Clinical features of 28 cases of anti-leucine-rich glioma-inactivated protein 1 encephalitis and anti-contactin-associated protein-like 2 encephalitis. / æŠ—å¯Œäº®æ°¨é ¸èƒ¶è´¨ç˜¤å¤±æ´»è›‹ç™½1æŠ—ä½“å’ŒæŠ—æŽ¥è§¦è›‹ç™½ç›¸å ³è›‹ç™½2抗体脑炎28例临床特征.

OBJECTIVES: Autoimmune encephalitis arising from autoantibodies against leucine-rich glioma-inactivated protein 1 (LGI1) and contactin-associated protein-like 2 (CASPR2) are rare and with high clinical heterogeneity. They are easily misdiagnosed and missing diagnosed. This study aims to explore the clinical characteristics, auxiliary examinations, therapies and prognosis of anti-LGI1 and anti-CASPR2 encephalitis. METHODS: Seventeen anti-LGI1 and 11 anti-CASPR2 encephalitis patients who were admitted to the Department of Neurology, Xiangya Hospital, Central South University between January 2018 and January 2021 were collected and retrospectively analyzed. Autoimmune encephalitis related antibodies and paraneoplastic antibodies were screened in all patients. The clinical manifestations, results of laboratory tests, imaging features, treatments and outcomes of 2 encephalitis groups were analyzed and compared. RESULTS: In the anti-LGI1 encephalitis group, the age of 17 patients was 28-83 (53.18±19.08) years old, and the ratio of male to female was 9꞉8. There were 10 patients with cognitive impairment, 7 seizures, 4 faciobrachial dystonic seizures, and 1 psychiatric disturbance. Hyponatremia was observed in 7 patients. Eight patients had increased slow waves and 5 had epileptic discharge in electroencephalogram (EEG). Brain magnetic resonance (MRI) showed T2-weighted imaging (T2WI) and fluid attenuated inversion recovery (FLAIR) hyperintense signal in the temporal lobe, hippocampus and basal ganglia in 13 patients. In the anti-CASPR2 group, the age of 11 patients was 17-68 (47.18±16.20) years old, and the ratio of male to female was 5꞉6, with 7 limbic encephalitis, 1 Morvan syndrome, and 3 acquired neuromyotonia (NMT). Three patients had increased slow waves and 2 had epileptic discharge in EEG. Brain MRI showed T2WI and FLAIR hyperintense signal in the temporal lobe, hippocampus in 2 patients. Steroids, intravenous immunoglobin, and plasma exchange were administrated in 16 anti-LGI1 encephalitis and 8 anti-CASPR2 encephalitis patients with good therapeutic responses. Among them, 1 patient with anti-LGI1 encephalitis and 3 with anti-CASPR2 encephalitis were administrated with mycophenolate mofetil for immune maintenance therapy. No recurrences were observed in all patients with immunotherapy except for 2 patients who lost of follow-up. There were significant differences in cognitive impairment, hyponatremia, and brain MRI abnormalities between anti-LGI1 and anti-CASPR2 encephalitis patients (all P<0.05). CONCLUSIONS: Limbic encephalitis is a common syndrome in both anti-LGI1 and anti-CASPR2 encephalitis patients. Anti-CASPR2 encephalitis has a wider clinical spectrum than anti-LGI1 encephalitis, presenting as NMT and Morvan syndrome, which has a closer relationship with tumors. Both of these 2 antibodies associated disorders are sensitive to immunotherapy and have a good prognosis.

Aquaporin-9 in the Brain Inflammatory Response: Evidence from Mice Injected with the Parkinsonogenic Toxin MPP.

More than 20 years have passed since the first demonstration of Aquaporin-9 (AQP9) in the brain. Yet its precise localization and function in brain tissue remain unresolved. In peripheral tissues, AQP9 is expressed in leukocytes where it is involved in systemic inflammation processes. In this study, we hypothesized that AQP9 plays a proinflammatory role in the brain, analogous to its role in the periphery. We also explored whether Aqp9 is expressed in microglial cells, which would be supportive of this hypothesis. Our results show that targeted deletion of Aqp9 significantly suppressed the inflammatory response to the parkinsonian toxin 1-methyl-4-phenylpyridinium (MPP+). This toxin induces a strong inflammatory response in brain. After intrastriatal injections of MPP+, the increase in transcript levels of proinflammatory genes was less pronounced in AQP9-/- mice compared with wild-type controls. Further, in isolated cell subsets, validated by flow cytometry we demonstrated that Aqp9 transcripts are expressed in microglial cells, albeit at lower concentrations than in astrocytes. The present analysis provides novel insight into the role of AQP9 in the brain and opens new avenues for research in the field of neuroinflammation and chronic neurodegenerative disease.

