Anti-N-Methyl-D-aspartate Receptor Encephalitis: A Severe, Potentially Reversible Autoimmune Encephalitis. Mediators Inflamm. 2017;2017:6361479. [PMID: 28698711 PMCID: PMC5494059 DOI: 10.1155/2017/6361479]

Anti-N-methyl-D-aspartate receptor encephalitis in adults: a systematic review and analysis

PURPOSE

To analyze predictors of treatment outcome for anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis in adults.

METHODS

We performed a comprehensive literature search of PubMed, PsycInfo, and OVID. We included 424 patients from case reports and case series. Demographics, anti-NMDAR antibodies, prodromal and presenting symptoms, diagnostic workup, and treatment variables were recorded. Inferential analyses were performed in the subset (n = 299) of those with known treatment outcomes. Multivariate multinomial logistic regression analysis for treatment outcome compared full recovery versus partial recovery and full recovery versus death.

RESULTS

Treatment outcomes consisted of 34.67% full recovery (n = 147), 30.90% partial recovery (n = 131), 4.95% death (n = 21), and 29.48% unknown (n = 125). Speech/language abnormality and abnormal electroencephalogram (EEG) were each significantly associated with a higher relative risk for a full recovery. Treatment with intravenous immunoglobulin and plasmapheresis were each significantly associated with a higher relative risk for partial recovery. The analysis comparing death to full recovery found that catatonia was significantly associated with a lower relative risk for death. Increased age, orofacial dyskinesia, and no tumor removal were each significantly associated with a higher relative risk for death.

CONCLUSION

Increased age, orofacial dyskinesia, and no tumor removal were associated with a higher relative risk for death in anti-NMDAR encephalitis in adults. Clinicians should monitor and appropriately treat anti-NMDAR encephalitis with these findings to minimize the risk of death.

Paraneoplastic NMDA encephalitis, a case report and an extensive review of available literature

Anti-N-methyl-D-aspartate receptor (NMDAr) encephalitis is a prevalent autoimmune condition marked by diverse neuropsychiatric symptoms, primarily impacting young females. The exact mechanisms underlying the development of NMDAr encephalitis have not been fully elucidated. Nonetheless, studies have demonstrated that auto-antibodies targeting the NR1-NR2 subunits of the NMDAr can trigger receptor dysfunction within the central nervous system, thus giving rise to the associated symptoms. Notably, an association exists between NMDAr encephalitis and an underlying neoplastic condition, with approximately 38% of cases exhibiting this paraneoplastic relationship with ovarian teratomas being the most commonly associated malignancy. While the association between NMDAr encephalitis and renal cell carcinoma (RCC) is exceedingly rare. This case report presents the clinical scenario of a 20-year-old female patient diagnosed with NMDAr encephalitis in conjunction with RCC discovered incidentally on a CT abdomen and pelvis performed to rule out an ovarian teratoma. The presented case underscores the importance of adopting a multidisciplinary approach in the diagnosis and treatment of NMDAr encephalitis, particularly when it is linked to an underlying malignancy. Furthermore, it emphasizes the significance of expanding our understanding of the molecular pathogenesis of NMDAr encephalitis to enhance patient care and optimize clinical outcomes. Additionally, a comprehensive review of the existing literature is included, summarizing all reported malignancies associated with NMDAr encephalitis.

Systematic review: clinical characteristics of anti-N-methyl-D-aspartate receptor encephalitis

Background

The number of reported cases of anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis has gradually increased since its discovery in 2007, while there are no uniform treatment guidelines.

Objective

To summarize the clinical characteristics of patients with anti-NMDAR encephalitis and to analyze the factors affecting the disease prognosis.

Methods

A systematic analysis of medical records was conducted, and PubMed, Embase, and Cochrane Library were searched from January 1, 2011, to December 31, 2021. Data were extracted, analyzed, and recorded in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines.

Results

This study included 472 case reports. Most patients had prodromal symptoms of about 2 weeks, including psychiatric symptoms (53.2%), flu-like symptoms (51.5%), and seizures (23.9%), among others. Poor prognoses were associated with patients who had autonomic instability (p = 0.010), central hypoventilation (p = 0.014), and ICU support (p = 0.002). Patients with a higher age of onset were more likely to develop central hypoventilation (OR 1.024, CI 1.006-1.042, p = 0.009), cognitive impairment (OR 1.023, CI 1.009-1.037, p = 0.001), and memory impairment (OR 1.034, CI 1.017-1.050, p < 0.001), whereas patients with a lower age were more likely to have seizures (OR 0.979, CI 0.965-0.993, p = 0.003). In this study, 97.0% of patients received immunotherapy, with the most commonly used treatment regimen being intravenous methylprednisolone (IVGC) and intravenous immunoglobulin (IVIG). When compared with other treatment regimens, the IVGC+IVIG regimen (p < 0.001) resulted in better prognoses.

Conclusion

When encountering patients with fever, headache, and initial psychiatric symptoms of unknown etiology, clinicians should test their CSF for antibodies to distinguish autoimmune encephalitis. Patients with autonomic instability, central hypoventilation, and ICU support had poorer prognoses. Clinicians should be aware that older patients are more likely to develop central hypoventilation, cognitive impairment, and memory impairment, while younger patients are more likely to develop seizures. The IVGC+IVIG treatment regimen has better prognoses than others. This study includes case reports, which have obvious selection bias, and there are no unified standards to measure the severity of the disease. Therefore, in the future, larger samples and randomized controlled trials are needed to evaluate the efficacy of different treatment regimens.

Patient with concurrent anti-NMDAR autoimmune encephalitis and immature teratoma of the ovary

In young women with anti-N-methyl-D-aspartate receptor (anti-NMDAR) autoimmune encephalitis (AE), co-occurrence with ovarian teratoma is common. While the management of mature teratoma with AE is well documented, literature on managing immature teratoma (IT) in tandem with AE is relatively scarce. Here, we report a case of a female patient in her early adolescence who presented with abdominal pain and was diagnosed with grade 3 IT combined with anti-NMDAR AE after an ovarian tumour was discovered and resected. Postsurgery, the patient received immunotherapy, chemotherapy and antiepileptic therapy, and two follow-up evaluations showed no signs of recurrence or sequelae. This case highlights the importance of a high index of suspicion for concurrent AE in the presence of ovarian teratoma, particularly IT, and the crucial role of concurrent administration of immunotherapy and chemotherapy following tumour resection in impacting prognosis.

