Receptor Encephalitis Research Articles

H-intensity scale score to estimate CSF GluN1 antibody titers with one-time immunostaining using a commercial assay.

Anti-NMDA receptor encephalitis is an autoimmune disorder caused by autoantibodies (abs) against the conformational epitope on GluN1 subunits. GluN1-abs have been determined with cell-based assay (CBA) co-expressing GluN1/GluN2 subunits. However, commercial fixed CBA expressing only GluN1 subunit has increasingly been used in clinical practice. The ab titers can be determined with serial dilutions, but its clinical significance remains unclear. We aimed to develop an H-intensity scale (HIS) score to estimate GluN1-ab titers in cerebrospinal fluid (CSF) with one-time immunostaining using both commercial CBA and immunohistochemistry and report its usefulness. "H" is the initial of a patient with high CSF GluN1-ab titers (1:2,048). We first determined the reliability of CBA in 370 patients with suspected autoimmune encephalitis by comparing the results between commercial CBA and established assay in Dalmau's Lab. Then, we made positive control panels using the patient H's CSF diluted in a fourfold serial dilution method (1:2, 1:8, 1:32, 1:128, 1:512, and 1:2,048). Based on the panels, we scored the intensity of ab reactivity of 79 GluN1-ab-positive patients' CSF (diluted at 1:2) on a scale from 0 to 6 (with ≥1 considered positive). To assess inter-assay reliability, we performed immunostaining twice in 21 patients' CSF. We investigated an association between the score of CSF obtained at diagnosis and the clinical/paraclinical features. The sensitivity and specificity of CBA were 93.7% (95% CI: 86.0-97.3) and 98.6% (95% CI: 96.5-99.5), respectively. Linear regression analysis showed a good agreement between the scores of the first and second assays. Patients with a typical spectrum, need for mechanical ventilation support, autonomic symptoms/central hypoventilation, dyskinesias, speech dysfunction, decreased level of consciousness, preceding headache, ovarian teratoma, and CSF leukocyte count >20 cells/µL had a higher median HIS score than those without, but HIS score was not associated with sex, age at onset, or seizure. HIS score at diagnosis had a significant effect on 1-year functional status. The severity of disease and four of the six core symptoms were associated with higher GluN1-ab titers in CSF at diagnosis, which may play a role in poor 1-year functional status. An incomplete phenotype can be attributed to low CSF GluN1-ab titers.

FLAMES overlaying anti-N-methyl-D-aspartate receptor encephalitis: a case report and literature review

BackgroundIn recent years, simultaneous or sequential occurrence of MOG antibody disease and anti-NMDAR encephalitis in the same patient has been reported with increasing frequency. Scholars refer to the overlapping occurrence of these two disorders as MOG antibody disease and anti-NMDAR encephalitis overlap syndrome (MNOS). Cortical T2-weighted fluid-attenuated inversion recovery (FLAIR) -hyperintense lesions in anti-MOG-associated encephalitis with seizures (FLAMES) is a rare clinical phenotype of MOGAD in which cortical FLAIR high-signal lesions are unilateral, with little spread to the cortex and meninges bilaterally. Although cases of FLAMES have been consistently reported. However, to our knowledge, such cases of FLAMES combined with NMDARE are rare.Case presentationHere, we describe a case of FLAMES combined with anti-NMDARE. The patient was a young male, 29 years old, admitted to our hospital with isolated seizures, whose MRI showed unilateral thalamic and bilateral frontal and parietal leptomeningeal involvement. Since we were unaware of the possibility of bilateral meningo-cortical MOGAD manifestations, the case was initially diagnosed as viral encephalitis and was given antiviral therapy. The diagnosis was not clarified until anti-NMDAR-IgG and MOG-IgG positivity was detected in the cerebrospinal fluid and serum. The patient was then treated with high-dose corticosteroids and his symptoms responded well to the steroids. Therefore, this case expands the clinical spectrum of MNOS overlap syndrome. In addition, we describe the clinical features of MNOS by summarizing the existing literature and exploring the possible mechanisms of its immune response.ConclusionsOur case serves as a reminder to clinicians that when patients present with atypical clinical manifestations such as seizures, consideration should be given to MNOS and conduct testing for various relevant autoantibodies (including MOG abs) and viruses in both serum and cerebrospinal fluid, as it is easy to misdiagnose the disease as other CNS diseases, such as viral meningoencephalitis. This syndrome exhibits a high responsiveness to steroids, highlighting the critical importance of recognizing the clinical and neuroimaging features of this overlap syndrome for prompt diagnosis and treatment. Furthermore, it enriches the disease spectrum of MNOS.

