Paediatric anti-N-methyl-D-aspartate receptor encephalitis: The first Italian multicenter case series

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

Background

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

Objective

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

Methods

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

Results

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

Conclusion

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

Evaluation, Treatment, and Outcomes of Viral and Autoimmune Encephalitis in Children

Viral encephalitis and autoimmune encephalitis are currently the most common causes of encephalitis. Determining the causative agent is helpful in initiating medical treatment that may help reduce long-term sequelae. Cerebrospinal fluid, neuroimaging, serologic, and electroencephalogram in combination with clinical manifestations play a role in determining the cause of the encephalitis. Although motor dysfunction tends to improve, there is a significant risk of long-term neurologic and cognitive sequelae. These persistent deficits that occur in childhood indicate the importance for ongoing rehabilitative services to maximize functional skills, improve cognitive deficits, and assist with community integration.

Clinical Characteristics and Prognosis of Antibody-Negative Autoimmune Encephalitis in Children: A Single-Center Retrospective Study

BACKGROUND

Autoimmune encephalitis (AE) is a group of immune-mediated brain diseases. However, new diagnostic criteria for AE in children indicate that partial pediatric patients with AE may be diagnosed without evidence of positive autoantibodies. Therefore, the clinical characteristics and prognosis of children with antibody-negative but probable AE require further investigation.

METHODS

Forty-one children with AE admitted to our hospital from April 2014 to January 2021 were retrospectively enrolled in this study. Children were divided into two groups according to positive or negative antibody tests. Clinical characteristics, cerebrospinal fluid, video electroencephalography, brain magnetic resonance imaging, and prognosis were analyzed, and the correlation between modified Rankin scale (mRS) and neutrophil-to-lymphocyte ratio (NLR) was examined.

RESULTS

Of 41 children, 16 cases tested positive for autoantibodies. The main features were psychiatric symptoms, cognitive disturbances, speech disturbances, movement disorders, and seizures. All the children were given a combination of intravenous methylprednisolone pulses with intravenous immunoglobulin therapy; 26 cases (63%) had a good outcome, and 15 cases (37%) had a poor outcome. Antibody-positive and antibody-negative but probable AE were analyzed by univariate analysis and showed lower lymphocyte counts and higher NLR and mRS scores in the antibody-negative group (P < 0.05). The Spearman rank correlation analysis showed a positive correlation between NLR level and mRS scores (P < 0.05).

CONCLUSIONS

Antibody-negative but possible AE is frequent in children who may have a more severe neurological impairment and higher NLR than antibody-positive AE. Aggressive immunotherapy in antibody-negative AE is essential to achieve a good prognosis.

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

Objective

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

Methods

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

Results

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

Conclusions

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

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

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

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.

Use and Safety of Immunotherapeutic Management of N-Methyl-d-Aspartate Receptor Antibody Encephalitis: A Meta-analysis

Question

What are the most effective treatments for N-methyl-d-aspartate receptor (NMDAR) antibody encephalitis?

Findings

In this meta-analysis of individual patient data including 1550 cases, treatment factors at first event that were significantly associated with good functional outcome 12 months from disease onset included first-line treatment with therapeutic apheresis alone, corticosteroids in combination with intravenous immunoglobulin (IVIG), or corticosteroids in combination with IVIG and therapeutic apheresis, while lack of immunotherapy within 30 days of disease onset was significantly associated with poor outcome. Rituximab and long-term IVIG use were significantly associated with nonrelapsing disease course.

Meaning

Separate treatment factors are associated with functional outcomes and relapsing disease biology in those with NMDAR antibody encephalitis.

Importance

Overall, immunotherapy has been shown to improve outcomes and reduce relapses in individuals with N-methyl-d-aspartate receptor (NMDAR) antibody encephalitis (NMDARE); however, the superiority of specific treatments and combinations remains unclear.

Objective

To map the use and safety of immunotherapies in individuals with NMDARE, identify early predictors of poor functional outcome and relapse, evaluate changes in immunotherapy use and disease outcome over the 14 years since first reports of NMDARE, and assess the Anti-NMDAR Encephalitis One-Year Functional Status (NEOS) score.

Data Sources

Systematic search in PubMed from inception to January 1, 2019.

Study Selection

Published articles including patients with NMDARE with positive NMDAR antibodies and available individual immunotherapy data.

Data Extraction and Synthesis

Individual patient data on immunotherapies, clinical characteristics at presentation, disease course, and final functional outcome (modified Rankin Scale [mRS] score) were entered into multivariable logistic regression models.

Main Outcomes and Measures

The planned study outcomes were functional outcome at 12 months from disease onset (good, mRS score of 0 to 2; poor, mRS score greater than 2) and monophasic course (absence of relapse at 24 months or later from onset).

Results

Data from 1550 patients from 652 articles were evaluated. Of these, 1105 of 1508 (73.3%) were female and 707 of 1526 (46.3%) were 18 years or younger at disease onset. Factors at first event that were significantly associated with good functional outcome included adolescent age and first-line treatment with therapeutic apheresis, corticosteroids plus intravenous immunoglobulin (IVIG), or corticosteroids plus IVIG plus therapeutic apheresis. Factors significantly associated with poor functional outcome were age younger than 2 years or age of 65 years or older at onset, intensive care unit admission, extreme delta brush pattern on electroencephalography, lack of immunotherapy within the first 30 days of onset, and maintenance IVIG use for 6 months or more. Factors significantly associated with nonrelapsing disease were rituximab use or maintenance IVIG use for 6 months or more. Adolescent age at onset was significantly associated with relapsing disease. Rituximab use increased from 13.5% (52 of 384; 2007 to 2013) to 28.3% (311 of 1100; 2013 to 2019) (P < .001), concurrent with a falling relapse rate over the same period (22% [12 of 55] in 2008 and earlier; 10.9% [35 of 322] in 2017 and later; P = .006). Modified NEOS score (including 4 of 5 original NEOS items) was associated with probability of poor functional status at 1 year (20.1% [40 of 199] for a score of 0 to 1 points; 43.8% [77 of 176] for a score of 3 to 4 points; P = .05).

Conclusions and Relevance

Factors influencing functional outcomes and relapse are different and need to be considered independently in development of evidence-based optimal management guidelines of patients with NMDARE.

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.

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.

