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

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

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

DISCUSSION

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

Infectious Encephalitis: A Persistent Clinical Challenge

Encephalitis is a serious neurologic condition that frequently results in long-term neurologic complications. Effective management in adults with suspected infectious encephalitis involves testing the cerebrospinal fluid for common pathogens, including herpes simplex virus-1, varicella-zoster virus, enteroviruses, and West Nile virus. Early initiation of high-dose intravenous acyclovir is recommended. Epidemiologic clues and immune status of the host should be considered when attempting to identify the cause of encephalitis. When no cause is identified, next-generation sequencing or a brain biopsy may be warranted. Further research should focus on developing new therapeutic options for this challenging clinical syndrome.

Multimodal prognostication of autoimmune encephalitis: an Australian autoimmune encephalitis consortium study

BACKGROUND AND OBJECTIVES

To identify factors predictive of a favourable modified Rankin score (mRS) at 12 months in patients with autoimmune encephalitis (AE). To evaluate predictors of a binary composite clinical-functional outcome measure, encompassing mRS, drug-resistant epilepsy (DRE) and memory impairment, at 12 months.

METHODS

Univariable and multivariable logistic regression analyses for predictors of a favourable mRS (i.e. mRS ≤ 2) and a composite clinical-functional outcome at 12 months were used.

RESULTS

A total of 231 patients with AE were recruited. Multivariable logistic regression identified factors predictive of reduced odds of favourable mRS at 12 months were older age (OR 0.97; 95% CI 0.95, 0.98; p < 0.001), T2/FLAIR hyperintensity on initial MRI (OR 0.27; 95% CI 0.13, 0.56; p < 0.001), RSE (OR 0.17; 95% CI 0.06, 0.52; p = 0.002) and first-line immunotherapy failure (OR 0.18; 95% CI 0.09, 0.37; p < 0.001). Anti-LGI1 antibody-mediated encephalitis relative to other subtypes (OR 4.46; 95% CI 1.55, 12.80; p = 0.006) was associated with a better 12-month mRS. We found concordant associations for a composite outcome at 12 months, with the addition of a diagnosis of definite autoimmune limbic encephalitis (AILE) predicting a poor outcome.

DISCUSSION

Older age, MRI T2/FLAIR hyperintensity, RSE and first-line immunotherapy failure predicted worse mRS and composite clinical-functional outcome at 12 months, while a diagnosis of anti-LGI1 antibody-mediated encephalitis was associated with favourable outcomes. Our data highlight acute clinical factors predictive of a more severe clinical and functional course at 12 months.

From immunobiology to intervention: Pathophysiology of autoimmune encephalitis

Autoimmune encephalitides (AEs) are neurological disorders caused by autoantibodies against neuronal and glial surface proteins. Nearly 20 years after their discovery, AE have evolved from being frequently misdiagnosed and untreated to a growing group of increasingly well-characterized conditions where patients benefit from targeted therapeutic strategies. This narrative review provides an immunological perspective on AE, focusing on NMDAR, CASPR2 and LGI1 encephalitis as the three most common forms of AE associated with anti-neuronal surface autoantibodies. We examine the autoreactive B cell subsets, the tolerance checkpoints that may fail, and the known triggers and predispositions contributing to disease. In addition, we discuss the roles of other immune cells, including T cells and microglia, in the pathogenesis of AE. By analyzing therapeutic strategies and treatment responses we draw insights into AE pathophysiology. Written at a time of transformative therapeutic advancements through cell therapies this work underscores the synergy between detailed immunological research and the development of innovative therapies.

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

INTRODUCTION AND IMPORTANCE

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

CASE PRESENTATION

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

CLINICAL DISCUSSION

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

CONCLUSION

Timely gynecologic intervention can be curative in these patients.

Intravenous immunoglobulin as first-line acute treatment in adults with autoimmune encephalitis caused by antibodies to NMDAR, LGI1 and CASPR2

BACKGROUND AND OBJECTIVES

Corticosteroids or plasma exchange are recommended for acute treatment of autoimmune encephalitis (AE). Intravenous immunoglobulins (IVIG) are suggested as an additional treatment option but data on treatment effect is scarce. The objective of the present study was to investigate the impact of the first-line treatment on the three most common forms of AE, in particular, to evaluate the effect of IVIG therapy in these diseases.

METHODS

A total of 1274 patients from the German Network for Autoimmune Encephalitis Research (GENERATE) were analyzed, and 388 patients were included in the study because they had either anti-NMDAR, anti-LGI1 or anti-CASPR2 antibodies and firs-line immunotherapy (ivMP monotherapy, ivMP + IVIG, ivMP + PE or ivMP + IVIG + PE) or no immunotherapy at all. For the statistical analyses, patients were stratified according to antibody type, distinguishing between anti-NMDAR (IgG1) and anti-LGI1 as well as anti-CASPR2 (predominantly IgG4). The primary endpoint was the clinical outcome at discharge, which was assessed using the modified Rankin Scale (mRS). The mRS scores were then compared between the different treatment groups over time, and the factors influencing the reduction in mRS at discharge were analyzed. Furthermore, a specific investigation was conducted to determine the differences in outcomes between patients treated with ivMP + IVIG and ivMP + PE, each split by antibody subtype.

RESULTS

In all treatment groups analyzed, significant improvements were observed at the time of discharge and after 12 months compared to disease onset, regardless of the type of first-line treatment. In untreated patients a significant improvement was not observed. The choice of IVIG or PE as an additional treatment to ivMP for anti-NMDAR encephalitis did not affect the primary outcome. In anti-LGI1 or anti-CASPR2 encephalitis, no influence on the primary outcome was observed when IVIG or PE was administered in addition to ivMP, too. However, a direct comparison of the individual antibody subgroups' mRS reductions, depending on the treatment approach (ivMP + IVIG vs. ivMP + PE), revealed that a more significant mRS reduction was observed with ivMP + PE in anti-NMDAR encephalitis.

DISCUSSION

The retrospective data give evidence that there is no difference in outcome for the use of ivMP + PE over ivMP + IVIG or vice versa in the treatment of encephalitis caused by antibodies against NMDAR, LGI1 or CASPR2. Furthermore, the specific method of plasma exchange, whether plasmapheresis or immunoadsorption, did not affect the mRS at discharge.

Management of severe acute encephalopathy in the ICU: an expert consensus statement from the french society of intensive care medicine

INTRODUCTION

Acute encephalopathy in the ICU poses significant diagnostic, therapeutic, and prognostic challenges. Standardized expert guidelines on acute encephalopathy are needed to improve diagnostic methods, therapeutic decisions, and prognostication.

METHODS

The experts conducted a review of the literature, analysed it according to the GRADE (Grading of Recommendation, Assessment, Development and Evaluation) methodology and made proposals for guidelines, which were rated by other experts. Only expert opinions with strong agreement were selected.

RESULTS

The synthesis of expert work and the application of the GRADE method resulted in 39 recommendations. Among the 39 formalized recommendations, 1 had a high level of evidence (GRADE 1 +) and 10 had a low level of evidence (GRADE 2 + or 2-). These recommendations describe indication for ICU admission, use of clinical scores and EEG for diagnosis, detection of complications, and prognostication. The remaining 28 recommendations were based on expert consensus. These recomandations describe common indications for blood and CSF studies, neuroimaging, use of neuromonitoring, and provide guidelines for management in the acute phase.

