Brain dysfunction in COVID-19 and CAR-T therapy: cytokine storm-associated encephalopathy

EEG as a predictive biomarker of neurotoxicity in anti-CD19 CAR T-cell therapy

OBJECTIVE

Immune effector cell-associated neurotoxicity syndrome (ICANS) is a potentially fatal complication of CD19-directed CAR T-cell therapy. The aim of this study was to investigate the role of EEG as a predictive biomarker of ICANS.

METHODS

In this prospective, monocentric, cohort study, consecutive refractory B-cell non-Hodgkin lymphoma patients undergoing CAR T-cell therapy had EEG assessments at fixed time points pre- and post-infusion. The risk of ICANS was evaluated according to EEG findings detected qualitatively, using a grading scale ranging from 0 (normal) to 3 (severely abnormal), and quantitatively, using power spectral and connectivity measures.

RESULTS

307 EEGs from 68 patients have been qualitatively evaluated, of whom 238 were eligible for quantitative analysis. Neurotoxicity manifested in 22/68 (32.4%) patients. Pre-infusion EEG abnormalities (grade 1 and 2) were qualitatively detected in 8/68 (11.7%) patients, emerging as a risk factor for ICANS [HR 5.8 (95%CI 2.6-12.9)]. Quantitative analysis of pre-infusion EEGs did not yield significative results. Post-infusion qualitative EEG abnormalities were associated to a higher risk of ICANS development [HR 11.6 (4.4-30.5) for grade 2; HR 9.7 (2.6-36.6) for grade 3]. Concerning the quantitative analysis, in post-infusion EEGs higher theta energy [HR 1.10 (1.03-1.16)] and delta + theta/alfa ratio [HR 1.37 (1.11-1.67)] were associated to higher risk of ICANS, while higher beta energy resulted protective [HR 0.91 (0.85-0.97)].

CONCLUSIONS

Our study establishes EEG as a predictive tool for identifying patients at risk for ICANS before CAR T-cell infusion, who may benefit from prophylactic treatments, and anticipating ICANS onset following infusion, enabling early intervention.

Blood neurofilament light chain and S100B as biomarkers of neurological involvement and functional prognosis in COVID-19: a multicenter study

BACKGROUND AND AIM

COVID-19 is associated with neurological complications, termed neuro-COVID, affecting patient outcomes. We aimed to evaluate the association between serum neurofilament light chain (NfL) and S100B biomarkers with the presence of neurological manifestations and functional prognosis in COVID-19 patients.

METHODS

A multicenter prospective cohort study was conducted in three hospitals in the Emilia-Romagna region, Italy, from March 2020 to April 2022. Hospitalized patients with PCR-confirmed COVID-19 were enrolled. Serum S100B and NfL levels were measured in the acute or subacute phase after admission. Diagnostic accuracy was assessed using receiver operating characteristic (ROC) analyses. Statistical analyses were performed to evaluate the association between biomarkers, clinical/laboratory variables, and prognosis, specifically focusing on worsening of the modified Rankin Scale (mRS) from admission to discharge.

RESULTS

A total of 279 patients (153 males, median age 76.7 years) were included. Among them, 69 (24.7%) developed neuro-COVID. Serum NfL levels were significantly higher in the neuro-COVID group (median 110 vs 68.3; p = 0.035) and correlated with severe encephalopathy and extracranial neurologic manifestations. The ROC analysis showed low accuracy in the discrimination between the two groups for both NfL and S100B. Key predictors of worsening mRS included mechanical ventilation (OR = 9.56, 95% CI = 1.67-54.75; p = 0.011), severe encephalopathy (OR = 5.10, 95% CI = 1.58-16.19; p = 0.006), and elevated S100B levels (OR = 2.62, 95% CI = 1.10-6.46; p = 0.037).

CONCLUSIONS

Serum NfL and S100B biomarkers were not accurate in discriminating neuro-COVID patients, however NfL levels were associated with severe and extracranial neuro-COVID, while S100B with functional outcomes, potentially informing clinical management.

Favorable outcomes and FDG-PET changes following tocilizumab treatment for febrile infection-related epilepsy syndrome in a child

Febrile Infection-Related Epilepsy Syndrome (FIRES) is an infrequent yet severe form of epilepsy that rapidly evolves into status epilepticus following a febrile episode. Prompt diagnosis coupled with effective treatment strategies is critical for improving patient outcomes. Herein, we describe the case of an 11-year-old male with FIRES who was successfully treated with tocilizumab, resulting in no further seizures or residual disability. The patient initially did not respond to antiseizure medications and first-line immunomodulatory therapy. Characteristic EEG patterns and elevated interleukin 6 levels in the cerebrospinal fluid contributed to an early presumptive diagnosis of FIRES. Tocilizumab was administered on day 10 after the seizure onset, leading to seizure cessation within 24 h, with no subsequent episodes. Serial cranial MRI imaging studies demonstrated transient abnormalities that resolved over time. Notably, on day 9, the patient exhibited bilateral frontal lobe hypermetabolism on FDG-PET, with EEG showing global slow waves predominantly in the bilateral frontal regions. As seizure control was achieved and encephalopathy symptoms improved, a follow-up EEG on day 25 revealed persistent slow waves in the bilateral frontal regions, with FDG-PET hypermetabolism present only in the left frontal lobe. By day 88, both EEG and FDG-PET had returned to normal. These findings suggest tocilizumab may play a role in the management of FIRES, though further studies are required to substantiate its therapeutic efficacy. Additionally, early bilateral frontal FDG-PET hypermetabolism and EEG slow-wave activity, may serve as an early biomarker in FIRES patients. However, more research is necessary to establish its validity.

Late-onset relapsing neurotoxicity after Brexucabtagene autoleucel associated with high chimeric antigen receptor T cells in cerebrospinal fluid

BACKGROUND AIMS

Mounting evidence suggests that persistent cell expansion is the main driver for both efficacy and toxicity of chimeric antigen receptor (CAR) T-cell therapy. Hereby, we describe a case of delayed recurrent neurotoxicity associated with late CAR T-cells re-expansion.

CASE DESCRIPTION

A 44-year-old man suffering from mantle cell lymphoma received brexu-cel. After infusion, he developed grade 2 cytokine release syndrome. On day +11, grade 3 neurotoxicity was reported and high-dose methylprednisolone was started with a complete resolution of neurological manifestations. On day +30, he experienced a late-onset CAR T-cell toxicity associated with CAR T-cell re-expansion. The patient was treated with tocilizumab and dexamethasone, with resolution of symptoms. On day +58, he was readmitted for new onset of neurotoxicity. Notably, a new CAR T-cell expansion was observed, with an unexpectedly elevated cerebrospinal fluid/blood ratio. The patient was promptly treated with dexamethasone and then escalated to high-dose methylprednisolone and anakinra, with resolution of his neurologic condition noted.

CONCLUSIONS

CAR T-cell-related neurotoxicity usually has an early monophasic course. To our knowledge, this is the first case of late-onset, recurrent neurotoxicity. Moreover, an elevated level of cerebrospinal fluid CAR T cells was observed, which may suggest that the delayed neurotoxicity was primarily caused by the brain infiltration of CAR T cells rather than driven by cytokine-mediated neuroinflammation.

Acute and long-term effects of COVID-19 on brain and mental health: A narrative review

BACKGROUND

COVID infection has been associated with long term sequalae (Long COVID) which include neurological and behavioral effects in thousands of patients, but the etiology and scope of symptoms is not well understood. This paper reviews long term sequelae of COVID on brain and mental health in patients with the Long COVID syndrome.

