Cognitive and neuropsychological evolution in children with anti-NMDAR encephalitis

Long-Term Cognitive, Functional, and Patient-Reported Outcomes in Patients With Anti-NMDAR Encephalitis

BACKGROUND AND OBJECTIVES

Anti-NMDA receptor (anti-NMDAR) encephalitis generally manifests in young adults. Although 80%-90% returns to independence, the majority experience persistent cognitive and psychosocial difficulties. Studies have demonstrated that cognitive recovery may continue for years; the temporal trajectory is largely unknown, as are factors influencing cognitive/psychosocial recovery. Objectives were to (1) describe the cognitive recovery trajectory, (2) assess self-reported outcomes, (3) identify factors relating to outcome, and (4) explore the relation between cognitive and self-reported outcomes, and participation.

METHODS

We performed a large-scale cross-sectional and prospective cohort study. We addressed our nationwide cohort, provided they were (1) older than 16 years, (2) independent preillness, and (3) able to perform cognitive tests and/or self-report. Patients completed Patient-Reported Outcome Measures and neuropsychological assessments (memory, language, perception and construction, and attention and executive functions), and functional outcomes were established (modified Rankin Scale [mRS] score and return-to-work/-education). Outcomes were compared with references and between groups based on clinical characteristics and functional outcomes (T-tests for normalized data and nonparametric tests for patient-reported data). Recovery was visualized by plotting outcomes against time-of-assessment.

RESULTS

We included 92 patients (age 29 ± 2 years; 77% female). Cognitive scores improved with time-of-assessment, up to 36 months after diagnosis (R = 0.35, p = 0.022), with the most enhanced improvement in the first 6 months. This result could be reproduced in prospective patients (n = 12). Beyond 36 months (n = 44), 34% of patients had a persistent impairment (z-score <-1.5 SD) and 65% scored below-average (<-1 SD) in 1 or more cognitive domains, despite a "favorable" outcome measured by mRS (≤2) in the majority (91%). Most affected were memory (mean -0.67 ± 0.89 SD, p = 0.25) and language (-0.75 ± 1.06 SD, p = 0.23). Self-reported complaints remained in emotional well-being (mean 72 ± 25 SD vs norm 82 ± 33 SD, p < 0.001), social functioning (73 ± 26 SD vs 84 ± 22 SD, p < 0.001), energy levels (57 ± 19 SD vs 69 ± 19 SD, p < 0.001), and quality of life (0.85 ± 0.14 SD vs 0.93 ± 0.11 SD, p < 0.001). Many patients did not resume school/work (30%) or needed adjustments (18%). Resuming school/work related to processing speed (-0.14 ± 0.78 SD vs -0.84 ± 1.05 SD, p = 0.039) and well-being (EuroQol 5 Dimensions 5 Levels median 0.90 vs 0.81, p = 0.016).

DISCUSSION

Recovery from anti-NMDAR encephalitis may continue for 3 years, with risk of persisting cognitive deficits, notably in memory and language, and sequelae in social functioning, energy levels, and well-being. The frequently applied outcome measure mRS does not fully capture outcomes. Almost half of patients struggled resuming school/work, associated with cognitive deficits and well-being.

Neurocognitive outcome in children and adolescents following infectious encephalitis

Infectious encephalitis in children is fairly uncommon, but unfavorable outcomes are seen in many survivors. The aim of this study was to prospectively describe the long-term neurocognitive consequences following infectious encephalitis in childhood. Children admitted to a primary and tertiary hospital in Sweden between 2011 and 2016 were asked to participate. Fifty-nine children were assessed at a median time of 18 months (IQR 18-20) after hospitalization. Follow-up included measures of intellectual functioning, attention, working memory, and executive functions. Caregiver ratings of executive functioning and behavioral - emotional symptoms were assessed with standardized questionnaires. Neurocognitive outcome and measures of executive functions and behavioral-emotional symptoms varied greatly among participants. Basic auditory attention, working memory, and mental processing speed were affected and significantly lower compared to a standardized mean. Other domains identified as areas of vulnerability included executive functions, sustained attention, and the exert of self-control. Behavioral-emotional symptoms were less common; however, somatic complaints and behaviors related to conduct problems were seen in about one-third of individuals. This study highlights the importance of a comprehensive neurocognitive examination to identify children with unfavorable outcomes.

