Anti-NMDA receptor encephalitis in Japan: long-term outcome without tumor removal

Successful Treatment of Anti-N-Methyl-D-Aspartate Receptor Encephalitis With Bilateral Ovarian Teratomas Through Three Surgeries Without Loss of Fertility

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is associated with ovarian teratomas in approximately half of all cases. Surgical removal of these teratomas, combined with immunotherapy, results in rapid improvement in about half of patients. However, the remaining patients exhibit slower improvement and are at risk of severe complications. Additional surgeries may be considered for these patients. Since even microscopic teratomas can contribute to treatment resistance, complete removal of the remaining ovaries is often selected as a surgical approach. However, this approach results in loss of fertility. We report the case of a 28-year-old woman with bilateral ovarian teratomas and a refractory clinical course after initial treatment, including left salpingo-oophorectomy and right cystectomy. She underwent two additional surgeries, one for a residual teratoma and the other for a recurrent teratoma, both involving cystectomies aimed at preserving fertility. She was discharged home a year after admission and gave birth to a baby two years later. Our case is unique in that three surgeries were performed for an anti-NMDA receptor encephalitis patient with teratomas without loss of fertility, and it documents the reproductive outcome of the patient.

Varied Clinical Features and Outcomes of Autoimmune Encephalitis: A Retrospective Case Series

INTRODUCTION

This study discusses the various clinical profiles, investigatory findings, treatment responses, and prognosticating factors in seven cases of autoimmune encephalitis (AE).

METHODS

The clinical records of seven AE patients admitted to the Neurology Department, SRM Medical College Hospital and Research Centre, Chennai, from July 2022 to December 2023 were retrospectively analyzed.

RESULTS

The patients' ages ranged from 18 to 35, and all experienced seizures. Only two patients exhibited cognitive decline and psychiatric problems. All seven cases were clinically diagnosed as AE: three were positive for anti-N-methyl-D-aspartate receptor (anti-NMDAR) antibodies, while the AE panel was negative in the remaining patients. In all cases, contrast imaging of the brain on MRI appeared normal.

CONCLUSION

Patients with AE need to be diagnosed early because prompt immunosuppressive therapy effectively reduces morbidity and mortality. A detailed history, clinical examinations, and relevant investigations are required. Mild and atypical forms with negative autoimmune antibody panels with relatively good outcomes are increasingly encountered.

Anti-NMDAR encephalitis with delayed ovarian teratoma in a young woman: a case report with 5 years of follow-up

BACKGROUND

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune disorder with a variety of clinical manifestations. It has been established that anti-NMDAR encephalitis may be related to ovarian teratoma in female patients. However, a considerable number of patients have no obvious evidence of ovarian teratoma during the onset of the disease.

CASE

A 25-year-old previously-healthy female experienced a series of acute symptoms within two days, including confusion, disorientation, short-term memory loss, auditory hallucinations, abnormal behavior, refractory status epilepticus, etc. Her brain MRI and abdominal imaging showed no definite abnormality while her electroencephalogram exhibited the presence of low to moderate amplitude sharp, spike, and multi-spike waves. Serum and cerebrospinal fluid tests yielded positive results for anti-NMDAR antibodies. However, an ultrasound scan failed to identify an ovarian teratoma. Consequently, the diagnosis of anti-NMDAR encephalitis without teratoma was made after 4 days onset. After the plasma exchange and immunoglobulin therapy, her neurological symptoms improved and obtained a clinical cure. In the next eight months of follow-up, the patient accidentally touched a lump in the lower abdomen without any symptoms, and abdominal ultrasound and CT scan revealed a left ovarian tumor. Then she underwent left ovarian teratoma resection surgery and histopathology showed a mature cystic teratoma with neural components. The patient continued to receive five years of follow-up, and her condition remained stable without any recurrence, except that there had been a low titer of anti-NMDAR antibody in her serum.

CONCLUSION

Our case demonstrated the importance of long-term follow-up for female patients with anti-NMDAR encephalitis, since anti-NMDAR encephalitis-associated ovarian teratomas may develop in a delayed manner, even without any symptoms.

Long-term rehabilitation with interferential current stimulation for persistent dysphagia in anti-N-methyl-d-aspartate receptor encephalitis: A case report

Anti-N-methyl-d-aspartate receptor encephalitis is an autoimmune disorder characterized by various neurological symptoms with a relatively favorable prognosis. We present a case of prolonged dysphagia successfully managed with outpatient rehabilitation, including interferential current stimulation and resistance exercises. Significant improvement was observed, highlighting the efficacy of combined treatment in overcoming chronic dysphagia.

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

Introduction

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).

Methods

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.

Results

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.

Discussion

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.

Global study of anti-NMDA encephalitis: a bibliometric analysis from 2005 to 2023

Background

Autoimmune diseases have always been one of the difficult diseases of clinical concern. Because of the diversity and complexity of its causative factors, unclear occurrence and development process and difficult treatment, it has become a key disease for researchers to study. And the disease explored in this paper, anti-NMDA encephalitis, belongs to a common type of autoimmune encephalitis. However, the quality of articles and research hotspots in this field are not yet known. Therefore, in this field, we completed a bibliometric and visualization analysis from 2005 to 2023 in order to understand the research hotspots and directions of development in this field.

Materials and methods

We searched the SCI-expanded databases using Web of Science's core databases on January 22, 2024 and used tools such as VOS viewer, Cite Space, and R software to visualize and analyze the authors, countries, journals, institutions, and keywords of the articles.

Results

A total of 1,161 literatures were retrieved and analyzed in this study. China was the country with the most total publications, and USA and Spain were the most influential countries in the field of anti-NMDA encephalitis. University of Pennsylvania from USA was the institution with the highest number of publications. While Dalmau Josep is the most prolific, influential and contributing author who published one of the most cited articles in Lancet Neurology, which laid the foundation for anti-NMDA encephalitis research, the top three appearances of keyword analysis were: "antibodies", "diagnosis", and "autoimmune encephalitis."

Conclusion

Bibliometric analysis shows that the number of studies on anti-NMDA encephalitis is generally increasing year by year, and it is a hot disease pursued by researchers. USA and Spain are leading in the field of anti-NMDA encephalitis, while China should continue to improve the quality of its own research. The suspected causes of anti-NMDA encephalitis other than ovarian teratoma and herpes simplex, the specific clinical manifestations that are not masked by psychiatric symptoms, the diagnostic modalities that are faster and more accurate than antibody tests, and the improvement of treatment modalities by evaluating prognosis of various types of patients are the hotspots for future research.

Cortical atrophy in early-stage patients with anti-NMDA receptor encephalitis: a machine-learning MRI study with various feature extraction

Conventional brain magnetic resonance imaging (MRI) of anti-N-methyl-D-aspartate-receptor encephalitis (NMDARE) is non-specific, thus showing little differential diagnostic value, especially for MRI-negative patients. To characterize patterns of structural alterations and facilitate the diagnosis of MRI-negative NMDARE patients, we build two support vector machine models (NMDARE versus healthy controls [HC] model and NMDARE versus viral encephalitis [VE] model) based on radiomics features extracted from brain MRI. A total of 109 MRI-negative NMDARE patients in the acute phase, 108 HCs and 84 acute MRI-negative VE cases were included for training. Another 29 NMDARE patients, 28 HCs and 26 VE cases were included for validation. Eighty features discriminated NMDARE patients from HCs, with area under the receiver operating characteristic curve (AUC) of 0.963 in validation set. NMDARE patients presented with significantly lower thickness, area, and volume and higher mean curvature than HCs. Potential atrophy predominately presented in the frontal lobe (cumulative weight = 4.3725, contribution rate of 29.86%), and temporal lobe (cumulative weight = 2.573, contribution rate of 17.57%). The NMDARE versus VE model achieved certain diagnostic power, with AUC of 0.879 in validation set. Our research shows potential atrophy across the entire cerebral cortex in acute NMDARE patients, and MRI machine learning model has a potential to facilitate the diagnosis MRI-negative NMDARE.