A case report of long-delayed diagnosis of pseudorabies virus encephalitis with endophthalmitis: lessons from metagenomic next generation sequencing.

BACKGROUND: Pseudorabies virus (PRV) was thought to only infect animals. Recent studies have shown that it can also infect human. CASE PRESENTATION: We report a case of pseudorabies virus encephalitis and endophthalmitis, diagnosed 89 days after onset, confirmed with intraocular fluid metagenomic next generation sequencing (mNGS) after the result of two cerebrospinal fluid (CSF) mNGS tests were negative. Although treatment with intravenous acyclovir, foscarnet sodium, and methylprednisolone improved the symptoms of encephalitis, significant diagnostic delay resulted in permanent visual loss. CONCLUSIONS: This case suggests that pseudorabies virus (PRV) DNA in the intraocular fluid may have a higher positivity than that in the CSF. PRV may persist in the intraocular fluid for an extended period and may thus require extended antiviral therapy. Patients with severe encephalitis and PRV should be examined with the focus on pupil reactivity and light reflex. A fundus examination should be performed in patients with a central nervous system infection, specifically, those in a comatose state, to help reduce eye disability.

[An Update on Therapeutic Management in Autoimmune Encephalitis].

In the last 15 years, the continual discovery of newly identified forms of autoimmune encephalitis (AE) associated with antibodies to the cell surface or synaptic proteins has changed the paradigms for diagnosing and treating disorders. AE is one of the most common causes of noninfectious encephalitis. It can be triggered by tumors or, infections, or it may be cryptogenic. These disorders can occur in children or young adults with or without cancer who develop psychosis, catatonic or autistic features, memory problems, abnormal movements, or seizures. Here, we review the therapeutic management of AE. The importance of early recognition and diagnosis of AE is paramount to the ultimate goal of optimal immunotherapy. Although no specific data are available for all autoantibody-mediated encephalitis syndromes, the two most common forms of AE, which are NMDA receptor encephalitis and LGI-1 encephalitis, are clear exemplars where improved patient outcomes are associated with early immunotherapy. First-line treatments for AE include intravenous steroids and intravenous immunoglobulins, which can be combined in most severe cases. Rituximab and cyclophosphamide are administered as second-line agents in unresponsive cases. A minority of patients may remain refractory to treatment, thus representing a major clinical challenge. In these cases, the treatment strategies are controversial, and no guidelines exist. Treatments proposed for refractory AE include (1) cytokine-based drugs such as tocilizumab, and (2) plasma cell-depleting agents such as bortezomib.

Clinical, imaging features and outcomes of patients with anti-GFAP antibodies: a retrospective study.

Objective: To evaluate and compare the clinical features, imaging, overlapping antibodies, and prognosis of pediatric and adult patients with anti-GFAP antibodies. Methods: This study included 59 patients with anti-GFAP antibodies (28 females and 31 males) who were admitted between December 2019 and September 2022. Results: Out of 59 patients, 18 were children (under 18 years old), and 31 were adults. The overall cohort's median age at onset was 32 years old, 7 for children, and 42 for adults. There were 23 (41.1%) patients with prodromic infection, 1 (1.7%) patient with a tumor, 29 (53.7%) patients with other non-neurological autoimmune diseases, and 17 (22.8%) patients with hyponatremia. Fourteen (23.7%) patients had multiple neural autoantibodies, with the AQP4 antibody being the most common. Encephalitis (30.5%) was the most common phenotypic syndrome. Common clinical symptoms included fever (59.3%), headache (47.5%), nausea and vomiting (35.6%), limb weakness (35.6%), and disturbance of consciousness (33.9%). Brain MRI lesions were primarily located in the cortex/subcortex (37.3%), brainstem (27.1%), thalamus (23.7%), and basal ganglia (22.0%). Spinal cord MRI lesions often involved the cervical and thoracic spinal cord. There was no statistically significant difference in the MRI lesion site between children and adults. Out of 58 patients, 47 (81.0%) had a monophasic course, and 4 died. The last follow-up showed that 41/58 (80.7%) patients had an improved functional outcome (mRS <3), and children were more likely than adults to have no residual disability symptoms (p = 0.001). Conclusion: There was no statistically significant difference in clinical symptoms and imaging findings between children and adult patients with anti-GFAP antibodies; Patients with anti-GFAP antibodies may present with normal MRI findings or delayed MRI abnormalities, and patients with overlapping antibodies were common. Most patients had monophasic courses, and those with overlapping antibodies were more likely to relapse. Children were more likely than adults to have no disability. Finally, we hypothesize that the presence of anti-GFAP antibodies is a non-specific witness of inflammation.