Teaching NeuroImage: Anti-NMDA Receptor Encephalitis Presenting With Cerebellitis in a Pediatric Patient.

Teaching NeuroImage: Anti-NMDA Receptor Encephalitis Presenting With Cerebellitis in a Pediatric Patient.

Efficacy and Safety of Different Oral Prednisone Tapering Course in Anti-N-M-methyl-D-aspartate Receptor Encephalitis: A Multicenter Cohort Study (P6-14.008)

Efficacy and Safety of Different Oral Prednisone Tapering Course in Anti-N-M-methyl-D-aspartate Receptor Encephalitis: A Multicenter Cohort Study (P6-14.008)

Characteristics and Clinical Significance of Initial MRI in Anti-NMDA Receptor Encephalitis (P5-14.019)

Characteristics and Clinical Significance of Initial MRI in Anti-NMDA Receptor Encephalitis (P5-14.019)

Treatment of Refractory Anti-NMDA Receptor Encephalitis with Daratumumab in Two Pediatric Patients (P6-14.005)

Treatment of Refractory Anti-NMDA Receptor Encephalitis with Daratumumab in Two Pediatric Patients (P6-14.005)

Initial MRI, EEG, and CSF White Cell Count Are Abnormal in Children with Anti-NMDA Receptor Encephalitis with Isolated Psychiatric Symptoms (P6-14.020)

Initial MRI, EEG, and CSF White Cell Count Are Abnormal in Children with Anti-NMDA Receptor Encephalitis with Isolated Psychiatric Symptoms (P6-14.020)

Anti-N-methyl-D-aspartate Receptor Encephalitis Associated with Acute West Nile Infection: A Case Report (P7-14.004)

Anti-N-methyl-D-aspartate Receptor Encephalitis Associated with Acute West Nile Infection: A Case Report (P7-14.004)

Racial and Ethnic Disparities in Incidence of Anti-NMDA Receptor Encephalitis (P5-14.011)

Racial and Ethnic Disparities in Incidence of Anti-NMDA Receptor Encephalitis (P5-14.011)

Post-infectious N-methyl-D-aspartate Receptor Encephalitis Antibody Associated with Coxsackie Virus Infection (P7-14.012)

Post-infectious N-methyl-D-aspartate Receptor Encephalitis Antibody Associated with Coxsackie Virus Infection (P7-14.012)

Non-Hodgkin’s Lymphoma of the Central Nervous System with N-Methyl-D-Aspartate Receptor Antibody Positivity - A Case Report

Purpose: Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, among the paraneoplastic syndromes, is a recently characterized autoimmune encephalitis most commonly associated with antibodies against subunits of the NMDAR in the central nervous system. As a paraneoplastic syndrome, anti-NMDAR encephalitis is commonly associated with ovarian teratomas, small cell lung carcinomas and testicular germ cell tumors. To our knowledge, there have been no cases with primary central nervous system lymphoma (PCNSL), a rare type of extranodal non-Hodgkin’s lymphoma, without lymph node involvement associated with anti-NMDAR encephalitis. Case Report: A 58-year-old right-handed male patient with complaints of instability in walking for two months, progressively smaller handwriting, hallucinations when falling asleep or waking up, decreased memory, inability to maintain attention was admitted to our hospital for further diagnosis and treatment. Lumbar puncture was performed with the diagnosis of possible encephalitis after many further examinations and CSF studies revealed NMDAR antibody positivity, leading to the initial diagnosis of anti - NMDAR encephalitis. He was treated with high dose methylprednisolone and intravenous immunoglobulin. Due to the continuation of the patient’s presenting symptoms and cranial magnetic resonance imaging findings, a stereotactic brain biopsy was performed from the area with contrast enhancement and the diagnosis was revised as PCNSL associated with NMDAR antibody positivity. Conclusion: This report emphasizes the importance of anti-NMDAR encephalitis as a paraneoplastic syndrome in previously undiagnosed PCNSL. Therefore, it is crucial to be aware of anti-NMDAR encephalitis as a paraneoplastic neurological syndrome that can present with non-Hodgkin’s lymphoma. It is necessary to continually observe the evolution of the disease and perform further diagnostic tests for early identification.

