Clinical experience and laboratory investigations in patients with anti-NMDAR encephalitis

Cognitive outcomes and performance of patients diagnosed and treated for N-Methyl-D-Aspartate receptor antibody-mediated (NMDAR) encephalitis compared with patients with schizophrenia and healthy controls

BACKGROUND

Cognitive dysfunction may be a sequelae of N-Methyl-D-Aspartate receptor encephalitis (NMDAR encephalitis) with working memory commonly affected. This study examined cognitive outcomes in patients treated for NMDAR encephalitis using a neurocognitive test battery and a working memory paradigm, compared with healthy controls & patients with schizophrenia.

METHODS

Adult patients previously treated for NMDAR encephalitis were assessed using the Cambridge Automated Neuropsychological Test Battery (CANTAB) for working memory & episodic memory. Patients completed the N-back task during functional MRI (fMRI) scanning. Results were compared to patients with schizophrenia and healthy controls from a prior study.

RESULTS

Twelve patients were recruited [11 women; mean (SD) age 37(12) years; Mean (SD) duration until immunotherapy treatment 7.09 (2.43) weeks]. Data were compared to 14 patients with schizophrenia [10 women; mean (SD) age 39 (12) years] and 14 healthy controls [7 women; mean (SD) age 30 (6) years]. Significant differences in letter number sequencing, spatial working memory, logical memory I, 1-back, and 2-back performance were observed (Cohen's d = 0.766 to 1.254, p< 0.05), driven by poorer performance by patients with schizophrenia. While patients with NMDAR encephalitis exhibited slightly lower performance compared with healthy controls, none of these differences were statistically significant. No significant differences in neural activation during 1-back or 2-back performance were observed.

CONCLUSIONS

Study findings suggest cognitive performance in patients treated for NMDAR encephalitis approaches normal over time. Prompt treatment with immunotherapy is associated with improved cognitive outcomes. Psychiatric services should be aware of the clinical features of autoimmune encephalitis.

Abnormal Brain MRI in Anti-NMDA Receptor Encephalitis: Clinical and Prognostic Implications

BACKGROUND AND OBJECTIVES

Abnormal brain MRI is associated with poor outcomes in anti-N-methyl-d-aspartate receptor encephalitis (NMDARE). We aimed to characterize the lesions on brain MRI in NMDARE and to assess the clinical and prognostic associations.

METHODS

This retrospective cohort study included patients with NMDARE identified at the French Reference Center for Autoimmune Encephalitis, with at least a one-year follow-up, and with available brain MRI results. In case of brain extralimbic lesion, the image files were reviewed when available. Clinical data were collected from medical records. Multivariable logistic regression analysis was used to study the outcomes at 2-year follow-up; recovery was defined as modified Rankin Scale score ≤1.

RESULTS

Among the 255 patients included, 37 (14.5%) had limbic hyperintensities and 41 (16.1%) had extralimbic lesions that included multiple sclerosis (MS)-like lesions (14/41, 34.1%); extensive lesions (5/41, 12.2%); and poorly demarcated fluffy lesions, either multifocal (10/41, 24.4%) or involving the cerebral cortex or cerebellum (6/41 each, 14.6%). Extralimbic lesions coexisting with limbic lesions (19/41 patients, 46.3%) were mostly fluffy lesions (11/19, 57.9%). Ten patients had overlapping demyelinating syndromes: 4 with MS, 4 with myelin oligodendrocyte glycoprotein-associated disorder, and 2 with neuromyelitis optica spectrum disorder; all had MS-like (7/10 patients) or extensive (3/10 patients) lesions, and none had fluffy lesions. Extralimbic lesions were associated with symptoms nontypical for NMDARE (23/41, 56.1%, p < 0.001), especially cerebellar ataxia (17/41, 41.5%) and motor impairment (12/41, 29.3%). At 2 years, patients with MS-like or extensive lesions had a lower recovery rate (5/12, 41.7%, and 1/4, 25%, respectively) compared with the patients without extralimbic lesions (124/162, 76.5%; p = 0.014 and p = 0.047, respectively). In multivariable analysis, MS-like lesions, but not hippocampal nor fluffy lesions, were associated with absence of recovery at 2 years (adjusted OR 0.1, 95% CI 0.03-0.42, p = 0.002; extensive lesions [n = 4] not included in the analysis).

DISCUSSION

Brain MRI lesions in NMDARE include limbic hyperintensities and 3 patterns of extralimbic lesions, which are associated with nontypical NMDARE symptoms. Moreover, MS-like and extensive lesions, but not fluffy nor hippocampal lesions, are associated with overlapping demyelinating syndromes and poor clinical outcomes at 2 years. These findings can have practical implications on the monitoring of patients with NMDARE.

Clinical and imaging features and treatment response of anti-NMDAR encephalitis combined with MOGAD

BACKGROUND

To investigate the clinical, imaging features, immunotherapy of anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) combined with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD).

METHODS

A total of 124 patients with NMDARE and 86 patients with MOGAD were screened from an ongoing prospective cohort study (Clinical and Imaging Patterns of Neuroinflammation Diseases in China, CLUE). Ten NMDARE combined with MOGAD patients, were finally enrolled in this study. Clinical and imaging data and follow-up results characteristics were collected and analyzed.

RESULTS

In these 10 patients with NMDARE combined with MOGAD, 7 patients (70 %) showed recurrent courses. In all 26 episodes, 14 episodes (53.8 %) showed encephalitis-related symptoms, 6 episodes (23.1 %) showed demyelination-related symptoms, 6 episodes (23.1 %) showed both. The median CSF leukocytes were 13/μL (range 1-413) and the median protein was 0.43 g/L (range 0.22-0.70). MRI lesions were found involving the optic nerve (2/10), spinal cord (3/10), deep gray matter (3/10), cortex (6/10), subcortex (7/10), brainstem (5/10) and cerebellum (4/10). Leptomeningeal enhancement was found in 3 patients. All patients received high-dose intravenous methylprednisolone and immunoglobulin therapy during attacks. Seven patients received rituximab (RTX). The median annualized recurrence rate (ARR) reduced significantly following RTX treatments (z = -2.201, p = 0.028), and achieved good outcomes at the last follow-up visit (modified Rankin scale score ≤ 2).

CONCLUSION

NMDARE combined with MOGAD represents a unique characteristic of autoantibody-mediated encephalitis. Coexistence of NMDAR and MOG antibody may indicate high recurrence risk. RTX may be a relatively efficient therapeutic option.

GTE score on evaluating the degree of neurological impairment in anti-NMDA receptor encephalitis

This study mainly analyzed the EEG changes and the development of neurological impairment at different stages of the disease, and explored the clinical role of the Grand Total EEG score (GTE score) in evaluating the degree of neurological impairment function damage in anti-NMDA receptor encephalitis. The GTE scores of patients with anti-NMDA receptor encephalitis at different disease stages and the diagnostic validity of the GTE scores for evaluating the degree of neurological impairment were analyzed. 153 EEG cases were included in this study, with a course of 2 to 960 days. The abnormal EEG rates were 92% in the acute phase, 83% in the recovery phase, 76% in the short-term prognosis phase, and 30% in the long-term prognosis phase. The GTE score: acute phase=(5, 0-15); recovery phase=(2, 0-14); short-term prognosis phase= (2, 0-9); long-term prognosis phase = (0, 0-6). When the total GTE score is 5.5, the patient was more likely to have moderate to severe neurological impairment (mRS = 4), with sensitivity and specificity > 0.9. When the total GTE score was 7.5, the patient was more likely to have severe neurological impairment (mRS = 5), with sensitivity and specificity > 0.9. GTE score has a high diagnostic efficacy for the rating of neurological impairment. The total GTE score was superior to the assessment of neurological damage degree solely from background activity frequency or diffuse slow wave activity.

Neuroimmunology and Sleep

The immune system and sleep are inextricably linked in both health and pathological conditions. Tightly regulated neuroimmune processes are critical for the physiological maintenance of healthy sleep. Reciprocally, sleep disturbances can detrimentally affect immune homeostasis and predispose to increased risk of autoimmune conditions, which themselves are bidirectionally associated with a higher risk of sleep disturbances. Autoimmune diseases of the central nervous system (CNS), particularly conditions that affect neuroanatomical regions involved in sleep homeostasis and nocturnal respiration, are associated with an increased risk sleep disorders that may impact diagnosis, clinical course, and management. This review summarizes the bidirectional relationship between sleep and immunity and highlights several exemplar autoimmune conditions of the CNS that include sleep disorders as a consequence or diagnostic feature of the disorder.

A case report of NMDAR encephalopathy - A neurologic condition that a gynecologist can cure

INTRODUCTION AND IMPORTANCE

Anti-NMDA receptor encephalitis is a rare autoimmune cause of acute psychosis in young women, often associated with ovarian teratomas. Surgical removal of the teratoma is a critical component of treatment.