Changing landscape in the field of paraneoplastic neurology: Personal perspectives over a 35-year career

Paraneoplastic neurologic syndromes are a group of rare disorders that have fascinated neurologists for more than a century. The discovery in the 1980s that many of these disorders occurred in association with antibodies against neuronal proteins revived the interest for these diseases. This chapter first traces the history of the paraneoplastic neurologic syndromes during the era that preceded the discovery of immune mechanisms and then reviews the immunologic period during which many of these syndromes were found to be associated with antibodies against intracellular onconeuronal proteins and pathogenic cytotoxic T-cell mechanisms. Alongside these developments, investigations on the antibody-mediated disorders of the peripheral nervous system, such as the myasthenic syndromes or neuromyotonia, provided suggestions for the study of the central nervous system (CNS) syndromes. These converging areas of research culminated with the groundbreaking discovery of a new category of CNS disorders mediated by antibodies against neuronal surface proteins or receptors. These disorders are not always paraneoplastic, and the understanding of these syndromes and mechanisms has changed the landscape of neurology and neurosciences.

Neurosyphilis with positive anti-N-methyl-D-aspartate receptor antibody: a case report

A case of neurosyphilis with a positive anti-N-methyl-D-aspartate receptor (NMDAR) antibody was reported. A 54-year-old man who presented with acute memory deficits was admitted to our hospital. Acute ischemic stroke (AIS) was initially considered, and he was prescribed intravenous thrombolysis with recombinant tissue-type plasminogen activator (rt-PA). However, the intermittent onset of episodic memory and orientation disorder still occurred. No diffusion restriction was indicated by magnetic resonance imaging (MRI), and subclinical seizures were frequently found by electroencephalogram (EEG). Rapid plasma reagin (RPR) test of serum showed positive results for syphilis. Analysis of cerebrospinal fluid (CSF) revealed elevated leukocyte count and protein level. RPR test, Treponema pallidum particle agglutination (TPPA) assay, and Treponema pallidum antibody (TP-Ab) in CSF showed positive results, and the anti-NMDAR antibodies were positive in CSF and serum. Finally, the patient was diagnosed with neurosyphilis with a positive anti-NMDAR antibody. The clinical symptoms were improved, and the leukocyte count in CSF was reduced after treatment with intravenous penicillin G and levetiracetam. This case suggests that in cases with positive results for neurosyphilis and NMDAR antibodies, the proper treatment has to be decided based on all of the available clinical and diagnostic testing data.

Anti-ganglionic acetylcholine receptor antibodies in functional neurological symptom disorder/conversion disorder

Objective

Autoimmune autonomic ganglionopathy (AAG) is a rare disorder characterized by autonomic failure associated with the presence of anti-ganglionic acetylcholine receptor (gAChR) antibodies; however, several studies have reported that individuals with anti-gAChR antibodies present with central nervous system (CNS) symptoms such as impaired consciousness and seizures. In the present study, we investigated whether the presence of serum anti-gAChR antibodies correlated with autonomic symptoms in patients with functional neurological symptom disorder/conversion disorder (FNSD/CD).

Methods

Clinical data were collected for 59 patients presenting with neurologically unexplained motor and sensory symptoms at the Department of Neurology and Geriatrics between January 2013 and October 2017 and who were ultimately diagnosed with FNSD/CD according to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition. Correlations between serum anti-gAChR antibodies and clinical symptoms and laboratory data were analyzed. Data analysis was conducted in 2021.

Results

Of the 59 patients with FNSD/CD, 52 (88.1%) exhibited autonomic disturbances and 16 (27.1%) were positive for serum anti-gAChR antibodies. Cardiovascular autonomic dysfunction, including orthostatic hypotension, was significantly more prevalent (75.0 vs. 34.9%, P = 0.008), whereas involuntary movements were significantly less prevalent (31.3 vs. 69.8%, P = 0.007), among anti-gAChR antibody-positive compared with -negative patients. Anti-gAChR antibody serostatus did not correlate significantly with the frequency of other autonomic, sensory, or motor symptoms analyzed.

Conclusions

An autoimmune mechanism mediated by anti-gAChR antibodies may be involved in disease etiology in a subgroup of FNSD/CD patients.

Unexplained Progressive Neurological Deficits after Corpus Callosotomy May Be Caused by Autoimmune Encephalitis: A Case of Suspected Postoperative Anti-NMDAR Encephalitis

The main causes of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis are ovarian teratoma and herpes simplex virus (HSV) encephalitis. We present a rare case of suspected anti-NMDAR encephalitis caused by corpus callosotomy (CC). An 18-year-old woman with Lennox-Gastaut syndrome underwent CC. Although left hemiplegic due to cerebral hemorrhage and impaired consciousness due to cerebral venous sinus thrombosis (CVST) appeared postoperatively, anticoagulant therapy quickly improved CVST and impaired consciousness. However, various unexplained symptoms such as insomnia, hallucination, impulsivity, impaired consciousness, and a new type of drug-resistant cluster seizures gradually developed over a 2-month period. Magnetic resonance imaging revealed the gradual extension of a hyperintense area from the right frontal lobe on fluid-attenuated inversion recovery images. Intravenous methylprednisolone pulse was initiated from postoperative day (POD) 74, followed by intravenous immunoglobulin (IVIg) therapy, although white blood cell counts were normal in all three cerebrospinal fluid (CSF) examinations. After IVIg therapy, the above unexplained symptoms promptly improved. On POD 103, antibodies against NMDAR were revealed in both the serum and CSF collected before these immunotherapies. The patient was transferred to a rehabilitation hospital due to residual left hemiplegia. Psychiatric symptoms and a new onset of drug-resistant seizures may be suggestive of postoperative anti-NMDAR encephalitis, even if CSF findings are mild.

Neuropsychological functioning in children and adolescents with anti-NMDA receptor encephalitis (anti-NMDARE)

The objective of this study was to describe neuropsychological functioning and associated medical features in pediatric patients with anti-NMDA receptor encephalitis (anti-NMDARE). Retrospective data were collected from electronic medical records and neuropsychological reports of 15 children and adolescents with cerebral spinal fluid antibody-confirmed anti-NMDARE who were 7-21 years old at the time of the neuropsychological evaluation. The median time between treatment initiation for anti-NMDARE and neuropsychological testing was 228 days (IQR 431, range 41-927). Consistent with the limited literature, this pediatric sample with anti-NMDARE generally had average IQs, but had scores falling in the low average range on tests of verbal and visual memory as well as aspects of executive functioning (set shifting and phonemic verbal fluency). Other relative weaknesses were observed in visuo-constructional ability and reading comprehension. Future prospective studies are needed to replicate these data and explore disease and treatment variables that reduce or exacerbate the risk for neuropsychological sequelae, while longitudinal analyses are required to better characterize academic, vocational, and social outcomes.