Anti-GABA-A Receptor Antibody-Mediated Epilepsia Partialis Continua After Treatment With Alemtuzumab: A Case Report.

BACKGROUND AND OBJECTIVES: Patients with anti-GABA-A receptor encephalitis characteristically experience therapy-refractory epileptic seizures. General anesthesia is often required to terminate refractory status epilepticus. The immunologic mechanisms leading to antibody formation remain to be elucidated. Described triggers of anti-GABA-A autoimmunity are tumors, mainly thymomas, and herpes simplex encephalitis. METHODS: We present a young woman with prediagnosis of relapse remitting multiple sclerosis (MS), treated with interferons, natalizumab, and alemtuzumab. Six months after one and only cycle of alemtuzumab, speech arrest and behavioral changes with aggressive and anxious traits appeared. She showed increasing motor convulsions resulting in focal status epilepticus. RESULTS: Anti-GABA-A receptor antibodies in CSF and serum were confirmed in different external laboratories, in a more extensive analysis after antibodies against NMDAR, CASPR2, LGI1, GABABR, and AMPAR were ruled out during in-house examination. Clinical condition improved temporarily with cortisone therapy, plasmapheresis, and IVIG but deteriorated rapidly after steroid discontinuation, resulting in brain biopsy. On histopathologic confirmation consistent with anti-GABA-A receptor antibody-associated CNS inflammation, completing the first rituximab cycle, continuing oral corticosteroids and supplementing immunosuppression with cyclosporine A led to quick recovery. DISCUSSION: Our case describes a severe autoantibody-induced encephalitis in a young patient with MS, with alemtuzumab as a potential trigger for anti-GABA-A receptor encephalitis.

Anti-LGI1 Encephalitis With Co-occurring IgLON5 Antibodies: Clinical Features and Human Leukocyte Antigen Haplotypes.

OBJECTIVES: Autoimmune encephalitis (AE) with antibodies against LGI1 and IgLON5 are clinically distinctive but share some particularities such as a strong association with specific human leukocyte antigen (HLA) class II alleles. METHODS: We clinically describe a patient with double positivity for LGI1 and IgLON5 antibodies. In addition, we conducted specific immunodepletion with the patient's serum and HLA typing and investigated the presence of serum IgLON5 antibodies in a cohort of 23 anti-LGI1 patients carrying the HLA predisposing for anti-IgLON5 encephalitis. RESULTS: A 70-year-old woman with a history of lymphoepithelial thymoma presented with subacute cognitive impairment and seizures. Investigations included MRI and EEG showing medial temporal involvement, increased CSF protein content, and polysomnography with REM and non-REM motor activity, along with obstructive apnea. Neural antibody testing revealed both LGI1 and IgLON5 antibodies in serum and CSF, and serum immunodepletion ruled out cross-reactivity. The patient carried DRB1*07:01 and DQA1*01:01∼DQB1*05:01, but no other IgLON5-positive case was identified in a cohort of anti-LGI1 patients carrying DQA1*01∼DQB1*05. Nearly full therapeutic response was obtained after intensified immunosuppressive treatment. DISCUSSION: We present a case of anti-LGI1 encephalitis with concomitant IgLON5 antibodies. Co-occurring IgLON5 antibodies in anti-LGI1 encephalitis are exceptional, but may appear in genetically predisposed individuals.

Chronic acetyl-L-carnitine treatment alleviates behavioral deficits and neuroinflammation through enhancing microbiota derived-SCFA in valproate model of autism.

Autism spectrum disorder is characterized by a variety of cellular and molecular abnormalities which leads to autism-associated behaviors. Besides behavioral defects, these individuals also suffer from various associated disorders such as gastrointestinal deficit, altered gut microbiota composition and their metabolite. This study examined the effect of ALC on microbiota SCFA production and its effects on brain inflammation in VPA autism model. After prenatal exposure to valproate (600 mg/kg, i.p.) on embryonic day 12.5, followed by ALC treatment (100 mg/kg during postnatal days 23-51, p.o.), ASD-like behaviors, SCFAs amount in feces, intestine integrity (Occludin and ZO-1 tight junction proteins), systemic and brain inflammation (TNF-α and IL-1ß) were assessed. Then, Golgi-Cox staining and Western blot for Iba1 protein were utilized to identify the changes in microglia profile in cerebral cortex. In the VPA model, we found that induction of autism was associated with demoted levels of SCFAs in feces and disintegration of intestine tissue which led to elevated level of TNF-α in the plasma. Further, we characterized an increased number of microglia in our histology evaluation and Iba1 protein in cerebral cortex. We also observed elevated level of TNF-α and IL-1ß in the cerebral cortex of VPA rat. All these abnormalities were significantly alleviated by ALC treatment. Overall, our findings suggest that alleviation of behavioral abnormalities by ALC therapy in the VPA model of autism is associated with an improvement in the gut microbiota SCFAs, intestinal barrier and recovery of microglia and inflammation in the brain.

