A score that predicts 1-year functional status in patients with anti-NMDA receptor encephalitis

Association between red blood cell distribution width-to-albumin ratio and the prognosis in patients with autoimmune encephalitis: a retrospective cohort study

Aim

Red blood cell distribution width-to-albumin ratio (RAR) is a combined new indicator reflecting immunology and has been reported to predict the prognosis of inflammation-related diseases and brain diseases. However, the association and predictive value of RAR in the prognosis of patients with autoimmune encephalitis (AE) has not been reported.

Methods

This was a retrospective cohort study, and data were collected from the Henan Provincial People's Hospital. RAR was categorized according to quartile. The prognosis was assessed using the modified Rankin Scale (mRS), and an mRS score of ≥3 was defined as a poor prognosis. The logistical regression model was used to explore the association between RAR and the prognosis, with results reported as odds ratio (OR) and 95% confidence interval (CI). The predictive value of RAR was evaluated by calculating the area under the receiving operating curve (AUC), sensitivity, specificity, and accuracy.

Results

A total of 175 eligible patients were included for analysis, and 51 patients were identified as having poor prognosis. After adjusting age, cancer, other diseases, histological subtype, antiepileptic therapy, anti-tumor treatment, ICU treatment, and length of stay, RAR in the highest quartile (Q4) was found to be significantly associated with the high odds of poor prognosis (OR = 5.63, 95%CI: 1.98-16.02) compared to RAR in the lowest quartile (Q1). In addition, RAR was identified as a predictor for the prognosis of AE patients (AUC = 0.660, 95%CI: 0.574-0.746).

Conclusion

This study found the close association and predictive value of RAR for the prognosis of AE patients, indicating that RAR might help clinicians identify high-risk populations.

Comparing clinical features, severity and prognosis of autoimmune encephalitis and with and without oligoclonal bands

Objective

This study aimed to examine the clinical distinctions among patients diagnosed with autoimmune encephalitis (AE) based on the presence or absence of cerebrospinal fluid (CSF) oligoclonal bands (OCBs). Additionally, it sought to explore the relationship between OCBs and the severity and prognosis of autoimmune encephalitis.

Methods

A retrospective analysis was conducted on 94 patients diagnosed with AE at the People's Hospital of Zhengzhou University between October 2016 and June 2022. The patients were divided into OCB-positive and OCB-negative groups based on CSF-OCBs. Patient severity at admission was assessed utilizing the Clinical Assessment Scale for Autoimmune Encephalitis (CASE) and the modified Rankin scale (mRS). Additionally, some oligoclonal-positive patients underwent dynamic longitudinal analysis of cerebrospinal fluid test indices. The mRS score was ultimately employed to evaluate patients' short-term prognosis (6 months) and long-term prognosis (at least 12 months) following immunotherapy.

Results

Of the 94 patients, 34 (36.2%) belonged to the OCB-positive group, while 60 (63.8%) belonged to the OCB-negative group. The group with anti-n-methyl-d-aspartate receptor (anti-NMDAR) encephalitis exhibited the highest rate of oligoclonal positivity at 27 (49.1%), followed by anti-aminobutyric acid B receptor (GABABR) encephalitis with 4 cases (30.8%), anti-contactin-associated protein-like 2 (CASPR2) encephalitis with 2 cases (20%), and anti-leucine-rich glioma inactivating protein 1 (LGI1) encephalitis with 1 case (6.25%). No statistically significant differences were found between the two groups regarding gender, age, prodromal symptoms, psychiatric disorders, seizures, language disorders, motor dysfunction, cognitive dysfunction, tumor incidence, and magnetic resonance imaging (MRI) abnormalities (p > 0.05). The OCB-positive group exhibited higher rates of autonomic dysfunction, intensive care unit (ICU) admission, CSF leukocytes, and IgG index compared to the OCB-negative group (p < 0.05). Additionally, the OCB-positive group had significantly higher median CASE and mRS scores prior to immunotherapy than the OCB-negative group (p < 0.001 and p < 0.001). Furthermore, in both short-term follow-up and long-term follow-up, the OCB-positive group had a significantly lower proportion of patients with a favorable prognosis compared to the OCB-negative group (50% vs. 71.7, 61.8% vs. 83.3%; p = 0.036, p = 0.002).

Conclusion

Autonomic dysfunction, ICU admission, leukocytes in the cerebrospinal fluid, and elevated IgG index are more commonly observed in OCB-positive patients. OCB-positivity has also been linked to the severity and prognosis of AE, making it a potential biomarker. Initial OCB testing aids clinicians in identifying potentially critically ill patients early and monitoring disease progression, thereby optimizing clinical treatment decisions.

[Autoimmune encephalitis: psychiatric aspects]

Autoimmune encephalitis is a group of diseases researched by both neurologists and psychiatrists. Despite a large number of studies and practical recommendations, the differential diagnosis and early diagnostics still remains an important issue. The most difficult to diagnose are cases that debut as mental disorders and/or occur without neurological symptoms. The literature review presents the current state of the problem with an emphasis on the practice of a psychiatrist.

Teratoma pathology and genomics in anti-NMDA receptor encephalitis

INTRODUCTION

Ovarian teratoma is a common occurrence in patients with anti-NMDA receptor encephalitis (NMDARe), and its removal is crucial for a favorable prognosis. However, the initial pathogenesis of autoimmunity in the encephalitic teratoma remains unclear. In this study, we aimed to investigate the genomic landscape and microscopic findings by comparing NMDARe-associated teratomas and non-encephalitic control teratomas.

MATERIALS AND METHODS

A prospective consecutive cohort of 84 patients with NMDARe was recruited from January 2014 to April 2020, and among them, patients who received teratoma removal surgery at Seoul National University Hospital were enrolled. We conducted a comparison of whole-exome sequencing data and pathologic findings between NMDARe-associated teratomas and control teratomas.

RESULTS

We found 18 NMDARe-associated teratomas from 15 patients and compared them with 17 non-encephalitic control teratomas. Interestingly, the genomic analysis revealed no significant differences in mutations between encephalitic and non-encephalitic teratomas. Pathologic analysis showed no discrepancies in terms of the presence of neuronal tissue and lymphocytic infiltration between the encephalitic teratomas (n = 14) and non-encephalitic teratomas (n = 18). However, rituximab-naïve encephalitic teratomas exhibited a higher frequency of germinal center formation compared to non-encephalitic teratomas (80% vs. 16.7%, P = 0.017). Additionally, rituximab-treated encephalitic teratomas demonstrated a reduced number of CD20+ cells and germinal centers in comparison to rituximab-naïve encephalitic teratomas (P = 0.048 and 0.023, respectively).

DISCUSSION

These results suggest that the initiation of immunopathogenesis in NMDARe-associated teratoma is not primarily attributed to intrinsic tumor mutations, but rather to immune factors present in the encephalitic patient group, ultimately leading to germinal center formation within the teratoma.

Antibodies to neural cell surface and synaptic proteins in paraneoplastic neurologic syndromes

Among patients with paraneoplastic neurologic syndromes (PNS), emphasis has historically been placed on neural antibodies against intracellular proteins that have a strong association with malignancy. Because of the intracellular location of their antigenic targets, these antibodies are typically considered to be non-pathogenic surrogate markers of immune cell-mediated neural injury. Unfortunately, patients with these antibodies often have suboptimal response to immunotherapy and poor prognosis. Over the last two decades, however, dramatic advancements have been made in the discovery and clinical characterization of neural antibodies against extracellular targets. These antibodies are generally considered to be pathogenic, given their potential to directly alter antigen structure or function, and patients with these antibodies often respond favorably to prompt immunotherapy. These antibodies also associate with tumors and may thus occur as PNS, albeit more variably than neural antibodies against intracellular targets. The updated 2021 PNS diagnostic criteria, which classifies antibodies as high-risk, intermediate-risk, or lower-risk for an associated cancer, better clarifies how neural antibodies against extracellular targets relate to PNS. Using this recently created framework, the clinical presentations, ancillary test findings, oncologic associations, and treatment responses of syndromes associated with these antibodies are discussed.

Neurological syndromes and potential triggers associated with antibodies to neuronal surface antigens

BACKGROUND

Autoantibodies against surface neuronal antigens have been associated with specific neurological presentations including autoimmune encephalitis (AE), with variable association with neoplasia and infections.

METHODS

We described the phenotype and environmental associations of patients with neurological syndromes associated with antibodies against neuronal surface antigens who were referred to a tertiary center in the South of Brazil. All patients were tested for neuronal autoantibodies using cell-based assays. Clinical, radiological, and laboratory findings were retrospectively reviewed.

RESULTS

We identified 16 patients, 15 had subacute, and one had a progressive disease course. Among patients with subacute onset, 11 (73 %) were N-Methyl-d-Aspartate receptor (NMDAr-IgG)+, 3 (20 %) were Leucine-rich Glioma-Inactivated-1 (LGI1-IgG)+, and 1 (6 %) was positive for Glycine receptor-IgG. The patient with a progressive disease course had antibodies against IgLON5. Most patients had disease onset in spring and summer suggesting environmental factors for the development of AE. Also, we observed a different pattern of brain lesions when NMDAr-IgG encephalitis followed herpes encephalitis and a previously unreported association with Rosai-Dorfman-Destombe disease. All patients with encephalopathy met criteria for possible AE and all proven NMDAr-IgG+ met criteria for NMDAr-IgG encephalitis. However, only one LGI1-IgG+ patient fulfilled clinical criteria for limbic encephalitis. All but one received high-dose intravenous methylprednisolone, 11 also had intravenous human immunoglobulin, and 4 plasma exchange. Furthermore, all patients received second-line immunotherapy. Importantly, most patients improved with immunotherapy, even when initiated later in the disease course.