CONCLUSION

This expert consensus statement aims to provide a structured framework to enhance the consistency and quality of care for ICU patients presenting with acute encephalopathy. By integrating high-quality evidence with expert opinion, it offers a pragmatic approach to addressing the complex nature of acute encephalopathy in the ICU, promoting best practices in patient care and facilitating future research in the field.

Prediction model for severe autoimmune encephalitis: a tool for risk assessment and individualized treatment guidance

Background

Severe autoimmune encephalitis (AE) can cause significant neurological deficits, status epilepticus, status dystonicus, and even death, which can be life-threatening to patients. Accurate risk stratification for severe AE progression is critical for optimizing therapeutic strategies. The comprehensive prediction models for severe AE based on routine clinical data and laboratory indicators remain lacking.

Objective

To develop and validate a prediction model for severe AE to optimize individualized treatment.

Methods

We collected clinical data and laboratory examination results from 207 patients with confirmed AE. The study population was divided into development and validation cohort. A prediction model for severe AE was constructed using a nomogram and was rigorously validated both internally and externally. Severe AE was defined as modified Rankin Scale (mRS) > 2 and Clinical Assessment Scale for Encephalitis (CASE) > 4.

Results

The variables ultimately included in the nomogram for the severe AE predictive model were age, psychiatric and/or behavioral abnormalities, seizures, decreased level of consciousness, cognitive impairment, involuntary movements, autonomic dysfunction, and increased intrathecal IgG synthesis rate. It demonstrated excellent discriminative capacity and calibration through internal-external validation.

Conclusion

The prediction model has highly feasibility in clinical practice, and holds promise as an important tool for risk assessment and guiding individualized treatment in patients with AE.

Autoimmune Encephalitis

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

Long-Term Clinical and Biological Prognostic Factors of Anti-NMDA Receptor Encephalitis in Children

BACKGROUND AND OBJECTIVES

Anti-NMDAR encephalitis (NMDARE) is a severe neurologic condition, and recently, the NMDAR Encephalitis One-Year Functional Status (NEOS) score has emerged as a 1-year prognostic tool. This study aimed to evaluate NEOS score and biomarker (neurofilament light chains [NfL], total-Tau protein, glial fibrillary acidic protein, and serum cytokines) correlation with modified Rankin Scale (mRS), cognitive impairment, and clinical recovery in pediatric NMDARE over 2 years.

METHODS

In this French multicenter observational study, 104 pediatric patients with NMDARE were followed for a minimum of 2 years. Clinical data and serum/plasma samples were collected. Biomarker levels, measured using electroluminescence mesoscale discovery (MSD) S-PLEX, were compared between patients and controls and assessed for correlations with disease activity, mRS, cognitive/language impairment, and recovery status at 2 years.

RESULTS

At a median follow-up of 39.5 months, 68 percent of patients had unfavorable recovery and 54% had significant cognitive impairment. Both outcomes were strongly associated with younger age at diagnosis (OR 6.10 [1.91-27.3] p < 0.01 and 5.69 [1.46-27.7] p = 0.02, respectively). A higher NEOS score was significantly correlated with increased cognitive impairment (OR 2.53 [1.52-4.21], p < 0.001), higher mRS scores (OR 2.12 [1.34-3.57], p < 0.01), and unfavorable recovery at 2 years (OR 2.00 [1.30-3.06], p = 0.015). Elevated NfL levels were significantly associated with unfavorable recovery (OR 3.62 [1.29-10.9] p = 0.012) and severe cognitive impairment (OR 3.77 [1.38-10.9] p = 0.012) at 2 years. The combined area under the curve (AUC) for NfL and NEOS was significantly higher than the AUCs of NEOS and NfL alone (p = 0.01).

DISCUSSION

The NEOS score strongly predicts long-term outcomes in NMDARE, with its predictive value extending beyond the first-year mR prediction. NfL levels at disease onset seem to improve accuracy in predicting poor outcomes, providing valuable information for treatment decisions and future clinical trials.

Immunoadsorption is equally effective as plasma exchange in paediatric neuroimmunological disorders - A retrospective multicentre study

BACKGROUND

Therapeutic apheresis (TA) are promising treatment option for neuroimmunological disorders. In paediatrics, the available data is limited, particularly for the use of IA. The aim of this study was to analyse the use of PE and IA in children and adolescents, with emphasis on outcome and neurological course after treatment as well as the safety of the two modalities.

METHODS

Clinical data from paediatric patients with neuroimmunological disorders treated with TA in two German university children's hospitals between 2015 and 2022 were retrospectively analysed.

RESULTS

In total, 39 patients underwent 322 sessions of TA, of which 184 were IA and 138 PE. The most common diagnosis was autoimmune encephalitis in 39 % (n = 15) of the patients. Other indications were central nervous system inflammatory demyelinating disorders in 21 % (n = 8), Guillain-Barré syndrome in 18 % (n = 7), Myelin Oligodendrocyte Glycopeptide-antibody associated syndromes in 8 % (n = 3), Myasthenia gravis in 5 % (n = 2) and other neurological disorders in 10 % (n = 4). Overall, there was an improvement in 76 % of patients (81 % with IA, 70 % with PE; p = 0.41) immediately after treatment and an improvement in 88 % of patients (90 % with IA, 85 % with PE; p = 0.63) one month after treatment. Complications occurred in 13 % of all sessions (13 % with IA and 13 % with PE; p = 1). Most complications were considered as moderate.

CONCLUSION

Both, IA and PE, are effective treatment options in the therapy of neuroimmunological disorders in children and adolescents, with no major differences in terms of efficiency or safety.

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.

Validation of the clinical assessment scale for autoimmune encephalitis in a severe autoimmune encephalitis cohort

Objective

The Clinical Assessment Scale for Autoimmune Encephalitis (CASE) is a novel tool tailored specifically for evaluating the severity of autoimmune encephalitis (AE). However, its application in severe AE patients is limited. This study aimed to evaluate the reliability and validity of the CASE and explore its clinical significance in a severe AE cohort.

Methods

The relevant clinical characteristics, laboratory data, and prognosis of patients diagnosed with severe AE between April 2017 and April 2023 were collected. The CASE and modified Rankin scale (mRS) were performed at admission, discharge, and 1-year follow-up, respectively. The reliability of CASE was validated by calculating the Cronbach's alpha value. The validity was evaluated by calculating the Spearman's rank correlation with the corresponding mRS. Univariate and multivariate logistic regression were utilized to identify risk factors for poor prognosis.

Results

A total of 140 patients were recruited for the study. The CASE scale presented great internal consistency, with Cronbach's α value of 0.768 for the total score. The Spearman's rank correlation analysis revealed strong criterion validity between CASE and mRS, with coefficients of 0.68, 0.92, and 0.95 at admission, discharge, and 1-year follow-up, respectively (all p < 0.001). ROC analysis identified CASE score at admission served as a promising predictive marker for clinical response to treatment, with an AUC of 0.67 (95% CI: 0.57-0.77, p = 0.003). The optimal cut-off point was 22.5. At 1-year follow-up, 72/140 (51.4%) patients achieved good functional status (mRS, 0-2). Multivariate logistic regression confirmed that higher CASE scores on admission and older age at onset were associated with poor short-term as well as 1-year prognosis, respectively. In addition, no clinical response to treatment (OR = 40.499; 95% CI: 7.077-231.746, p < 0.001) and longer duration of hospitalization (OR = 1.071; 95% CI: 1.017-1.128, p = 0.010) were associated with poor function states at 1-year follow-up.