Late-Onset Anti-GABAB Receptor Encephalitis: Clinical Characteristics and Outcomes Differing From Early-Onset Patients.

BACKGROUND AND OBJECTIVES: Existing evidence indicates anti-GABAB receptor encephalitis (GABABR-E) seems to occur more commonly later in life, yet the age-associated differences in clinical features and outcomes are not well determined. This study aims to explore the demographic, clinical characteristics, and prognostic differences between late-onset and early-onset GABABR-E and identify predictors of favorable long-term outcomes. METHODS: This is an observational retrospective study conducted in 19 centers from China. Data from 62 patients with GABABR-E were compared between late-onset (aged 50 years or older) and early-onset (younger than 50 years) groups and between groups with favorable outcomes (modified Rankin scale (mRS) ≤ 2) and poor outcomes (mRS >2). Logistic regression analyses were applied to identify factors affecting long-term outcomes. RESULTS: Forty-one (66.1%) patients experienced late-onset GABABR-E. A greater proportion of males, a higher mRS score at onset, higher frequencies of ICU admission and tumors, and a higher risk of death were demonstrated in the late-onset group than in the early-onset group. Compared with poor outcomes, patients with favorable outcomes had a younger onset age, a lower mRS score at onset, lower frequencies of ICU admission and tumors, and a greater proportion with immunotherapy maintenance for at least 6 months. On multivariate regression analysis, age at onset (OR, 0.849, 95% CI 0.739-0.974, p = 0.020) and the presence of underlying tumors (OR, 0.095, 95% CI 0.015-0.613, p = 0.013) were associated with poorer long-term outcomes, whereas immunotherapy maintenance for at least 6 months was associated with favorable outcomes (OR, 10.958, 95% CI 1.469-81.742, p = 0.020). DISCUSSION: These results demonstrate the importance of risk stratification of GABABR-E according to age at onset. More attention should be paid to older patients especially with underlying tumors, and immunotherapy maintenance for at least 6 months is recommended to achieve a favorable outcome.

[Long-term cognitive impairment in autoimmune encephalitis]. / Troubles cognitifs séquellaires dans le cadre d'une encéphalite auto-immune.

Autoimmune encephalitis (AE) are a group of rare inflammatory diseases of the central nervous system that can manifest as subacute cognitive impairment. Despite the presence of diagnostic criteria, it can be challenging to identify this disease in certain age groups. In this article, we present the two main clinical phenotypes of AE associated with cognitive impairment, the factors contributing to the long-term cognitive outcome and its management after the acute phase.

Les encéphalites auto-immunes (EAI) sont un groupe de maladies inflammatoires rares du système nerveux central (CNS) pouvant se manifester par une atteinte cognitive d'apparition subaiguë. Malgré la présence des critères diagnostiques, leur identification peut représenter un défi dans certains groupes d'âge. Dans cet article, nous exposons les deux principaux phénotypes cliniques d'EAI s'associant à des troubles cognitifs, les facteurs contribuant au pronostic cognitif et la prise en charge après la phase aiguë.

Diagnostic criteria for autoimmune encephalitis: utility and pitfalls for antibody-negative disease.

Increased awareness of autoimmune encephalitis has led to two unintended consequences: a high frequency of misdiagnoses and the inappropriate use of diagnostic criteria for antibody-negative disease. Misdiagnoses typically occur for three reasons: first, non-adherence to reported clinical requirements for considering a disorder as possible autoimmune encephalitis; second, inadequate assessment of inflammatory changes in brain MRI and CSF; and third, absent or limited use of brain tissue assays along with use of cell-based assays that include only a narrow range of antigens. For diagnosis of possible autoimmune encephalitis and probable antibody-negative autoimmune encephalitis, clinicians should adhere to published criteria for adults and children, focusing particularly on exclusion of alternative disorders. Moreover, for diagnosis of probable antibody-negative autoimmune encephalitis, the absence of neural antibodies in CSF and serum should be well substantiated. Neural antibody testing should use tissue assays along with cell-based assays that include a broad range of antigens. Live neuronal studies in specialised centres can assist in resolving inconsistencies with respect to syndrome-antibody associations. Accurate diagnosis of probable antibody-negative autoimmune encephalitis will identify patients with similar syndromes and biomarkers, which will provide homogeneous populations for future assessments of treatment response and outcome.

