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A 47-year-old woman with a history of substance abuse, depression, and insomnia experienced a collapse. Upon arrival at the hospital, the patient displayed low systolic blood pressure, confusion, dehydration, and renal failure. Urine tests confirmed an amphetamine and opioid overdose. Her condition fluctuated with reduced consciousness, myoclonic movements, fever, and suspected psychogenic seizures. Brain magnetic resonance imaging revealed abnormalities in the splenium of the corpus callosum, which later resolved. The patient's condition gradually improved without any specific treatment. This unique case represents the first report of mild encephalopathy/encephalitis with reversible splenial lesions associated with amphetamine and opioid use.

Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment, but they have been known to cause immune-related adverse events (irAEs) by promoting T-cell activation. Neurological irAEs are rare (1%) but have a high fatality rate (11.5%). Here we report the first case of Bickerstaff brainstem encephalitis (BBE) induced by an ICI. A woman in her 60s with metastatic breast cancer was treated with atezolizumab plus nab-paclitaxel once intravenously. Eighteen days later, she lost consciousness with ophthalmoplegia and was diagnosed with a neurological irAE. She recovered consciousness immediately with the administration of intravenous immunoglobulin (IVIG) but suffered severe permanent peripheral neuropathy. Although it is just one case, this experience shows that BBE occurring as a neurological irAE of ICI cancer treatment may be associated with more severe outcomes than conventional BBE in metastatic cancer. Creating a system for multidisciplinary treatment is essential for ICI therapy., Competing Interests: No potential conflict of interest relevant to this article was reported.

The traditional treatment for small-cell lung cancer (SCLC) has been traditional systemic platinum-containing chemotherapy because the response rate is 50-90%. Durvalumab is an immune checkpoint inhibitor that blocks the binding of programmed cell death protein 1 and programmed cell death 1 ligand 1. Durvalumab combined with traditional chemotherapy agents has been recommended as the first-line treatment for extensive-stage SCLC, but its use may cause immune-related adverse events. Autoimmune encephalitis is a rare and potentially fatal neurological adverse event. This current case report describes a male patient in his late 50s with ES-SCLC who developed autoimmune encephalitis associated with durvalumab treatment after three cycles of combination chemotherapy. This current case furthers the understanding of autoimmune encephalitis caused by durvalumab treatment., Competing Interests: Declaration of conflicting interestAll authors declare no conflicts of interest.

Treatment with atezolizumab and bevacizumab is the first-line therapy for unresectable hepatocellular carcinoma. Although immune checkpoint inhibitors are novel and effective treatments, they can induce immune-related adverse events. However, neurological immune-related adverse events have rarely been reported. We report the case of a man in his 40s with hepatocellular carcinoma who developed life-threatening encephalitis after atezolizumab plus bevacizumab was administered. The patient presented with fever, headache, altered mentality, and general epileptic seizures, ten days after administration. Cerebrospinal fluid analysis showed elevated white blood cells and elevated protein levels, but revealed no infection or malignancy. Brain magnetic resonance imaging showed diffuse leptomeningeal enhancement in both the cerebrum and cerebellum. As immune checkpoint inhibitor-induced encephalitis was strongly suspected, steroid pulse therapy was initiated and neurological symptoms quickly improved. The patient was discharged after 66 days of hospitalization, and administration of sorafenib and radiotherapy was started for the hepatocellular carcinoma on an outpatient basis. This case demonstrates the importance of recognizing neurological immune-related adverse events following atezolizumab and bevacizumab treatment for early intervention. We discuss this case in comparison to available literature and previous two cases of Atezolizumab- and bevacizumab- induced encephalitis in hepatocellular carcinoma., (© 2024. The Author(s).)

Background: Rituximab (RTX) resistance or early B-cells repopulation were observed in children but only few publications reported the use of Obinutuzumab and no recommendations were made concerning the dosage for children., Methods: This study was a single-center retrospective cohort study of all the children followed-up in the Pediatric Neurology Department of Necker-Enfants malades Hospital in Paris, France, and treated with obinutuzumab, between November 1, 2019, and November 1, 2021., Results: A total of eight children (three females, median age 4.5 years) were treated. Seven patients presented with autoimmune encephalitis and one with myeloradiculitis. The median delay of B-cell repopulation after a course of RTX was 87 days (range 41 to 160). A switch to obinutuzumab (anti-CD20) was performed for eight children. The median duration between the first RTX infusion and obinutuzumab administration was 6.6 months. The dosage regimen for obinutuzumab was one infusion of 1000 mg/1.73 m 2 , that is to say 580 mg/m 2 (maximum 1000 mg/infusion), by extrapolation from the adult dosage. The median delay of B-cell repopulation after one course of obinutuzumab was 230 days (range 66 to 303 days) vs 87 days after one course of RTX (P < 0.01). None of the patients presented side effects with obinutuzumab treatment. All patients had a favorable evolution at the last-follow up. Median follow-up was 1.6 years., Conclusions: This study reports the use of obinutuzumab in neurological inflammatory diseases in a pediatric population. Obinutuzumab seems to have a better biological efficacy than RTX with a longer time of B-cell repopulation., Competing Interests: Declaration of competing interest The authors declare that no conflicts of interest that could potentially influence or bias the submitted work exists., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Neonatal brain inflammation produced by intraperitoneal (i.p.) injection of lipopolysaccharide (LPS) results in long-lasting brain dopaminergic injury and motor disturbances in adult rats. The goal of the present work is to investigate the effect of neonatal systemic LPS exposure (1 or 2 mg/kg, i.p. injection in postnatal day 5, P5, male rats)-induced dopaminergic injury to examine methamphetamine (METH)-induced behavioral sensitization as an indicator of drug addiction. On P70, subjects underwent a treatment schedule of 5 once daily subcutaneous (s.c.) administrations of METH (0.5 mg/kg) (P70-P74) to induce behavioral sensitization. Ninety-six hours following the 5th treatment of METH (P78), the rats received one dose of 0.5 mg/kg METH (s.c.) to reintroduce behavioral sensitization. Hyperlocomotion is a critical index caused by drug abuse, and METH administration has been shown to produce remarkable locomotor-enhancing effects. Therefore, a random forest model was used as the detector to extract the feature interaction patterns among the collected high-dimensional locomotor data. Our approaches identified neonatal systemic LPS exposure dose and METH-treated dates as features significantly associated with METH-induced behavioral sensitization, reinstated behavioral sensitization, and perinatal inflammation in this experimental model of drug addiction. Overall, the analysis suggests that the implementation of machine learning strategies is sensitive enough to detect interaction patterns in locomotor activity. Neonatal LPS exposure also enhanced METH-induced reduction of dopamine transporter expression and [ 3 H]dopamine uptake, reduced mitochondrial complex I activity, and elevated interleukin-1β and cyclooxygenase-2 concentrations in the P78 rat striatum. These results indicate that neonatal systemic LPS exposure produces a persistent dopaminergic lesion leading to a long-lasting change in the brain reward system as indicated by the enhanced METH-induced behavioral sensitization and reinstated behavioral sensitization later in life. These findings indicate that early-life brain inflammation may enhance susceptibility to drug addiction development later in life, which provides new insights for developing potential therapeutic treatments for drug addiction., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objectives: Metronidazole central nervous system toxicity is a rare finding in patients receiving the medication. We report a peculiar case of metronidazole central nervous system toxicity in which both the underlying condition (Crohn disease) and the drugs used to treat it are potential causes of encephalopathy., Methods: A 26-year-old female with 6-year history of Crohn's disease for 6 years presented acute-onset encephalopathy. We provide bibliographic evidence to support metronidazole toxicity and potential Crohn disease-associated neurologic involvement., Results: The patient presented dystonia, cerebellar ataxia, and altered mental status. Magnetic resonance imaging of the brain revealed typical findings of metronidazole toxicity and white matter involvement of the centrum semiovale. Immunoelectrophoresis and immunofixation of serum and cerebrospinal fluid proteins were consistent with a systemic inflammatory process. We concluded on an association between drug toxicity and probable Crohn-associated neurologic involvement. Metronidazole was stopped and the patient was placed on vitamin therapy and diazepam to control dystonia. She deteriorated and was transferred to the intensive care unit where she expired., Conclusions: Acute behavioral changes in a young patient constitute an emergency and differential diagnoses should include infective, inflammatory, metabolic, and toxic causes. Metronidazole is a potential toxic etiology., Competing Interests: Conflicts of Interest and Source of Funding: The authors have no conflicts of interest to declare., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Objectives: Kelch-like protein-11 (KLHL11)-IgG is associated with rhombencephalitis and seminoma. It has not previously been described as a neurologic immune checkpoint inhibitor (ICI)-related adverse event (nirAE) or in association with esophageal adenocarcinoma., Methods: We describe a 61-year-old man with metastatic esophageal adenocarcinoma treated with folinic acid, fluorouracil, oxaliplatin (FOLFOX), and nivolumab, who subsequently developed diplopia, vertigo, and progressive gait ataxia after 8 weeks of treatment., Results: Owing to a concern for ICI-associated myasthenia gravis, nivolumab was held and he was treated with prednisone and pyridostigmine. EMG showed no neuromuscular junction dysfunction, and acetylcholine-receptor antibodies were negative. Brain MRI was unrevealing. Murine brain tissue immunofluorescence assay revealed KLHL11-IgG in both serum and CSF, confirmed by cell-based assay. Tumor histopathology demonstrated poorly differentiated, highly proliferative adenocarcinoma with increased mitotic figures and cytoplasmic KLHL11 immunoreactivity. He was initiated on 6 months of cyclophosphamide in addition to FOLFOX for post-ICI-associated KLHL11-IgG rhombencephalitis., Discussion: We report KLHL11-IgG rhombencephalitis associated with poorly differentiated esophageal cancer as a novel nirAE. Tumor staining revealed KLHL11 immunoreactivity, supporting a cancer-antigen-driven ICI-associated paraneoplastic syndrome. Recognition of novel nirAEs can expedite treatment and potentially prevent progressive neurologic disability.