Paraneoplastic motor disorders

Paraneoplastic neurological disorders (PNDs) are heterogeneous clinicopathologic syndromes that occur throughout the neuraxis resulting from damage to organs or tissues remote from the site of a malignant neoplasm or its metastases. The discordance between severe neurological disability and even an indolent malignancy suggests an underlying neuroimmunologic host immune response that inflicts nervous tissue damage while inhibiting malignant tumor growth. Motor system involvement, like other symptoms and signs, is associated with focal or diffuse involvement of the brain, spinal cord, peripheral nerve, neuromuscular junction or muscle, alone or in combination due to an underlying neuroimmune and neuroinflammatory process targeting neural-specific antigens. Unrecognized and therefore untreated, PNDs are often lethal making early detection and aggressive treatment of paramount importance. While the combination of clinical symptoms and signs, and analysis of detailed body and neuroimaging, clinical neurophysiology and electrodiagnostic studies, and tumor and nervous system tissue biopsies are all vitally important, the certain diagnosis of a PND rests with the discovery of a corresponding neural-specific paraneoplastic autoantibody in the blood and/or spinal cerebrospinal fluid.

Motor symptoms in nonparaneoplastic CNS disorders associated with neural antibodies

Motor symptoms are common, and sometimes predominant, in almost all nonparaneoplastic CNS disorders associated with neural antibodies. These CNS disorders can be classified into five groups: (1) Autoimmune encephalitis with antibodies against synaptic receptors, (2) cerebellar ataxias associated with neuronal antibodies that mostly target intracellular antigens. (3) Stiff-person syndrome and progressive encephalomyelitis with rigidity and myoclonus which have antibodies against glutamic acid decarboxylase and glycine receptor, respectively. Both diseases have in common the presence of predominant muscle stiffness and rigidity. (4) Three diseases associated with glial antibodies. Two present motor symptoms mainly due to the involvement of the spinal cord: neuromyelitis optica spectrum disorders with aquaporin-4 antibodies and myelin oligodendrocyte glycoprotein antibody-associated disease. The third disorder is the meningoencephalitis associated with glial fibrillar acidic protein antibodies which frequently also presents a myelopathy. (5) Two antibody-related diseases which are characterized by prominent sleep dysfunction: anti-IgLON5 disease, a disorder that frequently presents a variety of movement disorders, and Morvan syndrome associated with contactin-associated protein-like 2 antibodies and clinical manifestations of peripheral nerve hyperexcitability. In this chapter, we describe the main clinical features of these five groups with particular emphasis on the presence, frequency, and types of motor symptoms.

Psychiatric Illness or Immune Dysfunction-Brain Perfusion Imaging Providing the Answer in a Case of Anti-NMDAR Encephalitis

BACKGROUND

We investigated the potential use of SPECT quantification in addition to qualitative brain perfusion analysis for the detection of anti-NMDAR encephalitis. The question is how to normalize brain activity to be able to quantitatively detect perfusion patterns. Usually, brain activity is normalized to a structure considered unaffected by the disease.

METHODS

Brain [99mTc]-HMPAO SPECT was performed as a method to detect brain perfusion patterns. The patterns of abnormal brain perfusion cannot always be reliably and qualitatively assessed when dealing with rare diseases. Recent advances in SPECT quantification using commercial software have enabled more objective and detailed analysis of brain perfusion. The cerebellum and whole brain were used as the normalization structures and were compared with visual analysis.

RESULTS

The quantification analysis performed with whole brain normalization confirmed right parietal lobe hypoperfusion while also detecting statistically significant left-to-right perfusion differences between the temporal lobe and thalamus. Whole brain normalization further described bilateral frontal lobe hyperperfusion, predominantly of the left lobe, and was in accordance with visual analysis.

CONCLUSION

SPECT quantitative brain perfusion analysis, using the whole brain as the normalization structure rather than the cerebellum, in this case, improved confidence in the visual detection of anti-NMDAR encephalitis and provided unexpected solutions to atypical psychiatric dilemmas.

Diagnostic value of an algorithm for autoimmune epilepsy in a retrospective cohort

Purpose

This study aims to propose a diagnostic algorithm for autoimmune epilepsy in a retrospective cohort and investigate its clinical utility.

Methods

We reviewed 60 patients with focal epilepsy with a suspected autoimmune etiology according to board-certified neurologists and epileptologists. To assess the involvement of the autoimmune etiology, we used the patients' sera or cerebrospinal fluid (CSF) samples to screen for antineuronal antibodies using rat brain immunohistochemistry. Positive samples were analyzed for known antineuronal antibodies. The algorithm applied to assess the data of all patients consisted of two steps: evaluation of clinical features suggesting autoimmune epilepsy and evaluation using laboratory and imaging findings (abnormal CSF findings, hypermetabolism on fluorodeoxyglucose-positron emission tomography, magnetic resonance imaging abnormalities, and bilateral epileptiform discharges on electroencephalography). Patients were screened during the first step and classified into five groups according to the number of abnormal laboratory findings. The significant cutoff point of the algorithm was assessed using a receiver-operating characteristic curve analysis.

Results

Fourteen of the 60 patients (23.3%) were seropositive for antineuronal antibodies using rat brain immunohistochemistry. Ten patients had antibodies related to autoimmune epilepsy/encephalitis. The cutoff analysis of the number of abnormal laboratory and imaging findings showed that the best cutoff point was two abnormal findings, which yielded a sensitivity of 78.6%, a specificity of 76.1%, and an area under the curve of 0.81.

Conclusion

The proposed algorithm could help predict the underlying autoimmune etiology of epilepsy before antineuronal antibody test results are available.

Teenager with acute psychosis due to non-paraneoplastic anti-N-methyl-d-aspartate receptor encephalitis with a successful recovery: A case report

Introduction

Anti NMDAR encephalitis is a neuropsychiatric syndromic disease caused by an immunological response. Acute behavioral changes, psychosis, and catatonia are common clinical manifestations, are seizures, amnesia, speech difficulties, dyskinesia, and autonomic dysregulation.

Case presentation

We discuss the case of a 14-year-old girl who had psychotic symptoms and tested positive for anti-NMDAR antibodies.

Discussion

Patients present with psychiatric symptoms such as delusions, hallucinations, agitation, changes in speech mania, disorganized thinking, catatonia, insomnia, and often seizures. Anti-NMDAR encephalitis should be suspected in teenage patient with acute psychotic symptoms and seizure episodes. A multidisciplinary treatment strategy is required.

Conclusion

The delayed treatment can lead to complications and delayed recovery complicating the disease process so multidisciplinary approach of treatment is necessary.

•

Acute psychotic symptoms with seizure episodes in adolescent patient should have a suspicion of anti-NMDAR encephalitis.

•

The delayed treatment can lead to complications and delayed recovery complicating the disease process.

•

Multidisciplinary approach of treatment is necessary.

Association between clinical factors and orofacial dyskinesias in anti-N-methyl-D-aspartate receptor encephalitis

BACKGROUND AND PURPOSE

We aimed to determine whether demographic information, clinical characteristics, laboratory tests, and imaging features are associated with orofacial dyskinesias (OFLD) in patients with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis.