METHODS

This was a literature review which queried databases for Pubmed, Psychinfo, and Medline for the following topics for January 1, 2020-July 15, 2023: Long COVID, PASC, brain, brain imaging, neurological, neurobiology, mental health, anxiety, depression.

RESULTS

Tens of thousands of patients have developed Long COVID, with the most common neurobehavioral symptoms anosmia (loss of smell) and fatigue. Anxiety and mood disorders are elevated and seen in about 25% of Long COVID patients. Neuropsychological testing studies show a correlation between symptom severity and cognitive dysfunction, while brain imaging studies show global decreases in gray matter and alterations in olfactory and other brain areas.

CONCLUSIONS

Studies to date show an increase in neurobehavioral disturbances in patients with Long COVID. Future research is needed to determine mechanisms.

Polygenic Landscape of Cryptogenic New-Onset Refractory Status Epilepticus: A Comprehensive Whole-Genome Sequencing Study

Cryptogenic new-onset refractory status epilepticus (cNORSE) is a devastating condition with unclear pathogenesis. Here, we analyzed the genetic underprints of 31 cNORSE patients from an autoimmune encephalitis observational cohort through whole-genome sequencing. Compared to their controls, cNORSE patients exhibited elevated polygenic risk scores (PRS) for traits associated with autoimmune diseases. The individual PRS against these diseases were correlated with specific clinical phenotypes of cNORSE. The variants were enriched in genes expressed in the central nervous system and lymphocytes. These results suggest a shared genetic framework between cNORSE and other autoimmune/autoinflammatory diseases, and its involvement in the disease pathogenesis. ANN NEUROL 2024;96:1201-1208.

Increased occurrence of microstate class B as the independent risk factor for persistent psychiatric symptoms related to omicron infection

OBJECTIVE

This study aimed to investigate the EEG microstate characteristics in patients with persistent Omicron-related Psychiatric Symptoms (ORPS) as well as their correlations with the severity of ORPS.

METHODS

This study included 31 patients with ORPS, and they were divided into remission group (n=19) and non-remission group (n=12) according to the decrease of Brief Psychiatric Rating Scale (BPRS) at discharge. Multivariate logistic models were applied to analyze the risk features associated with non-remission of ORPS at discharge, and the Spearman rank correlation was adopted to analyze the correlation between the occurrence of microstate class B and BPRS score at admission.

RESULTS

The analysis revealed that an increased occurrence of EEG microstate class B was significantly associated with a higher likelihood of non-remission of ORPS at discharge (p < 0.05). Furthermore, a moderate positive correlation was observed between the occurrence of microstate class B and BPRS scores at admission (r = 0.390, p = 0.030), indicating that patients with more frequent microstate class B tended to exhibit more severe psychiatric symptoms at onset.

CONCLUSIONS

The findings suggest that an increased occurrence of EEG microstate class B is an independent risk factor for non-remission of ORPS at discharge. Additionally, the positive correlation between microstate class B and BPRS scores underscores the potential of microstate class B as a biomarker for the severity of psychiatric symptoms in ORPS patients.

SIGNIFICANCE

Identifying the increased occurrence of microstate class B at admission could serve as a novel marker for early assessment of ORPS severity and prognostic evaluation.

Cerebral Malformations Related to Coronavirus Disease 2019 during Pregnancy

The pandemic of severe-acute-respiratory-syndrome-related coronavirus (SARS-CoV-2) has shown a wide spectrum of possible consequences in children, ranging from asymptomatic patients to the development of severe conditions, such as multisystem inflammatory syndrome in children and encephalopathies related to cytokine storm. Specifically, neurological and neuroimaging abnormalities, ranging from mild-to-the severe ones, have been documented in children as well, such as postinfectious immune-mediated acute disseminated encephalomyelitis, myelitis, neural enhancement, cranial nerve enhancement, and cortical injury, also without neurological symptoms. Considering the neurotropism of coronaviruses and SARS-CoV-2, which has been well described in the literature, we reviewed the literature reporting possible cerebral malformation in neonates due to the infection of SARS-CoV-2 in pregnancy. Coronavirus disease 2019 (COVID-19) during pregnancy might develop cerebral disorders in several ways. Articles in English in the literature were screened using the following search terms: (1) “brain malformations” AND “COVID-19”; (2) “cerebral malformations” AND “COVID-19”; (3) brain malformations AND “Sars-Cov-2”; (4) “cerebral malformations “AND “Sars-Cov-2.” Considering the congenital brain malformation found in newborns exposed to infection of SARS-Cov-2 pre- or neonatally, we identified one paper which reported three neonates with cerebral malformation. Although sporadic, cerebral malformations like atypical signals in white matter with delayed myelination, brain dysplasia/hypoplasia with delayed myelination, and unusual signals in the periventricular regions have been documented.

Parallel electrophysiological abnormalities due to COVID-19 infection and to Alzheimer's disease and related dementia

Many coronavirus disease 2019 (COVID-19) positive individuals exhibit abnormal electroencephalographic (EEG) activity reflecting "brain fog" and mild cognitive impairments even months after the acute phase of infection. Resting-state EEG abnormalities include EEG slowing (reduced alpha rhythm; increased slow waves) and epileptiform activity. An expert panel conducted a systematic review to present compelling evidence that cognitive deficits due to COVID-19 and to Alzheimer's disease and related dementia (ADRD) are driven by overlapping pathologies and neurophysiological abnormalities. EEG abnormalities seen in COVID-19 patients resemble those observed in early stages of neurodegenerative diseases, particularly ADRD. It is proposed that similar EEG abnormalities in Long COVID and ADRD are due to parallel neuroinflammation, astrocyte reactivity, hypoxia, and neurovascular injury. These neurophysiological abnormalities underpinning cognitive decline in COVID-19 can be detected by routine EEG exams. Future research will explore the value of EEG monitoring of COVID-19 patients for predicting long-term outcomes and monitoring efficacy of therapeutic interventions. HIGHLIGHTS: Abnormal intrinsic electrophysiological brain activity, such as slowing of EEG, reduced alpha wave, and epileptiform are characteristic findings in COVID-19 patients. EEG abnormalities have the potential as neural biomarkers to identify neurological complications at the early stage of the disease, to assist clinical assessment, and to assess cognitive decline risk in Long COVID patients. Similar slowing of intrinsic brain activity to that of COVID-19 patients is typically seen in patients with mild cognitive impairments, ADRD. Evidence presented supports the idea that cognitive deficits in Long COVID and ADRD are driven by overlapping neurophysiological abnormalities resulting, at least in part, from neuroinflammatory mechanisms and astrocyte reactivity. Identifying common biological mechanisms in Long COVID-19 and ADRD can highlight critical pathologies underlying brain disorders and cognitive decline. It elucidates research questions regarding cognitive EEG and mild cognitive impairment in Long COVID that have not yet been adequately investigated.

Clinical and neuroimaging features in neurological Wilson's disease with claustrum lesions

According to early research, the incidence of claustrum lesions in patients with neurological Wilson's disease (WD) was inconsistent, ranging from 1.8 to 75% on magnetic resonance imaging (MRI). Our study aims to explore the incidence, clinical presentation features, iconography features, and possible pathological mechanisms in WD patients with claustrum lesions on magnetic resonance imaging (MRI), to characterize the clinical, and brain imaging findings and possible pathological mechanisms in the patients with WD. Retrospective cases meeting the inclusion criteria were studied for analyzing MRI characteristics and associated physicochemical examination data in neurological WD patients with claustrum lesions. 443 (66.3%) with brain MRI abnormalities were screened from 668 WD patients. The three (0.7%) patients with the claustrum lesions characteristics on MRI images were: (a) "bright claustrum" in T2-weighted and FLAIR sequences, (b) bilateral symmetrical, (c) non-isolated lesions, (d) occurred only in severe neurological manifestations. The claustrum lesions are not common in neurological WD and mainly appear in cases with severe neurological symptoms. On MRI, the "bright claustrum" signs may be a radiographic marker of neuroinflammation, the features of the lesions showed bilateral symmetry, and hyperintensity signals on T2-weighted, FLAIR, and DWI.