Very Long-Term Functional Outcomes and Dependency in Children With Anti-NMDA Receptor Encephalitis

OBJECTIVES

To assess the daily function of children with anti-N-methyl-d-aspartate receptor encephalitis (NMDARe) after a minimal follow-up of 5 years.

METHODS

Patients 18 years and younger by the time of disease onset, whose serum and CSF were studied in our center between 2013 and 2017, were included in the study. Patients' daily life function was assessed by their physicians using a 15-domain question format (Liverpool Outcome Score).

RESULTS

Of 76 patients, 8 (11%) died and 68 were followed for a mean of 7.1 years (SD 1.5 years, range: 5.0-10.1). Three outcome patterns were identified: full recovery (50; 73%); behavioral and school/working deficits (12; 18%); and multidomain deficits (6; 9%) involving self-care ability, behavioral-cognitive impairment, and seizures. Younger age of disease onset was significantly associated with multidomain deficits (OR 1.6, 95% CI 1.02-2.4, p = 0.04), particularly in children younger than 6 years, among whom 8 of 23 (35%) remained sociofamiliar dependent.

DISCUSSION

After a minimal follow-up of 5 years, most children with NMDARe had substantial or full functional recovery, but approximately one-fifth remained with behavioral and school/working deficits. The younger the patient at disease onset, the more probable it was to remain with multidomain deficits and dependent on sociofamiliar support.

Neuropsychological Testing in Autoimmune Encephalitis: A Scoping Review

BACKGROUND AND OBJECTIVES

Identifying optimal methods for evaluation and monitoring of cognitive outcomes in AE is important for clinical care and research. This scoping review aimed to evaluate neuropsychological tests (NPT) that are most frequently impaired in AE cohorts to provide recommendations for a standardized NPT battery for AE outcome.

METHODS

PubMed search for studies examining NPT in patients with AE was conducted on June 9, 2023. Studies were screened for inclusion/exclusion criteria as follows: at least 1 NPT, individual NPT test scores with comparison with healthy controls or normative data and neural-IgG status, total sample size ≥5, and English manuscript available.

RESULTS

The search yielded 5,393 studies, of which 3,359 were screened, 107 were full text reviewed, and 32 met inclusion/exclusion criteria, anti-NMDA-R (k = 18), anti-LGI1 (k = 10), anti-GABAB-R (k = 2), anti-GAD-65 (k = 4), and anti-CASPR2 (k = 3). The cognitive domains most frequently impaired were visual and verbal episodic memory, attention/working memory, processing speed, and aspects of executive functions.

DISCUSSION

Given the dearth of literature examining NPT in AE in combination with small sample sizes and methodological differences, more research in this area is needed. However, we provide recommendations for a test battery to be used in future studies, with the aim of standardizing research in this area. Based on the available literature, we recommend the use of comprehensive NPT batteries, spanning all cognitive domains. The highest yield measures may include the tests of (1) visual and verbal learning/memory, (2) basic and sustained attention, (3) processing speed, and (4) executive functions.

Atypical psychiatric presentation of relapsing anti-N-methyl-D-aspartate receptor encephalitis in childhood

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune encephalitis caused by antibodies (Ab) against the GluN1 subunit of the NMDAR. The disease typically presents with a combination of psychiatric and neurological symptoms. Presentation solely with psychiatric symptoms is rare, especially in childhood. After treatment substantial recovery with mild or no residual symptoms is seen in most cases in both children and adults. Relapse occurs in 10%-25% of patients, with recurrent episodes presenting less severe than initial presentation in most cases. We herein describe a child with a pure psychiatric presentation of anti-NMDAR encephalitis. Diagnosis and treatment was delayed because of the atypical presentation. The child relapsed several times and severe residual psychiatric symptoms persisted after recovery. This case illuminates the need to consider the diagnosis of anti-NMDAR encephalitis in both adults and children with an atypical psychiatric presentation. It also demonstrates the need for a multidisciplinary approach and brings attention to the possible severe impact of the disease on long-term psychosocial functioning.

A juvenile mouse model of anti-N-methyl-D-aspartate receptor encephalitis by active immunization

Introduction

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a common autoimmune encephalitis, and it is associated with psychosis, dyskinesia, and seizures. Anti-NMDAR encephalitis (NMDARE) in juveniles and adults presents different clinical charactreistics. However, the pathogenesis of juvenile anti-NMDAR encephalitis remains unclear, partly because of a lack of suitable animal models.