CASE PRESENTATION

A previously healthy woman was brought to the emergency department with acute psychosis, characterized by alternating episodes of catatonia and mania, regressive speech, and inappropriate behaviors such as disrobing. Despite treatment with antipsychotic medications at a psychiatric facility, her symptoms did not improve, prompting transfer to our institution. Neurological examination was non-focal, and laboratory results were unremarkable. Cerebrospinal fluid analysis showed no signs of infection, but anti-NMDA antibodies were detected. Gynecology was consulted, and a pelvic ultrasound was initially negative. However, pelvic MRI revealed an area of macroscopic fat in the left ovary, suggesting a teratoma. The patient underwent laparoscopic left salpingo-oophorectomy. Gross examination of the ovary appeared normal, but histological analysis confirmed the presence of a benign teratoma with ganglion cells and chronic inflammation. The diagnosis of anti-NMDA receptor encephalitis was confirmed. Postoperatively, the patient's mental status improved significantly, and she was discharged home.

CLINICAL DISCUSSION

This case illustrates the clinical, radiologic, and histopathologic features of the disease and underscores the importance of MRI in detecting ovarian teratomas when pelvic ultrasound is inconclusive.

CONCLUSION

Timely gynecologic intervention can be curative in these patients.

Encephalitis: intersections between infections and autoimmunity

BACKGROUND

Encephalitis is a serious condition accompanied by substantial morbidity. Although infections have long been recognized as causes, there has been growing appreciation of autoimmune aetiologies of encephalitis, most notably those associated with anti-neuronal antibodies.

OBJECTIVES

This narrative review focuses on points of commonality among clinical features, pathophysiology, and management of infectious and autoimmune encephalitis, while also noting important distinctions.

SOURCES

I identified studies, comprising research articles and reviews, that provide data on the epidemiology of infectious versus autoimmune encephalitis, and on clinical features that either co-occur or distinguish between them. In addition, I reviewed management practices, preclinical data, and clinical trials on the treatment of infectious and autoimmune encephalitis.

CONTENT

I first discuss the clinical overlap between infectious and autoimmune causes of encephalitis, highlighting features and syndromes that can confound the diagnosis. I next turn to the pathogenic overlap between the two, exemplified by the development of autoimmune encephalitis with antibodies against the N-methyl-D-aspartate receptor following a bout of herpes simplex encephalitis. Finally, I discuss management of infectious and autoimmune encephalitis, focusing on current and future avenues of treatment.

IMPLICATIONS

Although our understanding of causes of infectious and autoimmune encephalitis has improved considerably over the past decade, diagnosis remains challenging given the clinical and pathophysiological overlap between the two. Large multicentre clinical trials are needed to evaluate treatments that target inflammation and potentially benefit both.

Anti-N-methyl-d-aspartate Receptor Encephalitis Caused by a Teratoma Arising From the Retroperitoneum

Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is an autoimmune encephalitis, and 46% of women with anti-NMDAR encephalitis have tumors, of which 94% are ovarian teratomas. Patients with anti-NMDAR encephalitis rarely have extra-ovarian teratomas, particularly extra-ovarian mature cystic teratomas arising from the retroperitoneum. We herein report a 27-year-old woman who was diagnosed with anti-NMDAR encephalitis caused by a teratoma arising from the retroperitoneum. In patients with anti-NMDAR encephalitis, it is important to perform a systemic search, including for extra-ovarian teratomas. Plasma exchange significantly improved the patient's clinical symptoms.

Interference between immune cells and insomnia: a bibliometric analysis from 2000 to 2023

Background

Insomnia is a widespread sleep disorder that significantly affects the quality of life and contributes to immune dysfunction, which in turn leads to chronic diseases. Despite extensive research on sleep disturbances and immune modulation, the relationship between insomnia and immune responses remains underexplored.

Objectives

The primary objective of this study was to conduct a bibliometric analysis to explore the interaction between immune cells and insomnia, identifying key immune responses involved and their potential roles in the development of insomnia and associated comorbidities.

Methods

A bibliometric analysis was conducted using data from the Web of Science Core Collection (WoSCC), focusing on research articles published between 2000 and 2023. The analysis aimed to identify trends, key research areas, and the role of immune system cells (T cells, B cells, NK cells, etc.) in insomnia.

Results

The analysis revealed that various immune cells, including T cells, B cells, NK cells, neutrophils, and monocytes, play crucial roles in insomnia pathogenesis. These immune cells contribute to immune modulation and inflammatory responses, which are linked to sleep disturbances. The study also identified that insomnia is closely associated with comorbidities such as cardiovascular diseases, obesity, depression, and cancer, all of which involve immune dysfunction. The regulation of the immune system was found to be a key factor in improving sleep quality.

Conclusion

This study provides valuable insights into the complex interaction between the immune system and insomnia. The findings underscore the importance of immune regulation in the treatment of insomnia, suggesting that future research should focus on integrating immune modulation into therapeutic strategies for insomnia. Further studies are needed to explore targeted therapies for immune-related insomnia and its comorbidities, emphasizing interdisciplinary research in this area.

Intrathecal treatment of Anti-N-Methyl-D-Aspartate receptor encephalitis: a promising approach for refractory cases

BACKGROUND

Anti-N-methyl-D-aspartate receptor encephalitis is a severe neurological disorder. While standard treatments work for many patients, up to 25% are resistant to these treatments. In such challenging cases, there is growing interest in using intrathecal approaches.

METHODS

A narrative review of relevant papers was conducted.

RESULTS

Case reports and case series have demonstrated the successful use of intrathecal methotrexate, either alone or in combination with steroids, particularly in pediatric patients. Additionally, intrathecal rituximab has shown promise in select cases.

CONCLUSIONS

Although outcomes vary, this approach appears to be safe and has the potential to rescue refractory cases.

Current state and perspectives of CAR T cell therapy in central nervous system diseases

B cell-directed CAR T cell therapy has fundamentally changed the treatment of haematological malignancies, and its scope of application is rapidly expanding to include other diseases such as solid tumours or autoimmune disorders. Therapy-refractoriness remains an important challenge in various inflammatory and non-inflammatory disorders of the CNS. The reasons for therapy failure are diverse and include the limited access current therapies have to the CNS, as well as enormous inter- and intra-individual disease heterogeneity. The tissue-penetrating properties of CAR T cells make them a promising option for overcoming this problem and tackling pathologies directly within the CNS. First application of B cell-directed CAR T cells in neuromyelitis optica spectrum disorder and multiple sclerosis patients has recently revealed promising outcomes, expanding the potential of CAR T cell therapy to encompass CNS diseases. Additionally, the optimization of CAR T cells for the therapy of gliomas is a growing field. As a further prospect, preclinical data reveal the potential benefits of CAR T cell therapy in the treatment of primary neurodegenerative diseases such as Alzheimer's disease. Considering the biotechnological optimizations in the field of T cell engineering, such as extension to target different antigens or variation of the modified T cell subtype, new and promising fields of CAR T cell application are rapidly opening up. These innovations offer the potential to address the complex pathophysiological properties of CNS diseases. To use CAR T cell therapy optimally to treat CNS diseases in the future while minimizing therapy risks, further mechanistic research and prospective controlled trials are needed to assess seriously the disease and patient-specific risk-benefit ratio.

Machine learning for the early prediction of long-term cognitive outcome in autoimmune encephalitis

BACKGROUND AND OBJECTIVE

Autoimmune encephalitis (AE) is an immune-mediated disease. Some patients experience persistent cognitive deficits despite receiving immunotherapy. We aimed to develop a prediction model for long-term cognitive outcomes in patients with AE.

METHOD

In this multicenter cohort study, a total of 341 patients with AE were enrolled from February 2014 to July 2023. Cognitive impairment was identified using the telephone Mini-Mental State Examination (t-MMSE). Six machine learning (ML) algorithms were used to assess the risk of developing cognitive impairment.

RESULTS

The median age of the patients with AE was 30.0 years (23.0-48.25), and 48.90 % (129/264) were female in the training cohort.77 (29.2 %) patients were identified with cognitive impairment after a median follow-up of 49 months. Among 16 features, the following six features were finally selected to develop the model: Cognitive Reserve Questionnaire (CRQ), Clinical Assessment Scale for Autoimmune Encephalitis (CASE), status epilepticus (SE), age, MRI abnormalities, and delayed immunotherapy. Compared to other ML models, the random forest (RF) model demonstrated superior performance with an AUC of 0.90. The accuracy, sensitivity, and specificity in the testing cohort were 0.87, 0.79, and 0.90, respectively.

CONCLUSION

The RF model based on CRQ, CASE scores, SE, age, MRI abnormalities and delayed immunotherapy demonstrates superior predictive performance and shows promise in predicting the risk of long-term cognitive outcomes in patients with AE in clinical settings.

