Functional and structural brain connectivity in disorders of consciousness.

Brain connectivity, allowing information to be shared between distinct cortical areas and thus to be processed in an integrated way, has long been considered critical for consciousness. However, the relationship between functional intercortical interactions and the structural connections thought to underlie them is poorly understood. In the present work, we explore both functional (with an EEG-based metric: the median weighted symbolic mutual information in the theta band) and structural (with a brain MRI-based metric: fractional anisotropy) connectivities in a cohort of 78 patients with disorders of consciousness. Both metrics could distinguish patients in a vegetative state from patients in minimally conscious state. Crucially, we discovered a significant positive correlation between functional and structural connectivities. Furthermore, we showed that this structure-function relationship is more specifically observed when considering structural connectivity within the intra- and inter-hemispheric long-distance cortico-cortical bundles involved in the Global Neuronal Workspace (GNW) theory of consciousness, thus supporting predictions of this model. Altogether, these results support the interest of multimodal assessments of brain connectivity in refining the diagnostic evaluation of patients with disorders of consciousness.

Impaired creative cognition after surgery for an IDH-mutated glioma: A proof-of-concept study.

Assessment of high cognitive functions, such as creativity, is often overlooked in medical practice. However, it is crucial to understand the impact of brain tumors, specifically low-grade gliomas, on creative cognition, as these tumors predominantly affect brain regions associated with cognitive creativity. In this study, we investigated creative cognition using the Alternative Uses Task (AUT) and the Combination of Associates Task (CAT) in a cohort of 29 patients who underwent brain surgery for a low-grade glioma, along with 27 control participants. While the group of patients did not exhibit deficits in clinical neuropsychological assessments, our results revealed significant impairment in generating original and creative ideas compared to the control group. Furthermore, when analyzing the specific brain regions affected by the tumors, patients with lesions overlapping the left rostro-lateral prefrontal cortex, a critical region for creativity, displayed more pronounced impairments in the CAT compared to patients with lesions outside this region. These findings provide proof of concept that patients can experience impaired creative cognition following surgery for low-grade glioma, highlighting the importance of assessing higher-order cognitive functions, including creativity, in neurosurgical patients. Moreover, beyond its clinical relevance, our study contributes to advancing our understanding of the neuroscience of creativity.

Endothelial cell biomarkers in critically ill COVID-19 patients with encephalitis.

COVID-19 is associated with encephalitis in critically ill patients and endothelial dysfunction seems to contribute to this life-threatening complication. Our objective was to determine the hallmark of endothelial activation in COVID-19-related encephalitis. In an observational study in intensive care unit (ICU), we compared vascular biomarkers of critically ill COVID-19 patients with or without encephalitis. To be classified in the encephalitis group, patients had to have new onset of central neurologic symptom, and pathological findings on either brain magnetic resonance imaging (MRI) and/or electroencephalogram (EEG). Among the 32 critically ill COVID-19 consecutive patients, 21 were categorized in the control group and 11 in the encephalitis group. Encephalitis patients had a longer ICU stay than control patients (median length [25th-75th percentile] of 52 [16-79] vs. 20.5 [11-44] days, respectively, p = 0.04). Nine-month overall follow-up mortality reached 21% (7/32 patients), with mortality rates in the encephalitis group and the control group of 27% and 19%, respectively. Encephalitis was associated with significant higher release of soluble endothelial activation markers (sE-selectin, tumor necrosis factor-α (TNF-α), interleukin 6, placental growth factor, and thrombomodulin), but these increases were correlated with TNF-α plasmatic levels. The hypoxia-inducible protein angiopoietin-like 4 (ANGPTL4) was at significantly higher levels in encephalitis patients compared to control patients (p = 0.0099), and in contrary to the other increased factors, was not correlated with TNF-α levels (r = 0.2832, p = 0.1163). Our findings suggest that COVID-19-related encephalitis is a cytokine-associated acute brain dysfunction. ANGPTL4 was the only elevated marker found in encephalitis patients, which was not correlated with systemic inflammation, suggesting that ANGPTL4 might be a relevant factor to predict encephalitis in critically ill COVID-19 patients.