Methods

We developed a model of juvenile anti-NMDAR encephalitis using active immunization with an amino terminal domain peptide from the GluN1 subunit (GluN1356 - 385) against NMDARs in 3-week-old female C57BL/6J mice.

Results

Immunofluorescence staining suggested that autoantibody levels in the hippocampus increased, and HEK-293T cells staining identified the target of the autoantibodies as GluN1, suggesting that GluN1-specific immunoglobulin G was successfully induced. Behavior assessment showed that the mice suffered significant cognition impairment and sociability reduction, which is similar to what is observed in patients affected by anti-NMDAR encephalitis. The mice also exhibited impaired long-term potentiation in hippocampal CA1. Pilocarpine-induced epilepsy was more severe and had a longer duration, while no spontaneous seizures were observed.

Conclusion

The juvenile mouse model for anti-NMDAR encephalitis is of great importance to investigate the pathological mechanism and therapeutic strategies for the disease, and could accelerate the study of autoimmune encephalitis.

Long-term effects of anti-N-methyl-d-aspartate receptor encephalitis on quality of life

Background

Patients with anti-N-methyl-d-aspartate receptor encephalitis (NMDARE) usually achieve neurologically favorable outcomes in the post-acute-phase. Even when motor function recovers, many patients experience numerous non-motor sequelae and cannot resume their pre-NMDARE lives even years later. Additionally, the needs of patients with NMDARE may impose a severe caregiver burden. Unfortunately, few studies have comprehensively examined patients recovering from NMDARE. We investigated the long-term effects of NMDARE on patients' quality of life (QOL).

Methods

Data collected via structured self-reported questionnaires included clinical features, long-term outcomes, and QOL. These questionnaires were administered to adult members of the Japanese Anti-NMDARE Patients' Association. We used the NeuroQOL battery to assess QOL in physical, mental, and social domains. Raw NeuroQOL scores were converted to T-scores for comparison with controls.

Results

Twenty-two patients completed the questionnaire. The median interval between disease onset and questionnaire response was 78  months. Forty-six percent of patients reported persistent sequelae, with only 73% able to resume prior work/school activities. Although patients' Global QOL was similar to controls, patients with NMDARE had significantly worse social QOL. Patients with worse social QOL had more frequent sequelae than those with better social QOL. Furthermore, patients with persistent sequelae had significantly worse Global QOL than those without sequelae and controls.

Conclusion

Patients with NMDARE had worse social QOL than controls. Given the adverse effects of disease sequelae on QOL, treatment strategies that minimize sequelae during the acute-phase may improve patients' QOL, even years post-disease onset.

Retrospective Pediatric Cohort Study Validates NEOS Score and Demonstrates Applicability in Children With Anti-NMDAR Encephalitis

BACKGROUND AND OBJECTIVES

Anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) is the most common form of autoimmune encephalitis in children and adults. Although our understanding of the disease mechanisms has progressed, little is known about estimating patient outcomes. Therefore, the NEOS (anti-NMDAR Encephalitis One-Year Functional Status) score was introduced as a tool to predict disease progression in NMDARE. Developed in a mixed-age cohort, it currently remains unclear whether NEOS can be optimized for pediatric NMDARE.

METHODS

This retrospective observational study aimed to validate NEOS in a large pediatric-only cohort of 59 patients (median age of 8 years). We reconstructed the original score, adapted it, evaluated additional variables, and assessed its predictive power (median follow-up of 20 months). Generalized linear regression models were used to examine predictability of binary outcomes based on the modified Rankin Scale (mRS). In addition, neuropsychological test results were investigated as alternative cognitive outcome.

RESULTS

The NEOS score reliably predicted poor clinical outcome (mRS ≥3) in children in the first year after diagnosis (p = 0.0014) and beyond (p = 0.036, 16 months after diagnosis). A score adapted to the pediatric cohort by adjusting the cutoffs of the 5 NEOS components did not improve predictive power. In addition to these 5 variables, further patient characteristics such as the "Herpes simplex virus encephalitis (HSE) status" and "age at disease onset" influenced predictability and could potentially be useful to define risk groups. NEOS also predicted cognitive outcome with higher scores associated with deficits of executive function (p = 0.048) and memory (p = 0.043).