Autoimmune Encephalitis

Autoimmune encephalitides (AE) constitute a broad group of inflammatory brain disorders characterized by prominent neuropsychiatric symptoms, frequently in association with autoantibodies against neural (neuronal or glial) antigens. The most frequent AE are anti-NMDA receptor encephalitis, acute disseminated encephalomyelitis (associated with MOG antibodies in 60% of patients), and limbic encephalitis (with several immunologic subtypes, anti-LGI1 encephalitis being the most frequent). The first 2 predominantly affect children and young adults, whereas limbic encephalitis usually affects patients older than 50 years. Despite the severity of symptoms, prompt diagnosis and treatment lead to substantial recovery in most patients.

Autoimmune dementia

PURPOSE OF REVIEW

The aim of this review is to summarize clinical, radiological and laboratory findings in autoimmune dementia, to help clinicians in promptly identify this elusive condition.

RECENT FINDINGS

The rapid advances in the field of autoimmune neurology have led to the discovery of novel antibodies and associated disorders, which are more frequent than previously hypothesized. The correct and prompt identification of cognitive decline of autoimmune origin is vital to ensure early treatment and better outcomes. The diagnosis of autoimmune dementia relies on specific clinical and radiological features and on the detection of specific autoantibodies. Autoantibody specificities predict response to treatment and the occurrence of cancer. In recent years, the differential diagnosis of autoimmune dementia has become more relevant, as the overinterpretation of antibody results, clinical and radiological findings may lead to an erroneous diagnosis of autoimmune dementia, with potential harm to patients due to inappropriate exposure to immunosuppressants.

SUMMARY

Autoimmune dementia is a potentially treatable condition and should not be missed in clinical practice given the potential for reversibility with immunotherapy. The diagnosis of autoimmune dementia relies on a comprehensive review of clinical, radiological and laboratory data, and exclusion of other causes of dementia.

Long-term maintenance of mycophenolate mofetil in anti-NMDA receptor encephalitis (LEARN): a multicentre, open-label, blinded-endpoint, randomised controlled trial

BACKGROUND

Anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) is a severe autoimmune disorder with high morbidity and mortality. Current treatments have limitations including relapse, highlighting the need for effective maintenance therapy. This study evaluates the efficacy and safety of mycophenolate mofetil (MMF) as long-term adjunctive therapy to first-line treatment in newly diagnosed patients with NMDARE.

METHODS

We conducted a prospective, randomised, open-label trial in four academic centres in China. Patients aged 14 and older with acute NMDARE, who received first-line treatments within 2 weeks of presentation to the hospital and had a modified Rankin scale (mRS) score of 2 or more, were recruited. Participants were randomly assigned to receive first-line treatment with or without MMF (0.5 g two times per day for 24 months). Primary outcomes included relapse rates and time to relapse, with secondary outcomes including cognitive deficits, treatment response (the proportion of patients with≥1 point improvement in mRS within 4 weeks) and adverse events (AEs).

RESULTS

Of 100 patients (52% female; median age 27), those in the MMF group had fewer relapses (5.9% vs 26.5%; p=0.006) and better treatment response (84.3% vs 65.3%; p=0.03). No significant difference was found in long-term functional prognosis at 12 and 24 months. However, MMF patients had less fatigue, cognitive impairment, depression and seizures. AEs were mild-to-moderate, with no deaths or anaphylactic reactions.

CONCLUSIONS

This study provides Class II evidence that long-term adjunctive treatment of MMF to first-line treatment of NMDARE resulted in a lower risk of relapse and was well tolerated beyond the 24 months of treatment.

TRIAL REGISTRATION NUMBER

ChiCTR2100044362.

Anti-metabotropic glutamate receptor 5 coexistent anti-N-methyl-D-aspartate receptor encephalitis: a case report and literature review

Metabotropic glutamate receptor 5 (mGluR5) antibody encephalitis is an infrequent clinical disorder, initially reported in 2011 among two patients presenting with limbic encephalitis and Hodgkin's lymphoma. Mental and behavioral abnormalities are prevalent manifestations, accompanied by cognitive impairment, movement disorders, seizures, and other associated symptoms. In this report, we present the case of a young female patient who presented with abnormal mental behavior, seizures, and disturbances of consciousness. A cell-based assay (CBA) showed positive IgG metabotropic glutamate receptor 5 in both her serum and cerebrospinal fluid (CSF), as well as positive IgG N-methyl-D-aspartate receptor (NMDAR) in both her serum and CSF. She was diagnosed with mGluR5 overlapping NMDAR antibody encephalitis and received high-dose intravenous methylprednisolone pulse therapy and immunoglobulin therapy. Tumor screening suggested the presence of bilateral ovarian teratoma. However, unfortunately the prognosis was extremely poor. Clinical results suggested that patients with mGluR5-Abs mostly have good prognoses, excepting our case.

Successful sequential therapy with rituximab and telitacicept in refractory Anti-NMDA receptor encephalitis and MOG-associated demyelination: a case report and literature review

Clinical management of the rare and complex overlapping syndrome of MOG-antibody disease and anti-NMDAR encephalitis (MNOS), which has an uncertain pathogenesis and a high risk of recurrence, is highly challenging. We describe the case of a 19 years-old female patient, who first complained of headache, fever, and irritability. After that, she experienced frequent seizures and mood disorders. The diagnosis of MNOS was verified through antibody tests and imaging. For the patient, intravenous immunoglobulin and high-dose methylprednisolone were effective as first-line immunotherapy. Long-term immunotherapy with oral prednisone and mycophenolate mofetil was used to prevent relapses. However, over six years, the patient had five relapses when the mycophenolate mofetil dosage was reduced. The patient's condition stabilized after taking rituximab as second-line immunotherapy, with less than 1% of total lymphocytes being CD19+ cells. Eleven months later, the plasmablast ratio increased, and patients experienced new symptoms such as bilateral optic neuritis. After that, the patient got telitacicept injections regularly for 13 months, during which time her symptoms subsided, and there were no adverse effects or relapses. This case suggests that telitacicept may be a viable adjunct or sequential therapy option for the depletion of B cells in MNOS.

Diagnostic testing in psychiatry: insights and examples from a Bayesian perspective

OBJECTIVE

To demonstrate the application of Bayes' theorem to diagnostic testing in clinical settings, especially with respect to rare diseases, enhancing an understanding of pre-test probability and its implications.

CONCLUSION

Bayes' theorem enables the revision of the conditional probabilities of an event occurring when new information is acquired. It demonstrates that when the prevalence of a disease is very low, there are a high number of false positives, thereby reducing the clinical utility and cost benefit profile of the diagnostic test, even in the presence of relatively high sensitivities and specificities of the chosen test.

A Case of Anti-N-Methyl-D-Aspartate Receptor (NMDAR) Encephalitis With Video-Documented Psychogenic Nonepileptic Seizures (PNES)-Mimicking Episodes Initially Considered as Somatic Symptom Disorder

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune disorder characterized by psychiatric symptoms, seizures, and dyskinesias. This case report describes a 30-year-old woman who was initially suspected of having a somatic symptom disorder because of the development of seizures mimicking psychogenic non-epileptic seizures (PNES). At presentation, she was able to engage in conversation and follow instructions, but exhibited slight fever, sensory abnormalities, and non-stereotypical seizures. Over the course of two weeks, she fell into a catatonic stupor. Cerebrospinal fluid (CSF) analysis revealed only mild pleocytosis with CSF-restricted oligoclonal bands. Electroencephalogram, which was unremarkable at presentation, subsequently showed an extreme delta brush pattern. NMDAR antibodies were detected in CSF with two independent assays, confirming the diagnosis of anti-NMDAR encephalitis. First-line immunotherapy with steroids, plasma exchange, and immunoglobulins was ineffective, but second-line immunotherapy with cyclophosphamide led to improvement. This case underscores the importance of considering anti-NMDAR encephalitis in patients with PNES-mimicking episodes, which can be misleading and delay appropriate diagnosis and treatment.

Chaihu Guizhi Decoction prevents cognitive, memory impairments and sensorimotor gating deficit induced by N-methyl-d-aspartate receptor antibody in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Anti-NMDAR encephalitis is one of the most common types of autoimmune encephalitis, primarily presenting with prodromal symptoms, such as fever and headache, followed by a range of neurological and psychiatric symptoms. Chaihu Guizhi Decoction (CGD), a traditional Chinese medicine formulated by Zhang Zhongjing in the Eastern Han Dynasty, has been effectively used in clinical practice to treat the symptoms of Taiyang and Shaoyang disorders, including fever, headache, and psychiatric disorders.

AIM OF THE STUDY

To demonstrate the protective effects of CGD in an animal model of anti-NMDAR encephalitis and explore the potential mechanisms involved.

MATERIALS AND METHODS

UHPLC-HRMS was used to identify CGD's chemical components and serum metabolomic profiles. Network pharmacology and molecular docking were performed to predict potential targets of CGD for the treatment of anti-NMDAR encephalitis. The effect of CGD on anti-NMDAR encephalitis was evaluated using a mouse model induced by patients' antibodies. Behavioral tests were performed to assess cognitive impairment and schizophrenia-like behaviors. The effect of CGD on the cell-surface NMDAR GluN1 subunit in cultured neurons treated with patient antibodies was detected by immunofluorescence. Golgi staining was used to observe morphological changes in hippocampal dendrites. The expression of NMDAR-interacting proteins and various neuroreceptors in the hippocampus were examined to validate the targets predicted using network pharmacology and molecular docking.