Anti-N-Methyl-D-Aspartate Receptor Encephalitis Associated with Ovarian Teratoma in South China-Clinical Features, Treatment, Immunopathology, and Surgical Outcomes of 21 Cases

Objective

To study the clinical characteristics and surgical outcomes of anti-NMDAR encephalitis and the immunopathology of associated teratomas.

Methods

Twenty-one patients were enrolled in this retrospective study, who were diagnosed with anti-NMDAR encephalitis with ovarian teratoma and admitted to two tertiary hospitals in South China from July 2014 to December 2019. The clinical data of patients were reviewed. Comparisons were made between the patients with different outcomes after surgery. Immunohistochemical analyses of associated ovarian teratomas were performed.

Results

The mean age of the patients was 24.33 ± 5.12 years. The peak seasons of disease onset were autumn and winter (30.61% and 32.65%). The symptoms could be divided into 8 categories, including psychiatric abnormalities, seizures, movement dysfunction, consciousness disorders, autonomic dysregulation, speech disturbance, central hypoventilation, and memory deficits. All patients developed four or more categories of symptoms within the first four weeks. Twelve patients (57.1%) had a maximum mRS of 5, and 11 patients (52.4%) were admitted to ICU. Twenty patients received surgery, and only 3 patients were diagnosed pathologically with immature ovarian teratomas, while the other 17 patients had mature ovarian teratomas. After surgery, 17 patients (85.0%) got clinical improvement. The central hypoventilation symptom and mature ovarian teratomas were associated with surgical outcome. Immunohistochemical analysis revealed that there were NMDAR-positive neural tissues in all 8 teratomas and in which 3 cases also contained large numbers of NMDAR-positive sebaceous glands and squamous epithelial tissues.

Conclusion

The disease is of high prevalence in autumn and winter. The central hypoventilation symptom and mature ovarian teratomas were associated with surgical outcome. NMDAR-positive neural tissue is not the only etiological factor of encephalitis. We speculate that encephalitis development in some patients may result from NMDAR expression in sebaceous glands and squamous epithelial tissues.

A narrative review of pharmacologic approaches to symptom management of pediatric patients diagnosed with anti-NMDA receptor encephalitis

Anti-N-Methyl-D-Aspartate Receptor Encephalitis (ANMDARE) is one of the most common autoimmune encephalitis in the pediatric population. Patients with ANMDARE initially present with a prodrome of neuropsychiatric symptoms followed by progressively worsening seizures, agitation, and movement disorders. Complications can include problems such as aggression, insomnia, catatonia, and autonomic instability. Due to the complexity of this disease process, symptom management can be complex and may lead to significant polypharmacy. The goal of this review is to educate clinicians about the challenges of managing this disorder and providing guidance in symptom management.

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.

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

OBJECTIVES

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

DESIGN

Retrospective chart review and post hoc analysis.

SETTING

Pediatric inpatient rehabilitation unit.

PARTICIPANTS

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

INTERVENTIONS

Inpatient rehabilitation; pharmacologic treatments.

MAIN OUTCOME MEASURE

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

RESULTS

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

CONCLUSION

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

Bortezomib-Responsive Refractory Anti-N-Methyl-d-Aspartate Receptor Encephalitis

BACKGROUND

Anti-N-methyl-d-aspartate receptor encephalitis is a central nervous system inflammatory autoimmune disease affecting adults and children. The use of first- and second-line immunotherapies is supported. Recent reports suggest the efficacy of bortezomib in severe anti-N-methyl-d-aspartate encephalitis in adult patients not responsive to second-line treatment; there are no data about pediatric patients.

PATIENT DESCRIPTION

We describe an eight-year-old child with anti-N-methyl-d-aspartate encephalitis not responsive to first- and second-line treatments who experienced marked clinical improvement after bortezomib administration.

DISCUSSION

Bortezomib is a selective and reversible inhibitor of the 26S proteasome, which is used to treat oncologic and rare autoimmune disorders in pediatric patients. As observed in adult patients, bortezomib administration induced anti-N-methyl-d-aspartate antibody titer decline and clinical improvement with an acceptable risk profile.

CONCLUSION

This is the first report of the use of bortezomib in children with anti-N-methyl-d-aspartate encephalitis; it could be a useful therapeutic option in children with refractory anti-N-methyl-d-aspartate encephalitis.

Anti-N-methyl-D-aspartate receptor encephalitis with accompanying ovarian teratoma in female patients from East China: Clinical features, treatment, and prognostic outcomes

PURPOSE

The association between anti-N-methyl-D-aspartate receptor encephalitis (anti-NMDAR encephalitis) and teratoma is formally recognized. This study compared the clinical features, treatments and outcomes between female patients with or without accompanying teratomas and determined the potential influences of coexisting teratomas.

METHOD

Fifty-six female patients diagnosed with anti-NMDAR encephalitis were enrolled in two major tertiary hospitals in East China from January 2013 through March 2018 and were grouped as patients with or without teratoma. The clinical features were reviewed, and follow-up studies were performed. Comparisons were made between the two groups.

RESULTS

Patients with teratoma reported fewer viral prodromes (p = 0.0085) and stronger positive intensity of anti-NMDAR antibodies in cerebrospinal fluid (CSF) (p = 0.0368), while nontumor patients tended to demonstrate lymphocytic pleocytosis in CSF (p = 0.0306). Seizure types varied between individuals, with complex partial seizures more common in teratoma patients (p = 0.0105). Nontumor patients frequently required combinations of first-line and second-line immunotherapy (p = 0.0014), which may be attributed to higher mRS scores at admission (p = 0.0300). Also, they had higher mean mRS scores since the 12-month follow-up and greater probability of relapse than did patients with teratomas (p = 0.0286).

CONCLUSIONS

Symptomatology and auxiliary findings indicate that ovarian teratoma may be the immunologic trigger for anti-NMDAR encephalitis patients, while viral infection is likely to play a major part in pathogenesis for those without any detectable tumor. Overall, anti-NMDAR encephalitis patients with teratomas present with milder neurological symptoms and have better long-term outcomes after tumor removal.

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

AIM

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

METHOD

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

RESULTS

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

INTERPRETATION

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

WHAT THIS PAPER ADDS

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

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

Objective: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is the most common form of autoimmune encephalitis in pediatric patients. In this study, we aimed to investigate the clinical features and long-term outcomes of pediatric patients with anti-NMDAR encephalitis in China.

