Clinical Features, Treatment, and Outcomes Among Chinese Children With Anti-methyl-D-aspartate Receptor (Anti-NMDAR) Encephalitis

Analysis of the relation between cerebrospinal fluid antibody titers and clinical characteristics in pediatric patients with anti-N-methyl-D-aspartate receptor encephalitis

OBJECTIVE

This retrospective study aimed to investigate the relationship between cerebrospinal fluid (CSF) antibody titers of N-methyl-d-aspartate receptor (NMDAR), and clinical characteristics in pediatric patients with anti-NMDAR encephalitis.

METHODS

The clinical and laboratory characteristics of hospitalized patients with anti-NMDAR encephalitis, stratified by antibody titers in CSF and disease severity, were retrospectively studied. The demographics, clinical characteristics, main accessory examinations, immunotherapy, and prognosis of patients were recorded, and each observed indicator was statistically analyzed.

RESULTS

A total of 103 pediatric anti-NMDAR encephalitis patients were enrolled in the study, including 41 males (39.8%) and 62 females (60.2%) with a mean age of 8.0 ± 4.0 years. The proportion of patients with cognitive dysfunction and the positive pathogen was higher in the high-titer group than in the low-titer group (p = 0.023, p = 0.042). Consciousness disturbance that occurred as an initial symptom or during the course in the severe group was higher than in the non-severe group (p = 0.002, p < 0.001). More patients in the high-titer group received plasma exchange (PE) than in the low-titer group (p = 0.022). The cure rate of patients was higher with PE (65.2%) than with Corticosteroids and (or) intravenous immunoglobulin (58.1%).

CONCLUSIONS

Patients with symptoms of disturbance of consciousness may be severer. The severity in pediatric anti-NMDAR encephalitis patients was not correlated with anti-NMDAR antibody titers. Patients with high CSF antibody titers had a better prognosis after early PE therapy.

The Impact of Neuroimmunologic Disease and Developing Nervous System

Over the last two decades, neuroimmunologic disorders of childhood have been increasingly described, phenotyped, and treated. These disorders remain rare in the general population and while sharing common therapeutic interventions due to their immune pathophysiology, are heterogeneous with regard to presentation and risk of recurrence. As such, the impact of these disorders on the developing brain has come into the forefront of emerging research in pediatric neuroimmunology. Investigations into the singular impact of monophasic disease on long-term development and the impact of early and aggressive disease-modifying therapy in relapsing conditions are quickly becoming areas of ripe investigation as the field's most optimal way to treat and monitor these conditions over time. Although critically important in evaluating the developing brain, research has been heterogeneous among these diseases and limited by small cohort size. This narrative review details the role of common neuroimmunologic disorders in long-term neurological and cognitive outcomes in children as they develop.

Persistent psychosis associated with extreme delta brush in anti-NMDA receptor encephalitis: a case report

BACKGROUND

Anti-NMDAR encephalitis is an emerging differential diagnosis of first episode and persistent psychosis in the psychiatric community, as clinical manifestations include psychiatric symptoms, cognitive dysfunction, seizures, decreased consciousness, and dyskinesias. This disease is associated with extreme delta brush (EDB), but the significance and temporal course of this EEG pattern still needs to be determined. Herein, we report a case of anti-NMDAR encephalitis with persistent psychosis associated with EDB occurrence on multiple occasions during a 5-year disease course.

CASE PRESENTATION

A 15-year-old girl was diagnosed with anti-NMDAR encephalitis and treated with progressive improvement. Four years after initial manifestations, an EDB pattern was seen on electroencephalogram (EEG) without new neurological symptoms. She had residual symptoms of episodic auditory hallucinations and impulsivity. One year later, the patient had a recurrence of neurological symptoms (seizures, dyskinesias and impaired attention), persisting with EDB on EEG. Clinical symptoms and EDB resolved after second-line treatment with rituximab.

CONCLUSION

We describe the first case of persistent psychosis in anti-NMDAR encephalitis associated with extreme delta brush on multiple EEGs on prolonged follow-up. Electroencephalographic patterns such as EDB may serve as markers of residual disease activity, including psychiatric symptoms. Further studies with prolonged EEG monitoring are needed to better understand these findings.