Introduction: Autoimmune encephalitis is a rare immune-related adverse event of PD-1 inhibitors, nivolumab and pembrolizumab. Autoimmune hypophysitis can also be seen with the use of these agents. The relationship between these two phenomena is currently unknown., Case Report: We describe a 79-year-old man with anterior scalp melanoma who received adjuvant nivolumab therapy. Sixteen weeks after the completion of nivolumab therapy, the patient presented to the hospital with altered mental status, anterograde amnesia, and symptoms of nausea and vomiting. The patient's encephalopathy was associated with confabulations. Workup identified increased CSF protein without increased cellularity, along with decreased serum cortisol and ACTH levels. This was consistent with encephalitis and central adrenal insufficiency., Management and Outcome: The patient had a robust clinical response to steroids, with resolution of mental status changes and normalization of blood pressure. He continues to receive maintenance steroid therapy without any further symptoms six months later., Conclusions: We report herein a unique case of encephalopathy in the setting of nivolumab use for the treatment of melanoma. The condition resembled Korsakoff psychosis seen in the setting of alcoholism and was associated with central adrenal insufficiency. A prompt response to steroids was both diagnostic and therapeutic in our case, suggesting the resolution of autoimmune phenomena related to nivolumab., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Mycophenolate mofetil (MMF) is frequently used in the treatment of neurological autoimmune disorders. However, its effect on the relapse risk in anti-leucine-rich glioma-inactivated protein 1 (anti-LGI1) encephalitis is not well studied., Methods: In this prospective observational cohort study, anti-LGI1 encephalitis patients were grouped according to MMF treatment status (MMF and non-MMF groups). The primary outcome was relapse after disease onset., Results: A total of 83 patients were included, with a median onset age of 60 years. Fifty-four patients were men (65.1%). The MMF group comprised 28 patients and the non-MMF group comprised 55. Median follow-up from symptom onset was 26 months. Relapse occurred in 43 patients (51.8%). Median modified Rankin scale (mRS) score at enrollment was significantly higher in the MMF group than the non-MMF group (3 vs. 2; p = 0.001). Median mRS score at last follow-up was comparable between groups (1 vs. zero; p = 0.184). Both MMF treatment (HR 0.463; 95% CI, 0.231-0.929; p = 0.030) and cognitive impairment at enrollment (HR 3.391; 95% CI, 1.041-11.044; p = 0.043) were independent predictors of relapse. Starting immunotherapy before development of cognitive impairment trended towards reducing relapse risk. Outcome at last follow-up was good (mRS score 0-2) in all patients except for one in the non-MMF group. Adverse events associated with MMF treatment were mild and transient., Conclusion: Although the outcome of anti-LGI1 encephalitis patients is generally favorable, relapse is common, especially in those with cognitive impairment. MMF treatment is well-tolerated and can significantly reduce the risk of relapse., (© 2023. Fondazione Società Italiana di Neurologia.)