Multi-proteomic Analysis Revealed Distinct Protein Profiles in Cerebrospinal Fluid of Patients Between Anti-NMDAR Encephalitis NORSE and Cryptogenic NORSE

New-onset refractory status epilepticus (NORSE) is rare but intractable. Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis and cryptogenic etiologies are the two major causes of NORSE with distinct clinical features. To elucidate the underlying mechanisms, 6 patients with anti-NMDAR encephalitis NORSE and 5 with cryptogenic NORSE (C-NORSE) were enrolled. Five patients of cerebrovascular disorders were used as controls. Quantitative proteomic analysis of the cerebrospinal fluid (CSF) samples of the patients revealed 101 and 56 proteins were changed, respectively. The average fold-change of the upregulated proteins, namely up-proteomic score in this study, was positively correlated with the severity and prognosis of the diseases, including ICU stay (r = 0.9308, P = 0.0035 in NMDAR group; r = 0.8977, P = 0.0193 in C-NORSE group), mRS score at discharge (r = 0.9710, P = 0.0111 in NMDAR group; r = 0.7071, P = 0.2000 in C-NORSE group), and time taken for patients awaking from a coma (r = 0.8823, P = 0.0100 in NMDAR group; r = 0.7906, P = 0.2000 in C-NORSE group). Pathways involved in humoral immune response, wound healing, and epigenetic regulation of transcription were upregulated in anti-NMDAR encephalitis NORSE. Pathways of innate and lymphocyte mediated immune response, synaptic functions, ubiquitination, and cell apoptosis were up-regulated in C-NORSE, which was consistent with a mouse model of status epilepticus. Fc receptor and B cell mediated immunity signaling pathways were downregulated in C-NORSE. Immunome microarray analysis demonstrated high autoantibody targeting 48 proteins in CSF samples of anti-NMDAR encephalitis NORSE. While the reaction was kept at a very low level in C-NORSE. There is no significant difference in inflammatory cytokine level between each group. The level of IL-4 (r = 0.7435, P = 0.0451), IL-13 (r = 0.7643, P = 0.0384), IFN-γ (r = 0.7973, P = 0.0287) and TNF-α (r = 0.8598, P = 0.0141) in NMDAR group, and IL-6 (r = 0.8479, P = 0.0348), IL-8 (r = 0.9076, P = 0.0166) in C-NORSE group were positively correlated with the up-proteomic score. The present study suggests that the up-proteomic score of CSF could be a promising indicator for assessment of the severity of anti-NMDAR encephalitis NORSE and C-NORSE. The distinct CSF proteomes imply different pathogenic mechanisms of the two diseases, and immunotherapy strategies as well.

Paroxysmal speech disorder as the initial symptom in a young adult with anti-N-methyl-D-aspartate receptor encephalitis: A case report

BACKGROUND

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a treatable but frequently misdiagnosed autoimmune disease. Speech dysfunction, as one of the common manifestations of anti-NMDAR encephalitis, is usually reported as a symptom secondary to psychiatric symptoms or seizures rather than the initial symptom in a paroxysmal form. We report a case of anti-NMDAR encephalitis with paroxysmal speech disorder as a rare initial manifestation, and hope that it will contribute to the literature.

CASE SUMMARY

A 39-year-old man with anti-NMDAR encephalitis initially presented with paroxysmal nonfluent aphasia and was misdiagnosed with a transient ischemic attack and cerebral infarction successively. The patient subsequently presented with seizures, but no abnormalities were found on brain magnetic resonance imaging or electroencephalogram. Cerebrospinal fluid (CSF) analysis revealed mild pleocytosis and increased protein levels. Anti-NMDAR antibodies in serum and CSF were detected for a conclusive diagnosis. After immunotherapy, the patient made a full recovery.

CONCLUSION

This case suggests that paroxysmal speech disorder may be the presenting symptom of anti-NMDAR encephalitis in a young patient.

Autoimmune Encephalitis: A Physician’s Guide to the Clinical Spectrum Diagnosis and Management

The rapidly expanding spectrum of autoimmune encephalitis in the last fifteen years is largely due to ongoing discovery of many neuronal autoantibodies. The diagnosis of autoimmune encephalitis can be challenging due to the wide spectrum of clinical presentations, prevalence of psychiatric features that mimic primary psychiatric illnesses, frequent absence of diagnostic abnormalities on conventional brain MR-imaging, non-specific findings on EEG testing, and the lack of identified IgG class neuronal autoantibodies in blood or CSF in a subgroup of patients. Early recognition and treatment are paramount to improve outcomes and achieve complete recovery from these debilitating, occasionally life threatening, disorders. This review is aimed to provide primary care physicians and hospitalists who, together with neurologist and psychiatrists, are often the first port of call for individuals presenting with new-onset neuropsychiatric symptoms, with up-to-date data and evidence-based approach to the diagnosis and management of individuals with neuropsychiatric disorders of suspected autoimmune origin.

Autoimmune Encephalitis in Long-Standing Schizophrenia: A Case Report

Anti-N-methyl-D-aspartate (NMDA) receptor antibody (anti-NMDAR Ab)-mediated encephalitis is an autoimmune disorder involving the production of antibodies against NMDARs in the central nervous system that leads to neurological or psychiatric dysfunction. Initially described as a paraneoplastic syndrome in young women with teratomas, increased testing has found it to be a heterogeneous condition that affects both the sexes with varying clinical manifestations, severity, and aetiology. This case report describes a 67-year-old man with a 40-year history of relapsing, severe, treatment-refractory schizophrenia. Due to the worsening of his condition during a prolonged inpatient admission for presumed relapse of psychosis, a revisit of the original diagnosis was considered with extensive investigations performed including an autoimmune panel. This revealed anti-NMDAR Abs in both the serum and cerebrospinal fluid on two occasions. Following treatment with intravenous immunoglobulin and methylprednisolone, he demonstrated rapid symptom improvement. This is a rare case of a long-standing psychiatric presentation with a preexisting diagnosis of schizophrenia subsequently found to have anti-NMDAR Ab-mediated encephalitis. Whether the case is one of initial NMDAR encephalitis vs. overlap syndrome is unknown. Most importantly, this case highlights the need for vigilance and balanced consideration for treatment in cases of long-standing psychiatric presentation where the case remains treatment refractory to antipsychotics or when atypical features including seizures and autonomic dysfunction or focal neurology are observed.

White matter abnormalities and multivariate pattern analysis in anti-NMDA receptor encephalitis

OBJECTIVE

This study aimed to investigate white matter (WM) microstructural alterations and their relationship correlation with disease severity in anti-NMDA receptor (NMDAR) encephalitis. Multivariate pattern analysis (MVPA) was applied to discriminate between patients and healthy controls and explore potential imaging biomarkers.

METHODS

Thirty-two patients with anti-NMDAR encephalitis and 26 matched healthy controls underwent diffusion tensor imaging. Tract-based spatial statistics and atlas-based analysis were used to determine WM microstructural alterations between the two groups. MVPA, based on a machine-learning algorithm, was applied to classify patients and healthy controls.

RESULTS

Patients exhibited significantly reduced fractional anisotropy in the corpus callosum, fornix, cingulum, anterior limb of the internal capsule, and corona radiata. Moreover, mean diffusivity was increased in the anterior corona radiata and body of the corpus callosum. On the other hand, radial diffusivity was increased in the anterior limb of the internal capsule, cingulum, corpus callosum, corona radiata, and fornix. WM changes in the cingulum, fornix, and retrolenticular part of the internal capsule were correlated with disease severity. The accuracy, sensitivity, and specificity of fractional anisotropy-based classification were each 78.33%, while they were 67.71, 65.83, and 70% for radial diffusivity.