Therapeutic plasma exchange in a critically ill Covid-19 patient.

Here we describe the effect of therapeutic plasma exchange with 5% albumin as sole replacement solution for the management of Covid-19. A 74-year-old man was admitted for severe Covid-19 acute respiratory distress syndrome. Based on the growing body of evidence that cytokine release syndrome, and especially interleukin-6, plays a key role in critically ill Covid-19 patients, we decided to implement therapeutic plasma exchange as a rescue therapy. The patient's clinical status rapidly improved, and biological records showed convincing results of decrease in interleukin-6 and inflammatory parameters under treatment. This case presents a proof-of-concept for the use of therapeutic plasma exchange with 5% albumin as sole replacement solution in a critically ill Covid-19 patient with cytokine release syndrome. This could constitute a major benefit in terms of security compared to long-lasting immunosuppressive monoclonal antibodies, or to therapeutic plasma exchange with plasma as replacement fluid. Hence, we think that a further evaluation of risk-benefit balance of this therapy in severe cases of Covid-19 should rapidly be undertaken.

Coronavirus disease 2019 crisis in Paris: A differential psychological impact between regular intensive care unit staff members and reinforcement workers.

BACKGROUND: Intensive care unit (ICU) healthcare workers (HCWs) are at the forefront of the coronavirus disease 2019 pandemic. To overcome the lack of human resources during this crisis, some ICUs had to mobilise staff from a reinforcement pool, with no or outdated ICU experience. This study aimed to investigate and to compare the psychological impact of the pandemic on regular ICU staff members and reinforcement workers. MATERIAL AND METHODS: Self-assessment questionnaires were completed by HCWs who worked from March 1 to April 30, 2020, in our 16-bed neurological ICU at La Pitié-Salpêtrière Hospital in Paris, France, which was converted to a COVID ICU. The Hospital Anxiety and Depression Scale, the Post-traumatic Stress Disorder Checklist for DSM-5, McGill Quality of Life Questionnaire-Revised, and 10-item Connor-Davidson Resilience Scale were used to assess anxiety, depression and post-traumatic stress disorder, quality of life, and resilience, respectively. RESULTS: Sixty-nine ICU HCWs completed the survey (37 from the team of regular staff members, i.e., from the public health service, and 32 from a reinforcement pool, either from non-ICU public health service or from private healthcare interim employment agencies). Prevalence of anxiety, depression, and post-traumatic stress disorder symptoms was high, at 19%, 9%, and 16%, respectively, with limited impairment in quality of life or resilience scores. Depression symptoms were observed more in regular staff members than in welcomed reinforcement workers, at 16% and 0%, respectively. CONCLUSIONS: These results revealed that during the pandemic, HCWs from the team of regular staff members were at greater risk of developing psychological disorder compared with reinforcement workers, with higher levels of depressive symptoms.

Neuroprognostication of Consciousness Recovery in a Patient with COVID-19 Related Encephalitis: Preliminary Findings from a Multimodal Approach.

Predicting the functional recovery of patients with severe neurological condition due to coronavirus disease 2019 (COVID-19) is a challenging task. Only limited outcome data are available, the pathophysiology is poorly understood, and the time-course of recovery is still largely unknown. Here, we report the case of a patient with COVID-19 associated encephalitis presenting as a prolonged state of unresponsiveness for two months, who finally fully recovered consciousness, functional communication, and autonomy after immunotherapy. In a multimodal approach, a high-density resting state EEG revealed a rich brain activity in spite of a severe clinical presentation. Using our previously validated algorithms, we could predict a possible improvement of consciousness in this patient. This case report illustrates the value of a multimodal approach capitalizing on advanced brain-imaging and bedside electrophysiology techniques to improve prognosis accuracy in this complex and new aetiology.