CONCLUSION

We identified seasonal variability associated with neuronal surface antibodies suggesting environmental triggers. Also, we described the coexistence of NMDAr-IgG encephalitis with histiocytosis. In our series, most patients received second-line immunotherapy. We observed neurologic improvement after treatment even in cases of delayed diagnosis. Increasing the recognition and availability of tests and treatments for these conditions is of paramount importance in low- and middle-income countries.

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.

Chimeric autoantibody receptor T cells deplete NMDA receptor-specific B cells

Anti-NMDA receptor (NMDAR) autoantibodies cause NMDAR encephalitis, the most common autoimmune encephalitis, leading to psychosis, seizures, and autonomic dysfunction. Current treatments comprise broad immunosuppression or non-selective antibody removal. We developed NMDAR-specific chimeric autoantibody receptor (NMDAR-CAAR) T cells to selectively eliminate anti-NMDAR B cells and disease-causing autoantibodies. NMDAR-CAARs consist of an extracellular multi-subunit NMDAR autoantigen fused to intracellular 4-1BB/CD3ζ domains. NMDAR-CAAR T cells recognize a large panel of human patient-derived autoantibodies, release effector molecules, proliferate, and selectively kill antigen-specific target cell lines even in the presence of high autoantibody concentrations. In a passive transfer mouse model, NMDAR-CAAR T cells led to depletion of an anti-NMDAR B cell line and sustained reduction of autoantibody levels without notable off-target toxicity. Treatment of patients may reduce side effects, prevent relapses, and improve long-term prognosis. Our preclinical work paves the way for CAAR T cell phase I/II trials in NMDAR encephalitis and further autoantibody-mediated diseases.

Elevated serum levels of the NLRP3 inflammasome are associated with the severity of anti-NMDAR encephalitis in children

BACKGROUND

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is the most common autoimmune encephalitis, mainly impacting young females and children. The involvement of the Nod-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome and related cytokines in pediatric individuals with this condition remains unclear.

METHODS

We collected information from 27 children who had anti-NMDAR encephalitis and 12 individuals with non-inflammatory neurological disorders as controls. We used an enzyme-linked immunosorbent assay (ELISA) to identify NLRP3 inflammasome, interleukin (IL)-1β, and IL-18 expression in cerebrospinal fluid (CSF) and matching serum samples. The modified Rankin Scale (mRS) score was performed throughout the acute phase and at the 6-month follow-up to determine the severity of the disease. The area under the curve (AUC) of the receiver operating characteristic curve was utilized to calculate the prediction efficacy.

RESULTS

When compared to controls, individuals with anti-NMDAR encephalitis had significantly increased serum expression of the NLRP3 inflammasome (p < 0.001), IL-1β (p < 0.05), and IL-18 (p < 0.01). In the acute phase, mRS scores were correlated positively with serum levels of NLRP3 inflammasome (p = 0.008), IL-1β (p = 0.023), and IL-18 (p < 0.001). A positive connection was also found between serum levels of NLRP3 inflammasome and IL-1β (p = 0.005). Furthermore, the expression of IL-1β and IL-18 in serum correlated with the 6-month follow-up outcome. The AUC for NLRP3 inflammasome in distinguishing patients with severe neurologic impairments from those with moderate impairments was 0.808 (95 % CI: 0.645-0.972).

CONCLUSION

In our investigation, children with anti-NMDAR encephalitis have more severe first clinical presentations when their serum concentrations of the NLRP3 inflammasome and related cytokines were higher. These findings provide a potential role for the NLRP3 inflammasome pathway in the pathogenesis of NMDAR encephalitis and provide a basis for targeted therapeutic interventions.

Antibody-Negative Autoimmune Encephalitis: A Single-Center Retrospective Analysis

BACKGROUND AND OBJECTIVES

Autoimmune encephalitis (AE) refers to a heterogenous group of inflammatory CNS diseases. Subgroups with specified neural autoantibodies are more homogeneous in presentation, trigger factors, outcome, and response to therapy. However, a considerable fraction of patients has AE features but does not harbor detectable autoantibodies and is referred to as antibody-negative AE. Our aim was to describe clinical features, trigger factors, treatments, and outcome of a cohort of comprehensively tested antibody-negative AE patients.

METHODS

This retrospective monocentric study recruited adult patients whose serum and/or CSF was sent to our tertiary center for neural antibody testing between 2011 and 2020, who entered the diagnostic algorithm as possible antibody-negative AE and had the following: (1) probable antibody-negative AE, definite antibody-negative acute disseminated encephalomyelitis (ADEM), or definite autoimmune limbic encephalitis (LE) according to diagnostic criteria; (2) available data on MRI of the brain, CSF, and EEG; and (3) stored serum and/or CSF samples. These samples were reanalyzed using a comprehensive combination of cell-based and tissue-based assays.

RESULTS

Of 2,250 patients tested, 33 (1.5%) were classified as possible antibody-negative AE. Of these, 5 were found to have antibodies by comprehensive testing, 5 fulfilled the criteria of probable AE (3F:2M, median age 67, range 42-67), 4 of definite autoimmune LE (2F:2M, median age 45.5, range 27-60 years), one of definite antibody-negative ADEM, 2 of Hashimoto encephalopathy, one had no samples available for additional testing, and 15 had no further categorization. Of 10 probable/definite AE/LE/ADEM, one had a malignancy and none of them received an alternative diagnosis until the end of follow-up (median 18 months). In total, 80% (8/10) of patients received immunotherapy including corticosteroids, and 6/10 (60%) patients received rituximab, azathioprine, cyclophosphamide, plasma exchange, or IV immunoglobulins. Five (50%) patients improved, one (10%) stabilized, one (10%) worsened, and 3 (30%) died. All deaths were considered to be related to encephalitis. We did not observe differences of immunotherapy-treated patients in likelihood of improvement with or without nonsteroidal immunotherapy (with 2/6, without 1/2).

DISCUSSION

Antibody-negative AE should be diagnosed only after comprehensive testing. Diagnostic effort is important because many patients benefit from immunotherapy and some have malignancies.

VH2+ Antigen-Experienced B Cells in the Cerebrospinal Fluid Are Expanded and Enriched in Pediatric Anti-NMDA Receptor Encephalitis

Pediatric and adult autoimmune encephalitis (AE) are often associated with Abs to the NR1 subunit of the N-methyl-d-aspartate (NMDA) receptor (NMDAR). Very little is known regarding the cerebrospinal fluid humoral immune profile and Ab genetics associated with pediatric anti-NMDAR-AE. Using a combination of cellular, molecular, and immunogenetics tools, we collected cerebrospinal fluid from pediatric subjects and generated 1) flow cytometry data to calculate the frequency of B cell subtypes in the cerebrospinal fluid of pediatric subjects with anti-NMDAR-AE and controls, 2) a panel of recombinant human Abs from a pediatric case of anti-NMDAR-AE that was refractory to treatment, and 3) a detailed analysis of the Ab genes that bound the NR1 subunit of the NMDAR. Ag-experienced B cells including memory cells, plasmablasts, and Ab-secreting cells were expanded in the pediatric anti-NMDAR-AE cohort, but not in the controls. These Ag-experienced B cells in the cerebrospinal fluid of a pediatric case of NMDAR-AE that was refractory to treatment had expanded use of variable H chain family 2 (VH2) genes with high somatic hypermutation that all bound to the NR1 subunit of the NMDAR. A CDR3 motif was identified in this refractory case that likely drove early stage activation and expansion of naive B cells to Ab-secreting cells, facilitating autoimmunity associated with pediatric anti-NMDAR-AE through the production of Abs that bind NR1. These features of humoral immune responses in the cerebrospinal fluid of pediatric anti-NMDAR-AE patients may be relevant for clinical diagnosis and treatment.

Brazilian autoimmune encephalitis network (BrAIN): antibody profile and clinical characteristics from a multicenter study

Background

The frequency of antibodies in autoimmune encephalitis (AIE) may vary in different populations, however, data from developing countries are lacking. To describe the clinical profile of AIE in Brazil, and to evaluate seasonality and predictors of AIE in adult and pediatric patients.

Methods

We evaluated patients with possible AIE from 17 centers of the Brazilian Autoimmune Encephalitis Network (BrAIN) between 2018 and 2022. CSF and serum were tested with TBAs and CBAs. Data on clinical presentation, complementary investigation, and treatment were compiled. Seasonality and predictors of AIE in adult and pediatric populations were analyzed.