DISCUSSION

Our data support the applicability of the NEOS score in children with NMDARE. Although not yet validated in prospective studies, NEOS also predicted cognitive impairment in our cohort. Consequently, the score could help identify patients at risk of poor overall clinical outcome and poor cognitive outcome and thus aid in selecting not only optimized initial therapies for these patients but also cognitive rehabilitation to improve long-term outcomes.

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

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

Anti-NMDAR encephalitis with seizure-like activity and hemiplegia - a case report and literature review

Background

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis accounts for the vast majority of cases of autoimmune encephalitis. Its common clinical symptoms are psychiatric symptoms, behavioral dysfunction, seizures, speech impairment, cognitive impairment, movement disorders, decreased consciousness, and autonomic instability. This report was aimed to provide evidence for anti-NMDAR encephalitis with seizure-like activity, based on the clinical presentations, brain magnetic resonance imaging (MRI), and electroencephalogram (EEG) recordings.

Case presentation

We report a 11-year-old girl who suffered epigastric pain after vigorous physical activity. She felt weakness of the muscles. She had syncope only once and urinary incontinence on the way to the hospital and vomited at the arrival. The entire procedure lasted approximately 15 min. The next night she had recurrent headache attacks along with irritability, like someone “tapping” to the right occipital region. She experienced numbness in the left upper limbs and shallowing of the frontal lines on the left side. Holter monitoring showed normal findings, but brain MRI, EEG recording, and cerebrospinal fluid (CSF) antibody testing showed abnormal results. The patient was finally diagnosed with anti-NMDAR encephalitis. After treatment with glucocorticoids and acyclovir, she fully recovered and was discharged from the hospital.

Conclusions

Although the patient presented with pain and impaired limb movements, she did not have respiratory or (and) circulatory failure, and the symptoms entirely resolved. Early accurate diagnosis and timely treatment are essential for patients with anti-NMDAR encephalitis.

A systematic review and quantitative synthesis of the long-term psychiatric sequelae of pediatric autoimmune encephalitis

BACKGROUND

Long-term neuropsychiatric sequelae of autoimmune encephalitis (AE) remain understudied, particularly in pediatric-onset AE. We aimed to synthesize the published data on ongoing psychiatric symptoms in pediatric-onset AE.

METHODS

The Pubmed, PyscINFO, Web of Science databases were searched from their inception years to August 23, 2021, and 29 studies were identified and analyzed. We also performed a quantitative synthesis of available patient data from the 29 studies combined with a cohort of anti-NMDA receptor (NMDAR) AE from our institution to examine the associations between acute treatment course and long-term psychiatric outcome.

RESULTS

At long-term follow up, 52.4% of the cases with pediatric-onset AE had any persistent symptom and 36.0% had at least one psychiatric symptom. Pooled data found that 36.3% of pediatric-onset anti-NMDAR AE had ongoing psychiatric symptoms. Using a univariate logistic regression analysis, we found that abnormal initial EEG, use of certain immunotherapies, and persistent cognitive impairments were associated with ongoing psychiatric symptoms.

LIMITATIONS

Limitations of the existing literature included a significant paucity of outcomes measured using consistent, objective methods. Limitations of the systematic review included the wide variability among the studies reviewed, which rendered a meta-analysis impossible and beyond the scope of the paper.

CONCLUSION

Chronic psychiatric and behavioral problems remain present in one-third of children months to years after onset of AE. Larger scaled prospective observational studies with a consistent standardized battery of testing are needed to examine impact of specific clinical features and immunotherapies on long-term mental health outcomes.

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.

Neuropsychological outcomes in children and adolescents following anti-NMDA receptor encephalitis

Anti-N-methyl-d-aspartate receptor encephalitis (ANMDARE) is a neurologic disorder that is becoming more recognized in children and adolescents. Early studies suggested that patients typically recover well, but more recent data suggests that children may experience persistent cognitive deficits, especially in verbal memory and executive functioning. The aims of this study are to evaluate areas of impairment and to characterize neuropsychological outcomes in pediatric patients with ANMDARE. This was a multi-centered retrospective chart review. We identified 23 pediatric patients who were, on average, 18.5 months from diagnosis. Patients underwent comprehensive neuropsychological assessment, including measures of intellectual functioning, memory, reading, verbal fluency, visuomotor skills, attention, and working memory. Caregiver ratings and information regarding resource utilization were also collected (e.g., formal school services, outpatient rehabilitation, psychological support). Neuropsychological impairment index (NPI) scores were calculated for each patient. Neuropsychological outcomes highlighted variability across individuals. Memory and fine motor dexterity were particularly impacted. Almost 90% of caregivers reported more concerns than average on at least one measure of emotional-behavioral, adaptive, or executive functioning. More than two-thirds of the sample were considered impaired based on NPI scores on performance measures. More than three quarters of the sample received outpatient intervention, most often consisting of school-based services. Our findings provide additional quantitative evidence that pediatric patients recovering from ANMDARE demonstrate ongoing cognitive concerns. While most patients experience remarkable recoveries following appropriate diagnosis and treatment, ongoing monitoring and support is recommended over time for these patients.