Methods: We conducted a retrospective study of children (age range: 0–18 years) with anti-NMDAR encephalitis treated at Children's Hospital of Fudan University between July 2015 and November 2018. Demographic characteristics, clinical features, treatment, and outcomes were reviewed.

Results: Thirty-four patients with anti-NMDAR encephalitis were enrolled (age range: 5 months to 14 years; median age: 7 years; female: 18). The median follow- up duration was 20 months (range: 6–39 months). Eighteen (52.9%) patients initially presented with seizures and 10 (29.4%) with abnormal (psychiatric) behaviors or cognitive dysfunction. Thirty (88.2%) patients exhibited more than two symptoms during the disease course. No neoplasms were detected. Twelve (35.2%) patients had abnormal cerebrospinal fluid (CSF) findings, including leukocytosis, and increased protein concentration. Eighteen (52.9%) patients exhibited normal brain MRI findings. Electroencephalography revealed abnormal background activity in 27 (79.4%) patients, and epileptiform discharges in 16 (47.0%) patients prior to immunotherapy. All patients received first-line immunotherapy, with 30 (88.2%) and four (11.8%) patients achieving good (Modified Rankin Scale [mRS] score of 0–2) and poor outcomes (mRS score of 3–5), respectively. Initial mRS scores differed significantly between the good and poor outcome groups. Fourteen out of 18 patients (77.7%) with seizures accepted anti-epileptic drug (AED) administration, and seizure freedom was achieved in 12 out of 14 (85.7%) patients at the last follow-up. Ten of these 12 (83.3%) patients withdrew from AED treatment within 1 year.

Conclusions: Most patients achieved seizure freedom, so long-term use of AEDs may not be necessary for pediatric patients with anti-NMDAR encephalitis. Among our patients, 83.3% were sensitive to first-line immunotherapy and achieved good outcomes. Higher mRS scores before immunotherapy predicted poor outcomes, highlighting the need for a comprehensive assessment of patients with anti-NMDAR encephalitis.

Management of antibody-mediated autoimmune encephalitis in adults and children: literature review and consensus-based practical recommendations

Autoimmune encephalitis associated with antibodies against neuronal surface targets (NSAE) are rare but still underrecognized conditions that affect adult and pediatric patients. Clinical guidelines have recently been published with the aim of providing diagnostic clues regardless of antibody status. These syndromes are potentially treatable but the choice of treatment and its timing, as well as differential diagnoses, long-term management, and clinical and paraclinical follow-up, remain major challenges. In the absence of evidence-based guidelines, management of these conditions is commonly based on single-center expertise.Taking into account different published expert recommendations in addition to the multicenter experience of the Italian Working Group on Autoimmune Encephalitis, both widely accepted and critical aspects of diagnosis, management and particularly of immunotherapy for NSAE have been reviewed and are discussed.Finally, we provide consensus-based practical advice for managing hospitalization and follow-up of patients with NSAE.

Recognizing psychiatric presentations of anti-NMDA receptor encephalitis in children and adolescents: A synthesis of published reports

AIM

The aim of this study was to improve early recognition of anti-N-methyl-d-aspartate receptor encephalitis (anti-NMDArE) in children and adolescents by identifying characteristic temporal patterns of clinical features in patients likely to be referred for psychiatric evaluation. In this form of autoimmune encephalitis, NMDAr hypofunction is caused by autoantibodies to receptor surface components. Clinical outcomes following prompt immunotherapy are usually good, but delayed treatment often results in a protracted course with significant residual disability or death. Anti-NMDArE frequently mimics psychiatric disorders, so most patients are referred initially to a psychiatrist and treated for days or weeks before being correctly diagnosed.

METHODS

A systematic search of PubMed and EMBASE electronic databases identified all published reports of antibody-confirmed anti-NMDArE associated with psychiatric symptoms in patients <19 years old. Redundant reports were eliminated manually. For each patient, the order in which each feature was first observed was ranked relative to others. Median temporal ranks were used to compare the sequencing of individual features and major symptom domains.

RESULTS

One hundred and sixty seven cases (121 females) met the inclusion criteria. The most common features were dyskinesias (77.8%), seizures (72.5%), mutism or staring (40.7%), insomnia (39.5%), language dysfunction (36.5%), fever (31.1%), disorientation/confusion (28.7%), reduced arousal (28.1%), and memory disturbance (26.9%). The configuration and temporal sequencing of features were highly variable between individuals.

CONCLUSION

Clinicians need to suspect this disorder: if new behavioral symptoms arise in the context of a recent viral prodrome; if they are accompanied by dyskinesias, seizures or insomnia; or if psychiatric symptoms are unusual (e.g., non-verbal auditory hallucinations).

Mycophenolate mofetil, azathioprine and methotrexate usage in paediatric anti-NMDAR encephalitis: A systematic literature review

BACKGROUND

Available data on mycophenolate mofetil (MMF), azathioprine (AZA) and methotrexate (MTX) for paediatric-onset anti-N-methyl-d-aspartate receptor encephalitis (anti-NMDARE) is limited.

METHODS

Systematic literature review on patients treated with MMF/AZA/MTX for paediatric-onset anti-NMDARE, with focus on modes of use, efficacy and safety.

RESULTS

87 patients were included (age at onset median 11 years, range 0.8-18 years; 69% females). 46% had a relapsing course. 52% received MMF, 27% AZA, 15% MTX, and 6% a combination of MMF/AZA/MTX (7 patients received intrathecal MTX). Before MMF/AZA/MTX, 100% patients received steroids, 83% intravenous immunoglobulin and 45% plasma exchange, and 50% received second-line treatments (rituximab/cyclophosphamide). MMF/AZA/MTX were administered >6 months from onset in 51%, and only after relapse in 40%. Worst mRS before MMF/AZA/MTX was median 4.5 (range 3-5). At last follow-up (median 2 years, range 0.2-8.6), median mRS was 1 (range 0-6). Median annualised relapse rate was 0.4 (range 0-6.7) pre-MMF/AZA/MTX (excluding first events), and 0 on MMF/AZA/MTX (mean 0.03, range 0-0.8). 7% patients relapsed on MMF/AZA/MTX. These relapsing patients had low rate of second-line treatments before MMF/AZA/MTX (25%), long median time between onset and MMF/AZA/MTX usage (18 months), and frequently they were started on MMF/AZA/MTX only after relapse (75%). Relapse rate was lower among patients who received first immune therapy ≤30 days (25%) than later (64%), who received second-line treatments at first event (14%) rather than not (64%), who were started on MMF/AZA/MTX after the first (12%) rather than subsequent events (17%), and who were started on MMF/AZA/MTX ≤3 months from onset (33%) rather than later (53%). Adverse reactions to MMF/AZA/MTX occurred in 2 cases (cytomegalovirus colitis and respiratory infection), of grade 3 Common Terminology Criteria for Adverse Events v4.0.