CONCLUSION

Widespread WM lesions were detected in anti-NMDAR encephalitis. The correlation between WM abnormalities and disease severity suggests that these alterations may serve a key role in the pathophysiological mechanisms of anti-NMDAR encephalitis. The combination of tract-based spatial statistics and MVPA may provide more specific and complementary information at the group and individual levels.

Mature ovarian teratoma-associated encephalitis

Introduction. Autoimmune encephalitis associated with ovarian teratoma is a serious and potentially fatal pathology. While this clinical entity is known to neurologists, the available literature rarely mentions the role of a gynecologist in diagnostic imagining and treatment. Although several months have passed from the appearance of the symptoms to surgical treatment, this case shows that even then a complete recovery is possible. Case presentation. The patient was a 28-year-old female, brought to the hospital because a sudden onset of unusual behavior - an acute psychosis with suicidal thoughts and auditory hallucinations. Soon after the admission she became delirious, uncooperative and agitated. Blood check, neurological assessment and cranial computed tomography yielded normal results. Therefore, a psychiatric disorder was suspected. Electroencephalogram revealed a diffuse encephalitic insufficiency. As cerebrospinal fluid was negative for infections, the autoimmune etiology of the disease was suspected. Abdominal computer tomography showed a complex right ovarian mass measuring 50 x 40 x 30 mm, confirmed by vaginal ultrasound. Laparoscopy with right adnexectomy was performed. The pathohistological finding showed a mature teratoma. In the meantime, the result of the cerebrospinal fluid test came positive for anti NMDAR antibodies. Six months after surgery, the patient was in a good mental and neurological status without symptoms. Conclusion. Gynecologists should be aware of the presence of ovarian tumors in encephalitis cases. A timely diagnosis of the underlying gynecological cause of a neurological condition, allows for prompt treatment and can remarkably improve clinical conditions and, thus, be lifesaving.

Anti N-methyl-D-aspartate receptor (NMDAr) encephalitis during pregnancy: A case report

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Focal motor status epilepticus can be a presenting sign of anti-NMDA rencephalitis during pregnancy.

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After the immunomodulatory treatment, the patient showed only attention deficits with normal global cognition.

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The newborn presented normal birth weight kg with APGAR 10 with no sign of fetal distress nor major or minor malformations.

Anti-N-methyl-D-aspartate receptor (NMDAr) antibody encephalitis is an autoimmune disorder characterized by reduced synaptic activity of the NMDAr due to circulating antibodies that target the NR1 subunit. Few cases of anti-NMDAR encephalitis during pregnancy have been described. The permeation of anti-NR1 antibodies through the placenta can be instrumental in the development of complications in newborns. We describe a case of a young woman suffering from anti-NMDAR encephalitis during the first trimester of pregnancy and focus on diagnostic and therapeutic management.

Anti-NMDA Receptor Encephalitis in a Patient with Tuberous Sclerosis-Related Brain Tumor: A Case Report

Anti-NMDA receptor (NMDAR) encephalitis (NMDARE) is an important treatable cause of autoimmune psychosis in all age-groups, which is sometimes associated with tumors, especially ovarian teratomas. Tuberous sclerosis complex (TSC) is an autosomal dominant inherited neurocutaneous disease predisposing for development of benign tumors. We present a case of a 35-year-old woman with recurrent episodes of schizophrenia-like symptoms. Accidentally, MRI revealed TSC-related brain tumors. NMDAR antibody titers were strongly positive in serum and cerebrospinal fluid. This is the first case describing an overlap of NMDARE and TSC-related brain tumors. A review of brain tumors and NMDARE is given in the supplementary material. Although a causal link seems interesting from a pathophysiological point of view, we are in favor of a coincidence.

Anti-N-methyl-D-aspartate Receptor Encephalitis as a Paraneoplastic Presentation of Mature Ovarian Teratoma

Patient: Female, 26-year-old

Final Diagnosis: Anti NMDA receptor encephalitis • familial adenomatous polyposis

Symptoms: Autonomic instability • catatonia • ovarian cyst • psychosis

Medication: —

Clinical Procedure: Ovariectomy

Specialty: General and Internal Medicine

Autoimmune encephalitis and seizures, cerebrospinal fluid, imaging, and EEG findings: a case series

Antibody-mediated encephalitides constitute a group of inflammatory brain diseases characterized by prominent neuropsychiatric symptoms and are associated with antibodies against neuronal cell-surface proteins, ion channels, or receptors. The diagnosis and management of autoimmune encephalitis include evaluation of the clinical presentation, brain imaging, cerebrospinal fluid (CSF) findings, antibody detection, and electroencephalography (EEG) findings. This is a retrospective study of adults 18 years or older with autoimmune encephalitis due to antibodies against membrane surface antigens as well as anti-glutamic acid decarboxylase (anti-GAD) antibodies. The electronic medical record was reviewed for demographic data, clinical data, laboratory results, EEG, and imaging findings. Antibody screening was requested for 341 patients between May 2014 and December 2019. Antibody screening was positive in 37 patients presenting with seizures and/or encephalopathy. Of these, 10 patients tested positive for antibodies against neuronal surface antigens or anti-GAD antibodies-2 patients had anti-GAD antibody encephalitis, 5 had anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis, and 3 had anti-leucine-rich glioma-inactivated 1 (anti-LGI1) encephalitis. Demographics, clinical presentation, EEG, imaging, and CSF findings are reported. Autoimmune encephalitides are a diverse group of disorders with a few common clinical features and MRI findings. MRI, EEG, and CSF findings can be normal or show nonspecific findings in autoimmune encephalitis. Therefore, early diagnosis of these disorders requires a high level of suspicion to avoid delaying the diagnosis. Carefully looking for diagnostic clinical features (e.g., faciobrachial dystonic seizures in anti-LGI1 encephalitis), significant findings in MRI (e.g., limbic encephalitis), and some EEG patterns (e.g., extreme delta brush and generalized rhythmic delta activity in anti-NMDAR encephalitis) may help in early diagnosis.

Autoimmune neurology: Co-occurrence of anti-NMDAR encephalitis and anti-MOG associated disease, report of a case

We report the case of a patient with symptoms of anti-NMDAR encephalitis and anti-MOG associated disease simultaneously, in whom the identification of antibodies guided to a more aggressive treatment strategy, resulting in a good clinical outcome. MRI is an important tool to diagnose this kind of patients. The co-occurrence of both diseases in infrequent, but atypical symptoms should increase our awareness of the possibility of an overlap syndrome.

Neurological manifestation of cancer – paraneoplastic syndromes

Neurological paraneoplastic syndromes (NPS) belong to a heterogeneous group of disorders affecting the nervous system. NPS occur as a result of immunological reaction to the tumor. As a result, the isolated syndrome is formed and manifests itself in many different ways, for example: limbic encephalitis, ataxia, dominant cerebellar degeneration, psychiatric disturbances, myasthenia gravis or diffuse encephalomyelitis. Detection of NPS is solely based on the presence of specific anti-neural antibodies. Although NPS had been previously considered unresponsive to therapy, some research has shown that there are effective therapies, including cancer- and immunotherapy targeted therapies.