Results

Of the 564 patients, 145 (25.7%) were confirmed as seropositive, 69 (12.23%) were seronegative according to Graus, and 58% received immunotherapy. The median delay to diagnosis confirmation was 5.97 ± 10.3 months. No seasonality variation was observed after 55 months of enrolment. The following antibodies were found: anti-NMDAR (n=79, 54%), anti-MOG (n=14, 9%), anti-LGI1(n=12, 8%), anti-GAD (n=11, 7%), anti-GlyR (n=7, 4%), anti-Caspr2 (n=6, 4%), anti-AMPAR (n=4, 2%), anti-GABA-BR (n=4, 2%), anti-GABA-AR (n=2, 1%), anti-IgLON5 (n=1, 1%), and others (n=5, 3%). Predictors of seropositive AIE in the pediatric population (n=42) were decreased level of consciousness (p=0.04), and chorea (p=0.002). Among adults (n=103), predictors of seropositive AIE were movement disorders (p=0.0001), seizures (p=0.0001), autonomic instability (p=0.026), and memory impairment (p=0.001).

Conclusion

Most common antibodies in Brazilian patients are anti-NMDAR, followed by anti-MOG and anti-LGI1. Only 26% of the possible AIE patients harbor antibodies, and 12% were seronegative AIE. Patients had a 6-month delay in diagnosis and no seasonality was found. Findings highlight the barriers to treating AIE in developing countries and indicate an opportunity for cost-effect analysis. In this scenario, some clinical manifestations help predict seropositive AIE such as decreased level of consciousness, chorea, and dystonia among children, and movement disorders and memory impairment among adults.

Clinical scales in autoimmune encephalitis-A retrospective monocentric cohort study

OBJECTIVE

Assessing severity of antibody-mediated encephalitis (AE) or paraneoplastic encephalitis (PE) requires valid and reliable scores to guide treatment decisions and predict outcome both in clinical routine and studies. We aimed to validate the prognostic value of the clinical assessment scale in autoimmune encephalitis (CASE) and the anti-NMDAR-encephalitis one-year functional status (NEOS) score in patients suffering from AE and PE in a large monocentric cohort.

METHODS

We retrospectively applied the CASE and NEOS score to patients with definite AE and PE treated at a tertiary hospital. Correlations were established between the CASE and NEOS score and the modified Rankin scale (mRs). Multivariable analyses were calculated to identify predictors of outcome.

RESULTS

Thirty-four patients (27 AE, 7 PE) were included. Correlations between mRS and CASE score were strongest in patients with AE compared to PE at all intervals, but in the subgroups (LGI1, NMDAR, GAD, miscellaneous surface antibodies, PE) the correlation was strongest in the interval after baseline. Patients with AE seemed to display better outcomes compared to PE, which was underlined by multivariable analysis. Improvement was mostly observed within 6-12 months after disease onset, after which little or no further improvement was noted with some exception for two patients with anti-NMDARE who recovered substantially even after 12 months of treatment. The NEOS score significantly predicted the outcome at last follow-up in patients with AE with a sensitivity of 79% at a cut-off value of 2 points (AUC 0.79, 95% CI 0.58-0.99, p = 0.04).

INTERPRETATION

The CASE and NEOS score are suitable supplementary tools in addition to the mRS for capturing diverse symptoms, for grading and monitoring symptom severity.

The relevance of NMDA receptor antibody-specific index for diagnosis and prognosis in patients with anti-NMDA receptor encephalitis

The clinical implications of the presence of anti-N-methyl-D-aspartate receptor (NMDAR)-specific intrathecal immunoglobulin G synthesis and whether it determines the diagnosis of anti-NMDAR encephalitis have not been thoroughly investigated yet. Thus, the aim of this study was to investigate whether the detection of intrathecal anti-NMDAR-specific IgG synthesis contributes to the diagnostic confirmation of anti-NMDAR encephalitis, to disease severity, and to prognosis in patients with positive serum anti-NMDAR-IgG. In this study, patients with detectable anti-NMDAR IgG in serum and/or cerebrospinal fluid (CSF) were included and separated into two groups that either met the 2016 criteria by Graus et al. of definite anti-NMDAR encephalitis (n = 27) or did not (n = 15). In a total, of 80 paired CSF/serum samples, antibody titers were titrated manually and end-point titer levels were carefully determined in a blinded manner to the subgroup attribution. The disease course was assessed via the modified Rankin Scale (mRS) and prognosis was estimated by the anti-NMDAR Encephalitis One-Year Functional Status (NEOS) score. With respect to whether the diagnostic Graus criteria for definite anti-NMDAR encephalitis were fulfilled, a significantly unequal distribution of intrathecal anti-NMDAR antibody-specific synthesis could be shown with a high negative predictive value in case of a negative anti-NMDAR antibody-specific index (NMDAR AI, p = .008. OR = 23.9, sensitivity = 1.0, specificity = 0.4, negative predictive value = 1). A weak correlation was found between the CSF antibody titer and mRS value at the time of sample collection (rs = .37, p = .008, 95% CI [.09, .59]). During the disease course a higher delta-mRS value formed of the mRS at initial presentation minus that at the last recorded presentation correlated with a higher NMDAR AI at first lumbar puncture (rs = - .56, p = .017, 95% CI [- .83, - .11]). No association with the prognostic NEOS score was found. In conclusion, a negative antibody-specific index for anti-NMDAR IgG antibodies has a highly negative predictive value for the diagnosis of anti-NMDAR encephalitis. Yet, a positive NMDAR AI alone does not allow the diagnosis of anti-NMDAR encephalitis.

Validating Prediction Tools for Autoimmune Encephalitis in Adult Taiwanese Patients: A Retrospective Study

Autoimmune encephalitis (AE) is a neurological emergency. We aimed to analyze the application and effectiveness of the currently available prediction tools for AE patients in Taiwan. We retrospectively collected 27 AE patients between January 2008 and December 2019. Antibody Prevalence in Epilepsy (APE) score, Response to Immunotherapy in Epilepsy (RITE) score, and anti-NMDAR Encephalitis One Year Functional Status (NEOS) score were applied to validate their usability. Based on the defined cutoff values, the sensitivity and specificity of each score were calculated. A receiver operating characteristic (ROC) curve and the area under the curve (AUC) were generated for each scoring system. The AUC value of APE was 0.571. The AUC value of RITE was 0.550. The AUC values for the NEOS score at discharge and long-term follow-up were 0.645 and 0.796, respectively. The performance of APE and RITE scores was suboptimal in the Taiwanese cohort, probably due to the limitations of the small sample size and single ethnicity. On the other hand, the NEOS score performed better on long-term follow-up than at discharge.

MRI Features and Their Association With Outcomes in Children With Anti-NMDA Receptor Encephalitis

OBJECTIVES

How brain MRI lesions associate with outcomes in pediatric anti-NMDA receptor encephalitis (pNMDARE) is unknown. In this study, we correlate T2-hyperintense MRI brain lesions with clinical outcomes in pNMDARE.

METHODS

This was a multicenter retrospective cohort study from 11 institutions. Children younger than 18 years with pNMDARE were included. One-year outcomes were assessed by the modified Rankin Score (mRS) with good (mRS ≤2) and poor (mRS ≥3) outcomes.

RESULTS

A total of 175 pNMDARE subjects were included, with 1-year mRS available in 142/175 (81%) and 60/175 (34%) had abnormal brain MRIs. The most common T2-hyperintense lesion locations were frontal, temporal, and parietal. MRI features that predicted poor 1-year outcomes included abnormal MRI, particularly T2 lesions in the frontal and occipital lobes. After adjusting for treatment within 4 weeks of onset, improvement within 4 weeks, and intensive care unit admission, MRI features were no longer associated with poor outcomes, but after multiple imputation for missing data, T2 frontal and occipital lesions associated with poor outcomes.

DISCUSSION

Abnormal frontal and occipital lesions on MRI may associate with 1-year mRS in pNMDARE. MRI of the brain may be a helpful prognostication tool that should be examined in future studies.

Prognostic Value of Persistent CSF Antibodies at 12 Months in Anti-NMDAR Encephalitis

BACKGROUND AND OBJECTIVES

Anti-NMDA receptor (NMDAR) encephalitis is defined by the presence of antibodies (Abs) targeting the NMDAR in the CSF. This study aimed to determine the prognostic value of persistent CSF NMDAR-Abs during follow-up.

METHODS

This retrospective observational study included patients diagnosed with anti-NMDAR encephalitis in the French Reference Center for Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis and for whom CSF samples were obtained at diagnosis and >4 months of follow-up to evaluate CSF NMDAR-Ab persistence. Because patients were tested for CSF NMDAR-Abs at different time points, samples were stratified into different periods of follow-up (i.e., 12 months was considered for the 9- to 16-month follow-up period).

RESULTS

Among the 501 patients diagnosed with anti-NMDAR encephalitis between January 2007 and June 2020, 89 (17%) were tested between 4 and 120 months for CSF NMDAR-Abs after clinical improvement and included in the study (75/89 women, 84%; median age 20 years, interquartile range [IQR] 16-26). During follow-up, 21 of 89 (23%) patients had a relapse after a median time of 29 months (IQR 18-47), and 20 of 89 (22%) had a poor outcome (mRS ≥3) after a median last follow-up of 36 months (IQR 19-64). Most patients (69/89, 77%) were tested at the 12-month follow-up period, and 42 of 69 (60%) of them had persistent CSF NMDAR-Abs. When comparing patients with persistent or absent CSF NMDAR-Abs at 12 months, poor outcome at the last follow-up was more frequent in the former (38% vs 8%, p = 0.01), who had relapses more often (23% vs 7%), which also appeared earlier in the course of the disease (90% during the following 4 years of follow-up vs 20%), although no significant difference was observed at long-term follow-up (p = 0.15). In addition, patients with persistent CSF NMDAR-Abs at 12 months had higher titers of CSF NMDAR-Abs at diagnosis.