Long-Term Outcome of Pediatric Patients with Anti-NMDA Receptor Encephalitis in a Single Center

BACKGROUND

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is the most common autoimmune encephalitis in children. There is a high probability of recovery if treated promptly. We aimed to analyze the clinical features and long-term outcomes of pediatric patients with anti-NMDA receptor encephalitis.

METHOD

We conducted a retrospective study with definite diagnoses of anti-NMDA receptor encephalitis in 11 children treated in a tertiary referral center between March 2012 and March 2022. Clinical features, ancillary tests, treatment, and outcomes were reviewed.

RESULTS

The median age at disease onset was 7.9 years. There were eight females (72.7%) and three males (27.3%). Three (27.3%) patients initially presented with focal and/or generalized seizures and eight (72.7%) with behavioral change. Seven patients (63.6%) revealed normal brain MRI scans. Seven (63.6%) had abnormal EEG results. Ten patients (90.1%) received intravenous immunoglobulin, corticosteroid, and/or plasmapheresis. After a median follow-up duration of 3.5 years, one patient was lost to follow-up at the acute stage, nine (90%) had an mRS ≤ 2, and only one had an mRS of 3.

CONCLUSIONS

With the early recognition of anti-NMDA receptor encephalitis based on its clinical features and ancillary tests, we were able to treat patients promptly with first-line treatment and achieve favorable neurological outcomes.

Use of anti-seizure medications in different types of autoimmune encephalitis: A narrative review

Seizures are the main manifestation of the acute phase of autoimmune encephalitis (AE). Anti-seizure medications (ASMs) play an important role in controlling seizures in AE patients, but there is currently a lack of consensus regarding the selection, application, and discontinuation of ASMs. This narrative review focuses on the use of ASMs in patients with AE driven by different antibodies. The PubMed, Embase, and MEDLINE databases were searched up until 30 October 2022 using prespecified search terms. We identified 2,580 studies; 23 retrospective studies, 2 prospective studies and 9 case reports were evaluated based on our inclusion criteria. Anti-N-methyl-D-aspartic-acid-receptor (anti-NMDAR) encephalitis is the type of AE that responds best to ASMs, and long-term or combined use of ASMs may be not required in most patients with seizures; these results apply to both adults and children. Sodium channel blockers may be the best option for seizures in anti-leucine-rich-glioma-inactivated-1 (anti-LGI1) encephalitis, but patients with anti-LGI1 encephalitis are prone to side effects when using ASMs. Cell surface antibody-mediated AE patients are more likely to use ASMs for a long period than patients with intracellular antibody-mediated AE. Clinicians can score AE patients' clinical characteristics on a scale to identify those who may require long-or short-term use of ASMs in the early stage. This review provides some recommendations for the rational use of ASMs in encephalitis mediated by different antibodies with the aim of controlling seizures and avoiding overtreatment.

Case Report: Anti-GABAA Receptor Encephalitis in a Dog

Autoantibodies against neurotransmitter receptors detected in cerebrospinal fluid (CSF) and serum are increasingly recognized in people with human autoimmune encephalitis causing severe neurological deficits, such as seizures and behavioral abnormalities. This case report describes the first encephalitis associated with antibodies against the γ-aminobutyric acid-A receptor (GABA_AR) in a dog. A young male intact Cavalier King Charles Spaniel was presented with recent onset of initial multiple generalized tonic-clonic seizures progressing into a status epilepticus. Interictally, he showed alternating stupor and hyperexcitability, ataxia, pleurothotonus and circling behavior to the left side. Magnetic resonance imaging (MRI) of the brain showed breed-specific anatomical abnormalities. Standard CSF analysis was unremarkable. Despite treatment with multiple antiseizure medications (ASMs) seizures and behavior abnormalities sustained. Immunotherapy with dexamethasone was started on the fifth day after disease manifestation. This led to rapid improvement of clinical signs. An extensive antibody search in CSF and serum demonstrated a neuropil staining pattern on a tissue-based assay compatible with GABA_AR antibodies. The diagnosis was confirmed by binding of serum and CSF antibodies to GABA_AR transfected Human Embryonic Kidney cells. The serum titer was 1:320, the CSF titer 1:2. At the control visit 4.5 weeks after start of immunotherapy, the dog was clinically normal. The GABA_AR antibody titer in serum had strongly decreased. The antibodies were no longer detectable in CSF. Based on clinical presentation and testing for GABA_AR binding antibodies, this describes the first veterinary patient with an anti-GABA_AR encephalitis with a good outcome following ASM and corticosteroid treatment.