Conclusion

The CASE has proven suitable for evaluating disease severity and prognosis in severe AE patients. Besides, CASE score, age at disease onset, hospital stays, and response to immunotherapy are identified as independent risk factors for unsatisfactory prognosis in severe AE patients.

Recent advances in autoimmune encephalitis

Since the description of autoimmune encephalitis (AE) associated with N-methyl-D-aspartate receptor antibodies (anti-NMDARE) in 2007, more than 12 other clinical syndromes and antibodies have been reported. In this article, we review recent advances in pathophysiology, genetics, diagnosis pitfalls, and clinical phenotypes of AE associated with cell surface antibodies and anti-GAD associated neurological syndromes. Genetic studies reported human leukocyte antigen (HLA) associations for anti-LGI1, anti-Caspr2, anti-IgLON5, and anti-GAD. Follow-up studies characterized cognitive dysfunction, psychiatric symptoms, sleep disorders, and adaptative behavior dysfunction, mainly for anti-NMDARE. Late-onset anti-NMDARE and anti- GABA-B receptor (GABA-BR) encephalitis patients were described to have worse prognoses and different tumor associations. Additionally, the clinical spectrum of anti-LGI1, anti-AMPAR, anti-CASPR2, and anti-IgLON5 was expanded, comprising new differential diagnoses. The diagnostic criteria for AE were adapted to the pediatric population, and a diagnostic algorithm was proposed, considering potential mimics and misdiagnosis. We also review the limitations of commercial assays for AE and treatment recommendations, as well as clinical scales for short and long-term assessment of AE patients, along with cognitive evaluation.

Development of a novel nomogram for predicting prognosis of North Chinese with autoimmune cerebellar ataxia

PURPOSE

The aim of this study was to develop a prognostic nomogram which could predict the prognosis of north Chinese patients with autoimmune cerebellar ataxia (ACA) after immunotherapy.

METHODS

Patients with an initial diagnosis of ACA who accepted first-line immunotherapy at our hospital from March 2018 to May 2023 were retrospectively reviewed. Modified Rankin Scale (mRS) was used to evaluate neurological outcomes. According to the mRS scores after immunotherapy, patients with ACA were divided into good prognosis group (mRS 0-2) and poor prognosis group (mRS 3-6). The nomogram for poor prognosis of ACA patients were built based on logistic regression analysis. The validation of the prognostic model was evaluated by concordance index (C-index), calibration curves, and decision curve analyses (DCAs).

RESULTS

A total of 86 patients with ACA who received immunotherapy at our hospital were included in this study. They were randomly divided into a training cohort (n = 60) and a validation cohort (n = 26) at a ratio of 7:3. Multivariate analyses revealed that that prognostic variables significantly related to the poor prognosis of ACA were age, elevated cerebrospinal fluid (CSF) albumin (ALB) and abnormal magnetic resonance imaging (MRI). The nomogram was constructed based on above 3 factors. The C-index of the nomogram was 0.935 (95% CI: 0.884-0.991) in the training set and 0.933 (95% CI: 0.763-0.994) in the validation set. The calibration plots for the nomogram showed that predictions of risk of poor prognosis were almost consistent with actual observations. The DCAs showed great clinical usefulness of the nomograms.

CONCLUSION

We successfully developed a nomogram to predict poor prognosis for ACA patients using risk factors of age, elevated CSF-ALB and abnormal MRI.

Ofatumumab treatment for severe refractory anti-NMDAR encephalitis: A case series

Rituximab is recommended as the preferred second-line immunotherapy for autoimmune encephalitis (AE). However, Ofatumumab (OFA), a novel fully human anti-CD20 antibody, has been reported infrequently in patients with AE. Among the various forms of AE, anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis is the most common and severe. This study presents three cases of severe anti-NMDAR encephalitis treated with OFA following the failure of first-line immunotherapy. The results indicated that the patients experienced no significant adverse reactions after receiving OFA, and their clinical symptoms improved markedly within one week of treatment. One month post-treatment with OFA, scores on the Glasgow Coma Scale (GCS) and the Barthel Index of Activities of Daily Living (Barthel-ADL) increased, while scores on the modified Rankin Scale (mRS), Clinical Assessment Scale in Autoimmune Encephalitis (CASE), and Paroxysmal Sympathetic Hyperactivity Assessment Measure (PSH-AM) decreased. During the three-month and six-month follow-up periods, patients exhibited further symptomatic improvement, suggesting that OFA is a safe and effective treatment option for anti-NMDAR encephalitis. These findings propose a novel therapeutic strategy for severe refractory anti-NMDAR encephalitis.

Short delay to initiate plasma exchange or immunoadsorption as synergistic therapies for patients in the acute phase of anti-NMDAR encephalitis

Background

Combined first-line therapies have been frequently adopted for patients with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis. Plasma exchange (PE) or immunoadsorption (IA) was used as an add-on option following initial immunotherapies, including high-dose steroids and intravenous immunoglobulin (IVIG). However, whether a shorter delay of PE or IA can improve the early recovery prognosis of patients with anti-NMDAR encephalitis remains largely unknown.

Objective

To compare short-term clinical improvement between patients with early and late initiation of PE or IA in anti-NMDAR encephalitis.

Design

A retrospective study was conducted for patients admitted with anti-NMDAR encephalitis between January 2015 and December 2023 (n = 29), including 21 patients who received PE or IA as synergistic therapies.

Methods

The clinical prognosis was compared between the early PE/IA group and the late PE/IA group in the research. Primary outcome included changes in the Clinical Assessment Scale for Autoimmune Encephalitis (∆CASE) at 90 and 120 days after encephalitis onset. Secondary outcomes included changes in the modified Rankin scale (∆mRS) after 90 and 120 days from encephalitis onset, and the length of intensive care unit (ICU) stay for patients with severe anti-NMDAR encephalitis.

Results

The ∆CASE scores after 90 and 120 days from encephalitis onset revealed a significant difference between patients with early and late initiation of PE or IA (p ⩽ 0.05). A significant difference in the ∆mRS was also found between patients with early and late initiation of PE or IA in severe encephalitis (p ⩽ 0.05). No significant difference was found in the length of ICU admission (p = 0.101).

Conclusion

Our findings emphasize the importance of considering PE or IA as early as feasible for patients with anti-NMDAR encephalitis, even when steroids and IVIG are in use.

Catatonia in anti-NMDA receptor encephalitis: a case series and approach to improve outcomes with electroconvulsive therapy

Background

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis has been recognised to present with the syndrome of catatonia. In severe cases dysautonomia is representative of malignant catatonia. The treatment with benzodiazepines (BZDs) and electroconvulsive therapy (ECT) may decrease morbidity and mortality in patients presenting with anti-NMDA receptor encephalitis and catatonia.