Major depression disorder is a debilitating psychiatric disease affecting millions of people worldwide. This disorder is the leading cause of morbidity and mortality in high-income countries. Selective serotonin reuptake inhibitors such as fluoxetine are first-line drugs for treating depression-related disorders, but not all patients respond well to these antidepressants. This study aimed to evaluate whether fluoxetine combined with aerobic exercise can affect lipopolysaccharide (LPS)-induced depressive-like behavior, hypothalamic-pituitary-adrenal (HPA) axis dysregulation, and brain inflammation in mice. Male mice were exposed to fluoxetine, swimming exercise, or a combination of both and finally treated with LPS. We measured depression-related symptoms such as anhedonia, behavioral despair, weight gain, and food intake. Hormones (corticosterone and testosterone) and cytokines (IL-1β, IL-6, TNF-α, IL-10) were also measured in serum and brain (hippocampus and prefrontal cortex), respectively. The findings indicated that LPS induced anhedonia and behavioral despair and increased corticosterone, hippocampal IL-1β, TNF-α, and decreased testosterone and hippocampal IL-10 in mice. Fluoxetine and exercise separately reduced LPS-induced depressive-like behavior, while their combination synergistically reduced these symptoms in LPS-treated mice. We found fluoxetine alone increased food intake and body weight in LPS-treated mice. Fluoxetine and exercise combination reduced corticosterone, hippocampal TNF-α, and prefrontal IL-6 and TNF-α levels and increased testosterone and hippocampal and prefrontal IL-10 levels more effectively than fluoxetine alone in LPS-treated mice. This study suggests that swimming exercise combined with fluoxetine can affect depression-related behavior, HPA axis, and brain inflammation more effectively than when they are used separately., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: In 2021, four patients who had received solid organ transplants in the USA developed encephalitis beginning 2-6 weeks after transplantation from a common organ donor. We describe an investigation into the cause of encephalitis in these patients., Methods: From Nov 7, 2021, to Feb 24, 2022, we conducted a public health investigation involving 15 agencies and medical centres in the USA. We tested various specimens (blood, cerebrospinal fluid, intraocular fluid, serum, and tissues) from the organ donor and recipients by serology, RT-PCR, immunohistochemistry, metagenomic next-generation sequencing, and host gene expression, and conducted a traceback of blood transfusions received by the organ donor., Findings: We identified one read from yellow fever virus in cerebrospinal fluid from the recipient of a kidney using metagenomic next-generation sequencing. Recent infection with yellow fever virus was confirmed in all four organ recipients by identification of yellow fever virus RNA consistent with the 17D vaccine strain in brain tissue from one recipient and seroconversion after transplantation in three recipients. Two patients recovered and two patients had no neurological recovery and died. 3 days before organ procurement, the organ donor received a blood transfusion from a donor who had received a yellow fever vaccine 6 days before blood donation., Interpretation: This investigation substantiates the use of metagenomic next-generation sequencing for the broad-based detection of rare or unexpected pathogens. Health-care workers providing vaccinations should inform patients of the need to defer blood donation for at least 2 weeks after receiving a yellow fever vaccine. Despite mitigation strategies and safety interventions, a low risk of transfusion-transmitted infections remains., Funding: US Centers for Disease Control and Prevention (CDC), the Biomedical Advanced Research and Development Authority, and the CDC Epidemiology and Laboratory Capacity Cooperative Agreement for Infectious Diseases., Competing Interests: Declaration of interests LFW received research funding from Accelerate Diagnostics, bioMérieux, Hardy Diagnostics, Roche Molecular Systems, and Selux Diagnostics and honoraria from Roche Molecular Systems, Shionogi, and Talis Biomedical, all unrelated to this work. KSG received research support from ThermoFisher and has a royalty-generating collaborative agreement with ZeptoMetrix, both unrelated to this work. MRW received research grant funding from Roche/Genentech and Novartis and speaking honoraria from Genentech, Novartis, Takeda, and WebMD, all unrelated to this work. CYC received research grant funding from the Bay Area Lyme Disease Foundation and the Chan-Zuckerberg Biohub, unrelated to this work, and is on the scientific advisory board for Mammoth Biosciences, Poppy Health, and BiomeSense. MRW and CYC are consultants and co-founders of Delve Bio. CYC is a co-inventor on US patent 11380421, Pathogen Detection Using Next Generation Sequencing, under which algorithms for taxonomic classification, filtering, and pathogen detection are used by SURPI+ software., (Copyright © 2023 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Excitotoxicity and neuroinflammation are key contributors to perinatal brain injuries. Capsaicin, an active ingredient of chili peppers, is a potent exogenous agonist for transient receptor potential vanilloid 1 receptors. Although the neuroprotective and anti-inflammatory effects of capsaicin are well-documented, its effects on excitotoxic-induced neonatal brain injury and neuroinflammation have not previously been investigated. The aim of this study was to investigate the effects of capsaicin on brain damage, brain mast cells, and inflammatory mediators in a model of ibotenate-induced excitotoxic brain injury in neonatal rats. P5 rat-pups were intraperitoneally injected with vehicle, 0.2-, 1-, and 5-mg/kg doses of capsaicin, or the NMDA (N-methyl-d-aspartate) receptor antagonist MK-801 (dizocilpine), 30 min before intracerebral injection of 10 μg ibotenate. The naive-control group received no substance administration. The rat pups were sacrificed one or five days after ibotenate injection. Levels of activin A and interleukin (IL)-1β, IL-6, and IL-10 in brain tissue were measured using the enzyme-linked immunosorbent assay method. Cortex and white matter thicknesses, white matter lesion size, and mast cells were evaluated in brain sections stained with cresyl-violet or toluidine-blue. Capsaicin improved ibotenate-induced white matter lesions and cerebral white and gray matter thicknesses in a dose-dependent manner. In addition, it suppressed the degranulation and increased number of brain mast cells induced by ibotenate. Capsaicin also reduced the excitotoxic-induced production of neuronal survival factor activin A and of the pro-inflammatory cytokines IL-1β, and IL-6 in brain tissue. However, IL-10 levels were not altered by the treatments. MK-801, as a positive control, reversed all these ibotenate-induced changes, further confirming the success of the model. Our findings provide, for the first time, evidence for the therapeutic effects of capsaicin against excitotoxic-induced neonatal brain injury and brain mast cell-mediated neuroinflammation. Capsaicin may therefore be a promising candidate in the prevention and/or reduction of neonatal brain damage., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Introduction: The efficacy of immune checkpoint inhibitors (ICIs) against malignant melanoma and numerously solid tumors has been demonstrated in several clinical studies. The incidence of immune-related adverse effects (irAEs) has increased after the rapidly expanding indications and clinical applications of ICIs. We present a case of nivolumab and ipilimumab-induced encephalitis with rapidly worsening consciousness and full recovery following ICIs suspension and high-dose steroid coupled with intravenous immunoglobulin (IVIG)., Case Report: A 67-year-old woman was diagnosed with stage 4 BRAF wild malignant melanoma with metastasis to the axillary and mediastinal lymph nodes. Beyond progression with dacarbazine, ipilimumab and nivolumab combination were administered at the second-line treatment of metastatic setting. A week after the first cycle patient was reported to have a fever of more than 38°C. Subacute cognitive impairment including mild changes in behavior was reported on the third day of fever. She suddenly developed confusion, dysarthria, and motor dysfunction a few days later. Due to the altered mental status accompanied by fever, lumbar puncture was performed with a pre-diagnosis of encephalitis, meningitis, and leptomeningeal carcinomatosis., Management & Outcome: After excluding viral and autoimmune encephalitis, high-dose methylprednisolone was administered in addition to IVIG for 5 days with the diagnosis of immunotherapy-related encephalitis according to the recommendations for the management of irAEs. On the second day of the treatment patient's neurological status improved gradually., Discussion: Being aware of symptoms of serious neurological irAEs associated with ICIs can prevent complications and improve survival.

People who live or work in moldy buildings often complain of "brain fog" that interferes with cognitive performance. Until recently, there was no published research on the effects of controlled exposure to mold stimuli on cognitive function or an obvious mechanism of action, fueling controversy over these claims. The constellation of health problems reported by mold-exposed individuals (respiratory issues, fatigue, pain, anxiety, depression, and cognitive deficits) correspond to those caused by innate immune activation following exposure to bacterial or viral stimuli. To determine if mold-induced innate immune activation might cause cognitive issues, we quantified the effects of both toxic and nontoxic mold on brain immune activation and spatial memory in the Morris water maze. We intranasally administered either 1) intact, toxic Stachybotrys chartarum spores; 2) ethanol-extracted, nontoxic Stachybotrys chartarum spores; or 3) control saline vehicle to mice. Inhalation of nontoxic spores caused significant deficits in the test of long-term memory of platform location, while not affecting short-term memory. Inhalation of toxic spores increased motivation to reach the platform. Interestingly, in both groups of mold-exposed males, numbers of interleukin-1β-immunoreactive cells in many areas of the hippocampus significantly correlated with latency to find the platform, path length, and swimming speed during training, but not during testing for long-term memory. These data add to our prior evidence that mold inhalation can interfere with cognitive processing in different ways depending on the task, and that brain inflammation is significantly correlated with changes in behavior., Competing Interests: Declaration of Competing Interest The authors have no conflicts to report., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Pseudorabies virus (PRV) causes viral encephalitis, a devastating disease with high mortality worldwide. Curcumin (CUR) can reduce inflammatory damage by altering the phenotype of microglia; however, whether and how these changes mediate resistance to PRV-induced encephalitis is still unclear. In this study, BV2 cells were infected with/without PRV for 24 h and further treated with/without CUR for 24 h. The results indicated that CUR promoted the polarization of PRV-infected BV2 cells from the M1 phenotype to the M2 phenotype and reversed PRV-induced mitochondrial dysfunction. Furthermore, M1 BV2 cell secretions induced signalling pathways leading to apoptosis in PC-12 neuronal cells, and this effect was abrogated by the secretions of M2 BV2 cells. RNA sequencing and bioinformatics analysis predicted that this phenotypic shift may be due to changes in energy metabolism. Furthermore, Western blot analysis showed that CUR inhibited the increase in AMP-activated protein kinase (AMPK) phosphorylation, glycolysis, and triacylglycerol synthesis and the reduction in oxidative phosphorylation induced by PRV infection. Moreover, the ATP levels in M2 BV2 cells were higher than those in M1 cells. Furthermore, CUR prevented the increase in mortality, elevated body temperature, slowed growth, nervous system excitation, brain tissue congestion, vascular cuffing, and other symptoms of PRV-induced encephalitis in vivo. Thus, this study demonstrated that CUR protected against PRV-induced viral encephalitis by switching the phenotype of BV2 cells, thereby protecting neurons from inflammatory injury, and this effect was mediated by improving mitochondrial function and the AMPK/NF-κB p65-energy metabolism-related pathway., (© 2023. The Author(s).)