External Assessment of the Anti-N-Methyl-D-Aspartate Receptor Encephalitis One-Year Functional Status Score in Chinese Pediatric Patients

Objective

to assess the performance of the Anti-N-Methyl-D-Aspartate Receptor encephalitis (NMDAR) One-Year Functional Status (NEOS) score in predicting one-year functional outcome in Chinese children with anti-NMDAR encephalitis.

Methods

children with anti-NMDAR encephalitis at the Children’s Hospital of Chongqing Medical University were retrospectively enrolled from January 2014 to December 2020. Patients were categorized into two groups based on the modified Rankin Scale (mRS) at one-year follow-up. Discrimination of the NEOS score was assessed by the area under curve (AUC) of the receiver operating characteristic curve. Calibration of the NEOS score was assessed by comparing predicted probabilities with observed probabilities using a calibration curve and the Hosmer-Lemeshow test. The clinical practicability of the NEOS score was evaluated by performing a decision curve analysis.

Results

one hundred seventy-five children (101 females and 74 males) with anti-NMDAR encephalitis and a median age of 7.7 years were enrolled. Of those, 149 (85.1%) had a good outcome at 1 year (mRS ≤ 2), and the remaining 26 (14.9%) had a poor outcome (mRS > 2). Patients with a higher NEOS score had a significantly higher mRS at one-year follow-up [Spearman r = 0.3878, 95% confidence interval (CI): 0.2500-0.5103, P < 0.001]. The AUC of the NEOS score was 0.870 (95% CI: 0.801-0.938, P < 0.001). The observed probability and predicted probability showed moderate consistency in the calibration curve and the Hosmer-Lemeshow test (P = 0.912). The decision curve analysis showed that using the NEOS score to predict one-year outcomes could provide additional net benefit during clinical practice.

Conclusions

the NEOS score is a potentially reliable model to predict the one-year functional outcome in Chinese children with anti-NMDAR encephalitis.

N-Methyl-D-Aspartate (NMDA)-Type Glutamate Receptors and Demyelinating Disorders: A Neuroimmune Perspective

N-methyl-D-aspartate receptors (NMDARs) are ionotropic glutamate receptors, highly important in regulating substantial physiologic processes in the brain and the nervous system, and disturbance in their function could contribute to different pathologies. Overstimulation and hyperactivity of NMDARs, termed as glutamate toxicity, could promote cell death and apoptosis. Meanwhile, their blockade could lead to dysfunction of the brain and nervous system as well. A growing body of evidence has demonstrated the prominent role of NMDARs in demyelinating disorders and anti-NMDAR encephalitis. Herein, we provide an overview of the role of NMDARs' dysfunction in the physiopathology of demyelinating disorders such as multiple sclerosis and neuromyelitis optica spectrum disorders.

Case Report: Triphasic Waves in a 9-Year-Old Girl With Anti-NMDAR Encephalitis

BACKGROUND

Triphasic waves (TWs) are mainly described in association with metabolic encephalopathy, especially hepatic encephalopathy. Now, as different conditions including non-metabolic and structural abnormalities have been reported to be associated with TWs, the presence of TWs becomes a non-specific finding for metabolic encephalopathy.

CASE PRESENTATION

We report the first case of anti-NMDAR encephalitis in a 9-year-old girl presenting with TWs on EEG. The TWs background EEG lasted for about 12 h on the 40th day of the disease course. No epileptic wave was found during a series of EEG examinations. The child was discharged from the hospital and no neurological sequelae remained after a six-month follow-up.