Primary vs. pre-emptive anti-seizure medication prophylaxis in anti-CD19 CAR T-cell therapy

INTRODUCTION

Seizures may occur in up to 30% of non-Hodgkin lymphoma patients who received anti-CD19 CAR T-cell therapy, yet the optimal anti-seizure medication (ASM) prevention strategy has not been thoroughly investigated.

METHODS

Consecutive patients affected by refractory non-Hodgkin lymphoma who received anti-CD19 CAR T-cells were included. Patients were selected and assessed using similar internal protocols. ASM was started either as a primary prophylaxis (PP-group) before CAR T-cells infusion or as a pre-emptive therapy (PET-group) only upon the onset of neurotoxicity development.

RESULTS

One hundred fifty-six patients were included (PP-group = 88, PET-group = 66). Overall, neurotoxicity and severe neurotoxicity occurred in 45 (29%) and 20 (13%) patients, respectively, equally distributed between the two groups. Five patients experienced epileptic events (PET-group = 3 [4%]; PP-group = 2 [2%]). For all the PET-group patients, seizure/status epilepticus occurred in the absence of overt CAR-T-related neurotoxicity, whereas patients in the PP-group experienced brief seizures only in the context of critical neurotoxicity with progressive severe encephalopathy. ASMs were well-tolerated by all patients, even without titration. No patients developed epilepsy or required long-term ASMs.

CONCLUSION

Our data suggest that both primary and pre-emptive anti-seizure prophylaxis are safe and effective in anti-CD19 CAR T-cell recipients. Clinical rationale suggests a possible more favourable profile of primary prophylaxis, yet no definitive conclusion of superiority between the two ASM strategies can be drawn from our study.

The role of airways microbiota on local and systemic diseases: a rationale for probiotics delivery to the respiratory tract

INTRODUCTION

Recent discoveries in the field of lung microbiota have enabled the investigation of new therapeutic interventions involving the use of inhaled probiotics.

AREAS COVERED

This review provides an overview of what is known about the correlation between airway dysbiosis and the development of local and systemic diseases, and how this knowledge can be exploited for therapeutic interventions. In particular, the review focused on attempts to formulate probiotics that can be deposited directly on the airways.

EXPERT OPINION

Despite considerable progress since the emergence of respiratory microbiota restoration as a new research field, numerous clinical implications and benefits remain to be determined. In the case of local diseases, once the pathophysiology is understood, manipulating the lung microbiota through probiotic administration is an approach that can be exploited. In contrast, the effect of pulmonary dysbiosis on systemic diseases remains to be clarified; however, this approach could represent a turning point in their treatment.

Frontiers and hotspots evolution in cytokine storm: A bibliometric analysis from 2004 to 2022

Background

As a fatal disease, cytokine storm has garnered research attention in recent years. Nonetheless, as the body of related studies expands, a thorough and impartial evaluation of the current status of research on cytokine storms remains absent. Consequently, this study aimed to thoroughly explore the research landscape and evolution of cytokine storm utilizing bibliometric and knowledge graph approaches.

Methods

Research articles and reviews centered on cytokine storms were retrieved from the Web of Science Core Collection database. For bibliometric analysis, tools such as Excel 365, CiteSpace, VOSviewer, and the Bibliometrix R package were utilized.

Results

This bibliometric analysis encompassed 6647 articles published between 2004 and 2022. The quantity of pertinent articles and citation frequency exhibited a yearly upward trend, with a sharp increase starting in 2020. Network analysis of collaborations reveals that the United States holds a dominant position in this area, boasting the largest publication count and leading institutions. Frontiers in Immunology ranks as the leading journal for the largest publication count in this area. Stephan A. Grupp, a prominent researcher in this area, has authored the largest publication count and has the second-highest citation frequency. Research trends and keyword evaluations show that the connection between cytokine storm and COVID-19, as well as cytokine storm treatment, are hot topics in research. Furthermore, research on cytokine storm and COVID-19 sits at the forefront in this area.

Conclusion

This study employed bibliometric analysis to create a visual representation of cytokine storm research, revealing current trends and burgeoning topics in this area for the first time. It will provide valuable insights, helping scholars pinpoint critical research areas and potential collaborators.

High-dose glucocorticoids in COVID-19 patients with acute encephalopathy: clinical and imaging findings in a retrospective cohort study

OBJECTIVES

Acute encephalopathy (AE) has been described as a severe complication of COVID-19. Inflammation has been suggested as a pathogenic mechanism, with high-dose glucocorticoids (GC) showing a beneficial effect. Here, we retrospectively analyzed the clinical and radiological features in a group of COVID-19 AE patients who received GC treatment (GT) and in a non-treated (NT) group.

METHOD

Thirty-six patients with COVID-19 AE (mean age 72.6 ± 11 years; 86.11% men) were evaluated for GC treatment. Twelve patients (mean age 73.6 ± 4.5 years; 66.67% men) received GC, whereas 24 patients who showed signs of spontaneous remission were not treated with GC (mean age 70.1 ± 8.6 years; 95.83% men). Differences in clinical characteristics and correlations with imaging features were explored.

RESULTS

The GT group showed signs of vulnerability, with a longer hospitalization (p = 0.009) and AE duration (p = 0.012) and a higher hypertensive arteriopathy (HTNA) score (p = 0.022), when compared to NT group. At hospital discharge, the two groups were comparable in terms of clinical outcome (modified Rankin scale; p = 0.666) or mortality (p = 0.607). In our whole group analyses, AE severity was positively correlated with periventricular white matter hyperintensities (p = 0.011), deep enlarged perivascular spaces (p = 0.039) and HTNA score (p = 0.014).

CONCLUSION

This study suggests that, despite signs of radiological vulnerability and AE severity, patients treated by high-dose GC showed similar outcome at discharge, with respect to NT patients. Imaging features of cerebral small vessel disease correlated with AE severity, supporting the hypothesis that brain structural vulnerability can impact AE in COVID-19.

Current status and future prospects of chimeric antigen receptor-T cell therapy in lymphoma research: A bibliometric analysis

CAR-T cell therapy, a novel therapeutic approach that has attracted much attention in the field of cancer treatment at present, has become the subject of many studies and has shown great potential in the treatment of hematological malignancies, such as leukemia and lymphoma. This study aims to analyze the characteristics of articles published on CAR-T cell therapy in the lymphoma field and explore the existing hotspots and frontiers. The relevant articles published from 2013 to 2022 were retrieved from the Web of Science Core Collection. CiteSpace, VOSviewer, Bibliometric online analysis platform, Microsoft Excel, and R software were used for bibliometric analysis and visualization. The number of publications related to the research has been increasing year by year, including 1023 articles and 760 reviews from 62 countries and regions, 2092 institutions, 1040 journals, and 8727 authors. The United States, China, and Germany are the main publishing countries in this research field. The top 10 institutions are all from the United States, the journal with the highest impact factor is BLOOD, the author with the most publications is Frederick L Locke, and the most influential author is Carl H June. The top three keywords are "Lymphoma," "Immunotherapy," and "Therapy." "Maude (2014)" is the most cited and strongest burstiness reference over the past decade. This study provides a comprehensive bibliometric analysis of CAR-T cell therapy in lymphoma, which can help researchers understand the current research hotspots in this field, explore potential research directions, and identify future development trends.