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.

Immunotherapies for Anti-N-M-methyl-D-aspartate Receptor Encephalitis: Multicenter Retrospective Pediatric Cohort Study in China

Background: Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis has been discovered for more than a decade, but the establishment of standardized immunotherapy protocol for pediatric patients still needs more clinical evidence. Methods: A multicenter, retrospective study was conducted on pediatric patients diagnosed with anti-NMDAR encephalitis between November 2011 and December 2018. The clinical records including clinical manifestations, immunotherapy strategies, and outcomes were collected and analyzed. Results: A total of 386 patients were included in our study and the median onset age was 8.00 (IQR 4.83-10.90) years. All patients received first-line immunotherapy and the majority (341, 88.3%) used the standard combination of methylprednisolone pulses (MEP) and intravenous immunoglobulins (IVIG), but 211 patients did not show satisfactory improvement (mRS ≥ 3). Mainly three treatment strategies were applied after first-line immunotherapy: second-line immunotherapy, repetitive first-line immunotherapy, and maintaining oral prednisolone. For patients with mRS ≥ 4 after first-line immunotherapy, the incidence of poor outcome (mRS ≥ 3) in oral prednisolone group was higher than that in other treatment groups (p = 0.039). No difference in complete recovery rate (mRS = 0) was found between patients receiving second-line and repetitive first-line immunotherapy, or patients using long-term and short-term prednisolone. Out of 149 patients who received anti-myelin oligodendrocyte glycoprotein antibody (MOG-Ab) test, 27 (18.12%) were positive. Patients with concomitantly positive MOG-Ab showed milder conditions compared to patients with typical anti-NMDAR encephalitis and were more inclined to relapses. We also identified female, MOG-Ab positive, and not receiving second-line and/or repetitive first-line immunotherapy were risk factors for relapses. Conclusions: For patients with mRS ≥ 4 after first-line immunotherapy and patients with concomitantly positive MOG-Ab, second-line immunotherapy is recommended. When second-line immunotherapy is not applicable, repetitive first-line immunotherapy can be considered as an option. Both second-line and repetitive first-line immunotherapy are beneficial to reduce relapse rate. The duration of sequential oral prednisolone can be shortened after fully evaluating patients' conditions.

Clinical and Magnetic Resonance Imaging Outcome Predictors in Pediatric Anti-N-Methyl-D-Aspartate Receptor Encephalitis

OBJECTIVE

To evaluate disease symptoms, and clinical and magnetic resonance imaging (MRI) findings and to perform longitudinal volumetric MRI analyses in a European multicenter cohort of pediatric anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) patients.

METHODS

We studied 38 children with NMDARE (median age = 12.9 years, range =1-18) and a total of 82 MRI scans for volumetric MRI analyses compared to matched healthy controls. Mixed-effect models and brain volume z scores were applied to estimate longitudinal brain volume development. Ordinal logistic regression and ordinal mixed models were used to predict disease outcome and severity.

RESULTS

Initial MRI scans showed abnormal findings in 15 of 38 (39.5%) patients, mostly white matter T2/fluid-attenuated inversion recovery hyperintensities. Volumetric MRI analyses revealed reductions of whole brain and gray matter as well as hippocampal and basal ganglia volumes in NMDARE children. Longitudinal mixed-effect models and z score transformation showed failure of age-expected brain growth in patients. Importantly, patients with abnormal MRI findings at onset were more likely to have poor outcome (Pediatric Cerebral Performance Category score > 1, incidence rate ratio = 3.50, 95% confidence interval [CI] = 1.31-9.31, p = 0.012) compared to patients with normal MRI. Ordinal logistic regression models corrected for time from onset confirmed abnormal MRI at onset (odds ratio [OR] = 9.90, 95% CI = 2.51-17.28, p = 0.009), a presentation with sensorimotor deficits (OR = 13.71, 95% CI = 2.68-24.73, p = 0.015), and a treatment delay > 4 weeks (OR = 5.15, 95% CI = 0.47-9.82, p = 0.031) as independent predictors of poor clinical outcome.