RESULTS

CGD alleviated cognitive, memory, and sensorimotor gating deficits in mice treated with anti-NMDAR encephalitis patients' antibodies. Further experiments demonstrated the effect of CGD in preventing NMDAR reduction both in vitro and in vivo. Meanwhile, CGD regulated NMDAR-interacting proteins and dopamine receptors but did not affect hippocampal dendritic morphology and synaptic density. Additionally, CGD modifies metabolic pathways associated with anti-NMDAR encephalitis and other neurological and psychiatric disorders.

CONCLUSIONS

CGD exhibited protective effects against anti-NMDAR encephalitis by mitigating the antibody-induced reduction in NMDAR and NMDAR-interacting proteins.

Successful treatment with efgartigimod as an add-on therapy for acute attack of anti-NMDA receptor encephalitis: a case report

BACKGROUND

Anti-NMDA receptor encephalitis is an autoimmune, antibody-mediated inflammatory disease of the brain characterized by the presence of IgG antibodies targeting the excitatory N-methyl-D-aspartate receptor (NMDAR). Previous research has established that the neonatal Fc receptor (FcRn) regulates the transport and circulation of immunoglobulins (IgG). Efgartigimod, an FcRn antagonist, has been shown to enhance patient outcomes by promoting IgG clearance, and it has exhibited substantial clinical efficacy and tolerability in the treatment of myasthenia gravis. Efgartigimod has demonstrated potential efficacy in the treatment of various IgG-mediated autoimmune diseases. Nonetheless, to date, no studies have investigated the use of efgartigimod in the treatment of anti-NMDAR encephalitis.

CASE PRESENTATION

We present a case of a 42-year-old male patient diagnosed with anti-NMDAR encephalitis, initially treated with intravenous methylprednisolone(IVMP) and human immunoglobulin (IVIG) without clinical improvement. Subsequent administration of efgartigimod resulted in rapid clinical improvement; however, the patient experienced a relapse upon discontinuation of efgartigimod. Reintroduction of efgartigimod led to rapid and significant clinical improvement, accompanied by a marked decrease in anti-NMDAR antibodies and serum IgG levels in both serum and cerebrospinal fluid. The patient remained relapse-free during a 2-month follow-up period.

CONCLUSION

This case demonstrates that efgartigimod is a potentially rapid and effective therapy for the treatment of the acute phase of anti-NMDAR encephalitis.

Anti-NMDA Receptor Encephalitis, Human Papillomavirus, and microRNA

BACKGROUND

Anti-N-methyl-d-aspartate (Anti-NMDA) receptor encephalitis is a rare autoimmune disease, which is caused by antibodies attacking NMDA receptors in the brain. Previous studies revealed that this disorder might be induced by vaccination. Vaccination is the most useful strategy to prevent human or animal infectious diseases. Although vaccines can produce immunity against diseases, at low risk, they may trigger serious adverse events. Anti-NMDA receptor encephalitis has been studied to be related to the H1N1 (influenza A virus subtype H1N1), tetanus/diphtheria/pertussis and polio vaccine, Japanese encephalitis, yellow fever, and coronavirus disease 2019 (COVID-19) vaccination. Several cases have been reported that anti-NMDA receptor encephalitis could also be triggered by the human papillomavirus (HPV) vaccine. However, there is a lack of studies to investigate the underlying mechanism.

METHODS

In this paper, the association between anti-NMDA receptor encephalitis and HPV vaccination is discussed in terms of their microRNA (miRNA) biomarkers. Phylogenetic tree and distance similarity analyses are used to explore the relationship between their miRNA biomarkers.

RESULTS

The results show a higher degree of similarity between miRNA biomarkers associated with HPV and anti-NMDA receptor encephalitis or related vaccines when compared to the overall miRNAs. It indicates that while the risk of HPV triggering anti-NMDA receptor encephalitis is low, a connection between anti-NMDA receptor encephalitis and HPV vaccination cannot be ruled out.

CONCLUSION

This finding suggests that in cases where individuals receiving HPV vaccination experience psychiatric or neurological symptoms, it should be considered to diagnose anti-NMDA receptor encephalitis, given the exclusion of other possible complications.

Evidence-based diagnostic prediction score for pediatric NMDA receptor encephalitis

OBJECTIVE

Early diagnosis and treatment of anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) are crucial for a favorable prognosis. Detecting the causative autoantibodies can be challenging. Probable diagnostic criteria are useful in adults less so in children. We aimed to develop a novel diagnostic score for pediatric NMDARE using cohort data.

METHODS

We retrospectively analyzed pediatric participants (0-18 years) with suspected autoimmune encephalitis who underwent cerebrospinal fluid analysis for antineuronal antibodies (Abs) between January 2015 and March 2023. Clinical data, including symptoms and laboratory findings, were analyzed. Symptoms were selected through univariate analysis and then analyzed with multivariate logistic regression model. Resulting odds ratios were used to calculate scores. Scoring systems were developed and evaluated with five-fold validation and univariate logistic regression. One scoring system was selected to create a diagnostic prediction score for pediatric NMDARE.

RESULTS

Of the 504 patients, 264 met the inclusion criteria, and 39 tested positive for NMDAR Abs. Comparing clinical symptoms between cohorts and identified 15 variables significantly different (p < 0.05) to create a pediatric NMDARE prediction score. This score showed 82.1 % sensitivity and 82.2 % specificity, with an 8-point cutoff. The area under the curve was 0.888 (95 % confidence interval: 0.838-0.939). A five-fold cross-validation showed a sensitivity of 95.6 %, specificity of 71.4 %, and kappa coefficient of 0.670.

CONCLUSION

We developed a novel evidence-based diagnostic prediction score for pediatric NMDARE that incorporates specific clinical features and laboratory findings. This score may improve diagnostic accuracy and guide early therapy in children with suspected autoimmune encephalitis.

Disrupted callosal connectivity underlies long-lasting sensory-motor deficits in an NMDA receptor antibody encephalitis mouse model

N-methyl-d-aspartate (NMDA) receptor-mediated autoimmune encephalitis (NMDAR-AE) frequently results in persistent sensory-motor deficits, especially in children, yet the underlying mechanisms remain unclear. This study investigated the long-term effects of exposure to a patient-derived GluN1-specific mAb during a critical developmental period (from postnatal day 3 to day 12) in mice. We observed long-lasting sensory-motor deficits characteristic of NMDAR-AE, along with permanent changes in callosal axons within the primary somatosensory cortex (S1) in adulthood, including increased terminal branch complexity. This complexity was associated with paroxysmal recruitment of neurons in S1 in response to callosal stimulation. Particularly during complex motor tasks, mAb3-treated mice exhibited significantly reduced interhemispheric functional connectivity between S1 regions, consistent with pronounced sensory-motor behavioral deficits. These findings suggest that transient exposure to anti-GluN1 mAb during a critical developmental window may lead to irreversible morphological and functional changes in callosal axons, which could significantly impair sensory-motor integration and contribute to long-lasting sensory-motor deficits. Our study establishes a new model of NMDAR-AE and identifies novel cellular and network-level mechanisms underlying persistent sensory-motor deficits in this context. These insights lay the foundation for future research into molecular mechanisms and the development of targeted therapeutic interventions.

Autoimmune Encephalitis in Catatonic and Treatment-Resistant Psychotic Patients Referred to Electroconvulsive Therapy: Two Case Reports and Systematic Review

ABSTRACT

Autoimmune encephalitis (AE) tends to manifest as a mixture of neuropsychiatric and somatic symptoms, either of which may predominate, and often shows a progressive clinical course sometimes leading to life-threatening conditions. Catatonic and psychotic syndromes, regardless of whether associated with dysautonomia, are common manifestations of AE, especially concerning the anti-NMDAR subtype. Several autoantibodies targeting different neuronal epitopes have been linked to specific clinical manifestations and their detection is embedded in some of the diagnostic criteria for AE. Therapeutical management of AE is challenged by limited diagnostic abilities and poor understanding of the underlying pathophysiology for most of its subtypes. Although the prompt delivery of disease-modifying therapies represents the cornerstone of treatment and primarily affects prognosis, less is known about the role of symptom specific supportive measures like electroconvulsive therapy (ECT). Based on a systematic review of 26 patient-level descriptions of individuals, each with a diagnosis of AE treated with ECT, a favorable clinical response was found in more than ¾ of the revised cases (76.9%). The most common indications for ECT administration were catatonic and psychotic syndromes, often nonresponsive to prior pharmacotherapy with benzodiazepines, antipsychotic, and other psychotropic drugs. Noteworthy side effects were only reported for 3 of 26 patients. Though the low number of cases and publication bias should be considered as major limitations, current available reports are in support of the inclusion of ECT in the integrated therapeutic algorithm of AE to address psychiatric conditions such as severe psychosis and catatonia.