Effects of COVID-19 on cognition and brain health

COVID-19 is associated with a range of neurological, cognitive, and mental health symptoms both acutely and chronically that can persist for many months after infection in people with long-COVID syndrome. Investigations of cognitive function and neuroimaging have begun to elucidate the nature of some of these symptoms. They reveal that, although cognitive deficits may be related to brain imaging abnormalities in some people, symptoms can also occur in the absence of objective cognitive deficits or neuroimaging changes. Furthermore, cognitive impairment may be detected even in asymptomatic individuals. We consider the evidence regarding symptoms, cognitive deficits, and neuroimaging, as well as their possible underlying mechanisms.

COVID-19 as a polymorphic inflammatory spectrum of diseases: a review with focus on the brain

There appear to be huge variations and aberrations in the reported data in COVID-19 2 years now into the pandemic. Conflicting data exist at almost every level and also in the reported epidemiological statistics across different regions. It is becoming clear that COVID-19 is a polymorphic inflammatory spectrum of diseases, and there is a wide range of inflammation-related pathology and symptoms in those infected with the virus. The host's inflammatory response to COVID-19 appears to be determined by genetics, age, immune status, health status and stage of disease. The interplay of these factors may decide the magnitude, duration, types of pathology, symptoms and prognosis in the spectrum of COVID-19 disorders, and whether neuropsychiatric disorders continue to be significant. Early and successful management of inflammation reduces morbidity and mortality in all stages of COVID-19.

Pre-existing frontal lobe dysfunction signs as predictors of subsequent neurotoxicity in CAR T cell therapy: insights from a case series

BACKGROUND

Chimeric Antigen Receptor (CAR) T cell therapies are innovative treatments against hematological malignancies, with increasing therapeutic indications. Despite their great efficacy, these therapies are hampered by high rates of neurotoxicity (immune effector cell-associated neurotoxicity (ICANS)). In the past few years, several risk factors have been associated with ICANS and grouped together in the attempt to build validated models able to predict neurologic complications. However, little is known about pre-existing neurologic conditions possibly related to the development of neurotoxicity.

METHODS AND RESULTS

In our case series, including sixteen consecutive patients treated with CAR T cells, we observed that (i) neurotoxicity only occurred in the two patients who presented subtle clinical signs of frontal lobe impairment at baseline and (ii) neurologic manifestations of ICANS consisted of language disturbances and cortical frontal myoclonus, which were both manifestations of a frontal predominant dysfunction.

DISCUSSION

Based on our experience, we suggest that a pre-existing frontal lobe impairment, even if at a subclinical level, may eventually drive to ICANS, which in turn shows symptoms compatible with a frontal encephalopathy. It is remarkable that this focal neurotoxicity involved the same CNS regions that were responsible of subtle neurological signs at baseline. Future studies on larger numbers of patients are needed to confirm the possible role of baseline frontal lobe dysfunction as a predictor of ICANS, in order to enhance efforts to safely deliver CAR T cell therapy.

Brain FDG-PET findings in chimeric antigen receptor T-cell therapy neurotoxicity for diffuse large B-cell lymphoma

BACKGROUND AND PURPOSE

Chimeric antigen receptor (CAR) T-cell therapy is potentially associated with treatment-related toxicities mainly consisting of cytokine release syndrome (CRS) and immune-effector cell-associated neurotoxicity syndrome (ICANS). We evaluated brain metabolic correlates of CRS with and without ICANS in diffuse large B-cell lymphoma patients treated with CAR-T.

METHODS

Twenty-one refractory DLCBLs underwent whole-body and brain [18 F]-fluorodeoxyglucose (FDG) PET before and 30 days after treatment with CAR-T. Five patients did not develop inflammatory-related side effects, 11 patients developed CRS, while in 5 patients CRS evolved in ICANS. Baseline and post-CAR-T brain FDG-PET were compared with a local controls dataset to identify hypometabolic patterns both at single-patient and group levels (p < .05 after correction for family-wise error [FWE). Metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were computed on baseline FDG-PET and compared between patients' subgroups (t-test).

RESULTS

ICANS showed an extended and bilateral hypometabolic pattern mainly involving the orbitofrontal cortex, frontal dorsolateral cortex, and anterior cingulate (p < .003 FWE-corrected). CRS without ICANS showed significant hypometabolism in less extended clusters mainly involving bilateral medial and lateral temporal lobes, posterior parietal lobes, anterior cingulate, and cerebellum (p < .002 FWE-corrected). When compared, ICANS showed a more prominent hypometabolism in the orbitofrontal and frontal dorsolateral cortex in both hemispheres than CRS (p < .002 FWE-corrected). Mean baseline MTV and TLG were significantly higher in ICANS than CRS (p < .02).

CONCLUSIONS

Patients with ICANS are characterized by a frontolateral hypometabolic signature coherently with the hypothesis of ICANS as a predominant frontal syndrome and with the more prominent susceptibility of frontal lobes to cytokine-induced inflammation.

Pathophysiology, diagnosis, and management of neuroinflammation in covid-19

Although neurological complications of SARS-CoV-2 infection are relatively rare, their potential long term morbidity and mortality have a significant impact, given the large numbers of infected patients. Covid-19 is now in the differential diagnosis of a number of common neurological syndromes including encephalopathy, encephalitis, acute demyelinating encephalomyelitis, stroke, and Guillain-Barré syndrome. Physicians should be aware of the pathophysiology underlying these presentations to diagnose and treat patients rapidly and appropriately. Although good evidence has been found for neurovirulence, the neuroinvasive and neurotropic potential of SARS-CoV-2 is limited. The pathophysiology of most complications is immune mediated and vascular, or both. A significant proportion of patients have developed long covid, which can include neuropsychiatric presentations. The mechanisms of long covid remain unclear. The longer term consequences of infection with covid-19 on the brain, particularly in terms of neurodegeneration, will only become apparent with time and long term follow-up.

Multidisciplinary recommendations for the management of CAR-T recipients in the post-COVID-19 pandemic era

The outbreak of coronavirus disease 2019 (COVID-19) posed an unprecedented challenge on public health systems. Despite the measures put in place to contain it, COVID-19 is likely to continue experiencing sporadic outbreaks for some time, and individuals will remain susceptible to recurrent infections. Chimeric antigen receptor (CAR)-T recipients are characterized by durable B-cell aplasia, hypogammaglobulinemia and loss of T-cell diversity, which lead to an increased proportion of severe/critical cases and a high mortality rate after COVID-19 infection. Thus, treatment decisions have become much more complex and require greater caution when considering CAR T-cell immunotherapy. Hence, we reviewed the current understanding of COVID-19 and reported clinical experience in the management of COVID-19 and CAR-T therapy. After a panel discussion, we proposed a rational procedure pertaining to CAR-T recipients with the aim of maximizing the benefit of CAR-T therapy in the post COVID-19 pandemic era.

Neurological adverse effects of chimeric antigen receptor T-cell therapy

INTRODUCTION

Chimeric antigen receptor (CAR) T-cell is among the most prevalent approaches that act by directing T-cells toward cancer; however, they need to be optimized to minimize side effects and maximize efficacy before being used as standard treatment for malignancies. Neurotoxicity associated with CAR T-cell therapy has been well-documented in recent works.