DISCUSSION

Our literature review disclosed heterogeneity in the use of MMF/AZA/MTX in paediatric-onset anti-NMDARE. MMF/AZA/MTX usage is mostly restricted to retrospective cohort descriptions. These agents may reduce risk of relapse, and have a reasonable safety profile, however data on larger cohorts are required to definitively determine effect.

Clinical variability of children with anti-N-methyl-D-aspartate receptor encephalitis in southern Brazil: a cases series and review of the literature

PURPOSE

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an immune-mediated disease of the central nervous system (CNS). The aim of this study was to describe the variability of clinical presentation in anti-NMDAR encephalitis, treatment and outcomes in a case series of children and adolescents.

METHODS

Retrospectively analyse patients diagnosed with anti-NMDAR encephalitis, from 2010 to 2018.

RESULTS

The study population consisted of nine children with anti-NMDAR encephalitis from southern Brazil, six females and three males, aged 5 months to 16 years (mean 5 years). The time of follow-up varied between 1 and 7 years, with a mean of 3 years. The most frequent first manifestation consisted of seizures. All patients described had psychiatric symptoms and a wide spectrum of neurologic findings. Five patients had unilateral symptoms. Magnetic resonance imaging and electroencephalogram were normal in most patients. Cerebrospinal fluid pleocytosis occurred in five patients. All patients were administered immunoglobulin and/or steroids. Seven patients (78%) required cyclophosphamide and/or rituximab. Almost half of the patients fully recovered from all symptoms.

CONCLUSIONS

A wide variety of symptoms were observed in this study and, although unilateral symptoms are rarely reported in the literature, a high frequency was observed among Brazilian children. Alternatives to first-line therapy should be considered in patients with clinical suspicion, even if they have not had a good response with first-line therapy.

Neuropsychological And Psychopathological Profile Of Anti-Nmdar Encephalitis: A Possible Pathophysiological Model For Pediatric Neuropsychiatric Disorders

Objective

Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is a severe, but treatable, autoimmune disorder, characterized by autoantibodies causing hypofunction of blocking NMDA receptors leading to a unique constellation of cognitive, motor, and psychiatric symptoms. Neuropsychological and psychopathological outcome has not been fully explored, particularly in children. Aim of this study was to investigate pediatric anti-NMDAR encephalitis as a model of impairment of the complex frontal-subcortical circuits who are implicated in several of the childhood neuropsychiatric disorders.

Method

Seven children diagnosed with anti-NMDAR encephalitis at our department underwent an evaluation of the global mental functioning before discharge, a neuropsychological and psychological/behavioral standardized examination within one month after discharge and subsequently were followed up longitudinally for mean 35 months (range 24–48 months). Collected neuropsychological data were evaluated retrospectively.

Results

Deficits in attention, executive functions and/or visual motor functions involving executive functions were seen in all children within one month after discharge. These deficits were long lasting in about a half of the patients. In addition, four patients developed persistent psychopathological dysfunctions: difficulties to regulate their own behavior, impulsivity, hyperactivity, irritability, apathy, and obsessive-compulsive symptoms.

Conclusions

Our data are in line with research suggesting a crucial role of the executive functions impairments in cognitive outcome disturbance of anti-NMDAR encephalitis. We found also behavioral and psychological deficits pointing to a more comprehensive framework of frontal-subcortical dysfunction, in which the NMDA mediated transmission appear to have a role, as suggested by neurobiological, pharmacological, and neuroimaging studies.

Non-inflammatory cerebrospinal fluid delays the diagnosis and start of immunotherapy in anti-NMDAR encephalitis

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a form of autoimmune encephalopathy that presents with a wide variety of symptoms, including neuropsychiatric manifestations. The authors' aim for this study was to analyze the results of paraclinical studies of patients with a diagnosis of anti-NMDAR encephalitis and the association between symptom onset and diagnosis, and start of immunotherapy. Retrospective data of 29 patients with anti-NMDAR encephalitis were gathered and analyzed. Abnormal EEG was found in 27 patients (93.1%), whereas MRI was abnormal in 19 patients (65.5%). In contrast, an inflammatory pattern on CSF analysis was found in only 13 patients (44.8%). The absence of pleocytosis or increased proteins in the CSF was associated with a longer time from symptom onset to diagnosis and treatment (p = 0.003). The authors conclude that noninflammatory CSF may delay the correct diagnosis and start of immunotherapy in anti-NMDAR encephalitis. In the presence of suggestive clinical features, extensive studies including EEG are recommended.

Analysis and discussion of the rare complication of autoimmune encephalitis: Two case reports

RATIONALE

Autoimmune encephalitis related to many antibodies against neuronal cell surface or synaptic proteins, it is increasingly recognized as the cause of a variety of neuropsychiatric syndromes.

PATIENT CONCERNS

The two pediatric cases were about autoimmune encephalitis with rare complication. One patient was a 11-year-old girl and was diagnosed with Voltage-Gated Potassium Channel complex (VGKC) antibody-mediated encephalitis with rhabdomyolysis; the other was also a 11-year-old girl and was diagnosed with anti- N-methyl-D-aspartate receptor (NMDAR) encephalitis.

DIAGNOSES

Both patients were diagnosed as autoimmune encephalitis with rare complication.

INTERVENTIONS

Intravenous methylprednisolone, oral prednisone and intravenous immunoglobulin was administered to both patients.

OUTCOMES

One patient was discharged after a half month's hospitalization; the other was finally with intestinal function failure, gradually developed multiple organ failure, and eventually died.

LESSONS

The pathogenic mechanism of autoimmune encephalitis associated with autoimmune disease is not fully understood, but may be related to a common immune pathological mechanism with variance in susceptibility caused by genetic or environmental factors.