CONCLUSIONS

TWs are not specific to metabolic encephalopathy, but can also occur in children with autoimmune encephalitis. This case achieved a good prognosis after the early initiation of immunotherapy.

The clinical features, treatment and outcomes of 33 children from Northwestern China with Anti-N-methyl-D-aspartate receptor encephalitis

OBJECTIVES

We analyzed the clinical features and outcomes of children with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis in Northwestern China.

METHODS

We retrospectively recruited 33 pediatric patients with anti-NMDAR encephalitis in Northwestern China from December 2013 to April 2020. The demographics, clinical features, treatments, and outcomes were reviewed.

RESULTS

33 patients with anti-NMDAR encephalitis were enrolled in this study (a median age of 6.8 years, 20 females and 13 males). The initial symptoms included seizures (42.4%), psychiatric symptoms (39.4%), speech dysfunction (12.1%), and paralysis (6.1%). During the course of the disease, 31 patients (93.9%) presented with psychiatric symptoms, 29 patients (87.9%) presented with speech dysfunction, 25 patients (75.8%) presented with movement disorders and 24 patients (72.7%) presented with sleep disorders followed by seizures, consciousness disturbance, autonomic nervous dysfunction, paralysis, and hypoventilation. 12 patients (36.4%) had abnormal cerebrospinal fluid (CSF) findings, 10 patients (30.3%) exhibited abnormal brain magnetic resonance imaging (MRI) results, and 29 patients (87.9%) showed abnormal Electroencephalography (EEG) findings. None of the patients had tumors. All patients received first-line immunotherapy and 8 patients both received first and second-line immunotherapy. 30 of the 33 patients achieved good outcomes (score on the modified Rankin Scale [mRS] of 0-2), whilst the other 3 patients had poor outcomes (mRS score of 3-6).

CONCLUSIONS

Patients with higher CSF anti-NMDAR body titer were more likely to develop sleep disorders, consciousness disturbances and more severe disease states.

Pediatric Autoimmune Encephalitis in Sri Lanka: A Single-Center Experience over 7 Years

Pediatric autoimmune encephalitis (AE) remains a diagnostic and therapeutic challenge in resource-poor settings. Minimizing delay in diagnosis and appropriate escalation of treatment will help reduce both the short- and long-term neurodisabilities. A retrospective observational study was performed on children consecutively diagnosed with possible AE and then prospectively followed up in a single tertiary care children's hospital in Sri Lanka. Serum and cerebrospinal fluid were tested for neuroglial surface-binding autoantibodies using cell-based assays in majority of these children. Twenty-five children (mean age 7.6 years, standard deviation = 4) were recruited. In these children, presenting symptom was psychiatric in 11 children (44%), seizures in 10 (40%), language regression in 2 (8%), and combination of psychosis and convulsions in 2 (8%). Psychiatric presentations were more common in older (>6 years) compared with young children (p = 0.001), while neurological presentations were more common in children aged ≤6 years (p = 0.001). N-methyl-D-aspartate receptor (NMDAR) antibodies were detected in 9 (45%) and unspecified voltage-gated potassium channel antibodies in 1 (5%) of the 20 tested. All received intravenous steroids and immunoglobulins; 19 (76%) plasma exchange; 7 (29%) rituximab. Complete/substantial improvement at 3 months occurred in 64%. Pediatric Cerebral Performance Category score at last review was 1 (normal function for age) in 43%. Higher proportion of younger children required less intense therapy and had better recovery (56%). Death (8%), incomplete recovery (71%), and relapses (8%) were more in older children. Clinical presentation and disease outcomes were different in children aged <6 years compared with older age group. NMDAR antibody encephalitis was the commonest AE syndrome identified in this cohort.