Methods

This is a retrospective case series of eight patients with anti-NMDA receptor encephalitis treated with ECT. We use clinical prediction scores (Clinical Assessment Scale for Autoimmune Encephalitis [CASE] and anti-NMDAR Encephalitis One-Year Functional Status scores) to compare expected outcomes and observed outcomes.

Results

CASE scores in our group ranged between 5 and 19, with a mean score of 13.8 (median 15.5). NEOS scores ranged from 2 to 4, with a mean and median of 3. Of the eight patients, six had a favourable modified Rankin Score (0-2) at a follow-up of 8 to 12 months. Patients received an average of 29.9 ECT treatments in total.

Conclusions

Based on clinical prediction scores, this cohort had better than expected functional outcomes. We discuss the use of BZDs and ECT in these cases and propose a treatment algorithm for patients who present with catatonic syndrome in anti-NMDA receptor encephalitis.

MRI findings in autoimmune encephalitis

Autoimmune encephalitis encompasses a spectrum of conditions characterized by distinct clinical features and magnetic resonance imaging (MRI) findings. Here, we review the literature on acute MRI changes in the most common autoimmune encephalitis variants. In N-methyl-D-aspartate (NMDA) receptor encephalitis, most patients have a normal MRI in the acute stage. When lesions are present in the acute stage, they are typically subtle and non-specific white matter lesions that do not correspond with the clinical syndrome. In some NMDA receptor encephalitis cases, these T2-hyperintense lesions may be indicative of an NMDA receptor encephalitis overlap syndrome with simultaneous co-existence of multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD) or myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). Encephalitis with leucine-rich glioma-inactivated 1 (LGI1)-, contactin-associated protein-like 2 (CASPR2)- or glutamic acid decarboxylase (GAD)- antibodies typically presents as limbic encephalitis (LE) with unilateral or bilateral T2/fluid attenuated inversion recovery (FLAIR) hyperintensities in the medial temporal lobe that can progress to hippocampal atrophy. Gamma aminobutyric acid-B (GABA-B) receptor encephalitis also often shows such medial temporal hyperintensities but may additionally involve cerebellar lesions and atrophy. Gamma aminobutyric acid-A (GABA-A) receptor encephalitis features multifocal, confluent lesions in cortical and subcortical areas, sometimes leading to generalized atrophy. MRI is unremarkable in most patients with immunoglobulin-like cell adhesion molecule 5 (IgLON5)-disease, while individual case reports identified T2/FLAIR hyperintense lesions, diffusion restriction and atrophy in the brainstem, hippocampus and cerebellum. These findings highlight the need for MRI studies in patients with suspected autoimmune encephalitis to capture disease-specific changes and to exclude alternative diagnoses. Ideally, MRI investigations should be performed using dedicated autoimmune encephalitis imaging protocols. Longitudinal MRI studies play an important role to evaluate potential relapses and to manage long-term complications. Advanced MRI techniques and current research into imaging biomarkers will help to enhance the diagnostic accuracy of MRI investigations and individual patient outcome prediction. This will eventually enable better treatment decisions with improved clinical outcomes.

Predicting the future of autoimmune encephalitides

The concept that many neurologic and psychiatric disorders of unknown cause are immune-mediated has evolved fast during the past 20 years. The main contribution to the expansion of this field has been the discovery of antibodies that attack neuronal or glial cell-surface proteins or receptors, directly modifying their structure and function. These antibodies facilitate the diagnosis and prompt treatment of patients who often improve with immunotherapy. The identification of this group of diseases, collectively named "autoimmune encephalitides", was preceded by many years of investigations on other autoimmune CNS disorders in which the antibodies are against intracellular proteins, occur more frequently with cancer, and associate with cytotoxic T-cell responses that are less responsive to immunotherapy. Here, we first trace the recent history of the autoimmune encephalitides and address how to assess the clinical value and implement in our practice the rapid pace of autoantibody discovery. In addition, we review recent developments in the post-acute stage of the two main autoimmune encephalitides (NMDAR and LGI1) focusing on symptoms that are frequently overlooked or missed, and therefore undertreated. Because a better understanding of the pathophysiology of these diseases relies on animal models, we examine currently available studies, recognizing the existing needs for better and all-inclusive neuro-immunobiological models. Finally, we assess the status of biomarkers of disease outcome, clinical scales, current treatment strategies, and emerging therapies including CAR T-cell technology. Altogether, this overview is intended to identify gaps of knowledge and provide suggestions for improvement and insights for future research.

Clinical characteristics and prognosis analysis of acute symptomatic seizures secondary to autoimmune encephalitis

Objective

This study aimed to analyze the clinical characteristics and prognosis of patients with autoimmune encephalitis (PWAE) who experienced seizures during the acute phase.

Methods

Clinical data were collected from 84 patients diagnosed with AE at the General Hospital of Ningxia Medical University between January 2015 and January 2023. Patients were divided into seizure and non-seizure groups. Clinical characteristics of both groups were compared, including differences between anti-NMDAR and anti-LGI1 encephalitis within the seizure group. Due to the limited sample size and to avoid overfitting, we focused on univariate logistic regression analysis to identify individual prognostic factors.

Results

A total of 84 patients were enrolled, with 76.19% (64/84) in the seizure group and 23.81% (20/84) in the non-seizure group. The seizure group had a longer hospital stay (p = 0.013), higher rates of impaired consciousness (p = 0.001), and more frequent intensive care unit (ICU) admission (p = 0.011). They also had higher peripheral blood neutrophil-to-lymphocyte ratio (NLR), leukocyte count, and uric acid levels (p = 0.038, p = 0.006, p = 0.020), and were more likely to show slow-wave rhythms on electroencephalography (EEG) (p = 0.031). At 2-year follow-up, there was no significant difference in prognosis between the seizure and non-seizure groups (p = 0.653), with 35.94% (23/64) of the seizure group having a poor prognosis. Status epilepticus (SE), complications, endotracheal intubation, mRS score at discharge, APE2, and RITE2 scores increased the risk of poor prognosis (OR > 1), while intensive care and albumin reduced the risk (OR < 1).

Conclusion

Seizures are common in the early stages of AE, with faciobrachial dystonic seizures (FBDS) characteristic of anti-LGI1 encephalitis and SE and super-refractory status epilepticus (Sup-RSE) frequently observed in anti-NMDAR encephalitis. Seizure semiology across AE subtypes lacks specificity, and no symptoms clearly distinguish immune-mediated from non-immune causes. While seizures are linked to AE severity, particularly in anti-NMDAR encephalitis, they do not appear to impact overall prognosis. SE, complications, endotracheal intubation, modified Rankin Scale (mRS) score at discharge, Antibody-Prevalence in Epilepsy and Encephalopathy (APE2) score, Response to Immunotherapy in Epilepsy and Encephalopathy (RITE2) score, intensive care, and albumin were identified as significant prognostic factors.

Clinical features, cerebrospinal fluid changes, and prognosis in Chinese patients with autoimmune encephalitis

INTRODUCTION

Autoimmune encephalitis (AE) is a rare, treatable disease of the central nervous system (CNS) caused by an antibody-related immune response. This study is to investigate the correlation of clinical features, cerebrospinal fluid (CSF) characteristics, and prognosis in patients with AE.