DISCUSSION

In this study, patients with persistent CSF NMDAR-Abs at 12 months were more likely to have subsequent relapses and a poor long-term outcome. However, these findings should be interpreted with caution because of the variability in the time of sampling of this study. Future prospective studies are required to validate these results in larger cohorts.

Anti-NMDAR encephalitis in Southeast Asia - A single-centre, longitudinal study

AIMS

To describe the clinical features and outcomes of anti-NMDA receptor encephalitis (ANMDARE) in Southeast Asian (SEA) patients.

METHOD

SEA patients diagnosed and treated for ANMDARE at Singapore General Hospital between January 2010 and June 2020 were included in this observational study, in which their clinical features and outcomes were retrospectively analysed.

RESULTS

We studied 20 patients: 11 Chinese, 3 Tagalogs, 2 Malays, 2 Indians, 1 Eurasian and 1 Javanese. Their median age was 28 years. 15 were females, amongst whom teratomas were demonstrated in 13 (12 ovarian, 1 mediastinal). Delirium and seizures were the two commonest events leading to their presentation at our facility. 1 male had biliary neuroendocrine tumour. Comparison between genders revealed a strong male predilection for early seizures and insomnia; females were four times likelier than males to develop movement disorders or have underlying neoplasms. Patients with dysautonomia required longer ICU stay beyond 14 days, but their outcomes at 1 year did not differ. When reviewed at 1 year, none had clinical relapses, and outcomes were favourable (mRS 0-2) in nearly two-thirds.

CONCLUSIONS

SEA patients with ANMDARE frequently present with delirium and seizures. Underlying neoplasms are very common in females. Differences in clinical characteristics may exist between the two genders. Recognition of these can facilitate diagnosis, and permit earlier initiation of appropriate treatment strategies, and thus improve outcomes of SEA patients.

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.

Autoimmune encephalitis: Epidemiology, pathophysiology and clinical spectrum (part 2)

Autoimmune encephalitis (AE) represents a growing number of severe autoimmune-inflammatory diseases affecting both the white and grey matter of the brain. In part 1 of this series we focused on the epidemiology, pathophysiology and clinical presentation of this condition, with two illustrative cases. In this part, we will introduce the clinical criteria for AE, particularly for the diagnosis of anti-N-methyl-D-aspartate (NMDA) receptor encephalitis, which were developed to facilitate immune treatment in suspected cases before antibody results are available. We subsequently discuss the work up, differential diagnosis and treatment options for patients with this disease.  

Approach to acute encephalitis in the intensive care unit

PURPOSE OF REVIEW

Recent years have seen a dramatic increase in the identification of autoimmune encephalitis (AE) and the emergence of new causes of infectious encephalitis (IE). However, management of these patients remains challenging, with many requiring care in intensive care units. Here, we describe recent advances in the diagnosis and management of acute encephalitis.

RECENT FINDINGS

Advances in the identification of clinical presentations, neuroimaging biomarkers, and electroencephalogram patterns have enabled more rapid diagnosis of encephalitis. Newer modalities such as meningitis/encephalitis multiplex PCR panels, metagenomic next-generation sequencing, and phage display-based assays are being evaluated in an effort to improve detection of autoantibodies and pathogens. Specific advances in the treatment of AE include establishment of a systematic approach to first-line therapies and the development of newer second-line modalities. The role of immunomodulation and its applications in IE are actively being investigated. In the ICU, particular attention to status epilepticus, cerebral edema, and dysautonomia may improve outcomes.

SUMMARY

Substantial diagnostic delays still occur, with many cases left without an identified etiology. Antiviral therapies remain scarce, and optimal treatment regimens for AE still need to be clarified. Nevertheless, our understanding of diagnostic and therapeutic approaches to encephalitis is rapidly evolving.

Sleep Characteristics in Pediatric Anti-N-methyl-d-aspartate (NMDA) Receptor Encephalitis: A Retrospective Cohort Study

Background: Rates of sleep problems in children with anti-N-methyl-d-aspartate (NMDA) receptor encephalitis are unknown. Methods: We used a retrospective observational cohort database of children with a diagnosis of NMDA receptor encephalitis at a single freestanding institution. One-year outcomes were assessed with the pediatric modified Rankin Score (mRS), with 0 to 2 as good and 3 or greater as poor outcome. Results: Ninety-five percent (39/41) of children with NMDA receptor encephalitis had sleep dysfunction at onset; 34% (11/32) reported sleep problems at 1 year. Sleep problems at onset and propofol use were not associated with poor outcomes at 1 year. Poor sleep at 1 year correlated with mRS scores (range 2-5) at 1 year. Discussion: High rates of sleep dysfunction occur in children with NMDA receptor encephalitis. Persistent sleep problems at 1 year may correlate with outcomes as assessed by mRS at 1 year. Further studies comparing the relationship of poor sleep with outcomes in NMDA receptor encephalitis are needed.

Neuroimaging characteristics may aid in diagnosis, subtyping, and prognosis in autoimmune encephalitis

OBJECTIVE

To examine the utility of neuroimaging characteristics as biomarkers of prognosis in seropositive autoimmune encephalitis (AE).

METHODS

In this multi-center study, we retrospectively analyzed 66 cases of seropositive AE. The MRI and PET imaging was assessed by independent visual inspection. Whole brain and regional volumes were imputed by IcoMetrix, an automated volumetric assessment package. The modified Rankin Scale (mRS) was utilized to assess the patients' follow-up disability. Other outcomes were mortality, first line treatment failure, medial temporal lobe (MTL) atrophy, and clinical relapse. Univariate and multivariable regression analysis was performed.

RESULTS

Abnormalities on MRI were detected in 35.1% of patients, while PET was abnormal in 46.4%. Initial median whole brain and hippocampal volumes were below the 5th and 20th percentile respectively compared to an age-matched healthy database. After a median follow-up of 715 days, 85.2% had good functional outcome (mRS ≤ 2). Nine patients developed MTL atrophy during follow-up. On multivariable analysis, inflammatory MTL changes were associated with development of MTL atrophy (HR 19.6, p = 0.007) and initial hippocampal volume had an inverse relationship with mortality (HR 0.04, p = 0.011). Patients who developed MTL atrophy had a reduced chance of good final mRS (HR 0.16, p = 0.015).

CONCLUSIONS

Neuroimaging on initial hospital admission may be provide important diagnostic and prognostic information. This study demonstrates that structural and inflammatory changes of the MTL may have importance in clinical and radiological prognosis in seropositive AE.

Immune Mechanisms in Epileptogenesis: Update on Diagnosis and Treatment of Autoimmune Epilepsy Syndromes

Seizures and epilepsy can result from various aetiologies, yet the underlying cause of several epileptic syndromes remains unclear. In that regard, autoimmune-mediated pathophysiological mechanisms have been gaining attention in the past years and were included as one of the six aetiologies of seizures in the most recent classification of the International League Against Epilepsy. The increasing number of anti-neuronal antibodies identified in patients with encephalitic disorders has contributed to the establishment of an immune-mediated pathophysiology in many cases of unclear aetiology of epileptic syndromes. Yet only a small number of patients with autoimmune encephalitis develop epilepsy in the proper sense where the brain transforms into a state where it will acquire the enduring propensity to produce seizures if it is not hindered by interventions. Hence, the term autoimmune epilepsy is often wrongfully used in the context of autoimmune encephalitis since most of the seizures are acute encephalitis-associated and will abate as soon as the encephalitis is in remission. Given the overlapping clinical presentation of immune-mediated seizures originating from different aetiologies, a clear distinction among the aetiological entities is crucial when it comes to discussing pathophysiological mechanisms, therapeutic options, and long-term prognosis of patients. Moreover, a rapid and accurate identification of patients with immune-mediated epilepsy syndromes is required to ensure an early targeted treatment and, thereby, improve clinical outcome. In this article, we review our current understanding of pathogenesis and critically discuss current and potential novel treatment options for seizures and epilepsy syndromes of underlying or suspected immune-mediated origin. We further outline the challenges in proper terminology.

Quantitative EEG as a Prognostic Tool in Suspected Anti-N-Methyl- d -Aspartate Receptor Antibody Encephalitis

PURPOSE

Anti-N-methyl- d -aspartate receptor (anti-NMDAR) encephalitis is a form of autoimmune encephalitis associated with EEG abnormalities. In view of the potentially severe outcomes, there is a need to develop prognostic tools to inform clinical management. The authors explored whether quantitative EEG was able to predict outcomes in patients with suspected anti-NMDAR encephalitis.