AREAS COVERED

In this regard, two established syndromes exist. Immune effector cell-associated neurotoxicity syndrome (ICANS), previously called cytokine release encephalopathy syndrome (CRES), is a neuropsychiatric condition which can occur after therapy by immune effector cells (IEC) and T-lymphocytes utilizing treatments. Another syndrome is cytokine release syndrome (CRS), which may overlap with ICANS.

EXPERT OPINION

ICANS clinical manifestations include cerebral edema, mild lethargy, aphasia, and seizures. Notably, ICANS is associated with changes to EEG and neuroradiological findings. Therefore, it is necessary to make a timely and accurate diagnosis of neurological complications of CAR T-cells by clinical presentations, neuroimaging, and EEG. Since neurological events by different CAR T-cell products are heterogeneous, guides should be developed according to each product. Here, we provide an updated review of general information on CAR T-cell therapies and applications, neurological syndromes associated with their use, and risk factors contributing to ICANS.

COVID-19 delirium and encephalopathy: Pathophysiology assumed in the first 3 years of the ongoing pandemic

Background

The coronavirus disease (COVID-19) continues to spread worldwide. It has a high rate of delirium, even in young patients without comorbidities. Infected patients required isolation because of the high infectivity and virulence of COVID-19. The high prevalence of delirium in COVID-19 primarily results from encephalopathy and neuroinflammation caused by acute respiratory distress syndrome (ARDS)-associated cytokine storm. Acute respiratory distress syndrome has been linked to delirium and psychotic symptoms in the subacute phase (4 to 12 weeks), termed post-acute COVID-19 syndrome (PACS), and to brain fog, cognitive dysfunction, and fatigue, termed "long COVID," which persists beyond 12 weeks. However, no review article that mentions "COVID-19 delirium" have never been reported.

Basic Procedures

This narrative review summarizes data on delirium associated with acute severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and related neurological symptoms of persistent post-infection illness (PACS or long COVID) after persistence of cognitive dysfunction. Thus, we describe the pathophysiological hypothesis of COVID-19 delirium and its continuation as long COVID. This review also describes the treatment of delirium complicated by COVID-19 pneumonia.

Main Findings

SARS-CoV-2 infection is associated with encephalopathy and delirium. An association between COVID-19 infection and Alzheimer's disease has been suggested, and studies are being conducted from multiple facets including genetics, cytology, and postmortem study.

Principal Conclusions

This review suggests that COVID-19 has important short and long-term neuropsychiatric effects. Several hypotheses have been proposed that highlight potential neurobiological mechanisms as causal factors, including neuronal-inflammatory pathways by cytokine storm and cellular senescence, and chronic inflammation.

Acute Vaccine-Related Encephalopathy and Acute Disseminated Encephalomyelitis (ADEM) After COVID-19 Vaccination: A Case Series From Bangladesh

There are several reported cases of various neurological adverse effects following the COVID-19 vaccination globally. Acute vaccine-related encephalopathy and acute disseminated encephalomyelitis (ADEM) are included among them. Here we are reporting three cases of ADEM and one case of acute vaccine-related encephalopathy from Bangladesh, which have a possible association with COVID-19 vaccines. All three ADEM cases were elderly; two cases developed symptoms after receiving the second dose of the Sinopharm vaccine, and another case after receiving the second dose of the Sinovac vaccine. We have treated another case of acute vaccine-related encephalopathy following receiving the Moderna vaccine. The patients had features of encephalopathy, including altered consciousness and convulsions. The ADEM cases had MRI (magnetic resonance imaging) brain findings suggestive of ADEM. The other case had normal MRI findings. All the cases were treated with intravenous corticosteroids with full recovery, except for one ADEM patient, who developed aspiration pneumonia and died. Though it is not possible to conclude that COVID-19 vaccination is the causative agent behind these cases, this case series will help to increase awareness regarding the early detection and treatment of these serious adverse effects.

In vitro evidence against productive SARS-CoV-2 infection of human testicular cells: Bystander effects of infection mediate testicular injury

The hallmark of severe COVID-19 involves systemic cytokine storm and multi-organ injury including testicular inflammation, reduced testosterone, and germ cell depletion. The ACE2 receptor is also expressed in the resident testicular cells, however, SARS-CoV-2 infection and mechanisms of testicular injury are not fully understood. The testicular injury could be initiated by direct virus infection or exposure to systemic inflammatory mediators or viral antigens. We characterized SARS-CoV-2 infection in different human testicular 2D and 3D culture systems including primary Sertoli cells, Leydig cells, mixed seminiferous tubule cells (STC), and 3D human testicular organoids (HTO). Data shows that SARS-CoV-2 does not productively infect any testicular cell type. However, exposure of STC and HTO to inflammatory supernatant from infected airway epithelial cells and COVID-19 plasma decreased cell viability and resulted in the death of undifferentiated spermatogonia. Further, exposure to only SARS-CoV-2 Envelope protein caused inflammatory response and cytopathic effects dependent on TLR2, while Spike 1 or Nucleocapsid proteins did not. A similar trend was observed in the K18-hACE2 transgenic mice which demonstrated a disrupted tissue architecture with no evidence of virus replication in the testis that correlated with peak lung inflammation. Virus antigens including Spike 1 and Envelope proteins were also detected in the serum during the acute stage of the disease. Collectively, these data strongly suggest that testicular injury associated with SARS-CoV-2 infection is likely an indirect effect of exposure to systemic inflammation and/or SARS-CoV-2 antigens. Data also provide novel insights into the mechanism of testicular injury and could explain the clinical manifestation of testicular symptoms associated with severe COVID-19.

CAR t-cell therapy in BOlogNa-NEUrotoxicity TReatment and Assessment in Lymphoma (CARBON-NEUTRAL): proposed protocol and results from an Italian study

OBJECTIVE

To investigate neurotoxicity clinical and instrumental features, incidence, risk factors, and early and long-term prognosis in lymphoma patients who received CAR T-cell therapy.

METHODS

In this prospective study, consecutive refractory B-cell non-Hodgkin lymphoma patients who received CAR T-cell therapy were included. Patients were comprehensively evaluated (neurological examination, EEG, brain MRI, and neuropsychological test) before and after (two and twelve months) CAR T-cells. From the day of CAR T-cells infusion, patients underwent daily neurological examinations to monitor the development of neurotoxicity.

RESULTS

Forty-six patients were included in the study. The median age was 56.5 years, and 13 (28%) were females. Seventeen patients (37%) developed neurotoxicity, characterized by encephalopathy frequently associated with language disturbances (65%) and frontal lobe dysfunction (65%). EEG and brain FDG-PET findings also supported a predominant frontal lobe involvement. The median time at onset and duration were five and eight days, respectively. Baseline EEG abnormalities predicted ICANS development in the multivariable analysis (OR 4.771; CI 1.081-21.048; p = 0.039). Notably, CRS was invariably present before or concomitant with neurotoxicity, and all patients who exhibited severe CRS (grade ≥ 3) developed neurotoxicity. Serum inflammatory markers were significantly higher in patients who developed neurotoxicity. A complete neurological resolution following corticosteroids and anti-cytokines monoclonal antibodies was reached in all patients treated, except for one patient developing a fatal fulminant cerebral edema. All surviving patients completed the 1-year follow-up, and no long-term neurotoxicity was observed.

CONCLUSIONS

In the first prospective Italian real-life study, we presented novel clinical and investigative insights into ICANS diagnosis, predictive factors, and prognosis.