Clinical Characteristics and Long-Term Prognosis of Anti-LGI1 Encephalitis: A Single-Center Cohort Study in Beijing, China

Background: This study aimed to analyze the clinical characteristics of anti-leucine-rich glioma-inactivated protein 1 (LGI1) encephalitis patients and investigate prognostic factors by using a large-sample and long-term follow-up cohort.

Methods: The clinical data of 45 patients (29 males; mean age, 57.0 years) from May 2014 to August 2019 were collected. All patients were followed up by face-to-face interviews in the third month after discharge and then by telephone and/or face-to-face interviews every 6 months until November 2020. We evaluated each patient's response to the initial treatments at the first interview and divided them into “responders” and “nonresponders.” Relapses were recorded. At the end of follow-up, each patient was evaluated and reclassified into “complete recovery” or “unhealed” groups. Intergroup differences were assessed.

Results: All patients presented with seizures at the initial consultation. Other common manifestations included cognitive dysfunction (82.2%), psychiatric disturbance (66.7%), sleep disorder (54.5%), and hyponatremia (66.7%). During the follow-up period (32.8 ± 13.5 months), six patients experienced relapse within 6–37 months. We observed that the patients who did not respond to the initial treatments and those who relapsed all had a poor long-term prognosis. The patients in the “unhealed” group were older (p = 0.009), had a lower incidence of generalized tonic–clonic seizures (p = 0.041), and had a higher probability of cerebrospinal fluid (CSF) abnormalities (p = 0.024) than those in the “complete recovery” group.

Conclusion: Anti-LGI1 encephalitis was characterized by seizures, cognitive impairment, psychiatric disturbance, and sleep disorders and was often accompanied by hyponatremia. Patients who responded poorly to the initial treatments and those patients who relapsed had dismal long-term prognoses. Advanced age and CSF abnormalities may be risk factors for poor prognosis, but these still need to be verified.

Systemic lupus erythematosus associated with recurrent anti-NMDA receptor encephalitis during pregnancy

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is caused by autoantibodies against the NR1 subunit of NMDAR. Recurrent cases combined with systemic lupus erythematosus (SLE) during pregnancy have not been reported. We report the case of a 23-year-old woman with a past history of SLE who presented with the characteristic features of anti-NMDAR encephalitis during both of her two pregnancies.

[Isolated metamorphopsia and visual pseudohallucinations in a patient with anti-NMDA receptor encephalitis]

This article reports the case of a 40-year-old male patient with isolated metamorphopsia and visual pseudohallucinations lasting for 2 weeks. As the ophthalmological findings were not pathological, a further neurological examination was performed. After diagnosis of anti-N-methyl-D-aspartate (NMDA) receptor encephalitis, which can be manifested in various psychiatric, neurological and ophthalmological ways, the oligosymptomatic patient received high-dose corticosteroid treatment with intravenous immunoglobulins, which stopped the symptoms.

Case Report: Anti-NMDAR Encephalitis With Anti-MOG CNS Demyelination After Recurrent CNS Demyelination

Introduction: Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis, a serious neurological autoimmune disorder caused by autoantibodies with diverse clinical manifestations, may simultaneously onset with antimyelin oligodendrocyte glycoprotein (MOG) demyelination after recurrent central nervous system (CNS) demyelination.

Case Report: We present a case of anti-NMDAR encephalitis combining with anti-MOG CNS demyelination following recurrent CNS demyelination. A 38-year-old man admitted to hospital developed epileptic seizures following recurrent episodes of cross-sensory disturbance and dizziness. Magnetic resonance imaging (MRI) showed a demyelinating lesion in the right brainstem initially. Despite a good response to methylprednisolone pulse therapy at the beginning, the patient still had relapses and progression after corticosteroid reduction or withdrawal. Then brain MRI discovered new serpentine lesions involving extensive cerebral cortex on his second relapse. Repeat autoantibodies test indicated cerebrospinal fluid (CSF) NMDAR antibodies coexisted with MOG-Abs simultaneously, suggesting the diagnosis of anti-NMDAR encephalitis with anti-MOG CNS demyelination.

Results: After a definite diagnosis, the patient was treated with mycophenolate mofetil (MMF) and corticosteroid. He was discharged after his symptoms ameliorated. No neurological sequels remained, and there were no effects on his activities of daily living after 6 months of immunoregulatory therapy of MMF and corticosteroid.

Conclusion: For individuals with recurrent CNS demyelination, especially combining with cortical encephalitis, repeated detection of autoantibodies against AE, and demyelination in CSF/serum can be helpful to enable a definite early diagnosis. For patients who suffer from anti-NMDAR encephalitis combining with anti-MOG CNS demyelination, second-line immunotherapy is recommended when first-line treatment such as steroids, intravenous immunoglobulin G (IVIG) and plasma exchange has been proven ineffective to prevent the relapse of disease.

Neuronal Surface Antibody-Medicated Autoimmune Encephalitis (Limbic Encephalitis) in China: A Multiple-Center, Retrospective Study

Objective: The epidemiological characteristics of patients with antibody-medicated autoimmune encephalitis in China remain unclear, and a large-scale epidemiological survey is necessary.

Methods: A multiple-center retrospective study was performed. We collected 1,047 patients with suspected autoimmune encephalitis and ultimately enrolled 778 defined patients across centers in China. All patients were positive for serum [or cerebrospinal fluid (CSF)] antibodies. Demographic information and clinical data from January 2014 to January 2019 from 22 centers in China were reviewed.

Results: A total of 778 patients with autoimmune encephalitis were enrolled in the study. In general, the ratio of males to females was ~1.2:1. The main subtypes of autoimmune encephalitis were NMDAR-AE (61.35%), LGI-1-AE (20.61%), and GABAbR-AE (12.40%). According to the characteristics of age of onset, the incidence of autoimmune encephalitis showed a “double peak” distribution entailing a 20-year-old age group and a 60-year-old age group. We next analyzed the proportion of patients with tumors in this cohort. More specifically, there were 34 patients with tumors and 85 with tumor marker positivity. Relapse occurred in 81 patients within at least 1 year's follow up study: 52 with NMDAR-AE (18.2%); 19 with LGI-1-AE (16.8%); 5 with GABAbR-AE (9%); and 3 with CASPR2-AE.

Interpretation: Due to the vast differences in demographic features, the incidence of cancer and the genetic characteristics between the populations in China and Western countries, the demographics, sex distribution, concomitant tumor rate, clinical features, and relapse characteristics associated with autoimmune encephalitis in China shows a similar profile with Western countries with some minor differences.

Diagnosis of pediatric anti-NMDAR encephalitis at the onset: A clinical challenge

BACKGROUNDS

To investigate the clinical and instrumental features at the onset addressing to the diagnosis of anti-NMDAR encephalitis.

METHODS

Twenty children (age: 15 months-17 years; 7 males, 13 females) with initial suspected diagnosis of autoimmune encephalitis, observed between January 2008 and March 2018, were included. The final diagnosis was anti-NMDAR encephalitis in 7 children, other/probable autoimmune encephalitis in 7 children, and primary psychosis in the remaining 6 children.