METHODS

In this retrospective study, patients who were diagnosed with anti-NMDAR encephalitis were enrolled. All patients' factors, including demographic information, clinical characteristics, laboratory tests, and imaging features, were obtained at the time of hospitalization. The neurological function was assessed using the modified Rankin scale (mRS). Univariate and multivariate logistic regressions were used to examine the associations between clinical factors and OFLD.

RESULTS

In total, 119 patients (median age: 28.0 [19.0-41.0] years; 67 females) were recruited. Of 119 patients, 44 (37.0%) had OFLD. OFLD was associated with increased mRS at admission, serum sodium, lumbar puncture pressure, female biologic sex, fever, psychiatric symptoms, seizures, impaired consciousness, autonomic dysfunction, and central hypoventilation in univariate logistic regression, respectively. Multivariate regression analysis revealed that female biologic sex (odds ratios [OR], 4.73; 95% confidence interval [CI], 1.27-17.64; p = .021), increased mRS at admission (OR, 2.09; 95% CI, 1.18-3.71; p = .011), psychiatric symptoms (OR, 7.27; 95% CI, 1.20-43.91; p = .031), and seizures (OR, 5.11; 95% CI, 1.22-21.43; p = .026) were associated with OFLD, after adjusting for confounding factors.

CONCLUSIONS

Our analysis suggests that the following clinical factors are associated with OFLD: female biologic sex, increased mRS at admission, psychiatric symptoms, and seizures.

Anti-N-Methyl-D-Aspartate Receptor Encephalitis: Neuropsychiatric and Multidisciplinary Approach to a Patient Not Responding to First-Line Treatment

The understanding of anti-NMDA (N-methyl-D-aspartate) receptor encephalitis, recognized by Dalmau and colleagues in 2007, has come a long way in helping clinicians to recognize the significance of rapidly progressive psychiatric symptoms in patients who are actually suffering from autoimmune disease. This subtype of autoimmune encephalitis manifests from antibodies that target the NR1 and/or NR2 subunits of NMDA receptors in serum or cerebrospinal fluid. Since gaining notoriety among neurologists, it has shown an etiologic predilection for children, adolescents, and young adult females, often associated with ovarian teratomas. Conversely, it affects young males as well, though it is rarer to find co-occurring tumors. It is a multistage disorder, initially presenting with psychiatric symptoms that progress in varying fashion, including headache, fever, nuchal rigidity, emesis, seizure, autonomic instability, auditory and visual hallucinations, delusional ideation, agitation, altered sensorium, and motor disturbances (i.e. dyskinesia, catatonia, etc.). Early diagnosis is critical due to the relatively high (25%) mortality rate. In this case, we present the case of a 30-year-old male who presented to our institution’s Comprehensive Psychiatric Emergency Program (CPEP) exhibiting bizarre behavior and visual hallucinations, and was later confirmed to have anti-NMDA receptor encephalitis. The case report highlights the risk factors, disease course, and treatment modalities of anti-NMDA receptor encephalitis with special emphasis on the subsect of patients who may not respond to first-line therapies.

Ovarian teratoma related anti-N-methyl-D-aspartate receptor encephalitis: A case series and review of the literature

BACKGROUND

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a rare but important complication of ovarian teratoma. Between July 2012 and December 2019, six patients with ovarian teratoma-associated anti-NMDAR encephalitis were enrolled in our hospital and their clinical characteristics, treatment, and follow-up were reviewed. We also conducted a systematic literature review of ovarian teratoma related anti-NMDAR encephalitis reports between January 2014 and December 2019.

AIM

To better understand anti-NMDAR encephalitis through literature review and patients enrolled in our hospital.

METHODS

The six patients enrolled in the study were those diagnosed with anti-NMDAR encephalitis. Their history, clinical manifestations, and medications were recorded and optimum treatment provided in addition to maintaining a record of the follow-ups. In addition, we also extensively surveyed the literature and provide summarized data from 155 published cases of anti-NMDAR encephalitis from 130 case reports. PubMed and Scopus were the sources of these publications and the time period covered was 6 years ranging from January 2014 through December 2019.

RESULTS

The six patients enrolled for this study presented with typical symptoms resulting in a diagnosis of ovarian teratoma induced anti-NMDAR encephalitis. Appropriate interventions led to a positive outcome in all the patients, with five of six patients reporting full recovery and the sixth patient recovering with a few deficits. No death was recorded. The literature survey comprising of 155 patients cases across 130 case reports of anti-NMDAR encephalitis clearly indicated an upward trend in the reports/diagnosis in China, particularly in the surveyed time from 2014 through 2019. The majority of patients (150/155) underwent surgical intervention resulting in positive outcome. No treatment intervention was mentioned for one case while the four patients who were not surgically operated succumbed to the disease.

CONCLUSION

Suspected anti-NMDAR encephalitis should be quickly evaluated for anti-NMDAR antibodies since early diagnosis is important. In case of a tumor, its earliest and complete removal is recommended. Finally, early use of corticosteroids and IgG-depleting strategies (intravenous immunoglobulin or plasma exchange) may improve outcome.

Anti-NMDA Receptor Encephalitis: Retrospective Analysis of 15 Cases, Literature Review, and Implications for Gynecologists

Background

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is a rare form of autoimmune encephalitis caused by anti-NMDA receptor antibodies. This disease mainly affects women of childbearing age and is commonly associated with ovarian teratoma. However, the relationship between anti-NMDA receptor encephalitis and ovarian teratoma and the role of anti-NMDA receptor antibody in the relationship remain unclear.

Objectives

This study aimed to describe 15 cases of anti-NMDA receptor encephalitis (5 with ovarian teratoma), review literature, and reinforce the gynecologist's knowledge of this disorder.

Methods

Clinical data of 15 patients from January 2015 to December 2020 admitted to The Second Hospital of Hebei Medical University were collected and analyzed. The diagnosis of anti-NMDA receptor encephalitis was based on the presence of anti-NMDA receptor antibodies in cerebrospinal fluid (CSF) and/or serum. Laparoscopic teratoma removal was performed in patients with ovarian teratoma. All patients had received immunotherapy. In addition, a review of the literature was performed to reinforce the gynecologist's knowledge of this disorder.

Results

A total of 15 patients with anti-NMDA receptor encephalitis were screened, of whom 5 patients were confirmed with ovarian teratoma by pathology. The most common symptoms of anti-NMDAR encephalitis with teratoma are fever (5/5, 100%), seizure (5/5, 100%), mental and behavioral disorders (4/5, 80%), and decreased consciousness (4/5, 80%). Conversely, the most common symptoms of patients without teratoma were neuropsychiatric symptoms, including headache (6/10, 60%) and mental and behavioral disorders (7/10, 70%). All patients underwent immunotherapy, including steroids, intravenous immunoglobulin (IVIG), plasma exchange, and cyclophosphamide, and 4 out of 5 patients with ovarian teratomas underwent surgical treatment. All patients had a good outcome after systemic, surgical, and immunotherapy treatment. No patient who underwent surgical treatment developed a recurrence. Conversely, 2 of 10 patients without teratoma developed an anti-NMDA receptor encephalitis recurrence.

Conclusions

Patients with anti-NMDA encephalitis show severe mental and neurological symptoms. Resection of teratoma is beneficial to the relief or disappearance of symptoms and has a good prognosis. This disorder should be fully recognized by gynecologists, who play an important role in diagnosis and treatment.

Recurrence of Anti-N-Methyl-D-Aspartate Receptor Encephalitis: A Cohort Study in Central China

Objective

To investigate factors that could impact or predict the probability of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis recurrence in central China.