Lead (Pb) is a developmental neurotoxin that can disrupt brain development and damage the brain regions responsible for executive function, behavioral regulation and fine motor control. Sodium para-aminosalicylic acid (PAS-Na) is a non-steroidal anti-inflammatory drug that can cross the blood-brain barrier. The purpose of this study was to examine the effects of juvenile rat Pb exposure on behavioral changes and brain inflammation, and the efficacy of PAS-Na in ameliorating these effects. The results showed that Pb exposure during the juvenile period (from weaning to adult period) delayed rats' growth development and impaired their motor learning. Pb exposure not only increased Pb concentrations in several brain regions (including hippocampus, striatum and substantia nigra), but also disrupted metal-homeostasis in the brain, as higher levels of iron (Fe) and calcium (Ca) were observed in the substantia nigra. Moreover, Pb activated the MAPK pathway and increased levels of inflammatory factors such as IL-1β, TNF-α and IL-6 in the hippocampus, striatum and substantia nigra. Furthermore, Pb increased the levels of alpha-synuclein (α-syn) in these brain sites. PAS-Na improved the motor deficits and brain inflammation in the Pb-exposed rats. Moreover, the elevated Pb, Fe and Ca concentrations in the brain were significantly reduced by PAS-Na, which contains amino, carboxyl and hydroxyl functional groups, suggesting that it may act as a chelator of brain metals. In addition, PAS-Na inhibited the Pb-induced MAPK pathway activation and α-syn accumulation in the same brain regions. Taken together, our novel study suggest that PAS-Na shows efficacy in improving the Pb-induced behavioral changes in rats by inhibiting MAPK-dependent inflammatory pathways and reducing α-syn accumulation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Dysregulated inflammatory responses and blood-brain barrier (BBB) dysfunction are recognized as central factors in the development of psychiatric disorders. The present study was designed to evaluate the effect of niacin on BBB integrity in ketamine-induced model of psychosis. Meanwhile, mepenzolate bromide (MPN), a GPR109A receptor blocker, was used to investigate the role of this receptor on the observed niacin's effect. Male Wistar rats received ketamine (30 mg/kg/day, i.p) for 5 consecutive days and then niacin (40 mg/kg/day, p.o), with or without MPN (5 mg/kg/day, i.p), was given for the subsequent 15 days. Three days before the end of experiment, rats were behaviorally tested using open field, novel object recognition, social interaction, and forced swimming tests. Niacin significantly ameliorated ketamine-induced behavioral deficits, amended gamma aminobutyric acid and glutamate concentration, decreased tumor necrosis factor-α and matrix metallopeptidase 9 levels, and increased netrin-1 contents in the hippocampus of rats. Niacin also augmented the hippocampal expression of ZO-1, occludin, and claudin-5 proteins, indicating the ability of niacin to restore the BBB integrity. Moreover, the histopathologic changes in hippocampal neurons were alleviated. Since all the beneficial effects of niacin in the present investigation were partially abolished by the co-administration of MPN; GPR109A receptor was proven to partially mediate the observed antipsychotic effects of niacin. These data revealed that GPR109A-mediated signaling pathways might represent potential targets for therapeutic interventions to prevent or slow the progression of psychosis., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflicts of interest., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Vaccine-related immune responses are one of the causes of encephalitis. Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) have been administered worldwide due to the ongoing global pandemic; cases of SARS-CoV-2 vaccination-related encephalitis were scarcely reported. An 82-year-old female was diagnosed with acute encephalitis following her first dose of vaccination with mRNA-1273 against SARS-CoV-2. The patient presented with fever and headache five days after vaccination, followed by behavior change 17 days after vaccination. Electroencephalographic recordings revealed focal slow waves in the right frontoparietal regions. Brain MRI revealed the signal change in the right middle and posterior temporal lobe. Cerebrospinal fluid analysis showed mildly elevated protein. She responded well to steroid pulse therapy and made a full recovery. The severity of the immune response following COVID-19 vaccination may be alleviated if adequate treatment is achieved. Physicians must be alert for encephalitis after vaccination to help ensure a favorable outcome.