Anti-N-methyl-d-aspartate receptor encephalitis in children: Incidence and experience in Hong Kong

AIM

The study aims to analyze the incidence, clinical features, investigation findings and treatment outcomes of anti-N-methyl-d-aspartate receptor encephalitis in children from Hong Kong.

METHOD

A retrospective study was carried out on paediatric patients diagnosed with anti-NMDAR encephalitis in Hong Kong from January 2009 to December 2015.

RESULTS

Fifteen patients (67% female, 93% Chinese) were identified over seven years and the estimated incidence in Hong Kong was 2.2/million children per year (95% CI 1.2-3.6). The median age of presentation was 12 years (range 1-17 years). The most common symptom groups observed were abnormal psychiatric behavior or cognitive dysfunction (14/15, 93%) and seizures (14/15, 93%), followed by speech dysfunction (13/15, 87%), movement disorders (12/15, 80%), decreased level of consciousness (10/15, 67%) and autonomic dysfunction or central hypoventilation (5/15, 33%). The median number of symptom groups developed in each patient was 5 (range 3-6). All patients were treated with intravenous immunoglobulin and/or steroids. Three patients (20%) with more severe presentation required additional plasmapheresis and rituximab. Outcome was assessable in 14 patients. Among those eleven patients who had only received intravenous immunoglobulin and/or steroids, nine patients (82%) achieved full recovery. One patient (9%) had residual behavioral problem, while another one (9%) who developed anti-NMDAR encephalitis after herpes simplex virus encephalitis was complicated with dyskinetic cerebral palsy and epilepsy. Among those three patients who required plasmapheresis and rituximab, one (33%) had full recovery and two (66%) had substantial recovery. The median duration of follow up was 20.5 months (range 3-84 months).

CONCLUSION

Anti-NMDAR encephalitis is an acquired, severe, but potentially treatable disorder. Ethnicity may play a role in the incidence of anti-NMDAR encephalitis and we have provided a local incidence with the majority of patients being Chinese. The diagnosis of anti-NMDAR encephalitis should be considered in children presenting with a constellation of symptoms including psychiatric and neurological manifestations. Patients may respond to first line immunotherapy. For those who do not, second line therapy is indicated in order to achieve a better outcome.

Biological Drugs in Guillain-Barré Syndrome: An Update

Background:

Guillain-Barré Syndrome (GBS) is currently considered the most common global cause of acute flaccid paralysis. Currently, standard therapy for Guillain-Barré Syndrome includes intravenous immunoglobulin or plasma exchange. Despite medical advances regarding these treatments, many treated patients do not reach full recovery. Therefore several biological agents have attracted the attentions from researchers during the last decades, and various studies have investigated their role in Guillain-Barré Syndrome.

Objective:

The present study aims to address emerging biological approaches to GBS while considering their efficiency and safety in treating the disease.

Materials and Methods:

An extensive electronic literature search was conducted by two researchers from April 2016 to July 2016. Original articles, clinical trials, systematic reviews (with or without meta-analysis) and case reports were selected. Titles and abstracts of papers were screened by reviewers to determine whether they met the eligibility criteria, and full texts of the selected articles were retrieved.

Results:

Herein authors focused on the literature data concerning emerging biological therapeutic agents, namely anti-C5 monoclonal antibody (Eculizumab), anti-C1q monoclonal antibody, anti-T cell monoclonal antibody, anti-CD2 monoclonal antibody, anti L-selectin monoclonal antibody, anti-CD20 monoclonal antibody (Rituximab), anti-CD52 monoclonal antibody (Alemtuzumab) and cytokine targets. By far, none of these agents have been approved for the treatment of GBS by FDA.

Conclusion:

Literature findings represented in current review herald promising results for using these biological targets. Current review represents a summary of what is already in regards and what progress is required to improve the immunotherapeutic approach of treating GBS via future studies.

An Update on the Treatment of Pediatric Autoimmune Encephalitis

PURPOSE OF REVIEW

Autoimmune encephalitis (AE) is an increasingly recognized etiology for neuropsychiatric deficits that are highly responsive to immunotherapy. As a result, rheumatologists are often called upon to help with the diagnosis and treatment of these conditions. The purpose of this review is to provide an update on the pharmacologic treatment of AE.

RECENT FINDINGS

To date, there are no prospective randomized placebo-controlled trials to guide treatment recommendations for AE. First-line therapies include corticosteroids, intravenous immunoglobulin, and plasma exchange. Second-line therapies include rituximab and cyclophosphamide (CYC), as well as mycophenolate mofetil and azathioprine. For patients refractory to both first- and second-line therapy, there is emerging evidence for the interleukin-6 (IL-6) inhibitor tocilizumab, the proteasome inhibitor bortezomib, and low-dose IL-2. Early treatment initiation and treatment escalation in patients with refractory disease improve outcomes. Given the delayed time between dosing and treatment effects of second-line agents, continuing first-line treatment until the patients shows improvement is recommended.

SUMMARY

Although AE can present with dramatic, life-threatening neuropsychiatric deficits, the potential for recovery with prompt treatment is remarkable. First- and second-line therapies for AE lead to clinical improvement in the majority of patients, including full recoveries in many. Early treatment and escalation to second-line therapy in those with refractory disease improves patient outcomes. Novel treatments including IL-6 blockade and proteasome inhibitors have shown promising results in patients with refractory disease.

Clinical presentation of anti-N-methyl-d-aspartate receptor and anti-voltage-gated potassium channel complex antibodies in children: A series of 24 cases

OBJECTIVE

The symptomatology and paraclinical findings of antibody-mediated encephalitis, a relatively novel disorder, are still being characterized in adults and children. A high index of suspicion is needed in order to identify these cases among children presenting with various neurological symptoms. The aim of this study is to examine the clinical, demographic and laboratory findings and outcome of children with anti-NMDAR and anti-VGKC encephalitis for any typical or distinctive features.

METHODS

Cases diagnosed with anti-N-Methyl d-aspartate receptor (NMDAR) and anti-voltage gated potassium channel (VGKC) antibody-mediated encephalopathy in four major child neurology centers are described.