Methods

From November 2014 to October 2020, observational data of anti-NMDAR encephalitis inpatients in our institution were collected and analyzed prospectively. The demographics, clinical characteristics, tumor status, lesion locations on MRI and immunotherapies, etc. had entered into a Cox regression model for the identification of the factors associated with relapse-free survival.

Results

We enrolled 113 patients in a row (median age: 28 years, range: 1-61 years). The gender distribution was not statistically significant (p = 0.158), with 49 people (43.4%) being female. The median follow-up time was 16 (4-77) months. Among them, 16.8% of patients relapsed. The average interval between recurrences was 8 months (range 3-54 mo). The severity of the initial relapse was less severe than it had been at the start. The first relapse had considerably fewer symptoms (median 2, range 1-6) than the first episode (median 4, range 1-8, p = 0.005). The mRS at first relapse (median 3, mean 2.84, range 1-5) had been significantly lower than that at onset (median 4, mean 3.89, range 3-5, p = 0.004). The length of hospitalization at first relapse (median 17 days, range 5-46) was significantly shorter than the first episode (median 35 days, range 14-102, p = 0.002). In the survival analysis, the risk of recurrence was significantly higher for patients with a brainstem lesion (HR: 4.112, 95% CI: 1.205-14.030; p = 0.024) or ≥3 abnormal sites (HR: 2.926, 95% CI: 1.085-7.896; p = 0.034) on brain MRI at the first episode. There was no significant difference in neurological outcomes between the recurrent and monophasic groups at the most recent follow-up (mRS 0-2 in 17/19 vs. 86/94; p = 0.674).

Conclusions

Anti-NMDAR encephalitis can recur in around one out of every six cases, and symptoms are generally milder than when it first appears. Recurrence is not related to the severity in the acute phase or the prognosis at follow-up. Patients with ≥3 abnormal sites on MRI or lesions located in the brainstem at onset must be alert to the possibility of recurrence.

A video-based discussion of movement disorders in paediatric anti NMDAR encephalitis: A case series from Eastern India

PURPOSE

The spectrum of movement disorders associated with anti N-Methyl-d-Aspartate-Receptor (NMDAR) encephalitis is myriad, particularly in children, possibilities of which were investigated from two tertiary care centres.

METHODS

A retrospective study was conducted in two tertiary referral centres in Eastern India, analysing data of 8 paediatric patients diagnosed as anti NMDAR encephalitis, presenting with one or more movement disorders (MDs).

RESULTS

All the patients were of Bengali ethnicity with a median age of 9 years (3-16 years) and with female predilection (62.5%). CSF pleocytosis was a common feature in all. Seizures were described in 62.5%% of patients with a solitary patient exhibiting abnormalities on brain imaging. 3 out of 8 (37.5%) of patients presented with a single MD while the remaining had more than one type. Oro-linguo-facial dyskinesias and dystonia (37.5% each) were the most common movement type followed by chorea (12.5%). Complex stereotypies, myoclonus and facial tics were noted in one patient each. All patients received pulse methyl prednisolone. Escalation to second line therapy in form of rituximab was done for 5 patients (62.5%). Following immunotherapy, hyperkinetic movements resolved in 50% of patients, with persistence of movements in one (12.5%). A mortality of 37.5% was noted. Median duration of follow up was 26 months, during which none of the patients had evidence of systemic neoplasm.

CONCLUSION

MDs are a core feature of anti NMDAR encephalitis, particularly in the paediatric age group, understanding and characterization of which, is the key to early diagnosis and effective therapy.

Diagnosis and Management of Suspected Pediatric Autoimmune Encephalitis: A Comprehensive, Multidisciplinary Approach and Review of Literature

Autoimmune encephalitis is an increasingly recognized entity in children. When treated promptly, favorable outcomes are seen in a majority of pediatric patients. However, recognition of autoimmune encephalitis in young patients is challenging. Once autoimmune encephalitis is suspected, additional difficulties exist regarding timing of treatment initiation and duration of treatment, as evidence to guide management of these patients is emerging. Here, we review available literature regarding pediatric autoimmune encephalitis and present our institution's comprehensive approach to the evaluation and management of the disease. These guidelines were developed through an iterative process involving both pediatric neurologists and rheumatologists.

Contemporary advances in anti-NMDAR antibody (Ab)-mediated encephalitis

The study of antibody (Ab)-mediated encephalitis has advanced dramatically since the discovery of antibodies directed against the N-methyl-D-aspartate receptor (NMDAR) in association with a unique neuro-psychiatric syndrome, over a decade-and-a-half ago. Anti-NMDAR Ab-mediated encephalitis now represents the most well characterised form of autoimmune encephalitis. The disease most commonly manifests in young women, but all ages and both sexes can be affected. Autoantibodies may arise in the context of two well-recognised disease triggers in a proportion of patients, and ultimately facilitate NMDAR displacement from synapses. Various CSF cytokines, chemokines, and other molecules have been explored as candidate biomarkers but are limited in sensitivity and specificity. The clinical spectrum is diverse, with evolution and a combination of neuro-psychiatric abnormalities at disease nadir common. Anti-NMDAR Ab-mediated encephalitis is immunotherapy responsive, and a near-majority ultimately acquire a broadly favourable clinical outcome. The diagnosis, and more particularly, the management of the disease can still hold considerable challenges. Moreover, well-defined biomarkers remain elusive. The present review will therefore delineate pathogenic and clinical advances to date in anti-NMDAR antibody-mediated encephalitis.

Anti-NMDA Receptor Encephalitis Misdiagnosed As Generalized Anxiety Disorder: A Case Report

The autoimmune encephalitis is a rare group of neurological disorders mediated by immune mechanisms. Neuropsychiatric symptoms often occur in the early stages of the disease, so many patients seek treatment in psychiatry for the first time. If psychiatrists lack understanding and vigilance of the disease, it is very easy to be misdiagnosed as various primary psychiatric diseases, thus delaying diagnosis and treatment. Here, we report an older woman with autoimmune encephalitis. In the early stage, the patient was misdiagnosed as having generalized anxiety disorder because of obvious psychiatric symptoms, and then caused the doctor’s vigilance due to rapidly declining cognitive function, autonomic nervous dysfunction, involuntary movement, and other warning symptoms. Autoimmune encephalitis was diagnosed by cerebrospinal fluid examination, and the patient was cured and discharged after a period of immunotherapy.

Central Hypoventilation Is a Key Risk Factor for Mechanical Ventilation During the Acute Phase of Anti-N-Methyl-D-Aspartate Receptor Encephalitis

Objective: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an acute form of encephalitis of autoimmune etiology. We aimed to evaluate the risk factors that predicted the need for mechanical ventilation during the acute phase of anti-NMDAR encephalitis through an analysis of the clinical characteristics and biochemical test results of the patients with anti-NMDAR encephalitis.

Methods: In this retrospective study, patients who primarily presented with anti-NMDAR encephalitis and exhibited anti-NMDAR antibody positivity in the cerebrospinal fluid (CSF) between November 2015 and February 2020 were included. Data on the clinical characteristics, biochemical test results, and treatment methods selected for the patients were collected for the analysis of factors predicting the need for mechanical ventilation.