INTERPRETATION

Children with NMDARE exhibit significant brain volume loss and failure of age-expected brain growth. Abnormal MRI findings, a clinical presentation with sensorimotor deficits, and a treatment delay > 4 weeks are associated with worse clinical outcome. These characteristics represent promising prognostic biomarkers in pediatric NMDARE. ANN NEUROL 2020 ANN NEUROL 2020;88:148-159.

Long-term cognitive and neuropsychiatric outcomes in patients with anti-NMDAR encephalitis

OBJECTIVES

To evaluate the long-term cognitive or neuropsychiatric outcomes and potential risk factors associated with prolonged cognitive deficits or neuropsychiatric symptoms in patients with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis.

METHODS

In this cohort follow-up study, patients with a definitive diagnosis of anti-NMDAR encephalitis from the inpatient of West China Hospital between June 2012 and December 2017 were included and underwent a prospective cognitive and neuropsychiatric assessment every 3 months by cognitive impairment rating scale, Neuropsychiatric Inventory (NPI) and/or Montreal Cognitive Assessment.

RESULTS

Up to 97.5% patients had severe cognitive deficits and neuropsychiatric symptoms in acute phase. Decreasing proportion of patients with prolonged cognitive deficits was observed and time dependent. At 2 years' follow-up, 7.8% of patients with cognitive deficits were unable to complete some previous activities or return to work. The risk factors associated with persistent cognitive deficits included age of disease onset over 40 years old (HR, 1.77; 95% CI, 1.11-2.82; P = .01) and with clinical relapses (HR, 2.22; 95% CI, 1.21-4.09; P = .02). The predictors of prolonged neuropsychiatric symptoms included clinical relapses (HR, 2.79; 95% CI, 1.21-6.43; P = .02). Among the 12 neuropsychiatric symptoms of NPI, irritability was shown as the most prevalent and persistent.

CONCLUSIONS

Combined cognitive and neuropsychiatric assessment and intervention are essential elements of comprehensive care of anti-NMDAR encephalitis.

Voxel-based analysis and multivariate pattern analysis of diffusion tensor imaging study in anti-NMDA receptor encephalitis

PURPOSE

This study aimed to investigate brain white matter (WM) changes and their relationship to cognition in patients with anti-N-methyl-D-aspartate (anti-NMDA) receptor encephalitis. Multivariate pattern analysis (MVPA) was used to explore brain regions that play an important role in classification.

METHODS

Fifteen patients and fifteen controls underwent Montreal Cognitive Assessment (MoCA) and diffusion tensor imaging. Based on fractional anisotropy (FA) and mean diffusivity (MD) for MVPA classification, the weights of each brain region were calculated.

RESULTS

Compared with the controls, the patients showed an FA reduction in right middle temporal gyrus, left middle cerebellar peduncle, right praecuneus, and an MD increase in left medial temporal gyrus and left frontal lobe. The MoCA score for patients was lower than controls, especially in executive function, fluency, delayed recall and visual perception items. The FA value of right praecuneus was positively correlated with total MoCA score and fluency score. The MD of left frontal lobe was negatively correlated with total MoCA score, and MD of the left medial temporal gyrus was positively correlated with delayed recall. The accuracy, sensitivity and specificity of classification based on FA were 70%, 60% and 80%, respectively. Based on MD, they were each 80%. The brain regions with large weights from FA and MD overlap in temporal lobe, cerebellum and hippocampus.

CONCLUSIONS

These results suggest that WM changes are associated with cognitive deficits. MVPA based on FA and MD has good classification ability. Our study may provide new insights into the pathophysiological mechanisms of residual cognitive deficits.

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.