METHODS

A retrospective, observational study was conducted of patients admitted to a tertiary clinical neuroscience center with suspected anti-NMDAR encephalitis. Peak power and peak frequency within delta (<4 Hz), theta (4-8 Hz), alpha (8 - 13 Hz), and beta (13-30 Hz) frequency bands were calculated for the first clinical EEG recording. Outcome was based on the modified Rankin Scale (mRS) score at 1 year after hospital discharge. Binomial logistic regression using backward elimination was performed with peak frequency and power, anti-NMDAR Encephalitis One-Year Functional Status score, age, and interval from symptom onset to EEG entered as predictors.

RESULTS

Twenty patients were included (mean age 48.6 years, 70% female), of which 7 (35%) had a poor clinical outcome (mRS 2-6) at 1 year. There was no association between reported EEG abnormalities and outcome. The final logistic regression model was significant (χ 2 (1) = 6.35, P < 0.012) with peak frequency in the delta range (<4 Hz) the only retained predictor. The model explained 38% of the variance (Nagelkerke R2 ) and correctly classified 85% of cases. Higher peak frequency in the delta range was significantly associated ( P = 0.04) with an increased likelihood of poor outcome.

CONCLUSIONS

In this exploratory study, it was found that quantitative EEG on routinely collected EEG recordings in patients with suspected anti-NMDAR encephalitis was feasible. A higher peak frequency within the delta range was associated with poorer clinical outcome and may indicate anti-NMDAR-mediated synaptic dysfunction. Quantitative EEG may have clinical utility in predicting outcomes in patients with suspected NMDAR antibody encephalitis, thereby serving as a useful adjunct to qualitative EEG assessment; however, given the small sample size, replication in a larger scale is indicated.

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

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Autoimmune encephalitis with mGluR5 antibodies: A case series from China and review of the literature

Background

Only 15 patients of autoimmune encephalitis with metabotropic glutamate receptor 5 (mGluR5) antibodies have been reported worldwide since 2011, mostly from western countries. Patients with different genetic backgrounds are necessary to further clarify the clinical phenotype and prognosis of this rare disease.

Objective

We initially describe a case series from China to confirm the previous findings, expand the clinical phenotype, and identify the prognostic factors of autoimmune encephalitis with mGluR5 antibodies.

Methods

Observational data with follow-up were prospectively collected from autoimmune encephalitis patients with mGluR5 antibodies. Clinical information and outcomes on current and previously reported cases were combined and analyzed.

Results

We identified five patients (median age 35 years); two were female. The main clinical manifestations were behavioral/personality changes (five of five, 100%) and cognitive disorders (four of five, 80%), accompanied with other neurologic symptoms. Hypoventilation occurred in two (40%) patients, which was life-threatening. One patient had meningoencephalitis, suggesting a new phenotype in anti-mGluR5 encephalitis. All patients received immunotherapy. At the last follow-up (median 18 months), two (40%) patients showed complete recovery, two (40%) patients showed partial recovery, and one (20%) patient died. One (20%) patient had multiple relapses. Together with the 15 previously reported cases, associated tumors occurred in seven of 12 (58%) Western patients vs. one of eight (13%) Chinese patients. Modified Rankin Scale (mRS) scores at the last follow-up (median 31 months) were available in 16 patients. Patients with bad outcomes (mRS > 2, n = 4) were more likely to have hypoventilation at onset and higher mRS scores at peak of the disease.

Conclusions

In patients with different genetic background, as Chinese, the clinical phenotype of anti-mGluR5 encephalitis is similar. Fewer paraneoplastic cases were observed in Chinese patients. Most patients showed good responses to immunotherapy and cancer treatment. The clinical outcomes were favorable in most patients.

Brain magnetic resonance imaging predictors in anti-N-methyl-D-aspartate receptor encephalitis

OBJECTIVE

Brain magnetic resonance imaging (MRI) findings in anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis are nonspecific and rarely have obvious associations with clinical characteristics and outcomes. This study aimed to comprehensively describe the MRI features of patients with NMDAR encephalitis, examine their associations with clinical characteristics, and evaluate their predictive power for disease recurrence and prognosis.

METHODS

We retrospectively extracted the clinical data and brain MRI findings of 144 patients with NMDAR encephalitis. Patients underwent a 2-year follow-up to assess disease outcomes. We evaluated the associations of brain MRI findings at the onset with clinical characteristics, recurrence, and prognosis.

RESULTS

Initial MRI showed typical abnormalities in 65 patients (45.1%); of these, 34 (29.3%) developed recurrence and 10 (9.4%) had poor prognosis (mRS ≥3). Binary logistic regression analyses revealed that insula abnormalities were associated with acute seizure (odds ratio [OR] = 3.048, 95% confidence interval [CI]: 1.026-9.060) and white matter lesions were associated with cognitive impairment (OR = 2.730, 95% CI: 1.096-6.799). Risk factors for a poor 2-year prognosis included a higher number of brain MRI abnormalities (OR = 1.573, 95% CI: 1.129-2.192) and intensive care unit (ICU) admissions (OR = 15.312, 95% CI: 1.684-139.198). The risk factors for 2-year recurrence included abnormalities of the thalamus (HR = 3.780, 95% CI: 1.642-8.699).

INTERPRETATIONS

Brain MRI features of patients with NMDAR encephalitis were associated with clinical manifestations, prognosis, and recurrence. Higher numbers of MRI abnormalities and ICU admissions were predictive of poor prognosis. Abnormalities of the thalamus constituted a recurrence-related risk factor.

Early Immunotherapy and Longer Corticosteroid Treatment Are Associated With Lower Risk of Relapsing Disease Course in Pediatric MOGAD

BACKGROUND AND OBJECTIVES

We sought to identify early factors associated with relapse and outcome in paediatric-onset myelin oligodendrocyte glycoprotein antibody-associated disorders (MOGAD).

METHODS

In a multicenter retrospective cohort of pediatric MOGAD (≤18 years), onset features and treatment were compared in patients with monophasic vs relapsing disease (including cases with follow-up ≥12 months after onset or relapse at any time) and in patients with final Expanded Disability Status Scale (EDSS) 0 vs ≥1 at last follow-up (including cases with follow-up >3 months after last event or EDSS0 at any time). Multivariable logistic regression models were used to evaluate factors associated with relapsing disease course and EDSS ≥ 1 at final follow-up.

RESULTS

Seventy-five children were included (median onset age 7 years; median 30 months of follow-up). Presentation with acute disseminated encephalomyelitis was more frequent in children aged 8 years or younger (66.7%, 28/42) than in older patients (30.3%, 10/33) (p = 0.002), whereas presentation with optic neuritis was more common in children older than 8 years (57.6%, 19/33) than in younger patients (21.4%, 9/42) (p = 0.001). 40.0% (26/65) of patients relapsed. Time to first relapse was longer in children aged 8 years or younger than in older patients (median 18 vs 4 months) (p = 0.013). Factors at first event independently associated with lower risk of relapsing disease course were immunotherapy <7 days from onset (6.7-fold reduced odds of relapsing course, OR 0.15, 95% CI 0.03-0.61, p = 0.009), corticosteroid treatment for ≥5 weeks (6.7-fold reduced odds of relapse, OR 0.15, 95% CI 0.03-0.80, p = 0.026), and abnormal optic nerves on onset MRI (12.5-fold reduced odds of relapse, OR 0.08, 95% CI 0.01-0.50, p = 0.007). 21.1% (15/71) had EDSS ≥ 1 at final follow-up. Patients with a relapsing course had a higher proportion of final EDSS ≥ 1 (37.5%, 9/24) than children with monophasic disease (12.8%, 5/39) (p = 0.022, univariate analysis). Each 1-point increment in worst EDSS at onset was independently associated with 6.7-fold increased odds of final EDSS ≥ 1 (OR 6.65, 95% CI 1.33-33.26, p = 0.021).

DISCUSSION

At first attack of pediatric MOGAD, early immunotherapy, longer duration of corticosteroid treatment, and abnormal optic nerves on MRI seem associated with lower risk of relapse, whereas higher disease severity is associated with greater risk of final disability (EDSS ≥ 1).

Ovarian resection in anti-N-methyl-D-aspartate receptor encephalitis: A comparison of surgical approaches

BACKGROUND

For patients with anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) and ovarian teratoma, "conservative" surgical approaches (complete or partial unilateral oophorectomy or bilateral partial oophorectomies) are associated with clinical improvement. "Aggressive" ovarian resections (complete bilateral oophorectomy or "blind" ovarian resections without pre-operative evidence of teratoma) are also reported, although the evidence supporting these approaches is unclear.

OBJECTIVE

To compare the one-year functional outcomes of patients with NMDARE who underwent conservative vs. aggressive ovarian resections.

METHODS

Patients with NMDARE undergoing ovarian resection between January 1st, 2012 and December 31st, 2021 were retrospectively identified from three North American tertiary care centers. Primary outcome was a modified Rankin Scale score of 0-2 one year after ovarian resection. Fisher exact and Wilcoxon rank sum tests were used to compare demographic features, disease characteristics, and functional outcomes between the two surgical groups. A fixed-effects meta-analysis of studies reporting functional outcomes based on surgical approach was also performed.