Neuropsychological Sequelae, Quality of Life and Adaptive Behavior in Children and Adolescents with Anti-NMDAR Encephalitis: A Narrative Review

Anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis is a rare autoimmune illness characterized by a constellation of often severe, but treatable, psychiatric and neurological symptoms. Whereas symptoms such as psychosis and bizarre and abnormal motor behavior are common in adults, pediatric patients typically present with behavioral changes, irritability and sleep dysfunction. The recovery phase is usually slow and may be associated with longstanding adaptive, behavioral and neuropsychological problems. Very few studies explored the cognitive and adaptive sequelae in children with anti-NMDAR encephalitis. The present review article suggests that, although most children and adolescents return to their daily life and previous activities, they may have a low quality of life and show neuropsychological sequelae involving language, memory, especially verbal memory, and attentional resources, even after several months from the hospital discharge. In particular, the available results reveal difficulties in cognitive skills involving executive functions. This impairment is considered the “core” of the cognitive profile of young patients with anti-NMDAR encephalitis. On the other hand, some cognitive skills, such as general intelligence, show good overall recovery over time. Additional neuropsychological research evaluating larger samples, more homogenous methods and longitudinal studies is required.

Understanding Seizures and Prognosis of the Extreme Delta Brush Pattern in Anti-N-Methyl-D-Aspartate (NMDA) Receptor Encephalitis: A Systematic Review

Anti-N-methyl-d-aspartate (NMDA) receptor encephalitis (ANMDARE) is an autoimmune disorder with neurological and psychiatric features. The disease presents with a viral prodrome, followed by psychiatric manifestations. In the next phase, movement disorders or/and seizures occur. Finally, in the last phase, there is a decrease in the level of consciousness. Central hypoventilation and autonomic dysfunction can occur. Recently a unique EEG (electroencephalogram) pattern has been associated with anti-NMDA receptor encephalitis, the extreme delta brush (EDB). Although the association of the EDB with ANMDARE is known by the medical community, its significance is mainly unknown. A systematic review on NMDARE is also scarce. We decided to conduct a systematic review on this topic to consolidate the knowledge and establish the importance of the EDB as a prognostic factor. To conduct this systematic review, we used only studies conducted in humans, written in English, and published in the last 20 years. We used PubMed as a database and searched the following search terms: ("NMDA encephalitis"[Title/Abstract] AND "Epilepsy"[Title/Abstract]) OR (NMDA encephalitis"[Title/Abstract] AND "seizures" [Title/Abstract]) OR ("NMDA encephalitis"[Title/Abstract] AND "extreme delta brush"[Title/Abstract]). The protocol used for this systematic review was the Meta-analyses Of Observational Studies in Epidemiology (MOOSE) protocol, and to analyze the bias of the studies, we used the ROBINS-1 tool. Eight studies were collected from our search strategy. Our data pulling showed that seizures were present in 178/249 (71.48%) patients. Status Epilepticus was reported in 29/96 (30.20%), and the EBD was seen in 30.89% (55/178) patients with seizures. The range of EDB was 5.9%-33% among the studies. Because the sample size was small, the statistical power was decreased. We had a low overall risk of bias. The wide range in the results could be related to the timing of the EEG recording. EDB was associated overall with increased length of hospital stay, increased ICU admission, and incidence of status epilepticus. The etiology of the EDB remains mainly unknown. However, it has been postulated that in NMDAR encephalitis, there is a disruption of the rhythmic neuronal activity. When antibodies block/target the NMDAR, the rhythmic neuronal activity is disrupted, leading to the unique EDB pattern. Another theory suggests that delta activity is caused because of focal abnormalities in the brain, and the superimposition of the beta waves is related to the alterations of the NMDA receptors.

Spectrum of Anti-NMDA Receptor Antibody Encephalitis: Clinical Profile, Management and Outcomes

Background:

Anti-N-methyl D-aspartate receptor (anti NMDAR) antibody encephalitis is an immune-mediated entity characterised by a constellation of neuro-psychiatric symptoms.

Objective:

To describe clinical profile and treatment outcomes of patients with anti NMDAR antibody encephalitis.

Settings and Design:

Subjects were selected by screening for all patients satisfying Graus et al.'s criteria for probable anti NMDAR antibody encephalitis, admitted in neurology department of a tertiary care centre in Eastern India.