Aim: Immune checkpoint inhibitor-induced encephalitis (ICI-iE) is a rare but life-threatening toxicity of immune checkpoint inhibitor treatment. We aim to identify the characteristics of ICI-iE and describe factors that discriminate it from herpes simplex virus (HSV)-1 encephalitis and anti-leucine-rich glioma-inactivated 1 (anti-LGI1) encephalitis, as two alternative entities of encephalitis., Methods: In this retrospective multicentre cohort study, we collected patients with ICI-iE reported to the Side Effect Registry Immuno-Oncology from January 2015 to September 2021 and compared their clinical features and outcome with 46 consecutive patients with HSV-1 or anti-LGI1 encephalitis who were treated at a German neurological referral centre., Results: Thirty cases of ICI-iE, 25 cases of HSV-1 encephalitis and 21 cases of anti-LGI1 encephalitis were included. Clinical presentation of ICI-iE was highly variable and resembled that of HSV-1 encephalitis, while impairment of consciousness (66% vs. 5%, p = .007), confusion (83% vs. 43%; p = .02), disorientation (83% vs. 29%; p = .007) and aphasia (43% vs. 0%; p = .007) were more common in ICI-iE than in anti-LGI1 encephalitis. Antineuronal antibodies (17/18, 94%) and MRI (18/30, 60%) were mostly negative in ICI-iE, but cerebrospinal fluid (CSF) showed pleocytosis and/or elevated protein levels in almost all patients (28/29, 97%). Three patients (10%) died of ICI-iE. Early immunosuppressive treatment was associated with better outcome (r = 0.43)., Conclusions: ICI-iE is a heterogeneous entity without specific clinical features. CSF analysis has the highest diagnostic value, as it reveals inflammatory changes in most patients and enables the exclusion of infection. Early treatment of ICI-iE is essential to prevent sequelae and death., Competing Interests: Conflict of interest statement The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: LMJ, JMV, WB, PH, RM, AC, TH, FM, LR, PB, JAS, TE, MT, CH, LvB, THu, declare no conflicts of interest. SZ declares speaker's fees or travel grants from Bristol-Myers Squibb (BMS), Sun Pharma and Merck Sharp & Dohme (MSD). ME received funding from DFG under Germany's Excellence Strategy – EXC-2049 – 390688087, BMBF, DZNE, DZHK, EU, Corona Foundation, and Foundation Leducq. ME reports grants from Bayer and fees paid to the Charité from AstraZeneca, Bayer, Boehringer Ingelheim, BMS, Daiichi Sankyo, Amgen, GSK, Sanofi, Covidien, Novartis, Pfizer, all outside the submitted work. CUB received compensation (all paid to the institute except TRV) for advisory roles for BMS, MSD, Roche, Novartis, GlaxoSmithKline, AstraZeneca, Pfizer, Lilly, GenMab, Pierre Fabre Pharmaceuticals, Third Rock Ventures, received research funding (all paid to the institute) from BMS, Novartis, NanoString, and declares stockownership in Immagene BV, where he is co-founder. AG received speaker's honoraria from Allmiral, BMS, MSD and Roche; AG has intermittent advisory board relationships with Amgen, BMS, Novartis, MSD, Pierre Fabre Pharmaceuticals, Pfizer, Roche and Sanofi Genzyme; travel and congress fee support from BMS, MSD, Novartis, Pierre Fabre Pharmaceuticals and Roche. Clinical studies: Amgen, Array, BMS, GSK, Novartis, Merck, MSD, Pfizer, and Roche. MS received speaker's honoraria and travel grants from Abbvie, BMS, Merck, MSD, Novartis, Pfizer, and Sanofi. JCH has served as a consultant for GSK, MSD, Pierre Fabre Pharmaceuticals, Sunpharma (personal) and BMS, Immunocore, Nektar, Novartis, Philogen (institution); received speaker's honoraria from Almirall, Amgen, BMS, GSK, MSD, Novartis, Pfizer, Pierre Fabre Pharmaceuticals, Roche, Sanofi (personal); a scientific grant from BMS and Sunpharma (institution) and clinical trial honoraria for BioNTech, BMS, Genentech, Immunocore, Iovance, MSD, Novartis, Philogen, Pierre Fabre Pharmaceuticals, Regeneron, Roche, Sanofi, 4SC (institution). SU declares research support from Bristol Myers Squibb and Merck Serono; speakers and advisory board honoraria from Bristol Myers Squibb, MSD, Merck Serono, Novartis and Roche, and travel support from Bristol Myers Squibb, MSD, and Pierre Fabre Pharmaceuticals. LZ served as consultant and/or has received honoraria from BMS, MSD, Novartis, Pierre-Fabre Pharmaceuticals, Sunpharma and Sanofi; Research funding to institution: Novartis; travel support from MSD, BMS, Amgen, Pierre-Fabre Pharmaceuticals, Sunpharma, Sanofi and Novartis, outside the submitted work. LS declares advisory and speaker honoraria from Bristol Myers Squibb. KCK has served as consultant or/and has received honoraria from Amgen, Roche, Bristol Myers Squibb, Merck Sharp and Dohme, Pierre Fabre Pharmaceuticals, and Novartis, and received travel support from Amgen, Merck Sharp and Dohme, Bristol Myers Squibb, Amgen, Pierre Fabre Pharmaceuticals, Medac and Novartis. RSB has served as consultant for and/or received honoraria from Amgen, AstraZeneca, BMS, Celgene, Jansen-Cilag, MSD, Merck Seono, Novartis, Pfizer, and Roche. GVL is consultant advisor for Agenus, Amgen, Array Biopharma, Boehringer Ingelheim, BMS, Evaxion, Hexal AG (Sandoz Company), Highlight Therapeutics S.L., Innovent Biologics USA, MSD, Novartis Pharma AG, OncoSec, PHMR Limited, Pierre Fabre Pharmaceuticals, Provectus, Qbiotics, Regeneron. FS has received an honorarium from Gilead for an advisory board meeting. MS received speaker's honoraria and participated in advisory boards of BMS, Novartis, MSD, Roche, Pierre Fabre Pharmaceuticals, Kyowa Kirin, Immunocore, Recordati and Sanofi-Genzyme. MS received travel accommodation and expenses by Novartis, Pierre Fabre Pharmaceuticals, and Sun Pharma. LEF has served as consultant for Galderma, Janssen, Leo Pharma, Eli Lilly, Almirall, Union Therapeutics, Regeneron, Novartis, Amgen, Abbvie, UCB, Biotest, and InflaRx. SK received compensation for advising roles for Biogen. LH has served as consultant for Amgen, BMS, Biome-dx, EMA, Immunocore, Kyowa Kirin, MSD, Novartis, Pierre Fabre Pharmaceuticals, Roche, and Sanofi., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Autoimmune encephalitis (AE) with neuronal surface antibodies (NSAbs) presents pathogenesis mediated by B cell-secreting antibodies. Rituximab is a second-line choice for the treatment for AE with NSAbs, which can cause B cell depletion via targeting CD20. However, the optimal protocol and dosage of rituximab combined with first-line therapy for NSAbs-associated AE remains unclear so far. In this study, we explored the efficacy and safety of low-dose rituximab combined with first-line treatment for NSAbs-associated AE., Methods: Fifty-nine AE patients with NSAbs were enrolled, and retrospectively divided into common first-line therapy (41 patients) and combined low-dose rituximab (100 mg induction weekly with 3 circles, followed by 100 mg reinfusion every 6 months) with first-line therapy (18 patients). Outcome measures included changes in the Clinical Assessment Scale for Autoimmune Encephalitis (CASE) score (primary endpoint), changes in the modified Rankin Scale (mRS), the Mini-mental State Examination (MMSE), the patient and caregiver Neuropsychiatric Inventory (NPI) score at each visit (baseline, discharge, 6 months, 12 months and last follow-up) between two groups (secondary endpoint), as well as oral prednisone dosage, relapse and adverse effects during follow-up., Results: Compared with traditional first-line therapy group, for primary outcome, CASE scores at last follow-up were significantly improved in combined rituximab group, as well as markedly improving changes of CASE scores between baseline and each visit. While changes of mRS, MMSE and NPI scores, as secondary endpoint, were all markedly accelerating improvement between baseline and each visit, as well as both oral prednisone dosage and relapse were also greatly reduced during follow-up. Meanwhile, longitudinal analysis in combination of rituximab cohort also revealed persistently marked amelioration in a series of scales from baseline even more than 1 year. Moreover, analysis in rituximab subgroup showed no difference in any clinical outcomes between combination with single first-line and with repeated first-line treatment (≥ 2 times), while compared to delayed combination with rituximab (> 3 months), early initiation of combination (≤ 3 months) might achieve better improvements in CASE and MMSE assessment even 1 year later. No rituximab-correlated serious adverse events have been reported in our patients., Conclusions: Our simplified regimen of combined low-dose rituximab firstly showed significantly accelerating short-term recovery and long-term improvement for AE with NSAbs, in parallel with markedly reduced prednisone dosage and clinical relapses. Moreover, opportunity of protocol showed earlier initiation (≤ 3 months) with better long-term improvement., (© 2022. The Author(s).)

Background: Various vaccines, tumor-necrosis-factor-alpha inhibitors (TNFAIs), immune-checkpoint inhibitors (ICIs), and other immunomodulators have been linked to inflammatory CNS events. The prevalence of iatrogenic events in the neuroimmunology clinic is unknown., Objective: To evaluate the prevalence and clinical characteristics of iatrogenic CNS inflammation in a tertiary neuroimmunology clinic., Methods: We analyzed 422 consecutive patients seen over five years at a tertiary neuroimmunology clinic who were systematically screened for exposure to vaccines, TNFAIs, ICIs, or other immunomodulators. In patients with suspected iatrogenic events, the Naranjo Adverse Drug Reaction Probability Scale was used to score the probability of iatrogenicity., Results: In total, 27 potential iatrogenic events were observed, accounting for 6.4% of all new referrals. The average Naranjo score was 5.78 +/- 1.65 with 74% of the cases scored as probable and 26% scored as possible. The clinical phenotypes included MS relapses (37%); autoimmune encephalitis (30%); NMOSD attacks (15%); transverse myelitis (11%); optic neuritis (4%); and MOGAD attacks (4%). A monophasic course was observed in 44% of cases while 41% had a relapsing course. All patients stopped or interrupted treatment with the offending agent. In addition, 41% of the iatrogenic events were fully responsive to corticosteroids; 22% were partially responsive; and 15% resolved spontaneously. The most common potential triggers were vaccines (37%) followed by TNFAIs (33%) then ICIs (26%). A significantly higher number of probable iatrogenic events were observed among the ICI and vaccine groups compared to a higher number of possible events among the TNFAI group. The latter group also had a significantly longer interval since exposure. The ICI group was more likely to present with monophasic autoimmune encephalitis., Conclusion: Iatrogenic CNS inflammation is rare and typically involves steroid-responsive monophasic events. A subset of iatrogenic events can unmask or worsen relapsing disorders. The probability of iatrogenicity was higher in vaccine and ICI-related events compared to TNFAI-related events., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The purpose of this study is to elucidate risk factors for central nervous system infection and early seizure recurrence in children with febrile seizures (FSs) and thus facilitate outpatient management of complex FS. This single-center, retrospective cohort study investigated 688 children (6-60 months old) with FSs in Japan during 2011-2021. We investigated the incidence and clinical manifestations of children with acute encephalitis or bacterial meningitis. Logistic regression modeling was used to examine risk factors for seizure recurrence within 24 h. Among children with recurrent FSs, the distribution of intervals between first and second FS was assessed. Among 145 children with complex FSs, 2 patients (1.4%) had acute viral encephalitis and none had bacterial meningitis. Acute encephalitis was found in 2 of 8 patients (25%) with FSs prolonged ≥30 min and 2 of 3 patients (67%) requiring ≥2 intravenous anticonvulsants to stop seizures. Seizure recurrence within 24 h was observed in 16% of participants and was independently associated with preceding use of diazepam and family history of FS. In 82% of patients with FS recurrence within 24 h, early recurrences occurred within 8 h of the first seizure.      Conclusion: Patients with prolonged or refractory FSs are still indicated for hospital admission due to the risk of acute encephalitis. FS patients with a family history of FS may be managed safely by 8-h observation or single-dose rectal diazepam as prophylaxis against early recurrent seizure. What is Known: • Hospitalization has been recommended for children with complex febrile seizures due to the increased risk of central nervous infections. • Recent studies showed low incidences of bacterial meningitis (<1%) in children with complex febrile seizures in the presence of routine immunization. What is New: • Acute encephalitis was identified in 1.4% of children with complex febrile seizures, characterized by prolonged seizures ≥30 min and refractory seizures. • Early recurrent seizures may be safely managed by prophylactic diazepam or 8-h expectant observation., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Acute brain inflammation after status epilepticus (SE) is involved in blood-brain barrier (BBB) dysfunction and brain edema, which cause the development of post-SE symptomatic epilepsy. Using pilocarpine-induced SE mice, we previously reported that treatment with levetiracetam (LEV) after SE suppresses increased expression levels of proinflammatory mediators during epileptogenesis and prevents the development of spontaneous recurrent seizures. However, it remains unclear how LEV suppresses neuroinflammation after SE. In this study, we demonstrated that LEV suppressed the infiltration of CD11b + CD45 high cells into the brain after SE. CD11b + CD45 high cells appeared in the hippocampus between 1 and 4 days after SE and contained Ly6G + Ly6C + and Ly6G - Ly6C + cells. Ly6G + Ly6C + cells expressed higher levels of proinflammatory cytokines such as IL-1β and TNFα suggesting that these cells were inflammatory neutrophils. Depletion of peripheral Ly6G + Ly6C + cells prior to SE by anti-Ly6G antibody (NIMP-R14) treatment completely suppressed the infiltration of Ly6G + Ly6C + cells into the brain. Proteome analysis revealed the downregulation of a variety of inflammatory cytokines, which exhibited increased expression in the post-SE hippocampus. These results suggest that Ly6G + Ly6C + neutrophils are involved in the induction of acute brain inflammation after SE. The proteome expression profile of the hippocampus treated with LEV after SE was similar to that after NIMP-R14 treatment. Therefore, LEV may prevent acute brain inflammation after SE by suppressing inflammatory neutrophil infiltration.