Carotid free-floating thrombus in COVID-19: a cerebrovascular disorder of cytokine storm-related immunothrombosis

BACKGROUNDS

Several neurological manifestations, including stroke, have been reported in COVID-19 patients. The putative role of the COVID-19-related hyperinflammatory state in cerebrovascular disorders remains unclear.

METHODS

From March 2020 to September 2021, we searched for patients who exhibited an ischemic stroke related to carotid free-floating thrombus (CFFT) to investigate its incidence and relationship with COVID-19.

RESULTS

Of 853 ischemic strokes referred to our Stroke Centre during the study period, 5.7% (n = 49) were positive for SARS-CoV-2. Six had CFFT, of which two tested positive for SARS-CoV-2 (2/49 = 4.1%), and four did not (4/802 = 0.5%). The former were two middle-aged men suffering from COVID-19 pneumonia. Floating thrombi were promptly extracted by endarterectomy and endovascular thrombectomy, respectively, with no early and long-term complications. Notably, our COVID-19 patients exhibited little or no atherosclerosis burden on CT angiography, markedly elevated D-dimer levels, and extensive thrombus length.

CONCLUSIONS

COVID-19-induced immunothrombosis possibly played a significant pathogenic role in CFFT.

Case report: Reversible punctate inflammatory foci in the corpus callosum: A novel radiological finding of CAR T-cell therapy-related neurotoxicity

Introduction

Chimeric antigen receptor T-cell therapy-related neurotoxicity is a novel cytokine-mediated neurological syndrome that may present with a broad spectrum of manifestations. Descriptions of novel distinctive features are pivotal to untangling this condition's clinical and instrumental signature in order to inform diagnosis and pathophysiology.

Case

A 27-year-old female patient received anti-CD19 CAR T cells for a refractory primary mediastinal B-cell lymphoma. At 6 days after the infusion, she developed mild ideo-motor slowing, dysgraphia, and drowsiness. Despite specific treatment with dexamethasone, her neurological status progressively worsened to a comatose state within 24 h. EEG and CSF analyses were non-specific, showing background slowing and inflammatory findings. Brain MRI revealed multiple focal punctate areas of T2-weighted hyperintensity localized in the body and isthmus of the corpus callosum. Following the administration of high-dose intravenous methylprednisolone, her neurological status resolved within 48 h. Notably, the follow-up brain MRI did not reveal any abnormalities in the corpus callosum, except for a reduction of fractional anisotropy.

Conclusion

Reversible punctate inflammatory foci of the body and isthmus of the corpus callosum may represent a novel radiological finding of CAR T-cell therapy-related neurotoxicity.

Time course of serum cytokine level changes within 72 h after onset in children with acute encephalopathy and febrile seizures

BACKGROUND

Cytokine levels have been measured in acute encephalopathy (AE) to determine its pathology or as a diagnostic biomarker to distinguish it from febrile seizures (FS); however, the dynamics of cytokine level changes have not yet been fully captured in these two neurological manifestations. Thus, we aimed to explore the time course of serum cytokine level changes within 72 h after onset in AE and FS.

METHODS

We retrospectively measured cytokine level in residual serum samples at multiple timepoints in seven children whose final diagnoses were AE or FS.

RESULTS

The levels of 13 cytokines appeared to increase immediately after onset and peaked within 12-24 h after onset: interleukin (IL)-1β, IL-4 IL-5, IL-6, IL-8, IL-10, IL-17, eotaxin, fibroblast growth factor, granulocyte colony-stimulating factor, interferon gamma, interferon-inducible protein-10, and macrophage chemoattractant protein-1. There were no dynamic changes in the levels of three cytokines (IL-1 receptor agonist, macrophage inflammatory protein-1α, and platelet-derived growth factor-bb) 72 h after onset. Levels of some cytokines decreased to around control levels within 48 h after onset: IL-1β, IL-4, IL-5, IL-17, fibroblast growth factor, and interferon gamma. The levels of most cytokines appeared to be higher in AE, especially in hemorrhagic shock encephalopathy syndrome, than in FS.

CONCLUSIONS

Cytokine levels in both AE and FS change dynamically, such as the levels of several cytokines increased within a few hours after onset and decreased at 12-24 h after onset. Therefore, it will be desirable to make clinical decisions regarding the administration of anti-inflammatory therapy in 24 h after onset in AE.

Neurological Manifestations of Long COVID: A Single-Center One-Year Experience

PURPOSE

We report our single-center experience on the neurological manifestations of long COVID.

PATIENTS AND METHODS

This is a retrospective observational study. All consecutive patients referred to the neurological long COVID outpatient clinic of our institute from January 21 2021 to December 9 2021 underwent a general neurological objective examination. Treatments and investigations (brain MRI, neuropsychological evaluation, or others) were prescribed on an individual basis as per standard clinical practice. A follow-up visit was performed when appropriate. Descriptive statistics were presented as absolute and relative frequencies for categorical variables and as means, median, and ranges for continuous variables.

RESULTS

One hundred and three patients were visited (mean age 50.5 ±36 years, 62 females). The average time from acute COVID-19 infection to the first visit to our outpatient clinic was 243 days. Most patients presented with a mild form of acute COVID-19, with only 24 cases requiring hospitalization. The neurological symptoms mostly (n=70/103, 68%) started during the acute phase (before a negative swab for SARS-CoV-2). The most frequent acute manifestations reported, which lately became persistent, were fatigue (n=58/103, 56%), olfactory/taste dysfunction (n=58/103, 56%), headache (n=47/103, 46%), cognitive disorders (n=46/103, 45%), sleep disorders (n=30/103, 29%), sensitivity alterations (n=29/103, 28%), and dizziness (n=7/103, 7%). Tremor was also reported (n=8/103, 7%). Neuropsychological evaluation was performed in 30 patients and revealed alterations in executive functions (n=6/30, 20%), memory (n=11/30, 37%), with pathological depressive (n=9/30, 30%) and anxiety (n=8/30, 27%) scores. Brain MRIs have been performed in 41 cases, revealing nonspecific abnormal findings only in 4 cases. Thirty-six patients underwent a follow-up, where a general improvement was observed but rarely (n=2/36) a complete recovery.

CONCLUSION

The majority of patients presenting persistent neurological symptoms (most frequently fatigue, cognitive disorders, and olfactory dysfunctions) developed a previous mild form of COVID-19. Further studies are required to develop therapeutic strategies.

Infection and inflammation: radiological insights into patterns of pediatric immune-mediated CNS injury

The central nervous system (CNS) undergoes constant immune surveillance enabled via regionally specialized mechanisms. These include selectively permissive barriers and modifications to interlinked innate and adaptive immune systems that detect and remove an inciting trigger. The end-points of brain injury and edema from these triggers are varied but often follow recognizable patterns due to shared underlying immune drivers. Imaging provides insights to understanding these patterns that often arise from unique interplays of infection, inflammation and genetics. We review the current updates in our understanding of these intersections and through examples of cases from our practice, highlight that infection and inflammation follow diverse yet convergent mechanisms that can challenge the CNS in children.

Novel pathophysiological insights into CAR-T cell associated neurotoxicity

Chimeric antigen receptor (CAR) T cell therapy represents a scientific breakthrough in the treatment of advanced hematological malignancies. It relies on cell engineering to direct the powerful cytotoxic T-cell activity toward tumor cells. Nevertheless, these highly powerful cell therapies can trigger substantial toxicities such as cytokine release syndrome (CRS) and immune cell-associated neurological syndrome (ICANS). These potentially fatal side effects are now better understood and managed in the clinic but still require intensive patient follow-up and management. Some specific mechanisms seem associated with the development of ICANS, such as cytokine surge caused by activated CAR-T cells, off-tumor targeting of CD19, and vascular leak. Therapeutic tools are being developed aiming at obtaining better control of toxicity. In this review, we focus on the current understanding of ICANS, novel findings, and current gaps.