METHODS

A total of 71 patients diagnosed with antibody-positive AE were retrospectively analyzed. The patients were divided into three groups: anti-NMDAR group, anti-LGI1 group, and other types. Clinical data were collected to analyze clinical features and CSF results, and prognosis was determined by modified Rankin Scale (mRS).

RESULTS

There was statistical difference in the incidences of decreased consciousness level (P < 0.001), memory loss (P = 0.017), speech disorders (P = 0.035), and dyskinesia (P = 0.001) in different antibodies groups. Younger age (P = 0.018), elevated CSF chloride content (P = 0.006), and white blood cells > 50/mm3 (P = 0.026) were highly correlated with ICU admission. Anti-LGI1 encephalitis had a relatively small risk for ICU admission (P = 0.034), and a lower risk of poor functional recovery (P = 0.048) and recurrence (P = 0.041). Patients with first-line treatment failure (P = 0.021) had an increased risk of poor functional recovery. Delayed treatment (P = 0.011) would increase the risk of recurrence.

CONCLUSION

There are differences in age, gender, clinical characteristics, and CSF results in different subtypes of AE. First-line therapy failure would have poor functional recovery, and delayed therapy would increase the risk of relapse. Chloride ion content and white blood cell count in cerebrospinal fluid are positively correlated with the patient's exacerbation and admission to ICU. These indicators have certain clinical value for the prognosis of AE patients.

Pediatric Autoimmune Encephalitis: A Nationwide Study in Latvia

BACKGROUND

Autoimmune encephalitis (AE) is the third most common encephalitis in children. Diagnosis can be challenging due to overlapping and diverse clinical presentations as well as various investigation results. This study aims to characterize the clinical, diagnostic features, as well as treatment and outcomes of AE in children and determine the incidence of pediatric AE in Latvia.

METHODS

The study was conducted at the Children's Clinical University Hospital in Riga. The study participants were patients under the age of 18 years diagnosed with AE from 2014 to 2022. Data regarding clinical characteristics, investigation findings, treatment strategy, and outcomes were retrospectively collected from the medical history data system.

RESULTS

We included 18 pediatric patients diagnosed with AE. The mean incidence of pediatric AE in Latvia was 0.56 per 100,000 children. Most patients (66.6%) had seronegative AE. In the seropositive group, the most common was anti-methyl-D-aspartate receptor AE, with two patients having other antibodies. The most prevalent clinical features were personality change, cognitive impairment, autonomic dysfunction, and movement disorders. The majority of patients (58.8%) received first-line treatment only. More than half (55.6%) of our AE patient group had long-term sequelae.

CONCLUSIONS

Our study shows that the pediatric AE incidence in Latvia is similar to what has been previously reported in other studies. A relatively high proportion of seronegative AE was present in our cohort, indicating that awareness of possible misdiagnosis should be raised. Further research is needed to better understand the underlying mechanisms, characterize clinical features, and determine the treatment of choice in different situations to improve long-term outcomes.

Assessment of long-term psychosocial outcomes in N-methyl-D-aspartate receptor encephalitis - the SAPIENCE study protocol

BACKGROUND

N-methyl-D-aspartate-receptor (NMDAR) encephalitis is a rare neurological autoimmune disease with severe neuropsychiatric symptoms during the acute phase. Despite good functional neurological recovery, most patients continue to experience cognitive, psychiatric, psychological, and social impairments years after the acute phase. However, the precise nature and evolving patterns over time of these long-term consequences remain unclear, and their implications for the well-being and quality of life of predominantly young patients have yet to be thoroughly examined.

METHODS

SAPIENCE is a European multi-center (n = 3) prospective observational cohort study studying the long-term cognitive, psychiatric, psychological, and social outcome in patients with NMDAR encephalitis. The study consists of three interconnected levels. Level 1 comprises a qualitative interview and focus groups with patients and their caregivers. Level 2 consists of a condensed form of the interview, standardized questionnaires, and a detailed neuropsychological examination of patients. Level 3 involves an online survey that will be open to patients world-wide and explores patient-reported outcomes (PROMs), and patient-reported experiences (PREMs) in association with clinical and cognitive outcomes. Levels 1 to 3 will progressively contribute developing of structured interviews, survey questions, and treatment guidelines by informing one another.

DISCUSSION

SAPIENCE is an in-depth study of the long-term effects of NMDAR encephalitis and bridges the gap between standardized assessments and individual patient experiences, intending to improve patient care and to increase awareness of the psychosocial long-term consequences of the disease. Through collaboration of experts in clinical neurology and social and health psychology across Europe, SAPIENCE aims to create online assessment tools and formulate guidelines for patient-centered post-acute care that will help enhance the quality of life for patients and caregivers.

Kappa index in the diagnostic work-up of autoimmune encephalitis

BACKGROUND

The presence of inflammatory changes in the cerebrospinal fluid (CSF), including immunoglobulin intrathecal synthesis (IS), can support the diagnosis of autoimmune encephalitis (AE) and allow prompt treatment. The main aim of our study was to calculate the Kappa index as a marker of IS, in patients with AE.

METHODS

Charts of patients undergoing a diagnostic work-up for suspected AE between 2009 and 2023 were reviewed and the Graus criteria applied. CSF and serum kappa free light chains were determined using the Freelite assay (The Binding Site Group) and the turbidimetric Optilite analyzer.

RESULTS

We identified 34 patients with "definite" AE (9 anti-NMDAR AE and 25 limbic AE) and nine patients with "possible" AE. Five patients (15%) with definite AE had pleocytosis and twelve (34%) showed CSF-restricted oligoclonal bands (OCB) at isoelectric focusing. The Kappa index was >6 in 29.4% and > 3 in 50% of the definite AE patients. It was elevated (>3) in 36.4% of patients with definite AE who resulted negative to OCB testing and was the only altered parameter suggestive of an ongoing inflammatory process in the CNS in three definite AE patients with otherwise normal CSF findings (i.e. normal cell count and protein levels, no OCBs). In the possible AE group, one patient had a Kappa index >3 in the absence of OCB.

CONCLUSIONS

The Kappa index could be useful, as a more sensitive marker of IS and as a supportive marker of neuroinflammation, in the diagnostic work-up of suspected AE.

Innovation and optimization in autoimmune encephalitis trials: the design and rationale for the Phase 3, randomized study of satralizumab in patients with NMDAR-IgG-antibody-positive or LGI1-IgG-antibody-positive autoimmune encephalitis (CIELO)

Background

Autoimmune encephalitis (AIE) encompasses a spectrum of rare autoimmune-mediated neurological disorders, which are characterized by brain inflammation and dysfunction. Autoantibodies targeting the N-methyl-d-aspartic acid receptor (NMDAR) and leucine-rich glioma-inactivated 1 (LGI1) are the most common subtypes of antibody-positive AIE. Currently, there are no approved therapies for AIE. Interleukin-6 (IL-6) signaling plays a role in the pathophysiology of AIE. Satralizumab, a humanized, monoclonal recycling antibody that specifically targets the IL-6 receptor and inhibits IL-6 signaling, has demonstrated efficacy and safety in another autoantibody-mediated neuroinflammatory disease, aquaporin-4 immunoglobulin G antibody-positive neuromyelitis optica spectrum disorder, and has the potential to be an evidence-based disease modifying treatment in AIE.