Objective: To report a case of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor encephalitis (AMPARE) as a potential immune-mediated complication of palbociclib (a cyclin-dependent kinase 4/6 inhibitor)., Background: Medication-induced autoimmune encephalitis is an increasingly recognized entity. To date, cases have been reported with immune checkpoint inhibitors (ICIs), typically within 3 months and while cancer is responding to immunotherapy., Results: A 55-year-old woman with metastatic breast cancer presented with new-onset neurologic symptoms. After diagnosis and treatment in 2008, she was in remission from 2010 to 2021. In April 2021, she developed metastatic recurrence. She started palbociclib in June 2021. PET scan in August 2021 showed improved metastases without new lesions. In September 2021, she developed encephalopathy, vertical nystagmus, and ataxia. Workup revealed AMPA-R antibodies. Palbociclib was stopped, and she received steroids, IVIg, and rituximab with marked improvement in her neurologic symptoms., Discussion: AMPARE is a well-described paraneoplastic syndrome. However, it is now understood that paraneoplastic syndromes can be driven by immunomodulatory medications, namely ICIs. Although palbociclib primarily prevents tumor proliferation, emerging data suggest that it may also be immunomodulatory. Given that our patient's AMPARE developed shortly after initiation of palbociclib while her cancer was responding to therapy, we postulate that it may have been unmasked by palbociclib, similarly to what has been reported with ICIs., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

A 53-year-old woman with a 6-year history of rheumatoid arthritis (RA) presented with pharyngeal pain, fever, and altered mental status. The patient had been treated with methotrexate (MTX) 12 mg/week, baricitinib 4 mg/day, and tacrolimus 2 mg/day. Magnetic resonance imaging of the brain revealed diffuse high-intensity lesions in the cerebral white matter, basal ganglia, brainstem, and right cerebellar hemisphere. She was diagnosed with Epstein-Barr virus (EBV) encephalitis due to elevated levels of EBV-DNA in the cerebrospinal fluid and serum. Although MTX-associated lymphoproliferative disorders are well-known complications in patients with RA, EBV encephalitis requires careful attention for such patients undergoing treatment with multiple potent immunosuppressants., (© Japan College of Rheumatology 2022. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objective: Although intravenous immunoglobulin (IVIG) is the first-line immunotherapy in autoimmune encephalitis, all supporting evidence comes from retrospective case series. Here, we performed a prospective clinical trial of IVIG for functional recovery in autoimmune encephalitis., Methods: This single-arm, open-label study assessed the efficacy and safety of 10% intravenous IVIG treatment in newly diagnosed patients with possible autoimmune encephalitis. Patients received IVIG (0.4 g/kg/day) for 5 days. Rescue immunotherapy was permitted when the patient deteriorated before day 8 or showed no improvement at day 8. The primary outcome was the change in the modified Rankin Scale (mRS) score at day 8 and 29. The secondary outcomes were the mRS score improvement and the score changes and improvements on four other clinical scales., Results: Overall, 23 patients received IVIG (intension-to-treat, ITT), and 18 patients completed the study according to the protocol (per-protocol, PP). mRS improved significantly at days 8 and 29 compared to baseline in both the ITT and PP populations. Other secondary outcomes also improved significantly at day 8, 15, and 29 versus baseline. In the PP population, 6/18 patients achieved favorable outcomes with IVIG alone (mRS = 0~2 at day 8), and 12/18 patients received rescue immunotherapy. Five adverse events were reported in relation to IVIG, all of which were mild., Interpretation: IVIG improved neurological functional outcomes, and the improvement was evident by day 8. Adverse effects were tolerable. These data provide the prospective evidence regarding the efficacy of IVIG in improving the functional outcomes of autoimmune encephalitis., (© 2022 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.)

Immune-related adverse events (irAEs) are common in patients receiving immune checkpoint inhibitors for metastatic melanoma and other advanced malignancies. Cutaneous, gastrointestinal, and endocrine (thyroid) irAEs are most prevalent, whereas neurologic irAEs are rare. We present a 73-year-old man with dementia and metastatic melanoma who developed immunotherapy-associated encephalitis and subsequently, interstitial granulomatous dermatitis with nivolumab/ipilimumab. High-dose corticosteroids successfully treated both conditions, though he never regained his baseline mental status. We review the literature on interstitial granulomatous dermatitis and encephalitis with immunotherapy.

Purpose: Immune checkpoint inhibitors (ICIs) are associated with peculiar adverse events related to the mechanism of action. Less than 1% of patients treated with ICIs develop autoimmune encephalitis. The aim of this study was to compare the frequency of encephalitis development due to ICIs with encephalitis due to other drugs using the Japanese Adverse Drug Event Report (JADER) database and Bayesian confidence propagation neural networks for signal detection., Methods: Data from the JADER database from April 2004 to December 2020 were downloaded via the Pharmaceuticals and Medical Devices Agency (PMDA) website. The Information Component (IC) values were calculated as an index of signal detection based on the Bayesian method., Results: The lower bound of the 95% credible interval (CI) of the IC values for atezolizumab and pembrolizumab were greater than 0 in most of the periods. Thus, encephalitis occurred more frequently for atezolizumab and pembrolizumab than for other drugs. For nivolumab and ipilimumab, a significant signal was detected only for recent data. In contrast, the lower bounds of the 95% CIs for avelumab and durvalumab were smaller than 0 in most of the periods because encephalitis was seldom reported for avelumab and durvalumab., Conclusions: We showed that encephalitis occurs more frequently for atezolizumab, pembrolizumab, nivolumab, and ipilimumab compared with the frequency for other drugs. The time of onset varied widely, and patients should be monitored for more than 1 year after the last administration of ICIs., (© 2022. The Drug Information Association, Inc.)