Understanding Childhood Neuroimmune Diseases of the Central Nervous System

Immune-mediated diseases of the central nervous system (CNS) in childhood are a heterogeneous group of rare conditions sharing the inflammatory involvement of the CNS. This review highlights the growing knowledge of childhood neuroimmune diseases that primarily affect the CNS, outlining the clinical and diagnostic features, the pathobiological mechanisms and genetics, current treatment options, and emerging challenges. The clinical spectrum of these conditions is increasingly expanded, and the underlying mechanisms of dysregulation of the immune system could vary widely. Cell-mediated and antibody-mediated disorders, infection-triggered and paraneoplastic conditions, and genetically defined mechanisms can occur in previously healthy children and can contribute to different stages of the disease. The careful evaluation of the clinical presentation and temporal course of symptoms, the specific neuroimaging and immunological findings, and the exclusion of alternative causes are mandatory in clinical practice for the syndromic diagnosis. A common feature of these conditions is that immunotherapeutic agents could modulate the clinical course and outcomes of the disease. Furthermore, specific symptomatic treatments and comprehensive multidisciplinary care are needed in the overall management. We focus on recent advances on immune-mediated demyelinating CNS disorders, autoimmune encephalitis, interferonopathies, and possible neuroimmune disorders as Rasmussen encephalitis. Better knowledge of these conditions could allow prompt diagnosis and targeted immunotherapy, to decrease morbidity and mortality as well as to improve clinical outcomes, reducing the burden of the disease due to possible long-term neuropsychiatric sequelae. Persisting controversies remain in the rigorous characterization of each specific clinical entity because of the relative rarity in children; moreover, in a large proportion of suspected neuroimmune diseases, the immune "signature" remains unidentified; treatment guidelines are mostly based on retrospective cohort studies and expert opinions; then advances in specific molecular therapies are required. In the future, a better characterization of specific immunological biomarkers may provide a useful understanding of the underlying pathobiological mechanisms of these conditions in order to individualize more tailored therapeutic options and paradigms. Multicenter collaborative research on homogeneous groups of patients who may undergo immunological studies and therapeutic trials could improve the characterization of the underlying mechanisms, the specific phenotypes, and tailored management.

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.

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.

Cognitive Function Recovery Pattern in Adult Patients With Severe Anti-N-Methyl-D-Aspartate Receptor Encephalitis: A Longitudinal Study

Objective: To observe the dynamic characteristics of cognitive function following early application of immunotherapy in adult patients with severe anti N-methyl D-aspartate receptor (anti-NMDAR) encephalitis.

Methods: Serial neuropsychological assessments were performed at three sequential time points in five adult patients with severe anti-NMDAR encephalitis following early-initiated immunotherapy. The three sequential points were 1–2, 6, and 11–12 months after treatment. Five normal subjects without psychological or neurological diseases were assessed as a control group.

Results: Following early-initiated immunotherapy, all five patients demonstrated a gradual improvement of overall cognitive function over the 1-year follow-up period. All patients had suffered from a comprehensive cognitive function disorder from the early stages of the illness. Six months after the immunotherapy, the treatment group showed no significant differences in verbal episodic memory function compared with the control group. One year after the immunotherapy, non-verbal episodic memory function in the treatment group had normalized. The results of other tests related to frontoparietal cognitive function revealed damage of varying degrees during these three phases.

Conclusion: The results of this sequential observation study indicated a three-phase recovery pattern of cognitive function in adult patients with severe anti-NMDAR encephalitis following early initiated immunotherapy. These findings extend current understanding of the recovery mechanisms of cognitive function impairment in this disease.

Long-term neuropsychological outcome following pediatric anti-NMDAR encephalitis

OBJECTIVE

To provide detailed long-term outcome data of children and adolescents following pediatric anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis, to identify neuropsychological impairments, and to evaluate the influence of these factors on quality of life (QoL).

METHODS

All Dutch children diagnosed with anti-NMDAR encephalitis were identified. Patients currently aged 4 years or older were included in the follow-up study, consisting of a visit to our clinic for a detailed interview and a standardized neuropsychological assessment. The following domains were included: attention, memory, language, executive functioning, QoL, and fatigue. Primary outcome measures were z scores on sustained attention, long-term verbal memory, QoL, fatigue, and working memory.

RESULTS

Twenty-eight patients were included. Median Pediatric Cerebral Performance Category at last visit was 1 (interquartile range 1-2, range 1-4), and 64% (18/28) of patients returned consistently to their previous school level. Twenty-two patients were included in the cross-sectional part of the long-term follow-up study. Median follow-up time was 31 months (interquartile range 15-49, range 5-91). There were problems with sustained attention (z = -2.10, 95% confidence interval = -2.71 to -1.46, p < 0.0001) and fatigue (z = -0.96, 95% confidence interval = -1.64 to -0.28, p = 0.008). Cognitive deficits were not correlated with QoL, while fatigue was strongly correlated with QoL (r = 0.82, p < 0.0001).

