropsychological assessment six months after ICU-discharge.

RESULTS

Ninety-six patients (median [IQR] age 61 [55-69] years) were enrolled from March 2020 to June 2021 and divided into two cohorts: those who received no COVID-19-related immunotherapy (n = 28) and those treated with either dexamethasone or dexamethasone and tocilizumab (n = 68). Plasma NfL concentrations increased in 95 % of patients during their ICU stay, from median [IQR] 23 [18-38] pg/mL at admission to 250 [160-271] pg/mL after 28 days, p < 0.001. Besides age, glomerular filtration rate, immunomodulatory treatment, and C-reactive protein, more specific markers of systemic inflammation at day 14 (i.e., interleukin (IL)-8, tumour necrosis factor, and IL-1 receptor antagonist) were significant predictors of blood NfL levels at day 14 of ICU admission (R2 = 44 %, p < 0.001), illustrating the association between sustained systemic inflammation and neuroaxonal damage. Twenty-six patients (27 %) exhibited cognitive impairment six months after discharge from the ICU. NfL concentrations showed a more pronounced increase in patients that developed cognitive impairment (p = 0.03). Higher NfL predicted poorer outcome in information processing speed (Trail Making Test A, r = -0.26, p = 0.01; Letter Digit Substitution Test, r = -0.24, p = 0.02).

DISCUSSION

Prolonged systemic inflammation in critically ill COVID-19 patients is related to neuroaxonal damage and subsequent long-term cognitive impairment. Moreover, our findings suggest that plasma NfL concentrations during ICU stay may possess prognostic value in predicting future long-term cognitive impairment in patients that survived severe COVID-19.

Post-Approval Research in Drug Development: Priorities and Practices

A prescriber might ask if a new medication is a good option for use in the patients he or she sees in clinic, with their particular blends of demographic and comorbid clinical characteristics. Is this medicine more effective, safe, tolerable, or affordable than the options used in the past? A payer may ask if the new medication offers a more effective, cost-efficient, or convenient alternative to those treatments already being covered. These are the types of questions that are often difficult to answer on the basis of the clinical trials used to support a medication's initial approval, which are generally designed to evaluate a medication's efficacy, safety, and tolerability in narrowly defined patient populations. Consequently, in order to answer the questions most relevant to key stakeholders (i.e., regulators, patients, and clinicians), it is important to continue to examine a medication's impact and characteristics after it has received regulatory approval. Such studies vary in their purpose, scope, and methodology. In this chapter, we review the types of questions most likely to be investigated after regulatory approval, the methods generally used to investigate them, and the characteristics typically considered when prioritizing the allocation of resources.

Sensitivity of the EQ-5D-5L for fatigue and cognitive problems and their added value in Q-fever patients

Purpose

Measuring health-related quality of life (HRQoL) with the EQ-5D-5L might lack sensitivity for disease-specific health complaints. This cross-sectional study analyzed whether fatigue and cognitive problems are captured by the EQ-5D-5L in a Q-fever patient population with persistent fatigue/cognitive problems, and whether addition of fatigue/cognition improved the explained variance for HRQoL.

Methods

A Dutch sample of Q-fever patients filled out the EQ-5D-5L and EQ VAS, the fatigue subscale of the Checklist Individual Strength, and a cognition dimension in the EQ-5D-5L format. The extent to which fatigue and cognition were captured by the EQ-5D-5L was determined based on distributional effects, head-to-head comparisons, Spearman rank correlation coefficients, and regression analyses. Explanatory power was determined of the EQ-5D-5L for the EQ VAS with and without a fatigue and cognition dimension.

Results

Out of 432 respondents, 373(86%) reported severe fatigue, 387(90%) cognitive problems. EQ-5D-5L utility and EQ VAS scores of respondents reporting severe fatigue/cognitive problems were significantly lower. Fatigue was strongly correlated with EQ-5D-5L dimensions usual activities and pain/discomfort (r = 0.602 and r = 0.510) and moderately with other EQ-5D-5L dimensions (r = 0.305–0.476). Cognition was strongly correlated with usual activities (r = 0.554) and moderately with other dimensions (r = 0.291–0.451). Adding fatigue to the EQ-5D-5L increased explanatory power for the EQ VAS with 6%.

Conclusion

Fatigue and cognitive problems in Q-fever patients were partially captured by the EQ-5D-5L dimensions. The addition of fatigue to the EQ-5D-5L slightly improved explained variance for the EQ VAS. This potentially also accounts for patients who experience sequelae of other infectious diseases, such as COVID-19.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11136-021-03069-9.

Neuroinflammation in cognitive decline post-cardiac surgery (the FOCUS study): an observational study protocol

INTRODUCTION

Postoperative cognitive dysfunction occurs frequently after coronary artery bypass grafting (CABG). The underlying mechanisms remain poorly understood, but neuroinflammation might play a pivotal role. We hypothesise that systemic inflammation induced by the surgical trauma could activate the innate immune (glial) cells of the brain. This could lead to an exaggerated neuroinflammatory cascade, resulting in neuronal dysfunction and loss of neuronal cells. Therefore, the aims of this study are to assess neuroinflammation in vivo presurgery and postsurgery in patients undergoing major cardiac surgery and investigate whether there is a relationship of neuroinflammation to cognitive outcomes, changes to brain structure and function, and systemic inflammation.

METHODS AND ANALYSIS

The FOCUS study is a prospective, single-centre observational study, including 30 patients undergoing elective on-pump CABG. Translocator protein (TSPO) positron emission tomography neuroimaging will be performed preoperatively and postoperatively using the second generation tracer ¹⁸F-DPA-714 to assess the neuroinflammatory response. In addition, a comprehensive cerebral MRI will be performed presurgery and postsurgery, in order to discover newly developed brain and vascular wall lesions. Up to 6 months postoperatively, serial extensive neurocognitive assessments will be performed and blood will be obtained to quantify systemic inflammatory responses and peripheral immune cell activation.

ETHICS AND DISSEMINATION

Patients do not benefit directly from engaging in the study, but imaging neuroinflammation is considered safe and no side effects are expected. The study protocol obtained ethical approval by the Medical Research Ethics Committee region Arnhem-Nijmegen. This work will be published in peer-reviewed international medical journals and presented at medical conferences.

TRIAL REGISTRATION NUMBER

NCT04520802.