Immunocompetent hamsters as a model for orthobunyavirus-induced neuroinvasion and neuropathology.

BACKGROUND: Bunyavirus infections, including those caused by Bunyamwera serogroup orthobunyaviruses, represent a significant and yet likely still vastly underappreciated cause of mild to moderate human febrile infections. In severe cases, these infections can also cause neurological disease, particularly meningitis and encephalitis, and infection can even be fatal. However, with a few exceptions, information regarding the mechanisms underlying the neuroinvasion and neuropathogenesis of such infections is limited. This is due in part to a lack of animal models to facilitate such studies. METHODOLOGY/PRINCIPAL FINDINGS: In an effort to develop an immunocompetent model of infection with Bunyamwera serogroup orthobunyaviruses, we infected 4-6-week-old female hamsters via either the intraperitoneal or subcutaneous route with 106 pfu/animal of Bunyamwera virus (BUNV), Batai virus or Ngari virus. Only BUNV infection resulted in clinical disease, which was characterized by weight loss, lethargy and neurological signs (i.e. tremor of the head or limbs, loss of righting reflex, "waltzing"). While symptoms were of similar severity for both routes, they occurred more frequently following subcutaneous inoculation. Consistent with these clinical signs, both antigen staining and histopathological abnormalities were found extensively throughout the brain. CONCLUSIONS/SIGNIFICANCE: The reported hamster model of BUNV infection provides a new tool for studying orthobunyavirus infection, and particularly neuroinvasion and the development of neuropathology. This model is particularly significant because it makes use of immunologically competent animals and relies on a subcutaneous inoculation route that more closely mimics the natural infection route for arboviruses, thereby providing a more authentic cellular and immunological context at the initial site of infection.

Evaluation, Treatment, and Outcomes of Viral and Autoimmune Encephalitis in Children.

Viral encephalitis and autoimmune encephalitis are currently the most common causes of encephalitis. Determining the causative agent is helpful in initiating medical treatment that may help reduce long-term sequelae. Cerebrospinal fluid, neuroimaging, serologic, and electroencephalogram in combination with clinical manifestations play a role in determining the cause of the encephalitis. Although motor dysfunction tends to improve, there is a significant risk of long-term neurologic and cognitive sequelae. These persistent deficits that occur in childhood indicate the importance for ongoing rehabilitative services to maximize functional skills, improve cognitive deficits, and assist with community integration.

Risk factors of epilepsy secondary to viral encephalitis: A meta-analysis.

OBJECTIVE: To systematically evaluate the risk factors of post-encephalitis epilepsy (PEE). METHODS: Systematic computerized searches of databases such as Cochrane Library, PubMed and EMBASE were performed. The meta-analysis of pooled odds ratios and 95% confidence intervals for PEE risk were calculated. RESULTS: Sixteen studies with 2504 patients were included for meta-analysis. The results showed that PEE was associated with coma, seizure, status epilepticus, cranial MRI abnormality, focal EEG abnormality, and positive herpes simplex virus (HSV) in cerebrospinal fluid (CSF). CONCLUSION: Coma, seizures or status epilepticus, abnormal MRI and focal EEG, and HSV in CSF were the risk factors of PEE.

Cerebellar ataxia with anti-mGluR1 auto-antibody in a pediatric patient: A case report.

Cerebellar ataxia (CA) related to anti-metabolic glutamate receptor 1 (mGluR1) is a rare autoimmune encephalitis, which is manifested as acute or subacute CA in most cases.To the best of our knowledge, only three cases of pediatric patients have been reported in the literature so far. This article reports the 4th case of mGluR1 related CA in a pediatric patient.

Anti-LGI1 encephalitis: A family affair.

Here we describe the second ever-reported case of familial anti-leucine-rich glioma-inactivated protein 1 (LGI1) limbic encephalitis (LE). Two elderly Caucasian sisters presented with psychiatric symptoms and cognitive impairment, followed by faciobrachial dystonic seizures. Anti-LGI1 antibodies were detected in their serum. Considering they had been living in distant regions for decades, environmental factors could be ruled out. Human leukocyte antigen (HLA) genotyping revealed that both carried HLA-DRB1*07, found in 90% of anti-LGI1 encephalitis patients, HLA-DQA1*02:01 and HLA-DQB1*03:03, commonly associated with DRB1*07:01. Considering the exceptional nature of familial cases, as-yet-unknown genetic contributors other than HLA might play a role in our siblings.