Encephalopathy in 2 paediatric patients with SARS-CoV-2 infection benefited from early immunosuppressive treatment: a case report

Background

Reports of neurological involvement are building up ever since COVID-19 has become a pandemic. Although rare, SARS-CoV-2 encephalopathy is a devastating complication associated with poor prognosis. Cytokine storm has been implicated in its pathophysiology.

Case presentation

We are reporting two paediatric patients who have contracted with COVID-19 and developed encephalopathy, who presented with status epilepticus and altered consciousness. Early aggressive immunosuppressive treatment was initiated promptly and both of them were able to recover without neurological deficit.

Conclusion

Patients with SARS-CoV-2 encephalopathy should be put on immunosuppressive therapy early for better neurological outcome. This improvement after the use of immunosuppressants further strengthened the cytokine storm theory in SARS-CoV-2 encephalopathy.

Acute necrotizing encephalopathy associated with lymphoma-associated hemophagocytic lymphohistiocytosis: A case report and literature review

Damage associated with lymphoma-associated hemophagocytic lymphohistiocytosis (LA-HLH) to the central nervous system (CNS) is not uncommon. However, the combination with brain damage resembling acute necrotizing encephalopathy (ANE) is rarely reported. Herein, we introduce the diagnosis and treatment of a case of ANE associated with LA-HLH in our hospital and review the relevant literature. After treatment, the child was discharged with only dysarthria and decreased sucking ability. The child is now discharged from the hospital for 6 months with regular follow-up. There were no disease recurrence signs. LA-HLH and ANE were related to cytokine storm. Therefore, early steroid application is essential for treating these diseases.

In vitro evidence against productive SARS-CoV-2 infection of human testicular cells: Bystander effects of infection mediate testicular injury

The hallmark of severe COVID-19 involves systemic cytokine storm and multi-organ failure including testicular injury and germ cell depletion. The ACE2 receptor is also expressed in the resident testicular cells however, SARS-CoV-2 infection and mechanisms of testicular injury are not fully understood. The testicular injury can likely result either from direct virus infection of resident cells or by exposure to systemic inflammatory mediators or virus antigens. We here characterized SARS-CoV-2 infection in different human testicular 2D and 3D models including primary Sertoli cells, Leydig cells, mixed seminiferous tubule cells (STC), and 3D human testicular organoids (HTO). Data shows that SARS-CoV-2 does not establish a productive infection in any testicular cell types. However, exposure of STC and HTO to inflammatory supernatant from infected airway epithelial cells and COVID-19 plasma depicted a significant decrease in cell viability and death of undifferentiated spermatogonia. Further, exposure to only SARS-CoV-2 envelope protein, but not Spike or nucleocapsid proteins led to cytopathic effects on testicular cells that was dependent on the TLR2 receptor. A similar trend was observed in the K18h-ACE2 mouse model which revealed gross pathology in the absence of virus replication in the testis. Collectively, data strongly indicates that the testicular injury is not due to direct infection of SARS-CoV-2 but more likely an indirect effect of exposure to systemic inflammation or SARS-CoV-2 antigens. Data also provide novel insights into the mechanism of testicular injury and could explain the clinical manifestation of testicular symptoms associated with severe COVID-19.

Robust immune responses to SARS-CoV-2 in a pediatric patient with B-Cell ALL receiving tisagenlecleucel

Recipients of anti-CD19 targeted therapies such as chimeric antigen receptor (CAR)-T cell are considered at high risk for complicated Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) infection due to prolonged B cell aplasia and immunosuppression. These patients represent a unique cohort and so far, immune responses to SARS-CoV-2 have not been well characterized in this setting. We report a pediatric patient with B-cell acute lymphoblastic leukemia (B-ALL) who had asymptomatic SARS-CoV-2 infection while receiving blinatumomab, followed by lymphodepletion (LD) and tisagenlecleucel, a CD19 targeting CAR-T therapy. The patient had a complete response to tisagenlecleucel, did not develop cytokine release syndrome, or worsening of SARS-CoV-2 during therapy. The patient had evidence of ongoing persistence of IgG antibody responses to spike and nucleocapsid after LD followed by tisagenlecleucel despite the B-cell aplasia. Further we were able to detect SARS-CoV-2 specific T-cells recognizing multiple viral structural proteins for several months following CAR-T. The T-cell response was polyfunctional and predominantly CD4 restricted. This data has important implications for the understanding of SARS-CoV-2 immunity in patients with impaired immune systems and the potential application of SARS-CoV-2-specific T-cell therapeutics to treat patients with blood cancers who receive B cell depleting therapy.

Therapeutic Approaches to the Neurologic Manifestations of COVID-19

As of May 2022, there have been more than 527 million infections with severe acute respiratory disease coronavirus type 2 (SARS-CoV-2) and over 6.2 million deaths from Coronavirus Disease 2019 (COVID-19) worldwide. COVID-19 is a multisystem illness with important neurologic consequences that impact long-term morbidity and mortality. In the acutely ill, the neurologic manifestations of COVID-19 can include distressing but relatively benign symptoms such as headache, myalgias, and anosmia; however, entities such as encephalopathy, stroke, seizures, encephalitis, and Guillain-Barre Syndrome can cause neurologic injury and resulting disability that persists long after the acute pulmonary illness. Furthermore, as many as one-third of patients may experience persistent neurologic symptoms as part of a Post-Acute Sequelae of SARS-CoV-2 infection (Neuro-PASC) syndrome. This Neuro-PASC syndrome can affect patients who required hospitalization for COVID-19 or patients who did not require hospitalization and who may have had minor or no pulmonary symptoms. Given the large number of individuals affected and the ability of neurologic complications to impair quality of life and productivity, the neurologic manifestations of COVID-19 are likely to have major and long-lasting personal, public health, and economic consequences. While knowledge of disease mechanisms and therapies acquired prior to the pandemic can inform us on how to manage patients with the neurologic manifestations of COVID-19, there is a critical need for improved understanding of specific COVID-19 disease mechanisms and development of therapies that target the neurologic morbidities of COVID-19. This current perspective reviews evidence for proposed disease mechanisms as they inform the neurologic management of COVID-19 in adult patients while also identifying areas in need of further research.

The role of neurologists in the era of cancer immunotherapy: Focus on CAR T-cell therapy and immune checkpoint inhibitors

Cancer immunotherapy represents a novel anticancer strategy that acts directly on the immune system, promoting its activation toward cancer cells to enhance its natural ability to fight cancer. Among various treatments currently used or investigated, chimeric antigen receptors (CAR) T-cell therapy and immune checkpoint inhibitors (ICIs) have consistently proven their efficacy. These innovations are progressively improving the standard of care in cancer treatment, yet they are hampered by novel neurological adverse events, attributing to neurologists a key role in the multidisciplinary oncological team. Indeed, neurotoxicity may develop in up to 77% of patients who received CAR T-cell therapy and usually presents with encephalopathy characterized by a predominant frontal lobe dysfunction. This neurotoxicity is related to cytokine release syndrome, a systemic hyperinflammatory condition triggered by CAR T-cells. On the other hand, following treatment with ICIs, unrestrained T-cells may lead to central and peripheral neurological disorders by antigen-directed autoimmunity. Notably, biological and clinical similarities have been underlined between neurotoxicity related to CAR T-cell therapy and neurological manifestations of cytokine storms (e.g. COVID-19-related encephalopathy), as well as between a subgroup of ICI-related neurological adverse events and paraneoplastic neurological syndromes. Therefore, these cancer immunotherapy-related neurological syndromes may provide an unprecedented, perhaps transitory, opportunity to shed light on the underlying pathogenic mechanisms of a wide spectrum of neurological syndromes and to push forward our knowledge in neuroimmunology.