RESULTS

At the clinical onset, anxiety disorder was the main symptom that helped in distinguishing the group of psychotic children from children with non-infectious encephalitis (P = 0.05 OR = 0.001), while epileptic seizures strongly predicted anti-NMDAR encephalitis (P = 0.04 OR = 28.6). At the onset, anti-NMDAR encephalitis could be distinguished from other/probable autoimmune encephalitis for the presence of sleep/wake rhythm alteration (P = 0.05 OR = 15). Among the symptoms occurring during the hospitalization, movement disorders (P = 0.031 OR = 12) were predictive of non-infectious encephalitis rather than primary psychosis. More specifically, the occurrence of language impairment (P = 0.03 OR = 33), epileptic seizures (P = 0.04 OR = 28.6) and catatonia (P = 0.03, OR = 33), were predictive of anti-NMDAR encephalitis. Also at this stage, anxiety disorder (P = 0.03 OR = 0.033) was predictive of primary psychosis.

CONCLUSION

Our findings suggest that at the clinical onset epileptic seizures and sleep/wake rhythm alteration represent the main features addressing to the diagnosis of anti-NMDAR encephalitis rather than primary psychosis and other/probable autoimmune encephalitis, while anxiety disorder could be a solid predictor of primary psychosis.

Association of Polymorphisms in Inflammatory Cytokines Encoding Genes With Anti-N-methyl-D-Aspartate Receptor Encephalitis in the Southern Han Chinese

Background: Single nucleotide polymorphisms (SNPs) that occur within genes encoding inflammatory cytokines can result in quantitative or qualitative changes in their expression or functionality, potentially leading to the development of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. This study sought to evaluate the relationship between SNPs in inflammatory cytokines genes and the incidence of anti-NMDAR encephalitis in the Southern Han Chinese. Methods: In total, we enrolled 107 patients with anti-NMDAR encephalitis as well as 202 inpatient controls who had no first-degree relative with autoimmune diseases. Genotyping determination of all 309 patients was conducted for the IL-1β rs16944, IL-4 rs2243250, IL-4 rs2070874, IL-6 rs1800796, IL-10 rs1800872, and IL-17 rs2275913 gene SNPs. Results: We observed statistically significant differences in the frequencies of G allele in IL-1β rs16944 between anti-NMDAR encephalitis and controls (p = 0.017). Also, IL-1β, IL-4, IL-6, IL-10, and IL-17 SNPs were not associated with the disease (p > 0.05). Conclusions: We found that patients with anti-NMDAR encephalitis exhibit a distinct immunological profile, and we found that the decreased frequency of G allele in IL-1β rs16944 showed a protective role for anti-NMDAR encephalitis in the Southern Han Chinese.

Cerebrospinal Fluid Osteopontin and Inflammation-Associated Cytokines in Patients With Anti-N-Methyl-D-Aspartate Receptor Encephalitis

Anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis is an autoimmune neurological disorder. Osteopontin (OPN) is a secreted multifunctional phosphorylated glycoprotein that regulates various autoimmune and inflammatory diseases, but its diagnostic and prognostic values in anti-NMDAR encephalitis patients remain elusive. This retrospective study aimed to determine the levels of OPN and related cytokines in cerebrospinal fluid (CSF) of anti-NMDAR encephalitis patients and to assess their influence on disease severity so as to evaluate their efficacy as biomarkers for diagnosis and prognosis. CSF samples from 33 anti-NMDAR encephalitis, 13 viral encephalitis, and 21 controls were collected. All CSF were tested for levels of OPN and inflammation-associated cytokines [interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-α] via ELISA. In addition, 15 anti-NMDAR encephalitis patients without follow-up relapse were re-examined for these four parameters 3 months later. The clinical status was evaluated by modified Rankin Scale (mRS) scores. Results showed that the CSF levels of these cytokines were increased in anti-NMDAR encephalitis patients compared to controls but not viral encephalitis patients. Their levels were decreased in remission compared with that in acute stage. Moreover, CSF OPN positively correlated with IL-6, white blood cell (WBC) counts, and C-reactive protein (CRP) levels in anti-NMDAR encephalitis patients. However, no associations were found between OPN or related cytokines and mRS scores in acute stage in anti-NMDAR encephalitis patients. Overall, CSF OPN and related cytokines were increased when anti-NMDAR encephalitis patients are in acute stage and decreased in remission, suggesting the underlying neuro-inflammatory process in this disease. However, they are not qualified with diagnostic or prognostic value.

Lipid profiles and their potential inflammatory effects in anti-N-methyl-D-aspartate receptor encephalitis

BACKGROUND

Growing evidence suggests an association between dyslipidemia and autoimmune diseases. This study aimed to perform a preliminary analysis to investigate the role of lipid profiles in anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis and to preliminarily explore the potential inflammatory effects of lipids on this disease by analyzing the association of lipid profiles with different inflammatory markers.

METHODS

This retrospective study consisted of 40 anti-NMDAR encephalitis patients and 74 healthy controls. Serum lipid profiles and different inflammatory markers were analyzed upon admission and at each follow-up. Lipid profiles were compared among subgroups of patients, which were divided according to clinical characteristics. Correlations between lipid profiles and different inflammatory markers were assessed.

RESULTS

The results showed that lipid profiles were abnormal and were correlated with both disease severity and prognosis in patients with anti-NMDAR encephalitis. Correlations between lipid profiles and different inflammatory markers were observed. After 12 months of treatment, inflammatory markers changed with lipid profiles, and these changes were significantly correlated.

CONCLUSIONS

Lipid profiles are associated with pathogenesis and progression of anti-NMDAR encephalitis, and they are significantly correlated with different inflammatory markers, suggesting that the association of lipids with the disease might be influenced by the inflammatory response.

[Anti-NMDAR encephalitis associated with relapsing optic neuritis]

Autoimmune encephalitis with antibodies to NMDA receptors (anti-NMDAR encephalitis), is the most common form of autoimmune encephalitis. The disease is curable, however, the lack of timely therapy can lead to the disability of patients or to the death. Difficulties in the diagnosis of anti-NMDAR encephalitis are caused by the heterogeneity of its manifestations, a possible overlapping with other autoimmune diseases and insufficient awareness about this form of encephalitis. This article describes the case of anti-NMDAR encephalitis associated with recurrent optic neuritis which might be an atypical manifestation for this disease. Optic neuritis could not be explained by overlapping with multiple sclerosis or neuromyelitis optica spectrum disorders.

Anti-N-methyl-D-aspartate-receptor antibody encephalitis combined with syphilis: A case report

BACKGROUND

Anti-N-methyl-D-aspartate-receptor (NMDAR) encephalitis is a common type of autoimmune encephalitis characterized by complex clinical signs and variable imaging manifestations. The pathogenesis of the disease is unclear. Syphilis is an infectious disease caused by Treponema pallidum that can invade the nervous and immune systems and cause systemic symptoms. There are few reports of anti-NMDAR encephalitis with syphilis, and the association between them is unknown; both diseases are related to immune system damage. We report a case of anti-NMDAR encephalitis with syphilis.