Results: Thirty-one patients with a median age of onset of 31 years (inter-quartile range: 21–48 years) were included in this study, of which 15 were male (48.4%). Psychosis (23, 74.2%), seizures (20, 64.5%), and memory deficit (20, 64.5%) were the most common clinical manifestations. At admission, 17 patients (54.8%) presented with pyrexia, of which 12 (38.7%) had a body temperature ≥38°C, and six patients (19.4%) presented with central hypoventilation. All patients received first-line therapy (glucocorticoids, intravenous immunoglobulin, or plasmapheresis alone or combined), whereas two patients (6.5%) received rituximab, a second-line agent, as well. Seven patents required mechanical ventilation. Results of univariate logistic regression analysis revealed that body temperature ≥38°C [odds ratio (OR) = 18, 95% confidence interval (CI): 1.79–181.31, P < 0.05] and central hypoventilation at admission (OR = 57.50, 95% CI: 4.32–764.89, P < 0.05) were the risk factors for mechanical ventilation. Multivariate logistic regression analysis showed that central hypoventilation at admission was the only risk factor predicting the need for mechanical ventilation.

Conclusion: Central hypoventilation at admission is a key risk factor for mechanical ventilation during hospitalization in patients with anti-NMDAR encephalitis.

Characteristics of clinical relapses and patient-oriented long-term outcomes of patients with anti-N-methyl-D-aspartate receptor encephalitis

OBJECTIVE

The main syndrome of anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) is well-characterized, however, the difference in main symptoms between the initial episode and relapses and patient-oriented long-term outcomes has not been previously described.

METHODS

To investigate the difference in syndrome symptoms between episodes and patient-oriented outcomes, we administered a structured questionnaire survey for the patients with anti-NMDARE or their family members. From the answers, we analyzed the frequency of main symptoms (e.g., prodromes, abnormal behaviors, memory deficit, speech disorders, involuntary movements, hypo-ventilation) between episodes and patient-oriented outcomes that included the recovery rate for return to previous work or school.

RESULTS

Fifty-six patients were enrolled, and 14 (25%) showed clinical relapse. Details of symptoms at relapse were obtained from 11 patients. Prodrome (27% vs. 96%, p < 0.001), decreased level of consciousness (55% vs. 88%, p = 0.021), seizures (36% vs. 77%, p = 0.012), and involuntary movements (27% vs. 84%, p < 0.001) were significantly less frequent at relapse than initial episode. Although 80% (35/44) of the patients achieved favorable long-term outcomes (modified Rankin Scale score, 0-2), only 61% (27/44) returned to their previous work or school life.

CONCLUSION

Anti-NMDARE can relapse with milder and more limited symptoms than those of initial episode, and some patients did not return to their previous activities even after achieving a neurologically favorable outcome.

Decreased convulsive threshold and memory loss after anti-NMDAR positive CSF injection in zebrafish

Anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis initially promotes memory deficits, behavioral changes, and epileptic seizures. We developed a new animal model of anti-NMDAR encephalitis using a single cerebroventricular injection of CSF from patients in adult zebrafish. We observed a reduction of the seizure threshold and recent memory deficits in those animals injected with CSF from patients with anti-NMDAR encephalitis. The locomotor activity was similar in the CSF and control groups. This zebrafish model consistently recapitulates symptoms seen in patients with anti-NMDAR encephalitis. It may provide a reliable, fast and cost-effective platform to investigate new therapeutic strategies to anti-NMDAR encephalitis.

Pediatric Autoimmune Encephalitis and Its Relationship With Infection

Autoimmune encephalitis (AE) is an increasingly recognized inflammatory disorder of the central nervous system and is most often characterized by antibodies against intracellular and neuronal surface antigens. AE is a devastating disease that may result in developmental delay or regression in children. However, the pathogenesis of AE is not clear, and immune system disorders after infection likely play an important role in AE. Many studies have reported that patients with herpes simplex virus encephalitis develop anti-N-methyl-d-aspartate receptor encephalitis after antiviral treatment. It is critical to recognize pediatric AE early and to distinguish it from infectious forms because AE is treatable and responsive to immunotherapies. In this review, we discuss the clinical features of pediatric AE and focus on the relationship between AE and postinfection status. In addition, we review the probable mechanisms underlying infection-triggered AE, which include molecular mimicry, bystander activation, epitope spreading, immune system disorder, and genetic susceptibility.

Precocious puberty as a consequence of anti-NMDA receptor encephalitis in children

BACKGROUND

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is one of the most common autoimmune encephalitis in children. Most children recovered well after anti-NMDA receptor encephalitis. However, the NMDA receptor network functions are critical for the developing brain in children. The long-term consequences in pediatric patients of anti-NMDA receptor encephalitis are very infrequently reported.

METHODS

This case series study retrospectively enrolled 10 children aged below 18 years old with antibody-proved anti-NMDA receptor encephalitis in a tertiary medical center from 2010 to 2019. Long-term neurological consequences of anti-NMDA receptor encephalitis in children were followed.

RESULTS

One boy and nine girls were enrolled with a median onset age of 3.6 years. The most common initial presentation was verbal reduction and psychiatric symptoms soon after some flu-like prodromal symptoms. Nearly all patients then developed decreased level of consciousness, mutism, seizures and orofacial-lingual dyskinesia. Autonomic instability occurred in 5 patients, particularly in pre-pubertal children. Only one adolescent patient had ovarian teratoma. All patients survived after immunotherapy and were followed for 5.8 ± 3.3 years after discharge. Four had epilepsy within 2 years after encephalitis, four had a cognitive deficit, one had mild psychiatric symptoms of hallucination, and none had residual involuntary movements. Moreover, two pre-pubertal children developed central precocious puberty about 3 years after encephalitis, and one required gonadotropin-releasing hormone agonist treatment.

CONCLUSION

Central precocious puberty could be a consequence of anti-NMDA receptor encephalitis in the pre-pubertal children. The pediatrician should pay attention to its occurrence at follow-up.

Pediatric auto-immune encephalitis

Pediatric Auto-Immune Encephalitis (PAE) is a neuro-inflammatory disorder with a varied presentation. The discovery of the Anti NMDA receptor and other antibodies as the causative agents of PAE, has led to an increased need for guidelines for diagnosis and management of these disorders. PAE remains a challenging group of disorders due to their varying presentations and etiology with a prolonged clinical course. The wide spectrum of clinical symptoms involves altered mental status, movement disorders, acute behavioral changes, psychosis, delirium, seizures, and insomnia. This group of disorders was recently recognized in the children. This review provides clinicians with information on the most common PAE disorders, the spectrum of their clinical presentation, diagnostic tests and treatment protocols based on the current literature.

Anti-N-Methyl-D-aspartate receptor encephalitis masquerading as fever of unknown origin

Fever of unknown origin (FUO) is a diagnostic challenge. Anti-N-methyl-D-aspartate receptor encephalitis should be considered in children with FUO and new-onset neurological symptoms without significant encephalopathy.