Materials and Methods:

A prospective, longitudinal study was conducted by identifying 25 patients with anti NMDAR antibodies in CSF and or serum, between September 2018 to February 2020.

Statistical Analysis:

Chi square test was used to compare variables.

Results:

Out of 98 patients screened, 25 subjects (14 females: 11 male) were positive for anti NMDAR autoantibodies, with a mean age of 17 years. 13 subjects belonged to paediatric age group. Most common presenting feature was memory/learning deficit (88%) followed by behavioural abnormalities (84%) and seizures (68%). 11 patients (44%) patients needed escalation to second line therapy, rituximab. Seven (28%) and twelve (48%) patients underwent complete (mRS 0-1) and partial recovery (mRS 2-3) respectively, while 4 (16%) became disabled (mRS 4-5). Mortality was 8%. Paediatric population had a better outcome in terms of disability (p = 0.043).

Conclusion:

Anti NMDAR-Ab encephalitis is the most common cause of antibody positive autoimmune encephalitis worldwide. There are important clinical markers and investigational profiles which carry prognostic significance.

International Consensus Recommendations for the Treatment of Pediatric NMDAR Antibody Encephalitis

Objective

To create an international consensus treatment recommendation for pediatric NMDA receptor antibody encephalitis (NMDARE).

Methods

After selection of a panel of 27 experts with representation from all continents, a 2-step Delphi method was adopted to develop consensus on relevant treatment regimens and statements, along with key definitions in pediatric NMDARE (disease severity, failure to improve, and relapse). Finally, an online face-to-face meeting was held to reach consensus (defined as ≥75% agreement).

Results

Corticosteroids are recommended in all children with NMDARE (pulsed IV preferred), with additional IV immunoglobulin or plasma exchange in severe patients. Prolonged first-line immunotherapy can be offered for up to 3–12 months (oral corticosteroids or monthly IV corticosteroids/immunoglobulin), dependent on disease severity. Second-line treatments are recommended for cases refractory to first-line therapies (rituximab preferred over cyclophosphamide) and should be considered about 2 weeks after first-line initiation. Further immunotherapies for refractory disease 1-3 months after second-line initiation include another second-line treatment (such as cyclophosphamide) and escalation to tocilizumab. Maintenance immune suppression beyond 6 months (such as rituximab redosing or mycophenolate mofetil) is generally not required, except for patients with a more severe course or prolonged impairments and hospitalization. For patients with relapsing disease, second-line and prolonged maintenance therapy should be considered. The treatment of NMDARE following herpes simplex encephalitis should be similar to idiopathic NMDARE. Broad guidance is provided for the total treatment duration (first line, second line, and maintenance), which is dictated by the severity and clinical course (i.e., median 3, 9 and 18 months in the best, average, and worst responders, respectively). Recommendations on the timing of oncologic searches are provided.

Conclusion

These international consensus recommendations for the management of pediatric NMDARE aim to standardize the treatment and provide practical guidance for clinicians, rather than absolute rules. A similar recommendation could be applicable to adult patients.

Antibody-Mediated Encephalitis in Children: Focus on Diagnostic Clues and Acute Symptom Management

Antibody-mediated encephalitis is a treatable cause of encephalitis that manifests over days to weeks as changes in behavior and cognition, seizures, movement disorders, and autonomic dysfunction. Patients with autoimmune encephalitis develop a variety of symptoms. As such, they require a multidisciplinary approach to care. In this review we summarize the clinical presentation and practical diagnostic approach to pediatric autoimmune encephalitis, review treatments of the autoimmune process, and discuss the management of the acute symptoms encountered in children.

Clinical Features, Treatment Strategies, and Outcomes in Hospitalized Children With Immune-Mediated Encephalopathies

BACKGROUND

Autoimmune encephalitis (AE) and acute disseminated encephalomyelitis (ADEM) are immune-mediated brain conditions that can cause substantial neurological sequalae. Data describing the clinical characteristics, treatments, and neurological outcomes for these conditions are needed.

METHODS

This is a single-center retrospective review of children diagnosed with AE or ADEM over a nine-year period with discharge outcomes measured by the Modified Rankin Score.