RESULTS

Twenty-three patients were included. Eight underwent aggressive surgical management. There was a non-significant trend toward an association between aggressive surgical management and younger age-at-onset, higher baseline disease severity, and longer delays to treatment. There was no difference between "aggressive" (3/8, 38%) and "conservative" (11/15, 73%) management groups in achieving the primary outcome (OR95% = <0.1-1.9; p = 0.18). Findings were similar when considering data from 52 patients in two published studies (RR = 0.74; CI95% = 0.48-1.13; p = 0.16).

CONCLUSIONS

Aggressive ovarian resection was not associated with improved outcomes in patients with NMDARE in this series. Group differences may have contributed, recognizing that patients who underwent aggressive resection tended to be sicker, with procedures performed later in the disease course. Based on available evidence, we advocate for function-sparing resection in patients with imaging-confirmed/suspected teratoma, and repeated multi-modal imaging in at-risk patients with NMDARE refractory to conventional treatment.

Identification of cerebrospinal fluid biomarker candidates for anti-N-methyl-D-aspartate receptor encephalitis: High-throughput proteomic investigation

BACKGROUND

Although the diagnosis is mainly dependent on the detection of anti-N-methyl-D-aspartate receptor (NMDAR) antibodies in cerebrospinal fluid (CSF) and/or serum, there was no direct correlations between anti-NMDAR antibody titers in CSF and disease severity and prognosis in anti-NMDAR encephalitis patients. Here, we aimed to extensively identify CSF biomarkers related to the occurrence, development, and prognosis of anti-NMDAR encephalitis using a high-throughput proteomic approach.

METHODS

A CSF cytokine antibody array containing 80 cytokines and inflammatory mediators related to immune and inflammatory responses was applied to identify biomarker candidates in individual CSF samples from a well-characterized cohort comprising patients with anti-NMDAR encephalitis (n = 6) and controls (n = 6). Validation and specific detection were performed in an extended cohort consisting of anti-NMDAR encephalitis patients (n = 13), controls (n = 13), and viral encephalitis (n = 13) by enzyme-linked immunosorbent assay (ELISA). Additionally, the levels of some inflammatory proteins in three groups in cohort 2 reported in previous literatures that may be involved in the development of anti-NMDAR encephalitis were also tested by ELISA. Correlations between candidate biomarkers and clinical characteristics of anti-NMDAR encephalitis patients were analyzed.

RESULTS

Three differentially expressed cytokines and inflammatory mediators were screened from the 80-cytokine array in cohort 1. Functional enrichment analysis results suggested that these differentially expressed proteins were related to autophagy, immune/inflammatory responses, cell death, and other processes. In cohort 2, the elevations of cellular inhibitor of apoptosis protein-1 (cIAP-1), macrophage colony-stimulating factor (MCSF), CXC chemokine ligand 13 (CXCL13), and nucleotide binding oligomerization domain-like receptor protein 3 (NLRP3) in anti-NMDAR encephalitis were validated by ELISA. Linear regression revealed that the levels of CSF CXCL13 and cIAP-1 were positively correlated with the highest modified Rankin scale (mRS) score in the acute phase (p < 0.05). The level of cIAP-1 was positively correlated with the anti-NMDAR Encephalitis One-Year Functional Status (NEOS) score (p < 0.05).

CONCLUSION

These biomarkers show promising functions to evaluate severity or prognosis of anti-NMDAR encephalitis. The biological processes of immune/inflammatory responses, altered levels of autophagy, and the tumor necrosis factor (TNF) signal pathway may be involved in the pathophysiology of anti-NMDAR encephalitis to some extent.

Seronegative autoimmune encephalitis: clinical characteristics and factors associated with outcomes

Seronegative autoimmune encephalitis is autoimmune encephalitis without any identifiable pathogenic antibody. Although it is a major subtype of autoimmune encephalitis, many unmet clinical needs exist in terms of clinical characteristics, treatments and prognosis. In this institutional cohort study, patients diagnosed with seronegative autoimmune encephalitis with available 2-year outcomes were analysed for the disease course, 2-year outcome prediction system, effect of immunotherapy, necessity of further immunotherapy at 6 or 12 months and pattern of brain atrophy. Seronegative autoimmune encephalitis was subcategorized into antibody-negative probable autoimmune encephalitis, autoimmune limbic encephalitis and acute disseminated encephalomyelitis. Poor 2-year outcome was defined by modified Rankin scale scores 3-6, and the 2-year serial data of Clinical Assessment Scales in Autoimmune Encephalitis score was used for longitudinal data analyses. A total of 147 patients were included. The frequency of achieving a good 2-year outcome (modified Rankin scale 0-2) was 56.5%. The antibody-negative probable autoimmune encephalitis subtype exhibited the poorest outcomes, although the baseline severity was similar among the subtypes. The RAPID score, consisting of five early usable clinical factors, refractory status epilepticus, age of onset ≥60 years, probable autoimmune encephalitis (antibody-negative probable autoimmune encephalitis subtype), infratentorial involvement and delay of immunotherapy ≥1 month, was associated with poorer 2-year outcomes. Any immunotherapy was associated with clinical improvement in the patients with low risk for poor 2-year outcomes (RAPID scores 0-1), and the combination immunotherapy of steroid, immunoglobulin, rituximab and tocilizumab was associated with better outcomes in the patients with high risk for poor 2-year outcomes (RAPID scores 2-5). In patients with persistent disease at 6 months, continuing immunotherapy was associated with more improvement, while the effect of continuing immunotherapy for more than 12 months was unclear. In the longitudinal analysis of MRI, the development of cerebellar atrophy indicated poor outcomes, while the absence of diffuse cerebral atrophy or medial temporal atrophy indicated the possibility of a good outcome. This study provides information about the clinical characteristics and courses, the effect of immunotherapy and its duration, and prognostic factors in seronegative autoimmune encephalitis.

Presence of anti-nuclear antibody associated with worse clinical outcomes of anti-NMDAR encephalitis

Purpose

Systemic autoantibodies are important for the diagnosis of autoimmune diseases, but their roles in anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis are unknown. The purpose of our study is to investigate the characteristics and a prognosis of anti-NMDAR encephalitis with the prevalence of autoantibodies.

Methods

Systemic autoantibodies were evaluated in 64 patients with anti-NMDAR encephalitis and 14 patients with autoimmune encephalitis with other forms. Then, according to systemic autoantibodies, patients with anti-NMDAR encephalitis were divided into an anti-nuclear antibody (ANA) positive group and an ANA negative group. The clinical outcome was assessed by a modified Rankin score at 12 months after the disease onset.

Results

A total of 64 patients with anti-NMDAR encephalitis were enrolled, of which 28.13% (18/64) were positive for ANA. The titers of a positive anti-NMDAR antibody in CSF (p = 0.041) and serum (p = 0.031) in the ANA-positive group were significantly higher than the ANA-negative group. Patients with ANA positive than those with ANA negative showed lower rates of headache (p = 0.047) and speech disorder (p = 0.049). The presence of ANA was associated with a worse clinical outcome at 12 months (p = 0.043).

Conclusion

ANA was prevalent in patients with anti-NMDAR encephalitis, and associated with a worse prognosis and impaired neurological recovery.

The Role of Autoantibody Testing in Modern Personalized Medicine

Personalized medicine (PM) aims individualized approach to prevention, diagnosis, and treatment. Precision Medicine applies the paradigm of PM by defining groups of individuals with akin characteristics. Often the two terms have been used interchangeably. The quest for PM has been advancing for centuries as traditional nosology classification defines groups of clinical conditions with relatively similar prognoses and treatment options. However, any individual is characterized by a unique set of multiple characteristics and therefore the achievement of PM implies the determination of myriad demographic, epidemiological, clinical, laboratory, and imaging parameters. The accelerated identification of numerous biological variables associated with diverse health conditions contributes to the fulfillment of one of the pre-requisites for PM. The advent of multiplex analytical platforms contributes to the determination of thousands of biological parameters using minute amounts of serum or other biological matrixes. Finally, big data analysis and machine learning contribute to the processing and integration of the multiplexed data at the individual level, allowing for the personalized definition of susceptibility, diagnosis, prognosis, prevention, and treatment. Autoantibodies are traditional biomarkers for autoimmune diseases and can contribute to PM in many aspects, including identification of individuals at risk, early diagnosis, disease sub-phenotyping, definition of prognosis, and treatment, as well as monitoring disease activity. Herein we address how autoantibodies can promote PM in autoimmune diseases using the examples of systemic lupus erythematosus, antiphospholipid syndrome, rheumatoid arthritis, Sjögren syndrome, systemic sclerosis, idiopathic inflammatory myopathies, autoimmune hepatitis, primary biliary cholangitis, and autoimmune neurologic diseases.

Evaluation of multiple consensus criteria for autoimmune encephalitis and temporal analysis of symptoms in a pediatric encephalitis cohort

Objective

To evaluate the sensitivity and specificity of current criteria for the diagnosis of autoimmune encephalitis (AE) and the temporal onset of neuropsychiatric symptoms (NP) in a pediatric encephalitis cohort.

Background

Multiple criteria for AE have been developed, including the Graus and pediatric-focused Cellucci consensus criteria, and the Determining Etiology in Encephalitis (DEE) score for patients with encephalitis. Early identification and treatment of AE is crucial to improve outcomes, but this can be difficult given the frequent overlap of clinical presentation between AE and infectious encephalitis (IE).