To analyze the efficacy and safety of plasma exchange in the treatment of anti-NMDA receptor encephalitis

INTRODUCTION

To investigate the clinical efficacy and safety of plasma exchange (PE) in the treatment of glucocorticoid-insensitive patients with serum anti-N-methyl-d-aspartate (anti-NMDA) receptor antibody-negative and serum anti-NMDA receptor antibody-positive encephalitis.

METHODS

The clinical data of 20 patients with anti-NMDA receptor antibody encephalitis treated between January 2015 and December 2022 were collected. The general information, clinical symptoms, auxiliary examination, treatment (hormone, PE, etc.), adverse reactions, clinical efficacy, and other related data were retrospectively compared and analyzed.

RESULTS

A total of 8 cases had adverse reactions (9.76%, 8/82), including 4 cases (4.88%, 4/82) of allergy and 2 cases (2.44%,2/82) of thrombocytopenia. In patients with anti-NMDA receptor antibody encephalitis who were not sensitive to glucocorticoids, the effective rate of PE was 80.0% (p = 0.0005).

CONCLUSION

PE combined with glucocorticoid is more effective than glucocorticoid alone in the treatment of anti-NMDA receptor antibody encephalitis patients with positive or negative anti-NMDA receptor antibodies. Most adverse reactions were mild and easy to manage. It does not cause obvious blood cell loss. PE is a safe and acceptable treatment. However, our study has limitations, and due to the small number of people and the fact that plasmapheresis was performed after glucocorticoid therapy, further prospective clinical studies are warranted.

The therapeutic effect of ofatumumab in pediatric anti-NMDAR encephalitis: A case series

Ofatumumab (OFA) is an anti-CD20 antibody. We assessed the therapeutic potential of OFA in five pediatric anti-NMDAR encephalitis patients who showed poor responses to the first-line immunotherapy. OFA treatment showed clinical improvement including alleviation of clinical symptoms and mRS decrease accompanied by anti-NMDAR antibody turning negative in 3 patients and decline in 2 patients. And all patients achieved B cell depletion after OFA treatment. During follow-up, all patients' symptoms were stable. OFA treatment is safe and effective, easy to administer, and favorable for pediatric anti-NMDAE encephalitis patients who are refractory to the first-line immunotherapy.

Kidney injury: An overlooked manifestation in autoimmune encephalitis

AIM

To investigate the prevalence and clinical features of kidney injury in patients with autoimmune encephalitis (AE).

METHODS

Kidney injury was suspected in kidney-involving group due to persistent abnormal in urinary protein and serum albumin. Data on demographics and clinical features were compared between kidney-involving group and kidney-sparing group (patients without kidney injury) using Wilcoxon rank-sum test or chi-square test. Renal biopsy was conducted to identify the type of kidney injury.

RESULTS

Approximate 30 % (32 of 108) patients with AE were suspicious of kidney injury. Nine patients further tested 24 h urine total protein, and seven of them had an elevated urine protein higher than 150 mg. The predominantly patterns of kidney injury were elevated urine protein, decreased serum albumin and normal kidney function. Compared to kidney-sparing group, the spectrum of AE antibodies in kidney-involving group was different, manifested as less anti-N-methyl-d-aspartate receptor antibodies (50 % vs. 72.4 %, p = 0.025) and more anti-contactin-associated protein like 2 antibodies (18.8 % vs. 1.3 %, p = 0.003). Definite pathological changes indicative of IgA nephropathy and membranous nephropathy in renal biopsy of two cases provided evidence of autoimmune attacks.

DISCUSSION

Kidney injury occurred in considerable proportion of patients with AE. An in-depth screening for nephropathy could be essential for AE.

Anti-NMDAR encephalitis presenting with persistent fever and meningitis and responding well to distinctive individualized first-line treatment: A case report

RATIONALE

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune encephalitis characterized by diverse neurological and psychiatric symptoms. It predominantly affects young women, particularly those with ovarian teratomas. However, cases without teratomas are also commonly reported, often exhibiting poorer treatment responses and higher relapse rates. Persistent fever and signs of meningitis are rare in such cases. Diagnosis is confirmed through the detection of anti-NMDAR antibodies.

PATIENT CONCERNS

A 15-year-old female presented with episodic loss of consciousness, fever, nuchal rigidity, limb convulsions, and psychiatric symptoms following a stressful exam period. Initial symptomatic treatments were ineffective.

DIAGNOSIS

The diagnosis of anti-NMDAR encephalitis was confirmed through lumbar puncture, brain imaging, and the detection of anti-NMDAR antibodies in cerebrospinal fluid and serum.

INTERVENTIONS

The patient received tailored first-line therapy, including high-dose methylprednisolone and 3 courses of intravenous immunoglobulin (IVIG).

OUTCOMES

The patient exhibited significant clinical improvement, with a reduction in seizure frequency and eventual complete seizure control. Body temperature normalized, and follow-up showed progressive recovery in cognitive and motor functions.

LESSONS

This case highlights the importance of early diagnosis and individualized treatment in anti-NMDAR encephalitis. Repeated IVIG courses proved effective, underscoring the need for personalized treatment plans in managing this condition. Persistent fever and signs of meningitis were rare and contributed to the diagnostic challenge, highlighting the clinical complexity of this case.

RESILIENCE (Retrospective Linkage Study of Autoimmune Encephalitis): protocol for an Australian retrospective cohort study of outcomes in autoimmune encephalitis using data linkage techniques

INTRODUCTION

The autoimmune encephalitides (AE) are a heterogeneous group of neurological disorders with significant morbidity and healthcare costs. Despite advancements in understanding their pathophysiology, uncertainties persist regarding long-term prognosis and optimal management. This study aims to address these gaps, focusing on immunotherapeutic strategies, neoplastic associations and functional outcomes.

METHODS AND ANALYSIS

The Retrospective Linkage Study of Autoimmune Encephalitis project will use data linkage techniques to establish a retrospective 10-year population cohort of Australian patients with AE. Two cohorts will be analysed, the Reference Cohort (clinically confirmed AE cases obtained from hospital medical records, n=145) and the Operationally Defined Cohort (AE cases identified through administrative coding data, n≈5000). Univariate statistical methods will identify candidate coding elements for use in the operational case definition and multivariate models and evaluation methods used to identify and internally validate the optimal coding algorithms. The two study cohorts will be analysed separately due to the high likelihood of overlap. Primary outcomes include relapse rate, prevalence and control of epilepsy, cognitive disability, poor educational attainment, delayed tumour diagnosis and mortality. Statistical analyses, including random mixed-effects regression models, will assess treatment effects, covariates and outcomes.

ETHICS AND DISSEMINATION

This project has been approved by the leading investigators' institutional Human Research Ethics Committee (HREC), the St Vincent's Hospital Melbourne HREC, as well as the Australian Institute of Health and Welfare HREC and relevant jurisdictional HRECs where required. The dissemination of findings through peer-reviewed publications and patient advocacy channels will maximise the impact of this research.

Efficacy and Safety of Rituximab Treatment for Anti-N-Methyl-d-Aspartate Receptor Encephalitis Without Tumor in Children

BACKGROUND

To evaluate the efficacy and safety of rituximab treatment for anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis without tumor in children.

METHODS

Eighteen pediatric patients with NMDAR encephalitis treated with rituximab after failure of intravenous immunoglobulin (IVIG) and methylprednisolone treatment were analyzed retrospectively in terms of their medical history, clinical features, laboratory examination results, and treatments. The modified Rankin scale (mRS) score, peripheral blood CD19+ B cells, recurrence, and adverse events were used to evaluate the efficacy and safety of rituximab.

RESULTS

The patients were treated with rituximab 3.2 ± 1.0 days after the end of IVIG and methylprednisolone treatment. After initial rituximab treatment for four weeks, the mRS score and number of CD19+ B cells in all patients were significantly lower than those before treatment (P < 0.05). At the last follow-up (44.1 months, 17.7 S.D.), all patients had recovered well (mRS ≤2), 14 patients (77.8%) recovered completely (mRS = 0), three patients had recurrent seizures, and one patient had mental and language impairment. Two patients had transient mild adverse events during infusion, and none of the other patients experienced severe adverse events during hospitalization or follow-up.

CONCLUSIONS

Rituximab appears safe and may be effective for the treatment of anti-NMDAR encephalitis without tumor in children refractory to first-line agents.

In Children, N-Methyl-D-Aspartate Receptor Antibody Encephalitis Incidence Exceeds That of Japanese Encephalitis in Vietnam

Background

The recognition of autoimmune causes of encephalitis has led to epidemiological shifts in the worldwide characteristics of encephalitis. N-methyl-D-aspartate receptor (NMDAR) antibody encephalitis leads to well-established complex neuropsychiatric manifestations. In low- and middle-income countries, including Vietnam, its relative incidence, especially in children, is unknown and most neurologists currently consider infectious encephalitis prior to autoimmune etiologies.