RESULTS

In four years, 16 children with NMDAR and 8 children with VGKC antibody-associated disease were identified in the participating centers. The most frequent initial manifestation consisted of generalized seizures and cognitive symptoms in both groups. Movement abnormalities were frequent in anti-NMDAR patients and autonomic symptoms, in anti-VGKC patients. Cerebrospinal fluid (CSF) protein, cell count and IgG index were normal in 9/15 anti-NMDAR and 5/8 anti-VGKC patients tested. EEG and MRI findings were usually nonspecific and non-contributory. The rate and time of recovery was not related to age, sex, acute or subacute onset, antibody type, MRI, EEG or CSF results. Treatment within 3 months of onset was associated with normal neurological outcome.

CONCLUSIONS

Our results suggest anti-NMDAR and VGKC encephalopathies mostly present with non-focal neurological symptoms longer than 3 weeks. In contrast with adult cases, routine CSF testing, MRI and EEG did not contribute to the diagnosis in this series.

Failure to improve after ovarian resection could be a marker of recurrent ovarian teratoma in anti-NMDAR encephalitis: a case report

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a type of autoimmune encephalitis that can be paraneoplastic and usually responds to tumor resection and immunotherapy. More than 75% of patients with anti-NMDAR encephalitis fully recover or have only mild sequelae, whereas the remainder experience severe disability. It remains unknown why certain cases have refractory clinical disease courses. We report a case of anti-NMDAR encephalitis with bilateral ovarian teratomas who was refractory to tumor resection and early initiation of immunotherapy. During intensive care, immunohistochemical analyses of her cerebrospinal fluid showed persistently high reactivity of NMDAR antibody over time. Six months after the operation, pelvic computed tomography detected a recurrent ovarian teratoma. After total enucleation of the bilateral ovaries, with significant pathological findings of bilateral mature cystic teratomas, her clinical condition improved rapidly, paralleled by a decrease in anti-NMDAR reactivity. This case illustrates the need to keep considering why extensive treatment fails to influence the disease when we encounter patients with refractory anti-NMDAR encephalitis. Failure to improve after ovarian resection could be a marker of recurrent ovarian teratoma in anti-NMDAR encephalitis.

New Onset Insomnia in a Pediatric Patient: A Case of Anti-NMDA Receptor Encephalitis

Anti-NMDAR encephalitis is becoming more widely recognized as a cause of encephalopathy in both adults and children. Certain clinical features such as mood lability, movement disorders, speech dysfunction, seizures, and autonomic instability in a pediatric patient should prompt immediate concern and evaluation for autoimmune encephalitis among providers. We present the case of a pediatric patient with anti-NMDAR encephalitis in which the symptom prompting medical evaluation was insomnia. Insomnia has not previously been emphasized in the literature as a presenting feature of this disease in children and has a broad differential. Recognition of the symptoms of anti-NMDAR encephalitis and its variable presentation are key to early diagnosis and prompt initiation of treatment which may help to improve outcomes.

Herpes simplex virus-induced anti-N-methyl-d-aspartate receptor encephalitis: a systematic literature review with analysis of 43 cases

AIM

To conduct a systematic literature review on patients with biphasic disease with herpes simplex virus (HSV) encephalitis followed by anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis.

METHOD

We conducted a case report and systematic literature review (up to 10 December 2016), focused on differences between herpes simplex encephalitis (HSE) and anti-NMDAR encephalitis phases, age-related characteristics of HSV-induced anti-NMDAR encephalitis, and therapy. For statistical analyses, McNemar's test, Fisher's test, and Wilcoxon rank sum test were used (two-tailed significance level set at 5%).

RESULTS

Forty-three patients with biphasic disease were identified (31 children). Latency between HSE and anti-NMDAR encephalitis was significantly shorter in children than adults (median 24 vs 40.5d; p=0.006). Compared with HSE, anti-NMDAR encephalitis was characterized by significantly higher frequency of movement disorder (2.5% vs 75% respectively; p<0.001), and significantly lower rate of seizures (70% vs 30% respectively; p=0.001). Compared with adults, during anti-NMDAR encephalitis children had significantly more movement disorders (86.7% children vs 40% adults; p=0.006), fewer psychiatric symptoms (41.9% children vs 90.0% adults; p=0.025), and a slightly higher median modified Rankin Scale score (5 in children vs 4 in adults; p=0.015). During anti-NMDAR encephalitis, 84.6 per cent of patients received aciclovir (for ≤7d in 22.7%; long-term antivirals in 18.0% only), and 92.7 per cent immune therapy, but none had recurrence of HSE clinically or using cerebrospinal fluid HSV polymerase chain reaction (median follow-up 7mo).

INTERPRETATION

Our review suggests that movement disorder may help differentiate clinically an episode of HSV-induced anti-NMDAR encephalitis from HSE relapse. Compared with adults, children have shorter latency between HSE and anti-NMDAR encephalitis and, during anti-NMDAR encephalitis, more movement disorder, fewer psychiatric symptoms, and slightly more severe disease. According to our results, immune therapy given for HSV-induced anti-NMDAR encephalitis does not predispose patients to HSE recurrence.

Anti-N-methyl-d-aspartate receptor encephalitis in Māori and Pacific Island children in New Zealand

AIM

To investigate the incidence and severity of anti-N-methyl-d-aspartate (anti-NMDA) receptor encephalitis in children from New Zealand.

METHOD

A retrospective case series was undertaken of all children (≤18y) diagnosed with anti-NMDA receptor encephalitis from January 2008 to October 2015.

RESULTS

Sixteen patients were identified with anti-NMDA receptor antibodies in the cerebrospinal fluid, three of whom had an associated teratoma. Fifteen children had Māori and/or Pacific Island ancestry. The incidence of anti-NMDA receptor encephalitis in Māori children was 3.4 per million children per year (95% confidence interval [CI] 1.4-7.0) and the incidence in Pacific children was 10.0 per million children per year (95% CI 4.3-19.8) compared with 0.2 per million children per year (95% CI 0.0-1.0) in children without Māori or Pacific Island ancestry. Sixty-seven per cent of children had a good outcome (modified Rankin Score ≤2) at 2 years' follow-up. This compares unfavourably with other cohorts despite a shorter median time to first-line immunotherapy (13d; range 4-89) and a higher proportion of children being treated with second-line therapy (50%).