Design/methods

A retrospective review was conducted of patients seen at our institution from 2000 to 2021 with a final diagnosis of AE or IE. These were narrowed through multiple exclusions to etiology-confirmed IE or antibody-positive/negative AE. Time of onset or results of all symptoms and diagnostics were recorded. Sensitivity and specificity of each criterion under various clinical scenarios were calculated over the first month after initial NP symptom onset.

Results

A total of 23 antibody-positive AE, 9 antibody-negative AE and 23 IE patients were included in final analysis. Under an idealized scenario with rapid initial diagnostic evaluations, the sensitivity for pediatric AE by day 28 after onset of NP symptoms approached 90% for both Cellucci and Graus criteria. Specificity within these 28 days was low without infectious testing results, increasing the greatest with rapid PCR testing and second with infectious antibody testing-reaching ~90% with both. A DEE score of 3 provided a specificity of 100% in identifying IE, but low sensitivity (29%). Symptoms were noted to cluster within several days of onset in IE, but in AE were spread out. Personality/behavioral change, speech change, affective disorder, and sleep disturbance were noted more often in AE, while fever, elevated C-reactive protein or CSF protein, and abnormal MRI-Brain occurred more often in IE.

Conclusion

In this study, we provide the first evaluation of the Cellucci criteria and the first validation of the DEE score in the differentiation of pediatric AE and IE. Further refinement of AE criteria is needed to improve early detection and treatment of pediatric AE.

Th17 cells regulate the progress of anti-NMDAR encephalitis

OBJECTIVE

To explore the mechanism of immune regulation of Th17 in anti-NMDAR encephalitis disease.

METHODS

This is a retrospective study with 83 subjects included. All subjects were admitted to the Second Affiliated Hospital of Hainan Medical University from April 2018 to May 2021, including 35 patients with anti-NMDA encephalitis in an encephalitis group, and 48 patients with non-inflammatory central neuropathy in a control group. The cerebrospinal fluid (CSF) and blood samples were collected from two groups of patients, and the changes of Th17 cell, immunophenotypic characteristics, differentiation pathways and the effect were analyzed accordingly. Peripheral blood mononuclear cells (PBMCs) from patients with anti-NMDAR encephalitis were isolated and treated with different cytokines, namely IL-1β+IL-6 group, IL-1β+IL-23 group, IL-6+IL-23 group, IL-1β+IL-23+IL-6 group and TGF-β group. After co-culture, the proportion of Th17 cells and the expression level of Th17 cell-specific transcription factor RORγt mRNA were examined.

RESULTS

Th17 cells in CSF were dramatically uplifted in the encephalitis group. In terms of cell phenotype, the percentages of CD62L and CCR7 expressions in Th17 cell phenotype were significantly increased in the encephalitis group. IL-1β, IL-6, IL-7 and IL-23 mRNA in PBMCs and IL-1β, IL-6, IL-7 and IL-23 in serum were remarkably uplifted in the encephalitis group. The mRNA levels of Th17 and Th17 cell-specific transcription factor RORγ T were the highest in the IL-1β+IL-6+IL-23 group but the lowest in the TGF-β group. Th17 in CSF of patients with poor prognosis was notably higher than that of those with good prognosis.

CONCLUSION

The proportion of Th17 cells in patients with NMDAR encephalitis and the expressions of corresponding differentiation promoting cytokines were increased, and Th17 is closely associated with patients' treatment and prognosis. Th17 cells play crucial roles in tumorigenesis and progression of anti-NMDAR encephalitis.

Younger Age at Onset Is Associated With Worse Long-term Behavioral Outcomes in Anti-NMDA Receptor Encephalitis

BACKGROUND AND OBJECTIVES

Anti-NMDA receptor encephalitis (anti-NMDARE) is one of the most common causes of encephalitis. It typically presents in adolescence and young adulthood, but little is known about its potential long-term consequences across the lifespan. Adaptive behavior describes an individual's ability to respond and adapt to environmental demands and unanticipated changes in daily routines. In this study, we evaluate the relationship between features from clinical presentation, including age, and long-term adaptive behavior in participants with anti-NMDARE.

METHODS

Cross-sectional informant-reported data were collected between 2017 and 2019 from 41 individuals/caregivers of individuals with anti-NMDARE treated at 3 major academic hospitals. Neurologic disability was assessed by record review using the modified Rankin Scale (mRS). Functional outcomes were assessed using the validated Adaptive Behavior Assessment System, Third Edition (ABAS-3).

RESULTS

The mean age at the time of study enrollment was 23.4 years (SD 17.0 years), and the mean time from symptom onset to study enrollment was 4.0 years. Seventeen participants were aged <12 years at symptom onset, 19 participants were aged 12-30 years, and 5 participants were aged >30 years. Mean ABAS-3 scores at study enrollment for all participants were in the average range (mean general adaptive composite standard score 92.5, SD 18.7). Individuals aged <12 years at symptom onset had lower mean ABAS-3 scores and were in the below average range compared with those aged 12-30 years at symptom onset, whose mean scores were in the average range (87 vs 99, p < 0.05). Similar differences were seen in 3 of the individual subscales (functional academics, health and safety, and self-care). There were no significant differences in mRS scores between age groups (p > 0.05).

DISCUSSION

Although anti-NMDARE is associated with an overall favorable outcome, younger age at onset associates with worse long-term adaptive behavior despite no differences in neurologic disability. These findings suggest that the disease may have distinct consequences on the early developing brain. Future studies should evaluate behavioral recovery and quality of life after anti-NMDARE and identify additional factors associated with differential recovery.

Pulmonary infection and baseline mRS scores predict poor prognosis in anti-GABABR encephalitis

Purpose

Anti-gamma-aminobutyric-acid type B receptor (anti-GABABR) encephalitis is a rare autoimmune condition caused by the presence of GABABR antibodies in the limbic system. However, its clinical features and prognostic factors are poorly understood. In this study, we aimed to explore factors that affect the response to first-line treatment in patients with anti-GABABR encephalitis.

Methods

Thirty-four patients with an initial diagnosis of anti-GABABR encephalitis were retrospectively enrolled from December 2015 to June 2021. Clinical features and experimental data recorded within 24 h of admission were extracted from the patients’ medical records. The modified Rankin Scale (mRS) was utilized to assess disease severity at admission and functional recovery after immunotherapy. Independent prognostic factors were determined by ordinal logistic regression analysis.

Results

Of the 34 anti-GABABR encephalitis patients, 12 (35%) presented with cancer; all of these patients had lung cancer. According to multivariate regression analysis, the cancer group exhibited a decrease in the peripheral blood absolute lymphocyte count (ALC) (odds ratio [OR]: 0.063, 95% confidence interval [CI]: 0.006-0.639, P=0.019) and hyponatremia (OR: 9.268, 95% CI: 1.054-81.502, 0.045). In addition, the neutrophil/lymphocyte ratio (NLR), monocyte/lymphocyte ratio (MLR) and platelet/lymphocyte ratio (PLR) did not significantly differ according to mRS scores in patients receiving first-line treatment. No patients with mild or moderate mRS scores (0-2) at admission developed symptoms after treatment; in contrast, only 11 patients with a severe mRS scores (≥3, 11/18) experienced symptom alleviation. Ordinal regression analysis indicated that worse prognosis was associated with pulmonary infection (OR=9.885, 95% CI: 1.106-88.323, P=0.040) and baseline mRS scores (OR= 24.047, 95% CI: 3.294-175.739, P=0.002) in the adjusted model.

Conclusion

Our findings demonstrate that pulmonary infection and baseline mRS scores are independent risk factors for poor prognosis in patients with anti-GABABR encephalitis after first-line treatment. ALC and hyponatremia are potential biomarkers for anti-GABABR encephalitis cases accompanied by lung cancer.

Autoantibody Encephalitis: Presentation, Diagnosis, and Management

Autoantibody encephalitis causes distinct clinical syndromes involving alterations in mentation, abnormal movements, seizures, psychiatric symptoms, sleep disruption, spasms, and neuromyotonia. The diagnoses can be confirmed by specific antibody tests, although some antibodies may be better detected in spinal fluid and others in serum. Each disorder conveys a risk of certain tumors which may inform diagnosis and be important for treatment. Autoantibodies to receptors and other neuronal membrane proteins are generally thought to be pathogenic and result in loss of function of the targets, so understanding the pharmacology of the receptors may inform our understanding of the syndromes. Patients may be profoundly ill but the syndromes usually respond to immune therapy, although there are differences in the types of immune therapy that are thought to be most effective for the various disorders.

Risk Prediction Models for Early ICU Admission in Patients With Autoimmune Encephalitis: Integrating Scale-Based Assessments of the Disease Severity

Background

In patients with autoimmune encephalitis (AE), the prediction of progression to a critically ill status is challenging but essential. However, there is currently no standard prediction model that comprehensively integrates the disease severity and other clinical features. The clinical assessment scale in autoimmune encephalitis (CASE) and the modified Rankin Scale (mRS) have both been applied for evaluating the severity of AE. Here, by combining the two scales and other clinical characteristics, we aimed to investigate risk factors and construct prediction models for early critical care needs of AE patients.