CONCLUSIONS

Although follow-up is often reported as "good" following pediatric anti-NMDAR encephalitis, many patients have cognitive problems and fatigue, even up until adolescence, resulting in academic achievement problems and lower QoL. For physicians, it is essential to be aware of these problems, to provide valuable advice to patients and caregivers in the acute and follow-up phase, and to consider early neuropsychological counseling.

Pediatric NMDAR encephalitis: A single center observation study with a closer look at movement disorders

Anti-N-Methyl-d-aspartate-receptor (NMDAR) encephalitis is the most frequent autoimmune encephalitis in pediatric age. This retrospective observational study was aimed at describing the clinical characteristics of the disease in a cohort of children and teenagers. Eighteen patients (10 females and 8 males), with a median age of 12.4 years at symptom onset were enrolled. The clinical presentation of the disease was marked by neurological manifestations in 13 patients and by severe psychiatric and behavioral symptoms in 5. The symptoms at onset varied according to the age: all the children presented with prominent neurological symptoms, whereas psychiatric symptoms were prominent in teenagers. Regardless the age, movement disorders (MDs) were distinctive symptoms during the acute stage of the disease. Several MDs might coexist in a given patient, and persist during sleep. The complexity, and the oddness of MDs often challenged their definition and the differential diagnosis with psychiatric manifestations and epileptic seizures. Stereotyped motor phenomena were the most typical MDs, and were recorded in all patients. Among them, perseveration, reproduction of acquired complex motor activities, and orofacial dyskinesia were the most distinctive features. In children, hyperkinetic MDs dominate; in teenagers, by contrast, a constellation of symptoms consistent with catatonia was the most frequent syndrome observed. The management of the several symptoms requires their accurate recognition, definition and assessment, and the knowledge of the potential side effects of antiepileptic and psychotropic drugs which could either mimic or worsen symptoms of encephalitis.

Principles and approaches to the treatment of immune-mediated movement disorders

Immune mediated movement disorders include movement disorders in the context of autoimmune encephalitis such as anti-NMDAR encephalitis, post-infectious autoimmune movement disorders such as Sydenham chorea, paraneoplastic autoimmune movement disorders such as opsoclonus myoclonus ataxia syndrome, and infection triggered conditions such as paediatric acute neuropsychiatric syndrome. This review focuses on the approach to treatment of immune mediated movement disorders, which requires an understanding of the immunopathogenesis, whether the disease is destructive or 'altering', and the natural history of disease. Factors that can influence outcome include the severity of disease, the delay before starting therapy, use of multimodal therapy and whether the course is monophasic or relapsing. Although the four main conditions listed above have different pathophysiological processes, there are general themes that broadly apply including: early diagnosis and treatment is better, minimise the severity of disease, escalate treatment if the patient is not responding to initial treatments, and minimise relapse.

Cognitive and Social Functioning Deficits after Anti-N-Methyl-D-Aspartate Receptor Encephalitis: An Exploratory Case Series

BACKGROUND

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a recently described life-threatening autoimmune disorder associated with a characteristic multi-stage neuropsychiatric syndrome. Although it is known that the majority of patients experience neuropsychological disturbance post-treatment, some aspects of the cognitive profile remain unclear.

METHODS

This study sought to investigate patterns of cognitive functioning in a sample of anti-NMDAR encephalitis patients. Seven (6F:1M; mean age, 26.4 years; range, 16-37 years) treated patients completed a comprehensive set of neurocognitive and social functioning measures. Performance was analyzed using normative data (where available), and comparison with matched controls (10F:4M; mean age, 25.8 years; range, 16-38 years).

RESULTS

Individual cognitive profiles ranged from within normal limits to extensive dysfunction. Relative to controls, the patient group's performance was affected in the domains of verbal/ visual memory, working memory, attention, processing speed, executive functioning, and social cognition. The patient group also reported significantly higher levels of anxiety compared to controls.

CONCLUSIONS

These results add to the accumulating evidence that neurocognitive deficits, consistent with the distribution and functions of the NMDAR system can persist during recovery from anti-NMDAR encephalitis. This is the first study to provide evidence of performance decrements on measures of social cognition, including some involving theory of mind. (JINS, 2016, 22, 828-838).