RESULTS

Seventy-five patients (23 with ADEM and 52 with AE) were identified. Patients with ADEM had a higher percentage of abnormal magnetic resonance imaging findings (100% vs 60.8%; P < 0.001) and a shorter time from symptom onset to diagnosis (6 vs 14 days; P = 0.024). Oligoclonal bands and serum and cerebrospinal fluid inflammatory indices were higher in patients with AE. Nearly all patients received corticosteroids followed by plasmapheresis or intravenous immunoglobulin, and treatment strategies did not differ significantly between groups. Second-line immune therapies were commonly used in patients with AE. Finally, patients with AE had trends toward longer hospital lengths of stay (21 vs 13 days) and a higher percentage of neurological disability at hospital discharge (59.6% vs 34.8%).

CONCLUSIONS

Although patients with ADEM and AE may have similar presenting symptoms, we found significant differences in the frequency of imaging findings, symptom duration, and laboratory and cerebrospinal fluid profiles, which can assist in distinguishing between the diagnoses. Patients in both groups were treated with a combination of immunomodulating therapies, and neurological disability was common at hospital discharge.

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

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

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

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

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

Clinical and Neuroimaging Characteristics of Pediatric Acute Disseminating Encephalomyelitis With and Without Antibodies to Myelin Oligodendrocyte Glycoprotein

Objective: To compare the clinical and neuroimaging characteristics of anti-myelin oligodendrocyte glycoprotein antibody (MOG-ab) negative and positive pediatric acute disseminating encephalomyelitis (ADEM) patients.

Methods: Clinical characteristics, neuroimaging features, ancillary examination results, and outcomes of pediatric ADEM patients were retrospectively reviewed between February 2016 and July 2019.

Results: Among 37 pediatric ADEM patients, 24 patients (11 girls and 13 boys) fulfilled the inclusion criteria. The median age was 72 (range 19–156) months, and the median follow-up duration was 20 (range 12–48) months. Children with ADEM and MOG-abs presented with increased ataxia, reduced bladder/rectum dysfunction, and paralysis compared to children without MOG-abs. An important finding was that no significant differences existed in age at symptom onset, sex ratio, time from immunotherapy to clinical improvement and clinical recovery, or modified Rankin Scale (mRS) at the last follow-up. More typical cerebral MRI lesions were detected in patients with ADEM and MOG-abs than in children without MOG-abs [11/12 (91.7%) vs. 8/12 (66.7%)]. Cerebellar lesions were higher in ADEM patients with MOG-abs (7/12, 58.3%) than in those without MOG-abs (2/12, 16.7%). While seven children had abnormal spinal MRI findings (7/12, 58.3%) and five had longitudinally extensive transverse myelitis (LETM) (5/12, 41.7%) per group, the coexistence of spinal dysfunction and abnormal spinal MRI was lower in ADEM with MOG-abs (2/12, 16.7%) than in children without MOG-abs (7/12, 58.3%). Clinical improvement was achieved 1 week after immunotherapy. Most children in both groups achieved clinical recovery within 3 months after immunotherapy, although two (16.7%) patients with ADEM and MOG-abs had persistent neurological sequelae at the last follow-up.

Conclusion: MOG-abs-positive ADEM is a major subtype of pediatric ADEM. Ataxia is the most common clinical presentation in pediatric ADEM and MOG-abs. Children with ADEM and MOG-abs have similar patterns of lesions characterized by large, bilateral, widespread lesions, as well as more cerebellar lesions than children without MOG-abs. Most spinal lesions were subclinical in pediatric ADEM with MOG-abs. A favorable prognosis can be achieved for pediatric ADEM regardless of the MOG-abs status. However, some patients with MOG-abs are likely to have more severe neurological sequelae.