High-fat diet (HFD)-induced comorbid cognitive and behavioural impairments are thought to be the result of persistent low-grade neuroinflammation. Metformin, a first-line medication for the treatment of type-2 diabetes, seems to ameliorate these comorbidities, but the underlying mechanism(s) are not clear. Pituitary adenylate cyclase-activating peptide (PACAP) and vasoactive intestinal peptide (VIP) are neuroprotective peptides endowed with anti-inflammatory properties. Alterations to the PACAP/VIP system could be pivotal during the development of HFD-induced neuroinflammation. To unveil the pathogenic mechanisms underlying HFD-induced neuroinflammation and assess metformin's therapeutic activities, (1) we determined if HFD-induced proinflammatory activity was present in vulnerable brain regions associated with the development of comorbid behaviors, (2) investigated if the PACAP/VIP system is altered by HFD, and (3) assessed if metformin rescues such diet-induced neurochemical alterations. C57BL/6J male mice were divided into two groups to receive either standard chow (SC) or HFD for 16 weeks. A further HFD group received metformin (HFD + M) (300 mg/kg BW daily for 5 weeks) via oral gavage. Body weight, fasting glucose, and insulin levels were measured. After 16 weeks, the proinflammatory profile, glial activation markers, and changes within the PI3K/AKT intracellular pathway and the PACAP/VIP system were evaluated by real-time qPCR and/or Western blot in the hypothalamus, hippocampus, prefrontal cortex, and amygdala. Our data showed that HFD causes widespread low-grade neuroinflammation and gliosis, with regional-specific differences across brain regions. HFD also diminished phospho-AKT (Ser473) expression and caused significant disruptions to the PACAP/VIP system. Treatment with metformin attenuated these neuroinflammatory signatures and reversed PI3K/AKT and PACAP/VIP alterations caused by HFD. Altogether, our findings demonstrate that metformin treatment rescues HFD-induced neuroinflammation in vulnerable brain regions, most likely by a mechanism involving the reinstatement of PACAP/VIP system homeostasis. Data also suggests that the PI3K/AKT pathway, at least in part, mediates some of metformin's beneficial effects.

Background: Vaccination against COVID-19 continues apace, but side-effects, both common and severe, continue to be reported. We report here the first published case of COVID-19 vaccine-related encephalitis., Case Presentation: A young woman presented with acute neuropsychiatric symptoms following recent ChAdOx1 nCoV-19 vaccination. Extensive investigation did not identify alternative causes., Conclusions: This difficult case is here described, including presentation, investigation, and management. Further study on neuropsychiatric side-effects of COVID-19 vaccination, including investigation as to whether there may be a causal link, is required., (© 2021. The Author(s).)

This study was designed to determine the effect of acute caffeine (CAF) administration, which exerts a broad spectrum of anti-inflammatory activity, on the synthesis of pro-inflammatory cytokines and their receptors in the hypothalamus and choroid plexus (ChP) during acute inflammation caused by the injection of bacterial endotoxin-lipopolysaccharide (LPS). The experiment was performed on 24 female sheep randomly divided into four groups: control; LPS treated (iv.; 400 ng/kg of body mass (bm.)); CAF treated (iv.; 30 mg/kg of bm.); and LPS and CAF treated. The animals were euthanized 3 h after the treatment. It was found that acute administration of CAF suppressed the synthesis of interleukin (IL-1β) and tumor necrosis factor (TNF)α, but did not influence IL-6, in the hypothalamus during LPS-induced inflammation. The injection of CAF reduced the LPS-induced expression of TNF mRNA in the ChP. CAF lowered the gene expression of IL-6 cytokine family signal transducer ( IL6ST ) and TNF receptor superfamily member 1A ( TNFRSF1 ) in the hypothalamus and IL-1 type II receptor ( IL1R2 ) in the ChP. Our study on the sheep model suggests that CAF may attenuate the inflammatory response at the hypothalamic level and partly influence the inflammatory signal generated by the ChP cells. This suggests the potential of CAF to suppress neuroinflammatory processes induced by peripheral immune/inflammatory challenges.

Aims: Isoformononetin (IFN), a methoxyl isoflavone present in most of human dietary supplements. However, being a highly potent antioxidant and anti-inflammatory molecule, its activity against neuronal oxidative stress and neuroinflammation has not been explored till now. The present study was inquested to assess the antioxidant, anti-apoptotic and anti-inflammatory activity of IFN against streptozotocin induced neuroinflammation in different brain regions of rat., Main Methods: Four groups of animals were subjected to treatment as control, toxic control (STZ; single intracerebrovascular injection), third group (STZ + IFN; 20 mg/kg p.o.), fourth group (IFN) for 14 days. The different brain regions of rats were evaluated for inflammatory, apoptotic and biochemical antioxidant markers. The brain tissues were further assessed for gene expression, immunohistochemical and western blotting examination for localization of inflammasome cascade expression that plays a pivotal role in neuroinflammation., Key Findings: The modulation in oxidant/antioxidant status after exposure of STZ was significantly balanced after administration of IFN to rats. Further, IFN was also found to be an apoptotic agent as it modulates the apoptotic gene (Bax) and anti-apoptotic gene (BcL 2 ) expression. IFN significantly curtailed the augmented protein expression of NLRP3, NLRP2, ASC, NFκBP65, IL-1β and caspase-1 due to STZ administration in cortex and hippocampus rat brain regions., Significance: The aforementioned results proclaim the neuroprotective functioning of IFN against STZ induced inflammation. IFN significantly prevents the neuroinflammation by decreasing the generation of ROS that reduces the activation of NLRP3/ASC/IL-1 axis thereby exerting neuroprotection as evidenced in rat model of STZ induced neuroninflammation., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Chitotriosidase (CHIT1, chitinase 1) is increased in the cerebrospinal fluid and peripheral blood of Alzheimer's disease (AD) patients. Our previous study has shown that CHIT1 provides potential protection through microglial polarization and reduction of β-amyloid (Aβ) oligomers on rat models of AD. Histone deacetylase 3 (HDAC3) plays a significant role in the expression and regulation of proteins related to the pathophysiology of AD. In addition, nuclear factor-kappa B (NF-κB) signaling pathway activation in neurons is associated with the progression of AD. NF-κB activation is regulated by HDAC3 deacetylation. In the present study, we researched the role of CHIT1 in HDAC3/NF-κB signaling in D-galactose (D-gal) and aluminum-exposed rat model with cognitive impairments. Following CHIT1 treatment, we found that the protein and mRNA levels of HDAC3 and NF-κB were reduced, the expression level of IκBα increased, anti-inflammatory factors (Arg-1, IL-10, and CD206) were elevated while pro-inflammatory factors (TNF-a, iNOS, and IL-1β) were decreased in D-gal/aluminum-induced AD rats. These results indicate that CHIT1 can regulate brain inflammation via HDAC3/NF-κB p65 pathway, contributing to improvement of cognitive impairment., Competing Interests: Declaration of Competing Interest The authors report no declarations of interest., (Copyright © 2021 Elsevier B.V. and Japan Neuroscience Society. All rights reserved.)

Pembrolizumab, an immune-checkpoint inhibitor (ICI), is a humanized monoclonal antibody that binds to programmed cell death-1 receptor (PD-1) and thereby inhibits binding to its ligand, which inhibits the suppression of activated T cells by cancer cells, resulting in enhancing antitumour immunity. Although several cases of encephalitis have been reported as immune-related adverse effects of ICIs, epilepsy has not been reported following ICI treatment. We describe the case of an elderly woman with bladder carcinoma who experienced two episodes of generalized seizures after treatment with pembrolizumab. The episodes were atypical of encephalitis, because the seizures were completely responsive to AEDs and the CSF parameters normalized completely without immunotherapy. Since interictal EEG revealed persistent epileptic discharges after the seizures, pembrolizumab was considered to have induced a chronic state of epileptogenicity as the possible pathology, with a clinical picture similar to that of autoimmune epilepsy. The possibility that ICIs may cause an immune-related adverse effect, such as a chronic epileptic condition, should be considered, since ICIs are used widely.