Is anti-NMDA receptor encephalitis real? II. Therapeutic challenges

The first part of the review challenges the diagnostic concept of anti-NMDA receptor encephalitis (ANMDARE). The second part focuses on analyzing current therapeutic approaches. It is demonstrated that the use of antipsychotics or immunosuppressants poses the risk of severe complications, potentially leading to fatal outcomes, in the near or distant future. Comparing clinical and neurobiological effects associated with antibodies to the GluN1 subunit of the glutamate N-methyl-D-aspartate receptors (NMDAR1-AB) and the administration of subanesthetic doses of the non-competitive NMDA receptor antagonist Ketamine highly suggests a neuroprotective, health-promoting role of NMDAR1-AB, which should not be suppressed but rather potentiated. Benzodiazepines and electroconvulsive therapy (ECT) remain the treatment of choice for acute polymorphic hyperkinetic psychoses.

Does new knowledge allow to improve the diagnosis of mental disorders: the problem of anti-NMDA receptor encephalitis?

A narrative review of research studies discusses the clinical features, differential diagnosis, and treatment of anti-NMDA receptor encephalitis. Special attention is given to the controversial aspects of the etiology and pathogenesis of this disorder. The need for further research into on the role of antibodies to NMDA receptors in the development of psychiatric disorders is emphasized.

Rapamycin alleviates mitochondrial dysfunction in anti-NMDAR encephalitis mice

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is one of the most prevalent forms of autoimmune encephalitis, characterized by a series of neurological and psychiatric symptoms, including cognitive impairment, seizures and psychosis. The underlying mechanism of anti-NMDAR encephalitis remains unclear. In the current study, the mouse model of anti-NMDAR encephalitis with active immunization was performed. We first uncovered excessive mitochondrial fission in the hippocampus and temporal cortex of anti-NMDAR encephalitis mice, indicated by elevated level of Phospho-DRP1 (Ser616) (p-Drp1-S616). Moreover, blockade of the autophagic flux was also demonstrated, leading to the accumulation of fragmented mitochondria, and elevated levels of mitochondrial reactive oxygen species (mtROS) and mitochondrial DNA (mtDNA) in anti-NMDAR encephalitis. More importantly, we found that the mTOR signaling pathway was overactivated, which could aggravate mitochondrial fission and inhibit autophagy, resulting in mitochondrial dysfunction. While rapamycin, the specific inhibitor of the mTOR signaling pathway, significantly alleviated mitochondrial dysfunction by inhibiting mitochondrial fission and enhancing autophagy. Levels of mtROS and mtDNA were markedly reduced after the treatment of rapamycin. In addition, rapamycin also significantly alleviated cognitive dysfunction and anxious behaviors found in anti-NMDAR encephalitis mice. Thus, our study reveals the vital role of mitochondrial dysfunction in pathological mechanism of anti-NMDAR encephalitis and lays a theoretical foundation for rapamycin to become a clinically targeted drug for anti-NMDAR encephalitis.

Anti-N-methyl-D-aspartate Receptor Encephalitis in People Living with HIV: Case Report and Literature Review.

With the increase in the number of cases of autoimmune encephalitis (AE), the cerebrospinal fluid (CSF) of people living with HIV (PLWH) showing abnormal behavior, cognitive impairment or abnormal movements should be actively screened for the antibody panel of AE. Early recognition and treatment can prevent severe seizures or coma and markedly improve the prognosis of patients. The first-line immunotherapy for AE includes intravenous methylprednisolone and immunoglobulin. However, whether long-time immunosuppressive maintenance therapy is needed is debated. For PLWH, immunosuppressive therapy and even steroids could be more challenging. Here, we review and summarize the clinical characteristics often reported cases and report one case from our center to improve the diagnosis and treatment of anti-N-methyl-D-aspartate receptor encephalitis in PLWH.