CASE SUMMARY

A 32-year-old man was admitted to our hospital with complaints of cognitive decline, diplopia, and walking instability during the previous 6 mo. He developed dysarthria, difficulty swallowing, and involuntary shaking of his head, neck, and limbs during the month prior to presentation. Cranial magnetic resonance imaging showed symmetrical abnormal signals in the pons, midbrain, and bilateral basal ganglia, and inflammatory demyelination was considered. The diagnosis of syphilis was confirmed based on the syphilis diagnosis test and the syphilis rapid test. He was given anti-syphilis treatment, but the above symptoms gradually worsened. Anti-NMDAR antibody was positive in cerebrospinal fluid but was negative in serum. Due to the cerebrospinal fluid findings, anti-NMDAR encephalitis was a consideration. According to the patient’s weight, he was treated with intravenous methylprednisolone 1 g QD for 5 d, with the dose gradually decreased for 6 mo, and immunoglobulin 25 g QD for 5 d; his symptoms improved after treatment.

CONCLUSION

This case shows that anti-NMDAR encephalitis may be combined with syphilis, which should be recognized to avoid misdiagnosis and treatment delay.

[Anti-NMDAR encephalitis associated with relapsing optic neuritis: a case report and differential diagnosis]

Autoimmune encephalitis with antibodies to NMDA receptors, or anti-NMDAR encephalitis, is the most common form of autoimmune encephalitis. The disease is curable, however, the lack of timely therapy can lead to the disability of patients or to the death. Difficulties in the diagnosis of anti-NMDAR encephalitis are caused by the heterogeneity of its manifestations, a possible overlapping with other autoimmune diseases and insufficient awareness about this form of encephalitis. This article presents the literature review and describes the case of anti-NMDAR encephalitis associated with recurrent optic neuritis, which might be an atypical manifestation for this disease. Optic neuritis could not be explained by overlapping with multiple sclerosis or neuromyelitis optica spectrum disorders.

First report of concomitant cryptococcal meningitis and anti-NMDAR encephalitis

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune disorder, seen most often in young adults and children, triggered by tumors or infections. We report a case of cryptococcal meningitis in a patient with sarcoidosis, presenting prominent neuropsychiatric symptoms, electroencephalographic features of autoimmune encephalitis and positive anti-NMDAR antibodies in the cerebrospinal fluid, raising the hypothesis of an infectious immune-mediated mechanism triggering the production of anti-NMDAR antibodies. Since anti-NMDAR encephalitis is potentially fatal and has significant morbidity, further descriptions of its etiological associations are essential to early identification and prompt treatment.

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Cryptococcal meningitis is a rare complication of sarcoidosis and CD4 lymphopenia.

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Anti-NMDAR encephalitis is an autoimmune disorder triggered by tumors or infection.

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A case of concomitant cryptococcosis and anti-NMDAR encephalitis is presented.

Receptor autoimmunity: diagnostic and therapeutic implications

Receptor autoimmunity is one of the ways in which autoimmune diseases appear in humans. Graves' disease, myasthenia gravis, idiopathic membranous nephropathy, and autoimmune acute encephalitis are the major autoimmune diseases belonging to this particular group. Receptor autoimmune disease are dependent on the presence of autoantibodies directed against cell-surface antigens, namely TSH receptor in thyrocytes, acetylcholine receptor in neuromuscular junction, phospholipase 2 receptor in podocytes, and NMDA receptor in cortical neurons. In this article we outline the distinctive features of receptor autoimmunity and the specific relationship between the autoimmunology laboratory and the presence/concentration of autoantibodies. Some immunological features distinguish receptor autoimmunity. Anti-receptor autoantibody pathologies are considered T cell-dependent, B-cell-mediated autoimmune disorders: the knowledge about the presence of circulating and/or localized autoantibodies to target organs and identification of autoantigens involved in the autoimmune reaction is of paramount importance. Due to the close correlation between the concentration of anti-receptor autoantibodies, the autoimmune target of some cell-surface receptors and the intensity of symptoms, the measurement of these immunoglobulins has become central to diagnose autoimmune diseases in all affected patients, not just in clinically dubious cases. The measurement of autoantibodies is also relevant for differential diagnosis of autoimmune and non-autoimmune forms with similar symptoms. From the methodological point of view, quantitative immunoassay methods of measurement should be preferred over semi-quantitative ones, for the capacity of the first class of methods to define precisely the reference ranges and decision levels overcoming the measurement uncertainty of semi-quantitative methods.

Anti-N-methyl-D-aspartate receptor encephalitis: A review of pathogenic mechanisms, treatment, prognosis

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a treatable autoimmune disorder characterized by prominent neuropsychiatric symptoms that predominantly affects children and young adults. In this review, we discuss the pathogenic mechanisms and immunologic triggers of anti-NMDAR encephalitis, and provide an overview of treatment and prognosis of this disorder, with specific focus on the management of common symptoms, complications, and patients during pregnancy. Most patients respond well to first-line treatment and surgical resection of tumors. When first-line immunotherapy fails, second-line immunotherapy can often improve outcomes. In addition, treatment with immunomodulators and tumor resection are effective treatment strategies for pregnant patients. Benzodiazepines are the preferred treatment for patients with catatonia, and electroconvulsive therapy (ECT) may be considered when pharmacological treatment is ineffective. Age, antibody titer, cerebellar atrophy, levels of biomarkers such as C-X-C motif chemokine 13 (CXCL13), cell-free mitochondrial (mt)DNA in cerebral serum fluid (CSF), and timing from symptom onset to treatment are the main prognostic factors. Patients without tumors or those who receive insufficient immunotherapy during the first episode are more likely to relapse.

The diffuse involvement of anti-N-methyl-D-aspartate receptor encephalitis in brain: a case report

Background

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a severe and most common autoimmune encephalitis in patients under 40 years old. Anti-NMDAR encephalitis has various clinical and neuroimaging findings. Here we report a special case of an anti-NMDAR encephalitis who had diffuse lesions in bilateral hemispheres with mild mass effects in left basal ganglia area.

Case presentations

A 28-year-old female anti-NMDAR encephalitis patient mainly presented with headache and fever. Brain magnetic resonance image (MRI) showed slightly contrasted diffuse lesions, involving the left temporal and frontal lobes, left basal ganglia area and splenium of corpus callosum, as well as the right frontal lobe, with mild edema surrounded in the left basal ganglia area. Cerebrospinal fluid (CSF) revealed a moderate pleocytosis with normal protein and glucose levels. Anti-NMDAR antibodies were identified in CSF. Transvaginal ovarian ultrasound did not reveal an ovarian teratoma. The patient was treated with immunoglobulin and steroid, and had a good recovery.

Conclusions

Anti-NMDAR encephalitis has no special clinical manifestations and brain MRI is highly variable, which could be unremarkable or abnormal involving white and grey matters. The extensive lesions in frontal and temporal lobes, and basal ganglia area, with mild mass effects, have not been described previously. Recognition of various changes in brain MRI will enable the early detection of anti-NMDAR antibody and then effective treatments.

Electronic supplementary material

Supplementary information accompanies this papaer at 10.1186/s12883-019-1456-6.