Methods

The study was prospectively conducted at Children's Hospital 1 in Ho Chi Minh City between March 2020 and December 2022. Any child admitted to the Department of Infectious Diseases and Neurology fulfilling the case definition of encephalitis was eligible to participate. Cerebrospinal fluid samples were collected alongside meta-clinical data for analysis.

Results

We recruited 164 children with a clinical diagnosis of encephalitis. Etiologies were determined as NMDAR antibody encephalitis in 23 of 164 cases (14.0%), Japanese encephalitis virus in 14 of 164 (8.5%), and herpes simplex virus in 4 of 164 (2.4%). Clinical categorizations suggested idiopathic viral encephalitis in another 71 (43.3%), and autoimmune encephalitis of unknown origin in the remaining 52. Factors including demographics, specific clinical features, cerebrospinal fluid and electroencephalogram findings, and length of hospital stay were significantly different between NMDAR antibody encephalitis and Japanese encephalitis.

Conclusions

At a tertiary children's hospital in Vietnam, the prevalence of NMDAR antibody encephalitis exceeds that of Japanese encephalitis, the most common infectious encephalitis cause in Southeast Asia. NMDAR antibody encephalitis is associated with long hospital stay and poor outcomes. These findings should change pediatric diagnostics, to earlier consider autoimmune treatments in this clinical setting.

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.

Alternative treatment in adolescent with anti-NMDA receptor encephalitis catatonia

A 12-year-old adolescent diagnosed with Anti-N-Methyl-D-Aspartate receptor encephalitis (ANMDAE) with catatonia was successfully treated with a course of zolpidem after inadequate response and lack of tolerance to first-line treatments, including benzodiazepines and electroconvulsive therapy (ECT). ANMDAE is an immune-mediated disease comprising a complex neuro-psychiatric clinical presentation that can range from memory deficits, seizures, and psychosis, to malignant catatonia. Catatonia is a psychomotor disorder that can increase the risk of medical complications. Current catatonia treatment guidelines include the use of benzodiazepines followed by ECT. Benzodiazepines are highly effective to treat catatonia in adults, with lower remission rates in children and adolescents. However, there are no defined guidelines if a patient fails to respond to the aforementioned treatments. Other treatment options may include zolpidem. To our knowledge, there is little literature on the treatment of catatonia with zolpidem in adolescents with underlying neurological conditions such as ANMDAE. This brief report highlights the importance of early recognition and treatment of ANMDAE with catatonia. It also underscores the lack of treatment guidelines for adolescents treated with immunotherapy presenting catatonia refractory to treatment with benzodiazepines and ECT. Zolpidem may be an alternative treatment for catatonia for patients not responding or tolerating benzodiazepines or ECT.

The P38MAPK Pathway Mediates the Destruction of the Blood-Brain Barrier in Anti-NMDAR Encephalitis Mice

The clinical manifestations of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis may be closely related to the integrity of the blood-brain barrier (BBB). The P38 mitogen-activated protein kinase (P38MAPK) pathway plays a protective role in neurodegenerative diseases. However, whether the P38MAPK pathway is involved in the underlying mechanism of tight junction (TJ) protein disruption and neuronal damage has not been elucidated. Therefore, in this study, a mouse model of anti-NMDAR encephalitis was established by active immunization with NMDAR NR1356-385 peptides. The critical pathways of P38MAPK were screened by interaction network and co-enrichment analysis. The role of P38MAPK pathways was investigated by the injection of P38MAPK inhibitor SB203580 (10 mg/kg, i.p.). Compared with the control group, the expression of occludin and zonula occludens (ZO)-1 in NMDAR NR1356-385 group mice was downregulated, and the structure and function of BBB were damaged. However, after the intervention of SB203580, the activation of the P38MAPK was inhibited, the expression of matrix metalloproteinase 9 (MMP9) was reduced, and the function of BBB was improved. Meanwhile, inhibiting the P38MAPK pathway reversed the degradation of NMDAR NR1, while reducing the expression of the glial fibrillary acidic protein (GFAP) and pro-inflammatory factor tumor necrosis factor (TNF-α). It also relieved the damage of neuron-specific nucleus (NeuN), thus alleviating psychobehavioral symptoms. In conclusion, our results suggested that the P38MAPK pathway is involved in BBB destruction and neurobehavioral change in mice with anti-NMDAR encephalitis. Targeting the P38MAPK pathway may be a promising option for the treatment of anti-NMDAR encephalitis.

Autoimmune Encephalitis in a Patient with a Solitary Intracranial Plasmacytoma

A 65-year-old woman presented with fever and abnormal behavior. Magnetic resonance imaging showed swelling of the left medial temporal lobe and an intracranial extra-axial occipital tumor. While her neurological symptoms improved after the administration of corticosteroid therapy under the suspicion of autoimmune encephalitis, the occipital tumor unexpectedly shrank, and the diagnosis of a solitary plasmacytoma was confirmed by biopsy. Additional examinations revealed elevated anti-glutamate receptor antibodies in the cerebrospinal fluid. The patient was diagnosed with autoimmune encephalitis concurrent with an intracranial solitary plasmacytoma. Central nervous system involvement can be considered a neurological complication in patients with a solitary plasmacytoma.

Cerebrospinal fluid soluble CD27 is a sensitive biomarker of inflammation in autoimmune encephalitis

BACKGROUND

Autoimmune encephalitis (AE) comprises a group of rare, severe neuroinflammatory conditions. Current biomarkers of neuroinflammation are often normal in AE which therefore can be difficult to rule out in patients with seizures, cognitive and/or neuropsychiatric symptoms. Cerebrospinal fluid (CSF) soluble CD27 (sCD27) and soluble B-cell maturation antigen (sBCMA) have high sensitivity for neuroinflammation in other neuroinflammatory conditions. In this exploratory study we investigate the potential of sCD27 and sBCMA in CSF as biomarkers of neuroinflammation in AE.

METHODS

Concentrations of sCD27 and sBCMA were measured in CSF from 40 AE patients (20 patients were untreated (12 with anti-N-Methyl-d-Aspartate receptor antibodies (NMDA) and 8 with anti-Leucine-rich Glioma-Inactivated 1 antibodies (LGI1)), and 37 symptomatic controls (SCs).

RESULTS

CSF concentrations of sCD27 were increased in untreated NMDA AE patients (median 1571 pg/ml; p < 0.001) and untreated LGI1 AE patients (median 551 pg/ml; p < 0.05) compared to SCs (median 250 pg/ml). CSF sBCMA was increased in untreated NMDA AE patients (median 832 pg/ml) compared to SCs (median 429 pg/ml). CSF sCD27 and sBCMA correlated with the CSF cell count. Receiver operating characteristic curve analysis of untreated AE patients versus SCs showed an area under the curve of 0.97 for sCD27 and 0.76 for sBCMA.

CONCLUSION

CSF sCD27 is a suitable biomarker of neuroinflammation in AE with an ability to discriminate patients with NMDA AE and LGI1 AE from symptomatic controls. CSF sCD27 may be suited for ruling out AE and other neuroinflammatory conditions in the early phase of the diagnostic work-up.

Association of ovarian teratoma with anti-N-methyl-D-aspartate receptor encephalitis: a case report and narrative review

BACKGROUND

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a potentially life-threatening autoimmune disorder which is strongly associated with ovarian teratomas in young female patients. The primary aim is to highlight the importance of considering NMDAR encephalitis in the differential diagnosis of young female patients presenting with acute or subacute neuropsychiatric symptoms, especially when accompanied by ovarian teratomas.

CASE DESCRIPTION

This case report and literature review detail the presentation, diagnosis, and treatment of a 35-year-old G4P3 Indigenous woman who initially presented with neuropsychiatric symptoms and fever, having a history of extensive drug and alcohol use. Misdiagnosed initially, the patient's lack of response to standard treatments led to further investigations, revealing paraneoplastic anti-NMDAR encephalitis secondary to a left ovarian teratoma. The report examines the treatment regimen followed, including prednisolone, intravenous immunoglobulin, rituximab injections, and laparoscopic bilateral salpingo-oophorectomy.

CONCLUSIONS

This case underscores the critical need for increased clinical vigilance for anti-NMDAR encephalitis in patients, particularly young females, presenting with neuropsychiatric symptoms and potential ovarian teratomas. The literature review accompanying the case report provides valuable insights into the presentation, diagnosis, and management of this complex condition. Lastly, this study emphasised the diagnostic challenges inherent in paraneoplastic neuropsychiatric syndromes, advocating for a multidisciplinary approach in similar clinical scenarios.