AQP4-IgG-seropositive neuromyelitis optica spectrum disorder concurring with anti-N-methyl-D-aspartate receptor encephalitis at pediatric age: a case report

AQP4-IgG-seropositive neuromyelitis optica spectrum disorder concurring with anti-N-methyl-D-aspartate receptor encephalitis at pediatric age: a case report

Genetic predisposition to autoimmune encephalitis and paraneoplastic neurological syndromes.

We summarize the recent discoveries on genetic predisposition to autoimmune encephalitis and paraneoplastic neurological syndromes (PNS), emphasizing clinical and pathophysiological implications. The human leukocyte antigen (HLA) is the most studied genetic factor in autoimmune encephalitis and PNS. The HLA haplotype 8.1, which is widely known to be related to systemic autoimmunity, has been only weakly associated with a few types of autoimmune encephalitis and PNS. However, the strongest and most specific associations have been reported in a subgroup of autoimmune encephalitis that comprises antileucine-rich glioma-inactivated 1 (LGI1) limbic encephalitis, associated with DRB1∗07 : 01 , anticontactin-associated protein-like 2 (CASPR2) limbic encephalitis, associated with DRB1∗11 : 01 , and anti-IgLON5 disease, associated with DRB1∗10 : 01∼DQA1∗01∼DQB1∗05 . Non-HLA genes have been poorly investigated so far in autoimmune encephalitis, mainly in those lacking HLA associations such as anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, with only a few genome-wide association studies (GWAS) reporting equivocal results principally limited by small sample size. Genetic predisposition seems to be driven mostly by HLA in a group of autoimmune encephalitis characterized by being nonparaneoplastic and having predominantly IgG4 autoantibodies. The contribution of non-HLA genes, especially in those diseases lacking known or strong HLA associations, will require large cohorts enabling GWAS to be powerful enough to render meaningful results.

MyD88-mediated signaling is critical for the generation of seizure responses and cognitive impairment in a model of anti-N-methyl-D-aspartate receptor encephalitis.

We previously demonstrated that interleukin-1 receptor-mediated immune activation contributes to seizure severity and memory loss in anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. In the present study, we assessed the role of the myeloid differentiation primary response gene 88 (MyD88), an adaptor protein in Toll-like receptor signaling, in the key phenotypic characteristics of anti-NMDAR encephalitis. Monoclonal anti-NMDAR antibodies or control antibodies were infused into the lateral ventricle of MyD88 knockout mice (MyD88-/-) and control C56BL/6J mice (wild type [WT]) via osmotic minipumps for 2 weeks. Seizure responses were measured by electroencephalography. Upon completion of the infusion, the motor, anxiety, and memory functions of the mice were assessed. Astrocytic (glial fibrillary acidic protein [GFAP]) and microglial (ionized calcium-binding adaptor molecule 1 [Iba-1]) activation and transcriptional activation for the principal inflammatory mediators involved in seizures were determined using immunohistochemistry and quantitative real-time polymerase chain reaction, respectively. As shown before, 80% of WT mice infused with anti-NMDAR antibodies (n = 10) developed seizures (median = 11, interquartile range [IQR] = 3-25 in 2 weeks). In contrast, only three of 14 MyD88-/- mice (21.4%) had seizures (0, IQR = 0-.25, p = .01). The WT mice treated with antibodies also developed memory loss in the novel object recognition test, whereas such memory deficits were not apparent in MyD88-/- mice treated with anti-NMDAR antibodies (p = .03) or control antibodies (p = .04). Furthermore, in contrast to the WT mice exposed to anti-NMDAR antibodies, the MyD88-/- mice had a significantly lower induction of chemokine (C-C motif) ligand 2 (CCL2) in the hippocampus (p = .0001, Sidak tests). There were no significant changes in the expression of GFAP and Iba-1 in the MyD88-/- mice treated with anti-NMDAR or control antibodies. These findings suggest that MyD88-mediated signaling contributes to the seizure and memory phenotype in anti-NMDAR encephalitis and that CCL2 activation may participate in the expression of these features. The removal of MyD88 inflammation may be protective and therapeutically relevant.