Methods

Definite and probable AE patients who were admitted to the neurology department of Tongji Hospital between 2013 and 2021 were consecutively enrolled. The CASE and mRS scores were used to evaluate the overall symptom severity at the time of hospital admission. Using logistic regression analysis, we analyzed the association between the total scores of the two scales and critical illness individually and then we evaluated this association in combination with other clinical features to predict early intensive care unit (ICU) admission. Finally, we constructed four prediction models and compared their performances.

Results

Of 234 patients enrolled, forty developed critical illness and were early admitted to the ICU (within 14 days of hospitalization). Four prediction models were generated; the models were named CASE, CASE-plus (CASE + prodromal symptoms + elevated fasting blood glucose + elevated cerebrospinal fluid (CSF) white blood cell (WBC) count), mRS and mRS-plus (mRS + prodromal symptoms + abnormal EEG results + elevated fasting blood glucose + elevated CSF WBC count) and had areas under the ROC curve of 0.850, 0.897, 0.695 and 0.833, respectively. All four models had good calibrations. In general, the models containing “CASE” performed better than those including “mRS”, and the CASE-plus model demonstrated the best performance.

Conclusion

Overall, the symptom severity at hospital admission, as defined by CASE or mRS, could predict early ICU admission, especially when assessed by CASE. Adding other clinical findings, such as prodromal symptoms, an increased fasting blood glucose level and an increased CSF WBC count, could improve the predictive efficacy.

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

Objective

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

Methods

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

Results

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

Conclusions

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

Clinical Variables, Deep Learning and Radiomics Features Help Predict the Prognosis of Adult Anti-N-methyl-D-aspartate Receptor Encephalitis Early: A Two-Center Study in Southwest China

Objective

To develop a fusion model combining clinical variables, deep learning (DL), and radiomics features to predict the functional outcomes early in patients with adult anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis in Southwest China.

Methods

From January 2012, a two-center study of anti-NMDAR encephalitis was initiated to collect clinical and MRI data from acute patients in Southwest China. Two experienced neurologists independently assessed the patients’ prognosis at 24 moths based on the modified Rankin Scale (mRS) (good outcome defined as mRS 0–2; bad outcome defined as mRS 3-6). Risk factors influencing the prognosis of patients with acute anti-NMDAR encephalitis were investigated using clinical data. Five DL and radiomics models trained with four single or combined four MRI sequences (T1-weighted imaging, T2-weighted imaging, fluid-attenuated inversion recovery imaging and diffusion weighted imaging) and a clinical model were developed to predict the prognosis of anti-NMDAR encephalitis. A fusion model combing a clinical model and two machine learning-based models was built. The performances of the fusion model, clinical model, DL-based models and radiomics-based models were compared using the area under the receiver operating characteristic curve (AUC) and accuracy and then assessed by paired t-tests (P < 0.05 was considered significant).

Results

The fusion model achieved the significantly greatest predictive performance in the internal test dataset with an AUC of 0.963 [95% CI: (0.874-0.999)], and also significantly exhibited an equally good performance in the external validation dataset, with an AUC of 0.927 [95% CI: (0.688-0.975)]. The radiomics_combined model (AUC: 0.889; accuracy: 0.857) provided significantly superior predictive performance than the DL_combined (AUC: 0.845; accuracy: 0.857) and clinical models (AUC: 0.840; accuracy: 0.905), whereas the clinical model showed significantly higher accuracy. Compared with all single-sequence models, the DL_combined model and the radiomics_combined model had significantly greater AUCs and accuracies.

Conclusions

The fusion model combining clinical variables and machine learning-based models may have early predictive value for poor outcomes associated with anti-NMDAR encephalitis.

Disease progression and brain atrophy in NMDAR encephalitis: Associated factor & clinical implication

OBJECTIVE

We investigated the longitudinal pattern, determining factors, and clinical implications of brain volume changes in N-methyl d-aspartate receptor-antibody (NMDAR) encephalitis.

METHODS

Baseline clinical profiles, treatment profiles, and outcome measured using the Clinical Assessment Scale in Autoimmune Encephalitis (CASE) and modified Rankin scale (mRS) were obtained from a long-term clinical database documenting an NMDAR encephalitis cohort. In serial MRI, the change in the normalized volume of different brain regions from the baseline evaluation was measured. At each MRI evaluation time point, the cumulative disease burden (CASE score × months) and the cumulative duration of status epilepticus were also evaluated.

RESULTS

Thirty-six patients were followed-up for 28.5 months (range 12-63 months). The volume ratio at last MRI to baseline was the lowest in the cerebellum (94.4 ± 5.7%, p < 0.001). Once developed, cerebellar volume reduction followed a progressive course until 2 years from disease onset. The degree of cerebellar volume reduction was positively correlated with mRS and total CASE scores (all, p < 0.001), and CASE scores in the domains of memory, language, and psychiatric problems, gait instability/ataxia, and weakness (all, p < 0.01). In linear mixed model analyses, the degree of cerebellar volume reduction was associated with cumulative disease burden up to 2 years (p < 0.001) and duration of status epilepticus (p < 0.001), and delayed removal of teratoma for ≥1 month (p = 0.006).

INTERPRETATION

In NMDAR encephalitis, cerebellar volume reduction was progressive once developed. Cerebellar volume reduction might reflect disease burden and extent of progression and be associated with poor outcomes in multiple functional domains.

Immunotherapy in autoimmune encephalitis

PURPOSE OF REVIEW

Autoimmune encephalitis (AE) refers to immune-mediated neurological syndromes often characterised by the detection of pathogenic autoantibodies in serum and/or cerebrospinal fluid which target extracellular epitopes of neuroglial antigens. There is increasing evidence these autoantibodies directly modulate function of their antigens in vivo. Early treatment with immunotherapy improves outcomes. Yet, these patients commonly exhibit chronic disability. Importantly, optimal therapeutic strategies at onset and during escalation remain poorly understood. In this review of a rapidly emerging field, we evaluate recent studies on larger cohorts, registries, and meta-analyses to highlight existing evidence for contemporary therapeutic approaches in AE.

RECENT FINDINGS

We highlight acute and long-term treatments used in specific AE syndromes, exemplify how understanding disease pathogenesis can inform precision therapy and outline challenges of defining disability outcomes in AE.

SUMMARY

Early first-line immunotherapies, including corticosteroids and plasma exchange, improve outcomes, with emerging evidence showing second-line immunotherapies (especially rituximab) reduce relapse rates. Optimal timing of immunotherapy escalation remains unclear. Routine reporting of outcome measures which incorporate cognitive impairment, fatigue, pain, and mental health will permit more accurate quantification of residual disability and comprehensive comparisons between international multicentre cohorts, and enable future meta-analyses with the aim of developing evidence-based therapeutic guidelines.

Life after autoantibody-mediated encephalitis: optimizing follow-up and management in recovering patients

PURPOSE OF REVIEW

Timely diagnosis and treatment is essential to optimize outcomes in patients with antibody-mediated encephalitis (AME); yet even with early diagnosis and treatment, long-term outcomes may still fall short of expectations. Identifying patients at greater risk of adverse outcomes is key to personalizing care, supporting accurate counseling of patients and family members, and informing therapeutic decisions in patients with AME. This review considers long-term outcomes in recovering patients, including approaches to measure and manage common sequelae that influence life after AME.

RECENT FINDINGS

Cognitive impairment, fatigue, and sleep disturbances affect most recovering AME patients. This realization highlights the need for outcome measures that encompass more than motor function. Standardized questionnaires, surveys, and clinical assessment tools may be adapted to support comprehensive and reproducible clinical assessments and to identify patients who may benefit from additional therapies.

SUMMARY

Good outcomes continue to be reported in recovering patients, emphasizing the high potential for recovery following AME. However, cognitive, behavioral, and physical sequelae may limit the potential for great outcomes following AME. Multidisciplinary follow-up is needed to recognize and treat sequelae that compromise long-term recovery and limit quality of life in recovering patients.

Rapidly Progressive Dementia

PURPOSE OF REVIEW

This article presents a practical approach to the evaluation of patients with rapidly progressive dementia.

RECENT FINDINGS

The approach presented in this article builds upon the standard dementia evaluation, leveraging widely available tests and emergent specific markers of disease to narrow the differential diagnosis and determine the cause(s) of rapid progressive decline. The discovery of treatment-responsive causes of rapidly progressive dementia underscores the need to determine the cause early in the symptomatic course when treatments are most likely to halt or reverse cognitive decline.

SUMMARY

A pragmatic and organized approach to patients with rapidly progressive dementia is essential to mitigate diagnostic and therapeutic challenges and optimize patient outcomes.

AntI GABA auto-immune encephalitis as schizophrenia and status epilepticus in a female patient: A case report

Encephalitis is a severe neurological syndrome with a rapid progression to encephalopathy caused by brain swelling. One of its causes is antibodies against neuron surface proteins, ionic channels, or receptors so that they can start encephalitis with psychiatric symptoms. Worldwide, auto-immune encephalitis annual incidence is 12.6 per 100000 inhabitants. We present a case report of a 44-years-old female who developed behavioral changes and seizures in a time-lapse of months. She was diagnosed with anti-GABA auto-immune encephalitis, a rare type of this disease. Keywords. Auto-immune disease – Epilepsy – Mental disorders – Neurology – Critical Care