Objectives

CIELO will evaluate the efficacy, safety, pharmacodynamics, and pharmacokinetics of satralizumab compared with placebo in patients with NMDAR-immunoglobulin G antibody-positive (IgG+) or LGI1-IgG+ AIE.

Study design

CIELO (NCT05503264) is a prospective, Phase 3, randomized, double-blind, multicenter, basket study that will enroll approximately 152 participants with NMDAR-IgG+ or LGI1-IgG+ AIE. Prior to enrollment, participants will have received acute first-line therapy. Part 1 of the study will consist of a 52-week primary treatment period, where participants will receive subcutaneous placebo or satralizumab at Weeks 0, 2, 4, and every 4 weeks thereafter. Participants may continue to receive background immunosuppressive therapy, symptomatic treatment, and rescue therapy throughout the study. Following Part 1, participants can enter an optional extension period (Part 2) to continue the randomized, double-blind study drug, start open-label satralizumab, or stop study treatment and continue with follow-up assessments.

Endpoints

The primary efficacy endpoint is the proportion of participants with a ≥1-point improvement in the modified Rankin Scale (mRS) score from study baseline and no use of rescue therapy at Week 24. Secondary efficacy assessments include mRS, Clinical Assessment Scale of Autoimmune Encephalitis (CASE), time to rescue therapy, sustained seizure cessation and no rescue therapy, Montreal Cognitive Assessment, and Rey Auditory Verbal Learning Test (RAVLT) measures. Safety, pharmacokinetics, pharmacodynamics, exploratory efficacy, and biomarker endpoints will be captured.

Conclusion

The innovative basket study design of CIELO offers the opportunity to yield prospective, robust evidence, which may contribute to the development of evidence-based treatment recommendations for satralizumab in AIE.

Development of a short-term prognostic model for anti-N-methyl-D-aspartate receptor encephalitis in Chinese patients

BACKGROUND

Recognizing the predictors of poor short-term prognosis after first-line immunotherapy in patients with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is essential for individualized treatment strategy. The objective of this study was to ascertain the factors that forecast short-term prognosis in patients with anti-NMDAR encephalitis, develop a prognostic prediction model, and authenticate its efficacy in an external validation cohort. Further, all patients were followed-up long-term to assess the factors of long-term outcome and relapses.

METHODS

A prospective enrollment of patients diagnosed with anti-NMDAR encephalitis was conducted across five clinical centers in China from June 2014 to Mar 2022. The enrolled patients were divided into the derivation and validation sets based on enrollment time. The short-term prognostic model was visualized using a nomogram. Further, all patients were followed-up long-term to assess the factors of long-term outcome.

RESULTS

This study found that poor short-term prognosis was a risk factor for poor long-term outcome (6-month prognosis, OR 29.792, 95%CI 6.507-136.398, p < 0.001; 12-month prognosis, OR 15.756, 95%CI 3.384-73.075, p < 0.001; 24-month prognosis, OR 5.500, 95%CI 1.045-28.955, p = 0.044). Abnormal behavior or cognitive dysfunction (OR 8.57, 95%CI 1.48-49.79, p = 0.017), consciousness impairment (OR19.32, 95%CI 3.03-123.09, p = 0.002), autonomic dysfunction or central hypoventilation (OR 5.66, 95%CI 1.25-25.75, p = 0.025), CSF pleocytosis (OR 4.33, 95%CI 1.48-12.65, p = 0.007), abnormal EEG (OR 5.48, 95% CI 1.09-27.54, p = 0.039) were independent predictors for a poor short-term prognosis after first-line immunotherapy. A nomogram that incorporated those factors showed good discrimination and calibration abilities. The area under the curve (AUC) for the prognostic model were 0.866 (95%CI: 0.798-0.934) with a sensitivity of 0.761 and specificity of 0.869.

CONCLUSION

We established and validated a prognostic model that can provide individual prediction of short-term prognosis after first-line immunotherapy for patients with anti-NMDAR encephalitis. This practical prognostic model may help neurologists to predict the short-term prognosis early and potentially assist in adjusting appropriate treatment timely.

Validation of a risk score to differentiate autoimmune and viral encephalitis: a Nationwide Cohort Study in Denmark

BACKGROUND

A score to differentiate autoimmune (AE) and viral encephalitis (VE) early upon admission has recently been developed but needed external validation. The objective of this study was to evaluate the performance of the score in a larger and more diagnostically diverse patient cohort.

METHODS

We conducted a retrospective nationwide and population-based cohort study including all adults with encephalitis of definite viral (2015-2022) or autoimmune aetiology (2009-2022) in Denmark. Variables included in the score-model were extracted from patient records and individual risk scores were assessed. The performance of the score was assessed by receiver-operating characteristics (ROC) curve analyses and calculation of the area under the curve (AUC).

RESULTS

A total of 496 patients with encephalitis [AE n = 90, VE n = 287 and presumed infectious encephalitis (PIE) n = 119] were included in the study. The score was highly accurate in predicting cases of AE reaching an AUC of 0.94 (95% CI 0.92-0.97). Having a score ≥ 3 predicted AE with a PPV of 87% and an NPV of 91%. The risk score was found to perform well across aetiological subgroups and applied to the PIE cohort resulted in an AUC of 0.88 (95% CI 0.84-0.93).

CONCLUSION

The excellent performance of the score as reported in the development study was confirmed in this significantly larger and more diverse cohort of patients with encephalitis in Denmark. These results should prompt further prospective testing with wider inclusion criteria.

Therapeutic Approach to Autoimmune Neurologic Disorders

OBJECTIVE

Autoimmune neurologic disorders encompass a broad category of diseases characterized by immune system attack of the central, peripheral, or autonomic nervous systems. This article provides information on both acute and maintenance immunotherapy used to treat autoimmune neurologic disorders as well as a review of symptomatic management and special considerations when caring for patients with these diseases.

LATEST DEVELOPMENTS

Over the past 20 years, more than 50 antibodies have been identified and associated with autoimmune neurologic disorders. Although advances in diagnostic testing have allowed for more rapid diagnosis, the therapeutic approach to these disorders has largely continued to rely on expert opinion, case series, and case reports. With US Food and Drug Administration (FDA) approval of biologic agents to treat neuromyelitis optica spectrum disorder (NMOSD) and myasthenia gravis as well as ongoing clinical trials for the treatment of autoimmune encephalitis, the landscape of immunotherapy options continues to expand. Consideration of the unique pathogenesis of individual autoimmune neurologic disorders as well as the mechanism of action of the diverse range of treatment options can help guide treatment decisions today while evidence from clinical trials informs new therapeutics in the future.

ESSENTIAL POINTS

Recognizing patients who have a clinical history and examination findings concerning for autoimmune neurologic disorders and conducting a thorough and directed imaging and laboratory evaluation aimed at ruling out mimics, identifying specific autoimmune syndromes, and screening for factors that may have an impact on immunotherapy choices early in the clinical course are essential to providing optimal care for these patients. Providers must consider immunotherapy, symptomatic treatment, and a multidisciplinary approach that addresses each patient's unique needs when treating patients with autoimmune neurologic disorders.