Astrocytes undergo an inflammatory transition after infections, acute injuries and chronic neurodegenerative diseases. How this transition is affected by time and sex, its heterogeneity at the single-cell level and how sub-states are spatially distributed in the brain remains unclear. In this study, we investigated transcriptome changes of mouse cortical astrocytes after an acute inflammatory stimulus using the bacterial cell wall endotoxin lipopolysaccharide. We identified fast transcriptomic changes in astrocytes occurring within hours that drastically change over time. By sequencing ~80,000 astrocytes at single-cell resolution, we show that inflammation causes a widespread response with subtypes of astrocytes undergoing distinct inflammatory transitions with defined transcriptomic profiles. We also attribute key sub-states of inflammation-induced reactive astrocytes to specific brain regions using spatial transcriptomics and in situ hybridization. Together, our datasets provide a powerful resource for profiling astrocyte heterogeneity and will be useful for understanding the biological importance of regionally constrained reactive astrocyte sub-states., (© 2021. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Foetal alcohol spectrum disorder (FASD) is the umbrella term used to describe the physical and mental disabilities induced by alcohol exposure during development. Early alcohol exposure induces cognitive impairments resulting from damage to the central nervous system (CNS). The neuroinflammatory response accompanied by neurodegenerative mechanisms contribute to those detrimental alterations. Cannabidiol (CBD) has recently emerged as an anti-inflammatory drug that might be useful to treat several neuropsychiatric disorders. In our study, we assessed the effects of CBD on long-lasting cognitive deficits induced by early alcohol exposure. Furthermore, we analysed long-term pro-inflammatory and apoptotic markers within the prefrontal cortex and hippocampus. To model alcohol binge drinking during gestational and lactation periods, we used pregnant C57BL/6 female mice with time-limited access to 20% v/v alcohol solution. Following the prenatal and lactation alcohol exposure (PLAE), we treated the male and female offspring with CBD from post-natal day (PD) 25 until PD34, and we evaluated their cognitive performance at PD60. Our results showed that CBD treatment during peri-adolescence period ameliorates cognitive deficits observed in our FASD-like mouse model, without sex differences. Moreover, CBD restores the PLAE-induced increased levels of TNFα and IL-6 in the hippocampus. Thus, our study provides new insights for CBD as a therapeutic agent to counteract cognitive impairments and neuroinflammation caused by early alcohol exposure., (Copyright © 2021 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Objective: To determine the clinical and laboratory features of immune checkpoint inhibitor (ICPI)-associated autoimmune encephalitis (ICPI-AIE), an increasingly recognized adverse event with ICPI treatment., Methods: We searched PubMed, The Cochrane Library, and Embase for ICPI-AIE cases from the first description in 2015 until January 2020 using standard bibliographic measures including PRISMA guidelines and preregistration with PROSPERO., Results: Thirty-nine studies met inclusion criteria, resulting in 54 patients with ICPI-AIE (mean age 58.6 years; 43% female). Common cancers included melanoma (30%) and non-small cell lung cancer (30%). Brain metastases were found in 16 patients (30%). The most frequent ICPI was nivolumab (61%). Onset of ICPI-AIE occurred after a median of 3.0 treatment cycles, but very early and late presentations were common. Nonlimbic AIE was roughly twice as frequent as limbic AIE ( p < 0.05). The most common laboratory abnormalities included bitemporal fluid-attenuated inversion recovery lesions on MRI, continuous slow waves and diffuse slowing on EEG, and monocytic pleocytosis on CSF analysis. Intraneuronal antibodies were more frequent than neuronal surface antibodies and a significant predictor for lack of improvement after first-line immunotherapy ( p < 0.05)., Conclusions: ICPI-AIE consists of a heterogenous group of conditions. Neurologists will likely encounter ICPI-AIE more often in the future, but important unresolved questions include the pathophysiologic mechanisms, the epidemiology, and the best treatment approaches associated with ICPI-AIE., (© 2021 American Academy of Neurology.)

Importance: Encephalitis is a severe immune-related adverse event secondary to treatment with immune checkpoint inhibitors (ICIs). The spectrum of ICI-induced encephalitis (ICI-iE) ranges from disease that resolves fully to lethal forms. Moreover, ICIs may unmask a paraneoplastic encephalitis. To our knowledge, the factors associated with ICI-iE prognosis are unknown., Objectives: To evaluate the presentation of ICI-iE and to identify features helpful in assessing outcomes., Evidence Review: This systematic review pooled case series from the published literature (n = 77) and medical records from 1 center (n = 5) to assess the association between the form of ICI-iE presentation and its prognosis. Eligibility criteria included references identified by searches of PubMed and Web of Knowledge databases in the English literature from June 2000 (first patient dose of ipilimumab) to April 17, 2020, that examined patients with encephalitis with presumed autoimmune etiologic features induced by ICIs. Information regarding clinical, cerebrospinal fluid, and neuroimaging (magnetic resonance imaging) features, as well as treatment given, were extracted., Findings: A total of 82 patients (52 men [63%]; median age, 61.0 years [interquartile range, 52.5-70.0 years]) were included. Most patients presented with focal syndromes (39 [48%]) or meningoencephalitis (36 [44%]). Seven patients (9%) had nonclassifiable ICI-iE. Neuronal autoantibodies were detected in 23 patients with focal syndromes and 1 patient with nonclassifiable ICI-iE. Most autoantibodies were onconeuronal (17 of 24 [71%]), targeting intracellular antigens. Patients without a focal syndrome or with a negative-antibody focal syndrome had a good prognosis (49 of 55 [89%]). Among patients with autoantibodies, those with anti-glutamic acid decarboxylase or anticell surface responded to treatment and had a favorable prognosis (100%). However, patients with other autoantibodies had poor outcomes (17 of 24 [71%]). Antineuronal autoantibodies (13 of 24 [54%] vs 5 of 41 [12%]; P < .001), focal syndrome (16 of 39 [41%] vs 4 of 43 [9%]; P = .001), and abnormal magnetic resonance imaging findings (14 of 39 [36%] vs 4 of 32 [13%]; P = .02) were associated with poor outcomes. Conversely, fever (21 of 23 [91%] vs 41 of 59 [70%]; P = .04) and more inflammatory changes in cerebrospinal fluid (30 of 31 [97%] vs 21 of 33 [64%]; P = .001) were associated with a better prognosis., Conclusions and Relevance: Immune checkpoint inhibitors may induce mainly 2 different encephalitic syndromes: a focal limbic or extralimbic encephalitis and a meningoencephalitis. Immune checkpoint inhibitor-induced encephalitis is associated with an overall favorable outcome, with a low rate of fatal events. An undetected preexisting paraneoplastic encephalitic syndrome may be triggered by ICIs, and this type of syndrome has the worst outcome among all the different types of ICI-induced encephalitis syndromes. Clinical presentation and systematic measurement of autoantibodies will be a helpful guide for the therapeutic strategy and for counseling regarding prognosis.

The emergence of immune-based treatments for cancer has led to a growing field dedicated to understanding and managing iatrogenic immunotoxicities that arise from these agents. Immune-related adverse events (irAEs) can develop as isolated events or as toxicities affecting multiple body systems. In particular, this review details the neurological irAEs from immune checkpoint inhibitors (ICI) and chimeric antigen receptor (CAR) T cell immunotherapies. The recognition and treatment of neurological irAEs has variable success, depending on the severity and nature of the neurological involvement. Understanding the involved mechanisms, predicting those at higher risk for irAEs, and establishing safety parameters for resuming cancer immunotherapies after irAEs are all important fields of ongoing research.