Pathological Features and Neuroinflammatory Mechanisms of SARS-CoV-2 in the Brain and Potential Therapeutic Approaches

The number of deaths has been increased due to COVID-19 infections and uncertain neurological complications associated with the central nervous system. Post-infections and neurological manifestations in neuronal tissues caused by COVID-19 are still unknown and there is a need to explore how brainstorming promoted congenital impairment, dementia, and Alzheimer's disease. SARS-CoV-2 neuro-invasion studies in vivo are still rare, despite the fact that other beta-coronaviruses have shown similar properties. Neural (olfactory or vagal) and hematogenous (crossing the blood-brain barrier) pathways have been hypothesized in light of new evidence showing the existence of SARS-CoV-2 host cell entry receptors into the specific components of human nerve and vascular tissue. Spike proteins are the primary key and structural component of the COVID-19 that promotes the infection into brain cells. Neurological manifestations and serious neurodegeneration occur through the binding of spike proteins to ACE2 receptor. The emerging evidence reported that, due to the high rate in the immediate wake of viral infection, the olfactory bulb, thalamus, and brain stem are intensely infected through a trans-synaptic transfer of the virus. It also instructs the release of chemokines, cytokines, and inflammatory signals immensely to the blood-brain barrier and infects the astrocytes, which causes neuroinflammation and neuron death; and this induction of excessive inflammation and immune response developed in more neurodegeneration complications. The present review revealed the pathophysiological effects, molecular, and cellular mechanisms of possible entry routes into the brain, pathogenicity of autoantibodies and emerging immunotherapies against COVID-19.

CSF Biomarkers in COVID-19 Associated Encephalopathy and Encephalitis Predict Long-Term Outcome

Patients with coronavirus disease 2019 (COVID-19) frequently develop acute encephalopathy and encephalitis, but whether these complications are the result from viral-induced cytokine storm syndrome or anti-neural autoimmunity is still unclear. In this study, we aimed to evaluate the diagnostic and prognostic role of CSF and serum biomarkers of inflammation (a wide array of cytokines, antibodies against neural antigens, and IgG oligoclonal bands), and neuroaxonal damage (14-3-3 protein and neurofilament light [NfL]) in patients with acute COVID-19 and associated neurologic manifestations (neuro-COVID). We prospectively included 60 hospitalized neuro-COVID patients, 25 (42%) of them with encephalopathy and 14 (23%) with encephalitis, and followed them for 18 months. We found that, compared to healthy controls (HC), neuro-COVID patients presented elevated levels of IL-18, IL-6, and IL-8 in both serum and CSF. MCP1 was elevated only in CSF, while IL-10, IL-1RA, IP-10, MIG and NfL were increased only in serum. Patients with COVID-associated encephalitis or encephalopathy had distinct serum and CSF cytokine profiles compared with HC, but no differences were found when both clinical groups were compared to each other. Antibodies against neural antigens were negative in both groups. While the levels of neuroaxonal damage markers, 14-3-3 and NfL, and the proinflammatory cytokines IL-18, IL-1RA and IL-8 significantly associated with acute COVID-19 severity, only the levels of 14-3-3 and NfL in CSF significantly correlated with the degree of neurologic disability in the daily activities at 18 months follow-up. Thus, the inflammatory process promoted by SARS-CoV-2 infection might include blood-brain barrier disruption in patients with neurological involvement. In conclusion, the fact that the levels of pro-inflammatory cytokines do not predict the long-term functional outcome suggests that the prognosis is more related to neuronal damage than to the acute neuroinflammatory process.

Case of possible encephalopathy following receiving the first dose of Iranian COVID-19Vaccine; COVIran Barakat

We report a case of possible encephalopathy after receiving the first dose of Iran's COVIran Barekat vaccine. The patient had no history of neurological or mental illness. Clinical examinations and radiology reports were performed and differential diagnoses were analyzed by the treatment team. Finally, the possible association between vaccination and encephalopathy was concluded.

A Peek into Pandora’s Box: COVID-19 and Neurodegeneration

Ever since it was first reported in Wuhan, China, the coronavirus-induced disease of 2019 (COVID-19) has become an enigma of sorts with ever expanding reports of direct and indirect effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on almost all the vital organ systems. Along with inciting acute pulmonary complications, the virus attacks the cardiac, renal, hepatic, and gastrointestinal systems as well as the central nervous system (CNS). The person-to-person variability in susceptibility of individuals to disease severity still remains a puzzle, although the comorbidities and the age/gender of a person are believed to play a key role. SARS-CoV-2 needs angiotensin-converting enzyme 2 (ACE2) receptor for its infectivity, and the association between SARS-CoV-2 and ACE2 leads to a decline in ACE2 activity and its neuroprotective effects. Acute respiratory distress may also induce hypoxia, leading to increased oxidative stress and neurodegeneration. Infection of the neurons along with peripheral leukocytes’ activation results in proinflammatory cytokine release, rendering the brain more susceptible to neurodegenerative changes. Due to the advancement in molecular biology techniques and vaccine development programs, the world now has hope to relatively quickly study and combat the deadly virus. On the other side, however, the virus seems to be still evolving with new variants being discovered periodically. In keeping up with the pace of this virus, there has been an avalanche of studies. This review provides an update on the recent progress in adjudicating the CNS-related mechanisms of SARS-CoV-2 infection and its potential to incite or accelerate neurodegeneration in surviving patients. Current as well as emerging therapeutic opportunities and biomarker development are highlighted.

Mechanisms of immune effector cell-associated neurotoxicity syndrome after CAR-T treatment

Chimeric antigen receptor T-cell (CAR-T) treatment has revolutionized the landscape of cancer therapy with significant efficacy on hematologic malignancy, especially in relapsed and refractory B cell malignancies. However, unexpected serious toxicities such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) still hamper its broad application. Clinical trials using CAR-T cells targeting specific antigens on tumor cell surface have provided valuable information about the characteristics of ICANS. With unclear mechanism of ICANS after CAR-T treatment, unremitting efforts have been devoted to further exploration. Clinical findings from patients with ICANS strongly indicated existence of overactivated peripheral immune response followed by endothelial activation-induced blood-brain barrier (BBB) dysfunction, which triggers subsequent central nervous system (CNS) inflammation and neurotoxicity. Several animal models have been built but failed to fully replicate the whole spectrum of ICANS in human. Hopefully, novel and powerful technologies like single-cell analysis may help decipher the precise cellular response within CNS from a different perspective when ICANS happens. Moreover, multidisciplinary cooperation among the subjects of immunology, hematology, and neurology will facilitate better understanding about the complex immune interaction between the peripheral, protective barriers, and CNS in ICANS. This review elaborates recent findings about ICANS after CAR-T treatment from bed to bench, and discusses the potential cellular and molecular mechanisms that may promote effective management in the future. This article is categorized under: Cancer > Biomedical Engineering Immune System Diseases > Molecular and Cellular Physiology Neurological Diseases > Molecular and Cellular Physiology.