Features of the clinical course of Autoimmune Encephalitis Associated with various antibodies

Despite the increasing incidence of autoimmune encephalitis and the incomplete recovery observed in patients post-affliction, the issue of timely diagnosis remains unresolved. The primary objective of this study is identification the distinctive clinical presentation features evaluation the management strategies, and assess the outcomes of the disease in patients with various forms of autoimmune encephalitis. The research aims to contribute in a better understanding of the disease progression and facilitate the selection of optimal therapeutic interventions. A retrospective observational study enrolled 68 patients aged 18 years and older with verified autoimmune encephalitis who underwent treatment in state hospitals in Sofia, Bulgaria, from the beginning of 2014 to the end of 2022. The number of patients with pathology linked to antibodies against glycine receptors (Gly-R) was half as much, with 32 and 17 patients, respectively. The primary manifestations of autoimmune encephalitis included cognitive impairments observed in 51 patients, seizures occurring in 44 patients, and mood disorders observed in 22 patients. While the findings of imaging studies were nonspecific, hospitalizations for patients with this pathology, especially those with antibodies to CASPR2 and DPPX, were prolonged (114 and 232 days, respectively). In the vast majority of cases, incomplete recovery with residual symptoms was noted. Among the diverse forms of autoimmune encephalitis, the most prevalent is NMDA-R. Cognitive impairments predominate in the autoimmune encephalitis clinical presentation. Prolonged hospitalization periods and incomplete recovery of patients are characteristic features of autoimmune encephalitis, despite combined therapy involving intravenous administration of methylprednisolone and immunoglobulins.

Anti-N-Methyl-D-Aspartate Receptor (Anti-NMDAR) Encephalitis in Small Cell Lung Cancer: A Case Report

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an autoimmune encephalitis characterized by psychiatric and neurological symptoms. It often presents as a paraneoplastic manifestation and is rarely associated with small cell lung cancer. While treatment usually involves immunotherapy and treatment of underlying malignancy, the patient's condition can complicate treatment decisions. A 66-year-old man presented to the emergency department with a chief complaint of fever and impaired consciousness. Tests revealed anti-NMDAR encephalitis and small cell lung cancer. Despite immunotherapy, including steroids, intravenous immunoglobulin, and rituximab, chemotherapy was not possible due to the patient's poor condition. Immunotherapy treatment was continued, but there was no improvement in his state of consciousness, and death was confirmed on the 101st day of hospitalization. Anti-NMDAR encephalitis caused by small cell carcinoma is treated with immunotherapy and cancer therapy; only immunotherapy is not enough.

Efficacy and safety of different oral prednisone tapering courses in adult anti-NMDAR encephalitis: A multicenter prospective cohort study

OBJECTIVE

In adult anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis, corticosteroids are commonly used as first-line treatment. However, the optimal oral prednisone tapering (OPT) following intravenous methylprednisolone pulse therapy remains unclear. We aim to compare the efficacy and safety of different OPT courses in anti-NMDAR encephalitis.

METHODS

The CHASE study, a multicenter prospective observational cohort study, enrolled patients with autoimmune encephalitis from October 2011 to March 2023. Patients were grouped based on oral prednisone tapering course: ≤3 months (Group ≤3 month), 3-6 months (Group 3-6 months, including 3 months), and >6 months (Group > 6 months). Kaplan-Meier plots were used to analyze time to relapse and time to total recovery within 2 years.

RESULTS

Among 666 screened patients, 171 (median [IQR] age 27 [21.0-36.5] years, 55.0% female) met selection criteria. Responders at 3 months were prevalent in Group ≤3 months (OR 7.251 [95% CI 2.252 to 23.344] and Group 3-6 months (OR, 3.857 [95% CI 1.107 to 13.440] than in Group >6 months. Clinical Assessment Scale for Autoimmune Encephalitis (CASE) scores at 12 months were higher in Group >6 months than in Group ≤3 months and Group 3-6 months (β, -2.329 [95% CI -3.784 to -.875]; β, -2.871 [95% CI -4.490, -1.253]). CASE seizures subscore was higher in Group >6 months than in Group 3-6 months (β, -.452 [95% CI -.788 to -.116]). No significant difference in seizure freedom rates among the groups. Adverse events were higher in Group 3-6 months and Group >6 months than in Group ≤3 months (OR 6.045 [95% CI 2.352 to 15.538]; OR 6.782 [95% CI 1.911 to 24.073]).

SIGNIFICANCE

Longer oral prednisone courses for adult patients with anti-NMDAR encephalitis did not show superior effects compared to shorter courses in improving modified Rankin Scale (mRS) scores and CASE scores, reducing the risk of relapse within 2 years, or achieving seizure freedom. Instead, extended prednisone courses may lead to more side effects- particularly weight gain. This outcome recommends evaluating the possibility of shortening the duration of oral prednisone after a thorough patient assessment.

Trends in Clinico-radiological and Laboratory Characteristics of All-Cause Meningoencephalitis in Western Rajasthan

BACKGROUND AND OBJECTIVES

Meningoencephalitis encompasses the coexistence of meningitis and encephalitis in different proportions. This study aimed to delineate the clinical profile, laboratory parameters, radiological features, and outcome predictors of patients with meningoencephalitis.

METHODS

This prospective, observational, and descriptive study was conducted from July 2021 to March 2023. Patients satisfying the case definition of "meningitis" and "encephalitis" were enrolled. Mortality and morbidity (by modified Rankin Score [mRS]) were noted at discharge and at 1 and 3 months post-discharge.

RESULTS

Of 102 patients recruited, among infectious meningoencephalitis cases, 28 (27.5%) were viral, 11 (10.8%) were pyogenic, 32 (31.4%) were tubercular, four (3.9%) each were rickettsial, atypical bacterial, and fungal, and three (2.9%) were parasitic. Among noninfectious etiologies, 12 (11.8%) were antineuronal antibody mediated, three (2.9%) had systemic inflammatory etiology, and one (1%) had carcinomatous meningitis. Cerebrospinal fluid (CSF) analysis showed the highest protein content (336.82 ± 251.26 mg/dL) and cell count (476.73 ± 999.16/mm 3 ) in pyogenic followed by tubercular (200.29 ± 174.28/mm 3 ) meningoencephalitis. CSF glucose was lowest in tubercular group (38.30 ± 20.29 mg/dL). Imaging showed leptomeningeal enhancement predominantly in tubercular group (89.7%) and limbic involvement in viral etiology (38.5%). Overall mortality was highest in fungal and rickettsial groups (three out of four patients died at 1 month in each group). Pyogenic, atypical bacterial, and systemic inflammatory meningoencephalitis had maximum temporal improvement in mRS at 1 month, while tubercular, viral, and antineuronal antibody-mediated meningoencephalitis had decrease of at least 1 mRS at 3 months. Fever, altered sensorium, speech disturbances, neck stiffness, albumin, total leukocyte count, erythrocyte sedimentation rate, C-reactive protein, kidney and liver function tests showed significant association with mortality.

CONCLUSIONS

Tubercular, followed by viral meningoencephalitis, was the most common cause in our center in western India. Pyogenic, atypical bacterial, and systemic inflammatory groups had the best recovery at discharge, while fungal and rickettsial meningoencephalitis groups had worst mRS at 3 months.

Recurrent Anti-NMDAR Encephalitis Necessitating Oophorectomy in an Adolescent Patient: A Case Report

Background: Anti-NMDA receptor (A-NMDAR) encephalitis is an autoimmune condition often associated with ovarian teratoma. Surgical removal of the teratoma is generally curative, and recurrence is uncommon. Case: A 14-year-old female presented with psychiatric symptoms and was ultimately diagnosed with A-NMDAR encephalitis during a prolonged hospitalization. She was found to have bilateral ovarian teratomas, underwent laparoscopic bilateral ovarian cystectomy, and returned to neurologic baseline within 2 months. One year later, the patient was re-presented with similar symptoms and was diagnosed with recurrent A-NMDAR encephalitis. Initial imaging was negative for ovarian teratomas. After another prolonged hospitalization, repeat imaging ultimately demonstrated a suspected left ovarian teratoma. A left salpingo-oophorectomy was performed, and the patient's condition again fully recovered. Conclusion: This case of A-NMDAR encephalitis presented with many atypical features including neuropsychiatric presenting symptoms, bilateral teratomas, and severe recurrence of disease. While imaging is the recommended modality for investigation of etiology, no teratoma was identified on the second presentation, leading to an ethical and clinical conundrum in this adolescent patient. More research is needed to investigate other diagnostic methods for A-NMDAR encephalitis without distinct teratoma on imaging in female patients.

Ovarian teratoma-associated Anti-NMDAR encephalitis in women with first-time neuropsychiatric symptoms: A meta-analysis and systematic review of reported cases

Objective

Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is frequently associated with ovarian teratomas. The diverse clinical presentations and several stages of disease development pose a significant diagnostic challenge for clinicians. The main objective of this research was to show the prevalence of neuropsychiatric symptoms of ovarian-teratoma-associated anti-NMDAR encephalitis and to highlight the importance of multidisciplinary collaboration in the diagnosis, treatment, and prevention of disease progression.