INTERPRETATION

Māori and Pacific Island children have a higher incidence of anti-NMDA receptor encephalitis and possibly a more severe phenotype. These data suggest a genetic predisposition to anti-NMDA receptor encephalitis in these populations.

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

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is potentially lethal, but it is also a treatable autoimmune disorder characterized by prominent psychiatric and neurologic symptoms. It is often accompanied with teratoma or other neoplasm, especially in female patients. Anti-NMDAR antibodies in cerebrospinal fluid (CSF) and serum are characteristic features of the disease, thereby suggesting a pathogenic role in the disease. Here, we summarize recent studies that have clearly documented that both clinical manifestations and the antibodies may contribute to early diagnosis and multidisciplinary care. The clinical course of the disorder is reversible and the relapse could occur in some patients. Anti-NMDAR encephalitis coexisting with demyelinating disorders makes the diagnosis more complex; thus, clinicians should be aware of the overlapping diseases.

The Gut-brain Axis: A New Pathogenic View of Neurologic Symptoms - Description of a Pediatric Case

Recent literature data have given emphasis to the relationship between gastrointestinal (GI) disorders and neurologic diseases, underlying a new pathogenic pathway: The so-called “gut–brain axis.” Herein, authors report a case of a 10-month-old male infant, admitted for drug-resistant epilepsy, associated with irritable behavior and GI discomfort, secondary to cow's milk protein allergy. Seizures were described by parents as upward eye movements that were mostly deviated to the right and were associated with slight extension of his neck. They were infrequent at first, but had increased gradually during the course of 3 days (up to 15–20 times/day). No anticonvulsant therapy was effective. Only a cow's milk protein-free diet, accidentally started during a gastroenteritis episode, was effective in stopping seizures. Our case underlines the peculiar vulnerability of the blood–brain barrier under 1 year of age, for which children of this age group experience neurologic manifestations during episodes of systemic inflammation.

Pediatric Autoimmune Encephalitis

Autoimmune (antibody mediated) encephalitis (AE) is emerging as a more common cause of pediatric encephalopathy than previously thought. The autoimmune process may be triggered by an infection, vaccine, or occult neoplasm. In the latter case, onconeural autoantibodies are directed against intracellular neuronal antigens, but a recent heterogeneous group of encephalitic syndromes has been found not to have underlying tumor but is associated with autoantibodies to the neuronal surface or synaptic antigens. Neuropsychiatric symptoms are very common in autoimmune encephalopathy; as a result, affected children may be initially present to psychiatrists. Neurological features are movement disorders, seizures, altered conscious level, and cognitive regression. Hypoventilation and autonomic features may be an aspect. Inflammatory findings in the cerebrospinal fluid may be present but are relatively nonspecific. Magnetic resonance imaging (MRI) may also demonstrate abnormalities that provide clues for diagnosis, particularly on fluid-attenuated inversion recovery or T2-weighted images. AE is well responsive to immune therapy, with prompt diagnosis and treatment strongly beneficial. Patients with paraneoplastic encephalitis are more refractory to treatment compared to those in whom no malignancy is identified. Herein, the authors present an update of literature data on the clinical presentation, laboratory and imaging findings, therapy, and outcomes for the most common autoimmune encephalitides.

Long-term poor rapport, lack of spontaneity and passive social withdrawal related to acute post-infectious encephalitis: a case report

INTRODUCTION

Post-infectious encephalitis/encephalopathy is a neurological syndrome that sometimes develops following common viral or bacterial infections. The most common form is acute disseminated encephalomyelitis (ADEM). ADEM is a demyelinating disease of the central nervous system that typically presents as a monophasic disorder associated with multifocal neurologic symptoms and encephalitis. Anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis is another type of severe autoimmune disorder, characterized by seizures, movement disorders and psychiatric symptoms. In general, the prognosis and long-term outcomes of both ADEM and anti-NMDAR encephalitis are favorable. Most patients show complete, albeit slow recovery over a period of one to 2 years. There are few reports of patients with these disorders showing long-term residual psychiatric symptoms.

CASE PRESENTATION

We report the case of a 16-year-old Japanese male who suffered from acute post-infectious encephalitis. The patient followed an atypical recovery course, in that he showed poor rapport, lack of spontaneity and passive social withdrawal for more than 2 years after the initial symptoms. While treatment with small doses of antipsychotic drugs at the hospital had no effect on the symptoms, the patient recovered gradually over a prolonged period of five or so years.

CONCLUSIONS

This case report suggests that a type of acute post-infectious encephalitis with demyelinating features, possibly ADEM or anti-NMDAR encephalitis, or an overlap between the two, can cause a prodrome of behavioral changes and long-term residual psychiatric symptoms for many months, although it is eventually associated with a good prognosis.

Variations of movement disorders in anti-N-methyl-D-aspartate receptor encephalitis: A nationwide study in Taiwan

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is one of the most common autoimmune encephalitis that presents with a wide variety of movement disorders. The purpose of our study is to review the manifestations and duration of movement disorders in different ages with NMDAR encephalitis.A retrospective cohort of 28 patients (20 females and 8 males) with positive cerebrospinal fluid (CSF) anti-NMDAR antibody in a 5-year period from major hospitals in Taiwan was enrolled. They were categorized into 3 age groups: 7 patients were ≤10 years, 14 patients were 10 to 18 years, and 7 patients were >18 years.Total 28 patients (20 females and 8 males) with age ranging from 8 months to 38 years were enrolled. Nearly all patients (n = 27/28, 96%) presented with at least 2 types of disorders, including orofacial-lingual dyskinesia (OFLD; n = 20), catatonia (n = 19), tremor (n = 11), bradykinesia (n = 11), dystonia (n = 11), choreoathethosis (n = 9), and ballism (n = 3). Only 1 patient below 10 years presented with isolated periodic choreoathethosis without other movement disorders. OFLD was common in all age groups. Choreoathetosis was most common in patients aged ≤10 years, while catatonia was most common in patients aged >10 years (P = 0.001 and 0.020, respectively). Bradykinesia was also more common in patients aged >10 years (P = 0.020). The clinical presentations of movement disorders were not significantly different in the age of 10 to 18 years and those >18 years. Neither patient ≤10 years old nor male patients had associated tumors. All patients' movement disorders were improved after treatment, while female patients with tumors had worse short-term outcome (P = 0.014). Compared with other disorders, choreoathetosis persisted significantly longer in patients ≤10 years (P = 0.038), while OFLD and catatonia last longer in patients >10 years (P = 0.047 and 0.002, respectively).Our study shows that hyperkinetic movements such as choreoathetosis are more common and last longer in younger age groups, whereas hypokinetic movements such as catatonia and bradykinesia are more common and last longer in older age groups. Female patients with ovarian tumors had worse short-term outcome.