Efficacy and Safety of Rituximab in Chinese Children With Refractory Anti-NMDAR Encephalitis

Purpose: To assess the efficacy and safety of rituximab treatment as second-line immunotherapy in pediatric cases of anti-NMDA receptor (NMDAR) encephalitis. Methods: We retrospectively recruited 8 patients with anti-NMDAR encephalitis who were treated with rituximab as second-line immunotherapy. We evaluated the clinical features, laboratory examination results and treatment protocols of the Chinese children and defined good outcomes based on the modified Rankin scale (mRS) score (0-2) at the last follow-up. Results: A total of eight pediatric patients (median age 6.7 years; four female) with refractory anti-NMDAR encephalitis were recruited to the study. Rituximab was given after a median duration of disease of 57 days (range 50.5-113.75 days). The use of rituximab led to a significant reduction in the mRS and CD19+ B-cells compared to before rituximab infusion (P < 0.05). Five patients (62.5%) had a good outcome (mRS ≤ 2) including four patients (50%) who showed complete recovery (mRS = 0) at the last follow-up. Transient infusion adverse events were recorded in 2 patients (25%). Two patients (25%) had severe infectious adverse events (AEs) and two patients with grade 5 (death). None of the patients developed progressive multifocal leukoencephalopathy (PML). Conclusion: Our study provides evidence that rituximab can efficiently improve the clinical symptoms of anti-NMDAR encephalitis in children. However, due to the risk of adverse infections, rituximab should be restricted in pediatric patients with high rates of mortality and disability.

Clinical outcomes of pediatric Anti-NMDA receptor encephalitis

OBJECTIVE

To investigate the clinical features and long-term outcomes of pediatric Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis.

METHODS

Thirty-two anti-NMDAR encephalitis patients with positive anti-NMDAR antibody test results were recruited. Clinical outcomes were evaluated using the Clinical Assessment Scale in Autoimmune Encephalitis (CASE) and the modified Rankin Scale (mRS).

RESULTS

The median age of onset was 9.0 years (range, 0.7-17.2 years). Twenty-four patients (75.0%) were female. All patients received first-line immunotherapy including intravenous immunoglobulin and/or steroid therapy. The second-line immunotherapy was administered to 22 patients (68.8%). Clinical outcomes were evaluated in 27 patients who were followed for longer than 6 months after onset, among whom the median follow-up duration was 31.2 months (range, 6.3-82.9 months). The proportion of patients with ≤2 points on the mRS at their 12-month follow-up was 79.2% (19/24). The CASE scores of these 19 patients ranged from 0 to 5, with language and memory deficits accounting for most of these disabilities. When the outcome was assessed according to onset age (<12 years or 12-18 years), the younger group tended to show a slower recovery over their clinical course.

CONCLUSIONS

Despite overall favorable clinical outcomes, mild cognitive problems, including language and memory, may persist in pediatric anti-NMDAR encephalitis patients. A specific outcome measure, such as CASE, should be adopted to delineate clinical outcomes and aid the development of individualized treatment plans.

Therapeutic Plasma Exchange in Multiple Sclerosis and Autoimmune Encephalitis: a Comparative Study of Indication, Efficacy and Safety

Therapeutic plasma exchange (TPE) is a well-established method of treatment for steroid-refractory relapses in multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD). Little is known about indications and clinical responses to TPE in autoimmune encephalitis and other immune-mediated disorders of the central nervous system (CNS). We performed a retrospective chart review of patients with immune-mediated disorders of the CNS undergoing TPE at our tertiary care center between 2003 and 2015. The response to TPE within a 3- to 6-month follow-up was scored with an established rating system. We identified 40 patients including 21 patients with multiple sclerosis (MS, 52.5%), 12 with autoimmune encephalitis (AE, 30%), and 7 with other immune-mediated CNS disorders (17.5%). Among patients with AE, eight patients had definite AE (Immunolobulin G for N-methyl-D-aspartate receptor n = 4, Leucine-rich, glioma inactivated 1 n = 2, Ma 2 n = 1, and Alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid n = 1). Intravenous immunoglobulins had been given prior to TPE in all but one patient with AE, and indications were dominated by acute psychosis and epileptic seizures. While TPE has a distinct place in the treatment sequence of different immune-mediated CNS disorders, we found consistent efficacy and safety. Further research should be directed toward alternative management strategies in non-responders.