Relapse risk factors in anti-N-methyl-D-aspartate receptor encephalitis

AIM

To identify factors that may predict and affect the risk of relapse in anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis.

METHOD

This was a retrospective study of an Italian cohort of patients with paediatric (≤18y) onset anti-NMDAR encephalitis.

RESULTS

Of the 62 children included (39 females; median age at onset 9y 10mo, range 1y 2mo-18y; onset between 2005 and 2018), 21 per cent relapsed (median two total events per relapsing patient, range 2-4). Time to first relapse was median 31.5 months (range 7-89mo). Severity at first relapse was lower than onset (median modified Rankin Scale [mRS] 3, range 2-4, vs median mRS 5, range 3-5; admission to intensive care unit: 0/10 vs 3/10). At the survival analysis, the risk of relapsing was significantly lower in patients who received three or more different immune therapies at first disease event (hazard ratio 0.208, 95% confidence interval 0.046-0.941; p=0.042). Neurological outcome at follow-up did not differ significantly between patients with relapsing and monophasic disease (mRS 0-1 in 39/49 vs 12/13; p=0.431), although follow-up duration was significantly longer in relapsing (median 84mo, range 14-137mo) than in monophasic patients (median 32mo, range 4-108mo; p=0.002).

INTERPRETATION

Relapses may occur in about one-fifth of children with anti-NMDAR encephalitis, are generally milder than at onset, and may span over a long period, although they do not seem to be associated with severity in the acute phase or with outcome at follow-up. Aggressive immune therapy at onset may reduce risk of relapse.

WHAT THIS PAPER ADDS

Relapses of anti-N-methyl-D-aspartate receptor encephalitis may span over a long period. Relapses were not associated with severity in the acute phase or outcome at follow-up. Aggressive immune therapy at onset appears to decrease risk of relapse.

Anti-NMDA receptor encephalitis: a case study and illness overview

Anti-N-methyl D-aspartate (NMDA) receptor (anti-NMDAR) encephalitis is among one of the most common autoimmune encephalitides. However, variations in clinical presentation and nonsequential multiphasic course often lead to delays in diagnosis. The mild encephalitis (ME) hypothesis suggests a pathogenetic mechanism of low-level neuroinflammation sharing symptom overlap between anti-NMDAR encephalitis and other psychiatric disorders including schizophrenia. Clinical symptoms of anti-NMDAR encephalitis may mimic schizophrenia and psychotic spectrum disorders or substance-induced psychosis. Although initially described in association with ovarian teratomas in women, anti-NMDAR encephalitis has been reported in individuals without paraneoplastic association, as well as in males. It can affect all age groups but is usually lower in prevalence in individuals greater than 50 years old, and it affects females more than males. Clinical evaluation is supported by laboratory workup, which includes cerebrospinal fluid (CSF) assays. The latter often reveals lymphocytic pleocytosis or oligoclonal bands with normal to elevated CSF protein. CSF testing for anti-NMDAR antibodies facilitates diagnostic confirmation. Serum anti-NMDAR antibody assays are not as sensitive as CSF assays. Management includes symptomatic treatment and immunotherapy.

Neuronal Antibodies and Associated Syndromes

INTRODUCTION

Multiple well-recognized conditions, such as Lambert-Eaton myasthenic syndrome (LEMS) and myasthenia gravis (MG), have been associated with neuronal antibodies.

MATERIALS AND METHODS

A search was performed using Embase, PubMed, and CINAHL. An initial search of each database was conducted using keywords and terms related to the aim of the current review. Additional articles were obtained by examining the reference lists and citations in the selected records.

RESULTS

The studies identified through the search process used different designs and methods to explore neuronal antibodies and associated syndromes. Previous studies have shown that neurological and psychiatric disorders can be mediated and influenced by various antibodies. The identification of autoantibodies can help with the accurate diagnosis of conditions and commencement of early treatment.

DISCUSSION

A review of selected studies identified in the literature implicated that classic anti-neuronal antibodies, such as anti-Ri and anti-Hu, play a role in the development of neurological diseases. More recent studies have indicated that other novel antibodies act on neuronal cell surface antigens to contribute to the development of neurological disorders.

CONCLUSION

Existing research provides evidence revealing a spectrum of antibodies linked to the development and progression of neurological diseases. However, further antibody testing and studies should be performed to validate the relationship between conditions and antibodies.

New Onset British Accent, Acute Behavioral Changes, and Seizures: A Unique Presentation of NMDAR Encephalitis

The leading cause of autoimmune encephalitis is N-methyl-D-aspartate receptor (NMDAR) encephalitis. Symptoms can present as prominent behavioral abnormalities prompting inaccurate psychiatric diagnoses. Psychiatric features such as bizarre behavior, agitation, anxiety, delusions, and hallucinations are well noted in the current literature, but a manifestation of foreign accent syndrome has, to our knowledge, never been reported in cases of encephalitis. Once diagnosed, initiation of therapy can result in effective treatment. Here, we present a case of a 32-year-old female with new onset seizures and marked behavioral changes, such as speaking in a foreign accent, who was empirically treated for NMDAR encephalitis due to strong clinical suspicion, showed no improvement with first line therapy with IVIG and IV steroids, and finally had rapid resolution of symptoms with the early initiation of second line therapy of rituximab. In a young female presenting with nonspecific behavioral changes, NMDAR encephalitis should be on the differential and, although CSF antibodies are definitively diagnostic, there should be a low threshold to start empiric therapy and escalate to second line treatment.

Clinical Characteristics and Short-Term Prognosis of Autoimmune Encephalitis: A Single-Center Cohort Study in Changsha, China

Background and Purpose: The incidence and prevalence of autoimmune encephalitis is gradually increasing. This retrospective observational study primarily aimed to analyze the clinical characteristics of autoimmune encephalitis patients in the Second Xiangya Hospital and report patient prognoses after immunotherapy. Methods: The clinical data of 86 patients who were diagnosed with autoimmune encephalitis from October 2014 to September 2018 were collected, and their corresponding clinical characteristics, laboratory examination, treatment, and outcome data analyzed. Results: In our study, 72 patients (83.7%) were positive for anti-NMDAR (N-methyl-D-aspartate receptor) antibody; 5 patients (6%) for anti-GABABR (γ-aminobutyric acid receptor-A); 4 patients (4.7%) for anti-LGI1 (leucine-rich, glioma inactivated 1); 3 patients (3.5%) for anti-Caspr2 (contactin-associated protein-like 2) (1 patient was positive for both anti-LGI1 and anti-Caspr2 antibodies); and 3 patients (3.5%) for onconeural antibodies. Among the 86 patients diagnosed as having autoimmune encephalitis, 50% showed acute disease onset (≤2 weeks). The most common inducing factor was fever or cold (17/86, 19.8%). The main clinical symptoms included, among others, psychiatric disturbances (82.5%), epilepsy (60.5%), autonomic dysfunction (58.1%), sleep disorders (45.3%), consciousness disorders (45.3%), and speech disorders (46.5%). No significant correlation between ICU admission rates and CSF or serum antibody scores was observed. However, CSF antibody scores of (+ + +) and (++) were associated with longer lengths of hospitalization (p < 0.05) and a higher CSF WBC count when compared with CSF antibody scores of (+) in patients with anti-NMDAR encephalitis (p < 0.05). Additionally, there was no significant correlation between mRS score difference on admission and discharge (after immunotherapy) and age, sex, and choice of immune treatment, while immune therapy taken within 15 days from onset was more inclined to be associated with an mRS score difference ≥2 after immunotherapy in patients with anti-NMDAR encephalitis (p = 0.006). Conclusions: Autoimmune encephalitis has an acute or sub-acute onset and presents with psychotic symptoms, epilepsy, and autonomic dysfunction. The sex ratio in anti-NMDAR encephalitis was nearly balanced. Infection was a major factor inducing anti-NMDAR encephalitis, and the CSF antibody scores could be helpful in determining its prognosis since these scores showed associations with hospitalization duration and CSF WBC counts.