Hystero-epilepsy in the Tuesday Lessons and NMDA receptor function: A hypothesis for dissociative disorder

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis patients demonstrate characteristic multistage progression and movement disorders, which are analogous to hystero-epilepsy in Jean-Martin Charcot's Tuesday Lessons. First, based on a review of the Tuesday Lessons recorded by Charcot's pupils, we hypothesized that there were patients with anti-NMDAR encephalitis among those diagnosed with hystero-epilepsy in the nineteenth century. We found acute-onset multiple neuropsychiatric manifestations resembling anti-NMDAR encephalitis among patients with hystero-epilepsy. Patients with drug withdrawal syndrome, dissociative and conversion disorders and patients under hypnosis from the modern point of view were also identified. These results suggested that hystero-epilepsy in the Tuesday Lessons could encompass dissociative and conversion disorders, hypnosis, drug withdrawal syndrome, and anti-NMDAR encephalitis-like manifestations. Based on Charcot's observations and current progress in molecular biology, such as the identification of glutamate/NMDAR system dysfunction in drug withdrawal syndrome, we then hypothesized that patients with dissociative and conversion disorders and those under hypnosis could also have hypofunction of the glutamatergic system. The NMDAR hypofunction hypothesis is emerging as a pathogenesis of schizophrenia. NMDAR antagonists are known to evoke symptoms similar to schizophrenia, anti-NMDAR encephalitis and near-death experiences. In current clinical reports, spectrum disorders such as dissociative disorder and conversion disorder have been observed in patients with anti-NMDAR encephalitis. Our hypothesis will offer an expansion of the NMDAR hypofunction hypothesis from psychosis to functional neurological disorders and normal specific situations, such as hypnosis, thanatosis, and near-death experiences.

Rituximab Was Effective for Treatment of Anti-N-Methyl-d-Aspartate Receptor Encephalitis in Early Adolescence in Initially Suspected Dissociative Disorder

OBJECTIVES

Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is an increasingly recognized etiology of psychiatric symptoms. Because patients with anti-NMDAR encephalitis frequently show aggression, mania, hallucination, depression, or delusion, they are initially diagnosed with schizophrenia or mood disorders. There is only 1 case report of an initially diagnosed dissociative disorder.

METHODS

We obtained consent for the presentation and have not identified individuals for ethical reasons.

RESULTS

We first report an adolescent female patient with anti-NMDAR encephalitis who was initially suspected of having dissociative disorder but was responsive to immunotherapies including rituximab. In this case, her symptoms and electroencephalogram findings were proportional to the antibody titer in the cerebrospinal fluid.

CONCLUSIONS

It is important to consider the possibility of autoimmune encephalitis and immunotherapy including rituximab in cases of not only acute psychosis but also dissociation.

Anti-N-methyl-d-aspartate receptor encephalitis associated with intracranial cryptococcal infection: A case report and 2-year follow-up

Anti-N-methyl-d-aspartate (anti-NMDA) receptor encephalitis is a type of autoimmune encephalitis characterized by the rapid onset of neurologic dysfunction. Several studies have reported the important role of post-infectious effect in its pathogenesis. Herein, we report on a 68-year-old woman diagnosed with anti-NMDA receptor encephalitis with concomitant intracranial cryptococcal infection, who was followed up for two years and demonstrated clinical improvements after effective anti-fungal therapy. This case may help expand the clinical spectrum of post-infectious immune-mediated etiology of anti-NMDA receptor encephalitis. The pathogenic role of both disorders requires further investigation.

HSV encephalitis triggered anti-NMDAR encephalitis: a case report

BACKGROUND

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis (AE) is a common cause of nonviral infectious encephalitis, which can be triggered by herpes simplex virus infection. Previous studies have shown that approximately 27% of herpes simplex encephalitis (HSE) patients produce anti-NMDAR antibodies within 3 months. Immunotherapy is recommended in this situation, but some symptoms usually remain in the 1-year follow-up.

CASE PRESENTATION

A previously healthy 23-year-old Chinese young woman developed epileptic attack followed by psychiatric symptoms of confusion and irritation as well as cognitive deficits. Brain MRI showed hyperintense lesions of the right temporal lobe on DWI and T2 without contrast enhancement effects. Twenty-one days of acyclovir was administered based on the primary diagnosis of HSE. The anti-NMDAR antibody (IgG) was detected positively on day 11 after disease onset. She had improved cognitive function but suffered another grand mal epilepsy after the first course of intravenous immunoglobulin (IVIG) therapy combined with 1000 mg intravenous methylprednisolone. After discussion, another course of IVIG was started for 5 days. Her symptoms were well controlled with only mild cognitive deficits at the 1-year follow-up (mRS = 1).

CONCLUSIONS

Our case indicated that anti-NMDAR antibodies could develop earlier after HSE compared with previous data from adults. We suggested detecting AE antibodies simultaneously with each CSF analysis. Meanwhile, the second course of IVIG therapy was reasonable when symptoms were not controlled after the first course of IVIG combined with IV steroid treatment.

Anti-NMDAR encephalitis presenting as stroke-like episodes in children: A case series from a tertiary care referral centre from Southern India

Background:

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is one of the common causes of treatable encephalitis in children characterized by severe memory deficit, speech disturbances, seizures, autonomic dysfunction, and movement disorders. Hemiparesis/stroke-like episode is not a usual presenting complaint of NMDAR encephalitis. The objective of this study was to report confirmed cases of seropositive anti-NMDAR encephalitis in children who presented with hemiparesis/stroke-like episodes.

Materials and Methods:

Retrospective review of charts of patients with a diagnosis of NMDAR encephalitis was performed at the pediatric neurology department attached to a tertiary care hospital for 6 years from March 2014 to February 2020. Only those case records with NMDAR seropositivity in the cerebrospinal fluid were collected and those who presented with stroke-like episode/hemiparesis were retrieved separately and the data were extracted in a predesigned proforma and analyzed.

Results:

Six children of 24 seropositive anti-NMDAR encephalitis presented with hemiparesis/stroke-like episode. All the six patients presented with hemiparesis, behavioral changes, and regression of speech. Three children had seizures and one child had Epilepsia partialis continua. Two children had dystonia and choreoathetosis. Methylprednisolone followed by oral steroids were administered in all patients. Cases 1, 2, and 4 made a full recovery within 7 days, but cases 3, 5, and 6 showed improvement after 20 days following additional IVIG. Four children have cognitive decline and behavioral problems. Case 6 had relapse and recovered with rituximab.

Conclusion:

Anti-NMDA receptor encephalitis which is a potentially treatable disease should be considered in the differential diagnosis when a child presents with hemiparesis/stroke-like episode.

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.

Pharmacologic Treatment and Early Rehabilitation Outcomes in Pediatric Patients With Anti-NMDA Receptor Encephalitis

OBJECTIVES

To describe the immunotherapy and pharmacologic treatments administered to pediatric patients with N-methyl-D-aspartate receptor encephalitis (NMDARE) during inpatient rehabilitation as well as to examine clinical and demographic variables associated with early functional outcomes.

DESIGN

Retrospective chart review and post hoc analysis.

SETTING

Pediatric inpatient rehabilitation unit.

PARTICIPANTS

Pediatric patients (N=26; mean age, 10.79±5.17y) admitted to an inpatient rehabilitation unit with a confirmed diagnosis of NMDARE.

INTERVENTIONS

Inpatient rehabilitation; pharmacologic treatments.

MAIN OUTCOME MEASURE

FIM for Children (WeeFIM) Developmental Functional Quotient (DFQ).

RESULTS

All patients received first-line immunotherapies to treat NMDARE, and 69% also received second-line immunotherapies. Patients were prescribed an average of 8 medications for symptom management (range, 3-15 per patient), most often for the treatment of agitation (100%), psychiatric symptoms (92%), and seizures (65%). Sixty-five percent of patients demonstrated an improvement in Total WeeFIM DFQ over the course of inpatient rehabilitation, with 35% demonstrating limited to no change in Total WeeFIM DFQ ("unfavorable early outcome"). Those with unfavorable early outcome were significantly younger than those showing more favorable outcome. Pharmacologic treatment for seizures, movement disorders, and decreased arousal or level of consciousness were each associated with unfavorable early outcome independent of age differences.