Less common phenotypes of myelin oligodendrocyte glycoprotein antibody-related diseases in children deserve more attention

BackgroundTo facilitate the identification of less common clinical phenotypes of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) in children.MethodsWe retrospectively reviewed medical records of 236 patients with MOGAD. The following phenotypes were considered to be typical for MOGAD: ADEM, ON, TM, and NMOSD. Less common onset clinical phenotypes were screened out; their clinical and magnetic resonance imaging (MRI), diagnosis, treatment, and prognosis were summarized and analyzed.Results16 cases (6.8%) presented as cortical encephalitis, with convulsions, headache, and fever as the main symptoms. 15 cases were misdiagnosed in the early period. 13 cases (5.5%) showed the overlapping syndrome of MOGAD and anti-N-methyl-D aspartate receptor encephalitis (MNOS), with seizures (92.3%) being the most common clinical symptom. 11 cases (84.6%) showed relapses. The cerebral leukodystrophy-like phenotype was present in seven cases (3.0%), with a recurrence rate of 50%. Isolated seizures without any findings on MRI phenotype was present in three cases (1.3%), with the only clinical symptom being seizures of focal origin. Three cases (1.3%) of aseptic meningitis phenotype presented with prolonged fever.Conclusion40/236 (16.9%) of children with MOGAD had less common phenotypes. Less common clinical phenotypes of pediatric MOGAD are susceptible to misdiagnosis and deserve more attention.ImpactThis is the first comprehensive analysis and summary of all less commonl clinical phenotypes of MOGAD in children, while previous studies have only focused on a specific phenotype or case reports.We analyzed the characteristics of MOGAD in children and further revealed the reasons why these less common clinical phenotypes are prone to misdiagnosis and deserve more attention.Our research on treatment has shown that early detection of MOG antibodies and early treatment are of great significance for improving the prognosis of these patients.

Analysis of characteristics of movement disorders in patients with anti-N-methyl-D-aspartate receptor encephalitis.

Movement disorders (MDs) are common in anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis but are poorly studied. This study aimed to investigate the clinical characteristics of MDs and the clinical differences between patients with and without MDs in anti-NMDAR encephalitis. A retrospective study was conducted on patients with anti-NMDAR encephalitis who were first diagnosed and treated in the First People's Hospital of Yunnan Province from January 2017 to September 2022. According to the presence or absence of MDs, all patients were divided into two groups, and the clinical manifestations, auxiliary examinations, and prognosis of the two groups were compared. Patients in the MDs group were further subgrouped by different ages (<12 years, 12-17 years, and ≥ 18 years) and genders, and the prevalence of each MD was compared in different age and gender groups. (1) In our study there were 64 patients, of whom 76.6% (49/64) presented with MDs; the median age of onset in patients with MDs was 21 (15,35) years and 65.3% (32/49) were female. The three most common MDs were orofacial dyskinesia (OFLD) (67.3%), dystonia (55.1%), and stereotypies (34.7%). Patients <12 years were more likely to experience chorea than patients in other age groups (p = 0.003). (2) Compared with the non-MDs group, patients in the MDs group showed higher rates of prodromal manifestations, autonomic dysfunction, consciousness disorders, as well as pulmonary infection and gastrointestinal dysfunction (all p < 0.05). Peripheral blood neutrophil to lymphocyte ratio (NLR) (p = 0.014), the proportion of cerebrospinal fluid (CSF) NMDAR antibody titers ≥1:32 (p = 0.047), ICU admission rate (p = 0.04), length of stay (p = 0.007), maximum mRS score in the course of disease (p = 0.001) and mRS score at discharge (p = 0.006) in the MDs group were significantly higher than the non-MDs group. MDs associated with anti-NMDAR encephalitis were predominantly hyperkinetic. Chorea occurred more commonly in patients aged <12 years. Patients with MDs were prone to autonomic dysfunction, consciousness disorders, pulmonary infection, and gastrointestinal dysfunction; they had more intense inflammation, more severe disease, and a poorer short-term prognosis.