Anti-N-methyl-D-aspartate receptor encephalitis: A case report

RATIONALE

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an auto-immune and paraneoplastic encephalitis with prominent neuropsychiatric manifestations. The N-methyl-D-aspartate receptor is located in the forebrain and hippocampus and plays a role in learning and memory.

PATIENT CONCERNS

A 29-year-old female patient with anti-NMDAR encephalitis, was reported and we also reviewed the literature and summarised the characteristics of the cases.

DIAGNOSES

In the present study, we reported 1 patient with anti-NMDAR encephalitis diagnosed by the detection of anti-NMDAR antibodies in serum and cerebrospinal fluid (CSF).

INTERVENTIONS

The patient received glucocorticoids and anti-epilepsy treatment as well as human immunoglobulin treatment.

OUTCOMES

After treatment, the patient gradually regained consciousness and was discharged after 3 months of rehabilitation. At the follow-up 2 months later, the patient had the sequelae of memory impairment and limb movement disorders.

LESSONS

An accurate early diagnosis and active treatment are crucial to the improvement in the prognosis of patients with anti-NMDAR receptor encephalitis.

Systematic Review: Syndromes, Early Diagnosis, and Treatment in Autoimmune Encephalitis

In recent years, new antibodies have been discovered which mediate autoimmune encephalitis. This immunological response can be triggered by an infection or a tumor. Classical onconeuronal antibodies are directed against intracellular neuronal agents but recently, a novel group of antibodies to neuronal cell-surface and synaptic antigens associated with different CNS-syndromes, has been discovered. Interestingly, the syndromes in this group can be successfully treated with immunotherapy and frequently do not have underlying tumors. The aim of this review is to describe the current state of knowledge about autoimmune encephalitis, in order to provide clinicians with a concise, up-to-date overview. Thus, a comprehensive literature search was performed in medical databases. The literature was carefully studied and new findings focusing on the symptoms, diagnosis and treatment were summarized and interpreted. Even though it might be challenging in some cases, the awareness of certain symptom constellations and demographic information, in combination with laboratory- and MRI-results, allows clinicians to make the diagnosis of probable autoimmune encephalitis at an early stage. Treatment can therefore be initiated faster, which significantly improves the outcome. Further investigations could define the underlying pathogenic mechanisms. Randomized controlled trials, paired with increasing clinical experience, will be necessary to improve the identification of affected patients, treatment strategies, and outcomes in the years to come.

Amyloid-Beta 1-42 Cross-Reactive Antibody Prevalent in Human Sera May Contribute to Intraneuronal Deposition of A-Beta-P-42

Antibodies against many neural antigens are detected in the sera of both patients with Alzheimer's disease (AD) and some healthy individuals. Blood-brain barrier dysfunction could make it possible for brain-reactive autoantibodies to reach the brain, where they can react with amyloid ß peptide (AßP). The origin of these autoreactive antibodies in the blood is unclear. The goals of this study were as follows: (1) to examine the immune reactivity of anti-AßP-42 with 22 neuronal and other associated antigens, some of which are involved in the pathophysiology of AD; (2) to classify antibodies to these 22 different antigens into those that cross-react with AßP-42 and those that do not; (3) to determine whether these antibodies react with BBB proteins, nerve growth factors, and enteric neuronal antigens. Using monoclonal AßP-42 antibody and ELISA methodology, we found that the antibody was highly reactive with Aß protein, tau protein, presenilin, rabaptin-5, β-NGF, BDNF, mTG, and enteric nerve. The same antibody produced equivocal to moderate reactions with glutamate-R, S100B, AQP4, GFAP, MBP, α-synuclein, tTG-2, and tTG-3, and not with the rest. These antibodies were also measured in blood samples from 47 AD patients and 47 controls. IgG antibodies were found to be elevated against AßP-42 and many other antigens in a significant percentage of controls. Overall, the mean OD values were significantly higher against 9/23 tested antigens (p <0.001) in the samples with AD. We were indeed able to classify the detected neuronal antibodies into those that cross-react with AßP-42 and those that do not. Our main finding is that although these antibodies may be harmless in a subgroup of controls, in individuals with compromised BBBs these antibodies that cross-react with AßP-42 can reach the brain, where their cross-reactivity with AßP-42 may contribute to the onset and progression of AD, and perhaps other neurodegenerative disorders.

Anti-N-methyl-D-aspartate receptor encephalitis associated with mediastinal teratoma: a rare case report and literature review

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a recently identified neuroautoimmune disorder characterized by antibodies against the heteromeric NR1-NR2 receptor complex. To our best knowledge, anti-NMDAR encephalitis combined with mediastinal teratoma is extremely rare with only three cases been reported in literature worldwide. In this article, we present an 18 years old female diagnosed as anti-NMDAR encephalitis caused by a large mature mediastinal teratoma whose initial manifestations were acute headache and seizures. She was treated with intravenous immunoglobulin (IVIg) and surgical resection with a complete recovery. Our case shows that tumor resection along with prompt immunotherapy are effective treatment of the disease.

Complexity and wide range of neuromyelitis optica spectrum disorders: more than typical manifestations

Neuromyelitis optica (NMO), considered to be mediated by autoantibodies, often cause severely disabling disorders of the central nervous system, and predominantly cause optic nerve damage and longitudinally extensive transverse myelitis. Remarkable progress has been made in deciphering NMO pathogenesis during the past decade. In 2015, the International Panel for NMO Diagnosis proposed the unifying term "NMO spectrum disorders" (NMOSD) and the updated NMOSD criteria reflects a wide range of disease and maintains reasonable specificity. Moreover, cumulative findings have indicated that NMOSD are frequently associated with multiple autoimmune diseases, thereby presenting complex clinical symptoms that make this disease more difficult to recognize. Notably, most neurologists do not heed these symptoms or comorbid conditions in patients with NMOSD. Whereas previous reviews have focused on pathogenesis, treatment, and prognosis in NMOSD, we summarize the present knowledge with particular emphasis on atypical manifestations and autoimmune comorbidities in patients with NMOSD. Furthermore, we emphasized the identification of these atypical characteristics to enable a broader and better understanding of NMOSD, and improve early accurate diagnosis and therapeutic decision making.