CONCLUSION

Findings highlight the symptomatic heterogeneity and polypharmacy involved in the care and treatment of patients with NMDARE, with patients receiving a variety of immunotherapies and medications for symptom management. The presence of (and treatment for) seizures, movement disorders, and deteriorated neurologic status may each be associated with poor early outcomes in this population. Further investigation is needed to better classify presentations and treatments for this disease and to determine how differences are associated with long-term outcomes.

Long-term persistence of NMDAR antibodies after encephalitis with de novo occurrence of demyelinating disorder

The issue of persistence of NMDAR antibodies after encephalitis is not fully elucidated and their relationship with demyelinating disorders has been suggested. A female patient showed at the age of 18 an acute neurological disorder (with psychiatric symptoms, focal seizures, orofacial dyskinesias and hypoventilation requiring ventilatory support) clinically mimicking anti-NMDAR encephalitis. At that time specific laboratory tests were not available, CSF revealed oligoclonal bands and MRI was negative. The patient had full recovery after first line immunotherapy (i.v. steroids and immunoglobulins). Fifteen years later, at the age of 33, she was hospitalized with subacute right hemiparesis and MRI disclosed multiple T2 hyperintensities in the white matter, one of them in the left midbrain showing contrast enhancement. Serum and CSF NMDAR antibodies were positive while MOG and AQP4 antibodies were negative. Intravenous methylprednisolone led to complete recovery. This case report provides evidence of a long-term persistence of NMDAR antibodies even 15 years after the encephalitis and raises the suspicion of a possible causal relationship between NMDAR antibodies and demyelinating disorders in the form of multiple sclerosis.

Diagnosis and treatment of limbic encephalitis in the cancer patient

Limbic encephalitis is an inflammatory process involving the limbic structures of the brain, manifested with short-term memory deficits, confusion, depression and seizures. It is usually a paraneoplastic condition but it may also appear as a nonparaneoplastic syndrome. Patients with this condition may exhibit a variety of antibodies in their serum or/and cerebrospinal fluid targeting basement membrane components that bind to a variety of neurotransmitter receptors such as α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid and GABA B and proteins associated to the ion channels such as LGI1, Caspr2 or intracellular components. Flurodeoxyglucose PET/computed tomography usually demonstrates increased uptake in the limbic structures, and it may reveal the site of the primary tumor. Treatment consists of tumor removal if possible. Symptomatic treatment includes steroids, gamma immune globulin, plasma exchange, immunosuppressive therapies and anti-epileptic drugs. Prognosis is better when it is associated with antibodies against basement membrane rather than intracellular antibodies.

Clinically based score predicting cryptogenic NORSE at the early stage of status epilepticus

Objective

To determine whether a clinically based score predicts cryptogenic new-onset refractory status epilepticus (C-NORSE) at the early stage of status epilepticus (SE) with prominent motor symptoms (SE-M) of unclear etiology.

Methods

The score (range 0–6) included 6 clinical features: highly refractoriness to antiseizure drugs, previously healthy individual, presence of prodromal fever, absence of prodromal psychobehavioral or memory alterations, absence of dyskinesias, and symmetric brain MRI abnormalities (the first 2 mandatory). We retrospectively assessed the usefulness of a high scale score (≥5) in predicting C-NORSE in 83 patients with SE-M of unclear etiology, who underwent testing for neuronal surface antibodies (NS-Abs) between January 2007, and December 2019.

Results

Thirty-one (37.3%) patients had a high score. Patients with a high score had more frequent prodromal fever (28/31 vs 24/52), mechanical ventilatory support (31/31 vs 36/52), and symmetric MRI abnormalities (26/31 vs 12/52), had less frequent involuntary movements (2/31 vs 30/52), and had absent prodromal psychobehavioral alterations (0/31 vs 27/52), CSF oligoclonal band detection (0/27 vs 11/38), tumor association (0/31 vs 13/52), or NS-Abs (0/31 vs 29/52) than those with a low score (<5). Thirty-three patients (median age, 27 years; 18 [54.5%] female) were finally regarded as C-NORSE. The sensitivity and specificity of a high score for predicting C-NORSE were 93.9% (95% CI 0.87–0.94) and 100% (95% CI 0.95–1.00), respectively.

Conclusions

Patients with a high score in the indicated scale are more likely to have C-NORSE, making it a useful diagnostic tool at the early stage of SE-M before antibody test results become available.

[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.

Clinical characteristics of children and adults with anti-N-methyl-D-aspartate receptor encephalitis

OBJECTIVES

To investigate the clinical characteristics of children and adults with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis.

METHODS

Patients who tested positive for the anti-NMDAR antibody (by a cell-based assay) in the cerebrospinal fluid were enrolled. They were divided into two groups based on age (<16 years or older).

RESULTS

Three children (two males and one female) and four adults (one male and three females) were examined. The age at onset was 3.0 ± 1.41 years (range: 2-5 years) for the children and 31.8 ± 6.80 years (range: 20-36 years) for the adults. The follow-up duration was 82.7 ± 23.80 months (range: 52-110 months) for the children and 61.5 ± 12.54 months (range: 43-78 months) for the adults. Prodromal symptoms such as fever and headache were observed in three adults. Two children received influenza vaccination before the onset of encephalitis. Brain magnetic resonance imaging abnormalities were observed in three children and one adult. Basal ganglia lesions were observed in two children and one adult, and the two children showed dystonia. Two children and one adult without neoplasms experienced recurrences. The modified Rankin Scale scores at the final follow-up tended to be worse in children than in adults.

CONCLUSION

Three patients had basal ganglia lesions, and two of them showed dystonia. Dystonia with basal ganglia lesions has been rarely reported in anti-NMDAR encephalitis but should be noted as a significant symptom, which severely affects the activities of daily life.

Olanzapine and Lorazepam Used in the Symptomatic Management of Excited Catatonia Secondary to Anti-N-Methyl-D-Aspartate Receptor Encephalitis

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis has become one of the more well-known autoimmune diseases affecting the brain and it is characterized by a multitude of progressive neuropsychiatric symptoms. The following case describes the clinical course of an 18-year-old female with excited type catatonia secondary to anti-NMDA receptor encephalitis. The patient had been brought to the ED by her parents in an acutely psychotic state characterized by profound disorganization and vivid visual hallucinations. She was admitted to psychiatry and her hospital course was significant for both retarded and excited type catatonia, autonomic instability, and sensitivity to multiple neuroleptics. Given the atypicality of her symptoms and a family history of autoimmune disease, workup for autoimmune encephalitis was performed. MRI of the pelvis showed an indeterminate ovarian mass and laboratory studies were generally unremarkable. The catatonic symptoms resolved over the course of three weeks, eventually responding to a combination of lorazepam and olanzapine. Following discharge, a cerebrospinal fluid (CSF) panel resulted with positive titers for anti-NMDA receptor antibodies. This case illustrates the need to consider autoimmune encephalitis in cases of catatonia. It also presents a case in which symptoms of anti-NMDA receptor encephalitis potentially remitted without immunotherapy or mass resection.