Methods

Literature searches were carried out using PubMed, Scopus, and Web of Science Core Collection. The following data were retrieved: authors' names, year of publication, type of study, number and age of patients included, diagnostic methods of disease evaluation, prevalence of anti-NMDAR antibodies, psychiatric manifestations, other symptoms, initial diagnosis, treatment strategies, and histopathology results. Data analyses were performed and considered statistically significant when p < 0.05.

Results

Our study included 98 female patients with encephalitis associated with a teratoma. The study group reported specific symptoms more often than expected in the general population (p < 0.05). The incidence of seizures deviated most from rates in the general population. The major significant differences were observed in cases of psychosis, seizures, hypoventilation, aphasia, and coma.

Conclusions

Teratoma-associated anti-NMDAR encephalitis diagnosis should be systematically investigated in patients presenting with first-time psychotic episodes. Prompt diagnosis and treatment are imperative for prevention of disease progression and better outcomes. Screening and identification of anti-NMDAR antibodies and considering the association of ovarian teratoma and neuropsychiatric symptoms suggesting encephalitis are critical for establishing the proper diagnosis.

Increased serum phenylalanine/tyrosine ratio associated with the psychiatric symptom of anti-NMDAR encephalitis

Background

Encephalitis associated with antibodies against the N-methyl-D-aspartate receptor (NMDAR) results in a distinctive neuro-psychiatric syndrome. It has been reported that the serum phenylalanine-tyrosine (Phe/Tyr) ratio increases during infection. However, the connection between phenylalanine-tyrosine metabolism and psychiatric symptoms remains unclear.

Methods

We enrolled 24 individuals with anti-NMDAR encephalitis and 18 individuals with non-inflammatory neurological diseases (OND). Chromatography was used to measure serum levels of phenylalanine and tyrosine. Serum and cerebrospinal fluid (CSF) TNF-α levels were obtained from the clinical database. The modified Rankin Scale (mRS) score and Glasgow Coma Scale (GCS) score were recorded during the acute phase. The area under the curve (AUC) of the receiver operating characteristic curve was used to assess prediction efficacy.

Results

In NMDAR patients, levels of serum Phe and the ratio of serum Phe/Tyr were higher compared to OND patients. The serum Phe/Tyr ratio was also elevated in NMDAR patients with psychiatric syndrome. Furthermore, serum Phe and Tyr levels were correlated with inflammatory indexes.

Conclusion

The serum Phe/Tyr ratio is elevated in NMDAR patients with psychiatric syndrome and is associated with severity. Therefore, the serum Phe/Tyr ratio may serve as a potential prognostic biomarker.

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.

Case report: Rapid symptom relief in autoimmune encephalitis with efgartigimod: a three-patient case series

Introduction

Autoimmune encephalitis (AE) comprises a group of inflammatory brain disorders mediated by autoimmune responses. Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, anti-leucine-rich glioma-inactivated 1 (LGI1) encephalitis, and anti-γ-aminobutyric acid-B receptor (GABABR) encephalitis are the most prevalent forms, characterized by the presence of antibodies against neuronal cell-surface antigens. Efgartigimod, an antagonist of the neonatal Fc receptor, has proven efficacy in myasthenia gravis treatment. This clinical case report describes the clinical progression and functional outcomes of AE in three patients who received efgartigimod treatment.

Case presentations

Case 1 was a 60-year-old man exhibiting memory impairment and psychiatric disturbances over 11 days. Case 2 was a 38-year-old man with a 1-month history of rapid cognitive decline and seizures. Case 3 was a 68-year-old woman with mental behavioral changes and seizures for 4 months. Anti-GABABR, anti-LGI1, and anti-NMDAR antibodies were confirmed in the respective patients' cerebrospinal fluid or serum. All three patients experienced marked and swift symptomatic relief after four cycles of efgartigimod treatment, with no complication.

Conclusion

Current first-line and second-line treatments for AE have limitations, and efgartigimod has demonstrated potential in the rapid and efficacious treatment of AE, emerging as a promising option for the management of this disease.

Comparison of B Cell Variable Region Gene Segment Characteristics in Neuro-autoantibodies

Autoimmune pediatric neurologic diseases have variable phenotypes and presentations, making diagnosis challenging. The pathologic mechanisms are also distinct, including cell-mediated and Ab-mediated autoimmunity, paraneoplastic syndromes, and postinfectious processes. In recent years a number of studies have described the characteristics of the autoantibodies involved in a number of these diseases. Some of the described Abs use a restricted set of variable gene segments. We sought to compare the Ab characteristics of autoantibodies related to some of the more common disorders to discover whether specific Ab signatures are universally associated with neuroautoimmune diseases. We initially performed a literature review to summarize the Ab characteristics of autoantibodies related to some of the more common disorders, including N-methyl-d-aspartate receptor (NMDAR) and leucine-rich, glioma-inactivated 1 (LGI-1). Next, we performed data analysis from selected studies that sequenced Ig genes to further characterize NMDAR and LGI-1 autoantibodies including CDR3 length distribution, variable gene sequence usage, and isotype use. We found that CDR3 length of NMDAR autoantibodies was normally distributed whereas the CDR3 length distribution of LGI-1 autoantibodies was skewed, suggesting that there is no global structural restriction on types of autoantibodies that can cause encephalitis. We also found that IgG1-IgG3 were the main NMDAR autoantibody isotypes detected, while IgG4 was the major isotype used in autoantibodies from LGI-1 encephalitis. These findings are useful for our understanding of autoimmune encephalitis and will help facilitate better diagnosis and treatment of these conditions in the future.

Clinical features and outcomes in children with seronegative autoimmune encephalitis

AIM

To characterize the presenting features and outcomes in children with seronegative autoimmune encephalitis, and to evaluate whether scores at nadir for the Modified Rankin Scale (mRS) and Clinical Assessment Scale for Autoimmune Encephalitis (CASE) or its paediatric-specific modification (ped-CASE) are predictive of outcomes.

METHOD

This observational study included children younger than 18 years of age with seronegative autoimmune encephalitis. Demographics and clinical data were collected. The mRS and CASE/ped-CASE scores were used to evaluate disease severity. Descriptive statistics and logistic regression were used for data analysis and to evaluate associations between scale scores and outcomes.

RESULTS

Sixty-three children were included (39 [62%] females, median age 7 years, interquartile range [IQR] 4 years 1 months-11 years 6 months), with follow-up available for 56 out of 63 patients (median follow-up 12.2 months, IQR 13.4-17.8). The most frequent presenting neurological manifestation was encephalopathy (81%). Median CASE/ped-CASE and mRS scores at nadir were 12.0 (IQR 7.0-17.0) and 1.0 (IQR 0-2.0) respectively. Thirty-three patients (59%) had persistent neurological deficits at follow-up. Both scoring systems suggested good functional recovery (mRS score ≤2, 95%; CASE/ped-CASE score <5, 91%). CASE/ped-CASE score was more likely than mRS to distinguish children with worse outcomes.

INTERPRETATION

Children with seronegative autoimmune encephalitis are likely to have neurological deficits at follow-up. CASE/ped-CASE is more likely to distinguish children with worse outcomes than MRS.

WHAT THIS PAPER ADDS

Encephalopathy was the most common reason for presentation in children with seronegative autoimmune encephalitis. Children with seronegative autoimmune encephalitis are likely to have neurological deficits at follow-up. The Clinical Assessment Scale for Autoimmune Encephalitis or its paeditric version at nadir was better at distinguishing children with poor outcomes than the Modified Rankin Scale.

Therapeutic Effects Of Combined and Chronic Treatment of Tat-GluA23y and D-Serine on Cognitive Dysfunction in Postmenopausal Rats

BACKGROUND

The incidence of Alzheimer's disease (AD) in female gender compared with male has been addressed as a health concern, particularly in menopausal age. We here hypothesized that co-administration of NMDARs agonist (D-serine) and AMPARs endocytosis inhibitor (Tat-GluA23y) might be a potential target for alleviating memory impairment in sporadic Alzheimer model of rats.

METHODS

Forty-eight female Wistar rats weighing 200-220 randomly divided into six groups. One month later, ovariectomized rats underwent stereotaxic surgery and were cannulated into the brain lateral ventricles. Streptozotocin was injected (3 mg/kg), then animals received the related treatments until the day 51, which experienced acquisition of spatial memory in Morris Water Maze test. Finally, the level of phosphorylated cAMP response element binding protein (CREB) in the hippocampus was measured by Western blotting.

RESULTS

Co-administration of D-serine and GluA23y significantly enhanced the acquisition and retrieval of impaired spatial memory in ovariectomized rats with AD (p < .001). Compared to Glu-A 23, D-serine caused more improvement in the mentioned parameters above, however, these values for both groups were still significantly different from the control group (P < .05).

CONCLUSION

Simultaneous treatment with D-serine and GluA23y synergistically improved STZ induced spatial memory impairment in OVX rat, probably partly via increase in phosphorylated CREB protein.