Plasma exchange in pediatric anti-NMDAR encephalitis: A systematic review

OBJECTIVE

To clarify the most frequent modalities of use of plasma exchange (PE) in pediatric anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis and to establish the most effective association with other immunotherapies.

METHODS

Systematic literature review on PE in pediatric anti-NMDAR encephalitis (2007-2015).

RESULTS

Seventy-one articles were included (mostly retrospective), reporting a total of 242 subjects (73.2%, 93/127 females; median age at onset 12years, range 1-18). Median time to immunotherapy was 21days (range 0-190). In most cases, PE was given with steroids and IVIG (69.5%, 89/128), or steroids only (18%, 23/128); in a minority, it was associated with IVIG only (7%, 9/128), or was the only first-line treatment (5.5%, 7/128). In 54.5% (65/119), PE was the third treatment after steroids and IVIG, in 31.1% (37/119) the second after steroids or IVIG; only in 14.3% (17/119) was it the first treatment. Second-line immunotherapies were administered in 71.9% (100/139). Higher rates of full/substantial recovery at follow-up were observed with immunotherapy given ⩽30days from onset (69.4%, 25/36) compared to later (59.2%, 16/27), and when PE was associated with steroids (66.7%, 70/105) rather than not (46.7%, 7/15). Significant adverse reactions to PE were reported in 6 patients.

CONCLUSION

Our review disclosed a paucity of quality data on PE in pediatric anti-NMDAR encephalitis. PE use in this condition has been increasingly reported, most often with steroids and IVIG. Despite the limited number of patients, our data seem to confirm the trend towards a better outcome when PE was administered early, and when given with steroids.

[Subacute anti-N-methyl-D-aspartate receptor encephalitis. A serie of 13 paediatric cases]

INTRODUCTION

Subacute anti-NMDA receptor encephalitis was recognised in 2007 as a clinical entity, and was first described in young women with ovarian teratoma. The first paediatric series unrelated with tumours was reported in 2009.

OBJECTIVE

To present the clinical features, treatment, and prognosis of 13 patients with anti-NMDA receptor encephalitis in Chile.

PATIENTS AND METHOD

A description is presented of 13 children, 9 males, aged between 1 and 16 years, diagnosed between 2009 and 2016 in 7 hospitals. All patients were evaluated with cerebral magnetic resonance and electroencephalogram. Cytochemical, oligoclonal bands and virus studies (PCR and antibodies) were performed in cerebrospinal fluid. All patients were evaluated in search of anti NMDA receptor in serum and cerebrospinal fluid. Tumor imaging studies were performed in all children.

RESULTS

All children began the disease with psychiatric symptoms, and 11/13 had seizures. All of them subsequently presented with psychomotor agitation, dystonia, and bucolingual dyskinesias, with 11/13 loss of language and 6/13 autonomic disorders. All of them (13/13) had positive anti-NMDA receptor antibodies. CSF was normal in 12/13 children, positive oligoclonal bands in 6/10 patients, normal brain resonance in 13/13 children, EEG changes in 11/13 children, and abnormal SPECT in 6/6 children. A methylprednisolone bolus of 30mg/kg was given for 3-5 days to 12/13 children, and 6 received immunoglobulin 2g/kg. The large majority (12/13) of children recovered 1-4 months after disease onset. One child had a recurrence one year later, and recovered quickly.

CONCLUSIONS

Subacute encephalitis due to NMDA anti-receptor antibodies should be suspected in children with psychiatric disorders and abnormal movements. Functional studies, such as EEG and SPECT are valuable diagnostic support. Early detection of this encephalitis leads to a faster recovery of patients.

Anti-N-Methyl-D-Aspartate Receptor Encephalitis in Children and Adolescents

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune disease that is becoming increasingly recognized in the pediatric population. It may be the most common cause of treatable autoimmune encephalitis. The majority of cases of anti-NMDAR encephalitis are idiopathic in etiology, but a significant minority can be attributed to a paraneoplastic origin. Children with anti-NMDAR encephalitis initially present with a prodrome of neuropsychiatric symptoms, often with orofacial dyskinesias followed by progressively worsening seizures, agitation, and spasticity, which may result in severe neurologic deficits and even death. Definitive diagnosis requires detection of NMDAR antibodies in the cerebrospinal fluid. Optimal outcomes are associated with prompt removal of the tumor in paraneoplastic cases, as well as aggressive immunosuppressive therapy. Early detection is essential for increasing the chances for a good outcome. Close follow-up is required to screen for relapse and later onset tumor presentation. The nurse practitioner plays a major role in the research, screening, diagnosis, treatment, follow-up, and rehabilitation of a child or adolescent with anti-NMDAR encephalitis.

Autoimmune neurologic disorders in children

Autoimmune neurologic diseases are of major clinical importance in children. Antibody-mediated diseases of the central nervous system are now increasingly recognized in childhood, where the antibodies bind to cell surface epitopes on neuronal or glial proteins, and the patients demonstrate either focal or more generalized clinical signs depending on the extent of brain regions targeted by the antibodies. The antibodies are directed towards ion channels, receptors, and membrane proteins; and the diseases include limbic encephalitis and N-methyl-d-aspartate receptor-antibody encephalitis, among many others. Additionally there are conditions where the wider immune system is implicated. Neurologic features like seizures, movement disorders, autonomic dysfunction, and sleep disorders, with neuroimaging and electrophysiologic features, may indicate a specific antibody-mediated or immune disorder. Often, phenotypic overlap is observed between these conditions, and phenotypic variation seen in children with the same condition. Nevertheless, many patients benefit from immunotherapy with substantial improvement, although huge efforts are still required to optimize the outcome for many patients. In many patients no antibodies have yet been identified, even though they respond to immunotherapies. Here we describe the known antibodies and associated diseases, discuss conditions that are thought to be immune-mediated but have no known immunologic biomarker, and provide guidelines for the investigation and classification of these disorders.