Amyloid and Tau as cerebrospinal fluid biomarkers in anti-N-Methyl-D-aspartate receptor encephalitis

INTRODUCTION

Neuroinfection is associated with the deposition of amyloid-beta (Aβ) peptides, and subsequent decrease in cerebrospinal fluid (CSF) amyloid levels. However, whether autoimmune encephalitis involves extracellular deposition of Aβ peptides in the brain is unreported.

METHODS

We examined CSF amyloid and tau values in adults with anti-N-methyl-D-aspartate receptor encephalitis (NMDAR-E). Forty-two patients with NMDAR-E, 35 patients with viral and bacterial neuroinfections, and 16 controls were included. We measured CSF Aβ1-42 (cAβ1-42), Aβ1-40 (cAβ1-40), t-Tau (ct-Tau), and p-Tau181 (cp-Tau181) levels and assessed their efficacies regarding differential diagnosis and predicting prognosis.

RESULTS

NMDAR-E patients had lower cAβ1-42 levels; however, they were higher than those of patients with bacterial meningitis. ct-Tau levels in NMDAR-E patients were lower than those in patients with neuroinfections. No changes were observed in controls. cAβ1-42 and ct-Tau were combined as an excellent marker to distinguish NMDAR-E from neuroinfections. cAβ1-42 levels in NMDAR-E patients were positively correlated with Montreal Cognitive Assessment scores. We observed an inverse relationship between cAβ1-42 levels and modified Rankin Scale scores. Patients with poor outcomes exhibited low cAβ1-42 levels and high levels of several blood parameters. cAβ1-42 was the highest quality biomarker for assessing NMDAR-E prognosis. Correlations were found between cAβ1-42 and some inflammatory indicators.

CONCLUSION

cAβ1-42 was decreased in NMDAR-E patients. cAβ1-42 levels indicated NMDAR-E severity and acted as a biomarker for its prognosis. Combining cAβ1-42 and ct-Tau levels could serve as a novel differential diagnostic marker for NMDAR-E.

The clinical and predictive value of 18F-FDG PET/CT metabolic patterns in a clinical Chinese cohort with autoimmune encephalitis

AIMS

To investigate the diagnostic and predictive role of 18F-FDG PET/CT in patients with autoimmune encephalitis (AE) as a whole group.

METHODS

Thrty-five patients (20 females and 15 males) with AE were recruited. A voxel-to-voxel semi-quantitative analysis based on SPM12 was used to analyze 18F-FDG PET/CT imaging data compared to healthy controls. Further comparison was made in different prognostic groups categorized by modified Rankin Scale (mRS).

RESULTS

In total, 24 patients (68.6%) were tested positive neuronal antibodies in serum and/or CSF. Psychiatric symptoms and seizure attacks were major clinical symptoms. In the acute stage, 13 patients (37.1%) demonstrated abnormal brain MRI results, while 33 (94.3%) presented abnormal metabolism patterns. 18F-FDG PET/CT was more sensitive than MRI (p < 0.05). Patients with AE mainly presented mixed metabolism patterns compared to the matched controls, demonstrating hypermetabolism mainly in the cerebellum, BG, MTL, brainstem, insula, middle frontal gyrus, and relatively hypometabolism in the frontal cortex, occipital cortex, temporal gyrus, right parietal gyrus, left cingulate gyrus (p < 0.05, FWE corrected). After a median follow-up of 26 months, the multivariable analysis identified a decreased level of consciousness as an independent risk factor associated with poor outcome of AE (HR = 3.591, p = 0.016). Meanwhile, decreased metabolism of right superior frontal gyrus along with increased metabolism of the middle and upper brainstem was more evident in patients with poor outcome (p < 0.001, uncorrected).

CONCLUSION

18F-FDG PET/CT was more sensitive than MRI to detect neuroimaging abnormalities of AE. A mixed metabolic pattern, characterized by large areas of cortical hypometabolism with focal hypermetabolism was a general metabolic pattern. Decreased metabolism of right superior frontal gyrus with increased metabolism of the middle and upper brainstem may predict poor long-term prognosis of AE.

Brazilian consensus recommendations on the diagnosis and treatment of autoimmune encephalitis in the adult and pediatric populations

BACKGROUND

 Autoimmune encephalitis (AIE) is a group of inflammatory diseases characterized by the presence of antibodies against neuronal and glial antigens, leading to subacute psychiatric symptoms, memory complaints, and movement disorders. The patients are predominantly young, and delays in treatment are associated with worse prognosis.

OBJECTIVE

 With the support of the Brazilian Academy of Neurology (Academia Brasileira de Neurologia, ABN) and the Brazilian Society of Child Neurology (Sociedade Brasileira de Neurologia Infantil, SBNI), a consensus on the diagnosis and treatment of AIE in Brazil was developed using the Delphi method.

METHODS

 A total of 25 panelists, including adult and child neurologists, participated in the study.

RESULTS

 The panelists agreed that patients fulfilling criteria for possible AIE should be screened for antineuronal antibodies in the serum and cerebrospinal fluid (CSF) using the tissue-based assay (TBA) and cell-based assay (CBA) techniques. Children should also be screened for anti-myelin oligodendrocyte glucoprotein antibodies (anti-MOG). Treatment should be started within the first 4 weeks of symptoms. The first-line option is methylprednisolone plus intravenous immunoglobulin (IVIG) or plasmapheresis, the second-line includes rituximab and/or cyclophosphamide, while third-line treatment options are bortezomib and tocilizumab. Most seizures in AIE are symptomatic, and antiseizure medications may be weaned after the acute stage. In anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis, the panelists have agreed that oral immunosuppressant agents should not be used. Patients should be evaluated at the acute and postacute stages using functional and cognitive scales, such as the Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA), the Modified Rankin Scale (mRS), and the Clinical Assessment Scale in Autoimmune Encephalitis (CASE).

CONCLUSION

 The present study provides tangible evidence for the effective management of AIE patients within the Brazilian healthcare system.

Autoimmune encephalitis: Early and late findings on serial MR imaging and correlation to treatment timepoints

Introduction

MRI is negative in a large percentage of autoimmune encephalitis cases or lacks findings specific to an antibody. Even rarer is literature correlating the evolution of imaging findings with treatment timepoints. We aim to characterize imaging findings in autoimmune encephalitis at presentation and on follow up correlated with treatment timepoints for this rare disease.

Methods

A full-text radiological information system search was performed for "autoimmune encephalitis" between January 2012 and June 2022. Patients with laboratory-identified autoantibodies were included. MRI findings were assessed in correlation to treatment timepoints by two readers in consensus. For statistical analysis, cell-surface vs intracellular antibody groups were assessed for the presence of early limbic, early extralimbic, late limbic, and late extralimbic findings using the χ2 test.

Results

Thirty-seven patients (female n = 18, median age 58.8 years; range 25.7 to 82.7 years) with 15 different autoantibodies were included in the study. Twenty-three (62%) patients were MRI-negative at time of presentation; 5 of these developed MRI findings on short-term follow up. Of the 19 patients with early MRI findings, 9 (47%) demonstrated improvement upon treatment initiation (7/9 cell-surface group). There was a significant difference (p = 0.046) between the MRI spectrum of cell-surface vs intracellular antibody syndromes as cell-surface antibody syndromes demonstrated more early classic findings of limbic encephalitis and intracellular antibody syndromes demonstrated more late extralimbic abnormalities.

Conclusion

MRI can be used to help narrow the differential diagnosis in autoimmune encephalitis and can be used as a monitoring tool for certain subtypes of this rare disease.

Anti-NMDAR encephalitis in a child with long impaired consciousness and persistent antibodies: a case report and mini review

We described a challenging case of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis in a young girl. Despite enduring months of reduced consciousness with ongoing antibody presence, she ultimately exhibited remarkable improvement within a 5-year follow-up period. Additionally, we conducted a concise review of relevant literature on anti-NMDAR encephalitis, with a specific focus on anti-NMDAR antibodies. Our findings enhance the clinical comprehension of anti-NMDAR encephalitis and offer valuable insights to clinicians for its management.

Autoimmune encephalitis in Israeli children - A retrospective nationwide study

Immune-mediated or autoimmune encephalitis (AE) is a relatively new, rare and elusive form of encephalitis in children. We retrospectively collected seropositive children (0-18 years old) with well characterized antibodies through 3 reference laboratories in Israel. Clinical symptoms, MRI and EEG findings and treatment courses were described. A total of 16 patients were included in the study, with 10 females. Anti NMDA encephalitis was most common followed by anti HU and anti mGLuR1. Psychiatric symptoms, abnormal movements, seizures and behavioral changes were the most common presentation. Pathological MRI and EEG findings were described in 37% and 56% of children, respectively. Treatment with corticosteroids, Intravenous immunoglobulins (IVIG) was first line in most children. Following inadequate response children were treated with plasmapheresis and/or rituximab. Two patients relapsed following both first and second line protocols. In terms of long term prognosis, 9 children (56%) had one or more residual behavioral, psychiatric or neurologic findings. Three children required hospitalization for rehabilitation. AE remains a rare diagnosis with variable presenting symptoms, requiring a high index of suspicion. Consensus recommended treatment is generally effective in the pediatric population. Female gender was associated with a higher chance of severe disease. Larger cohorts would be needed to identify prognostic factors in the pediatric population.

H-intensity scale score to estimate CSF GluN1 antibody titers with one-time immunostaining using a commercial assay

Introduction

Anti-NMDA receptor encephalitis is an autoimmune disorder caused by autoantibodies (abs) against the conformational epitope on GluN1 subunits. GluN1-abs have been determined with cell-based assay (CBA) co-expressing GluN1/GluN2 subunits. However, commercial fixed CBA expressing only GluN1 subunit has increasingly been used in clinical practice. The ab titers can be determined with serial dilutions, but its clinical significance remains unclear. We aimed to develop an H-intensity scale (HIS) score to estimate GluN1-ab titers in cerebrospinal fluid (CSF) with one-time immunostaining using both commercial CBA and immunohistochemistry and report its usefulness. "H" is the initial of a patient with high CSF GluN1-ab titers (1:2,048).

Methods

We first determined the reliability of CBA in 370 patients with suspected autoimmune encephalitis by comparing the results between commercial CBA and established assay in Dalmau's Lab. Then, we made positive control panels using the patient H's CSF diluted in a fourfold serial dilution method (1:2, 1:8, 1:32, 1:128, 1:512, and 1:2,048). Based on the panels, we scored the intensity of ab reactivity of 79 GluN1-ab-positive patients' CSF (diluted at 1:2) on a scale from 0 to 6 (with ≥1 considered positive). To assess inter-assay reliability, we performed immunostaining twice in 21 patients' CSF. We investigated an association between the score of CSF obtained at diagnosis and the clinical/paraclinical features.

Results

The sensitivity and specificity of CBA were 93.7% (95% CI: 86.0-97.3) and 98.6% (95% CI: 96.5-99.5), respectively. Linear regression analysis showed a good agreement between the scores of the first and second assays. Patients with a typical spectrum, need for mechanical ventilation support, autonomic symptoms/central hypoventilation, dyskinesias, speech dysfunction, decreased level of consciousness, preceding headache, ovarian teratoma, and CSF leukocyte count >20 cells/µL had a higher median HIS score than those without, but HIS score was not associated with sex, age at onset, or seizure. HIS score at diagnosis had a significant effect on 1-year functional status.

Discussion

The severity of disease and four of the six core symptoms were associated with higher GluN1-ab titers in CSF at diagnosis, which may play a role in poor 1-year functional status. An incomplete phenotype can be attributed to low CSF GluN1-ab titers.

Risk factors and a predictive model for the occurrence of adverse outcomes in patients with new-onset refractory status epilepsy

Objectives

To determine risk factors for the occurrence of adverse outcomes in patients with new-onset refractory status epilepsy (NORSE) and to construct a concomitant nomogram.

Methods

Seventy-six adult patients with NORSE who were admitted to the Department of Neurology, First Affiliated Hospital of Sun Yat-sen University between January 2016 and December 2022 were enrolled for the study. Participants were divided into two-those with good and poor functional outcomes-and their pertinent data was obtained from the hospital medical recording system. Univariate analysis was used to identify potential causes of poor outcomes in both groups and a multivariate logistic regression model was used to identify risk factors for the occurrence of poor outcomes. Using the R programming language RMS package, a nomogram was created to predict the occurrence of poor outcomes.

Results

The NORSE risk of adverse outcome nomogram model included four predictors, namely duration of mechanical ventilation (OR = 4.370, 95% CI 1.221-15.640, p = 0.023), antiviral therapy (OR = 0.045, 95% CI 0.005-0.399, p = 0.005), number of anesthetics (OR = 13.428, 95% CI 2.16-83.48, p = 0.005) and neutrophil count/lymphocyte count ratio (NLR) (OR = 5.248, 95% CI 1.509-18.252, p = 0.009). The nomogram had good consistency and discrimination in predicting risk and can thus assist clinical care providers to assess outcomes for NORSE patients. Through ordinary bootstrap analyses, the results of the original set prediction were confirmed as consistent with those of the test set.

Conclusion

The nomogram model of risk of adverse outcomes in NORSE adult patients developed in this study can facilitate clinicians to predict the risk of adverse outcomes in NORSE patients and make timely and reasonable interventions for patients at high risk of adverse outcomes.

Autoimmune and inflammatory neurological disorders in the intensive care unit

PURPOSE OF REVIEW

The present review summarizes the diagnostic approach to autoimmune encephalitis (AE) in the intensive care unit (ICU) and provides practical guidance on therapeutic management.

RECENT FINDINGS

Autoimmune encephalitis represents a group of immune-mediated brain diseases associated with antibodies that are pathogenic against central nervous system proteins. Recent findings suggests that the diagnosis of AE requires a multidisciplinary approach including appropriate recognition of common clinical syndromes, brain imaging and electroencephalography to confirm focal pathology, and cerebrospinal fluid and serum tests to rule out common brain infections, and to detect autoantibodies. ICU admission may be necessary at AE onset because of altered mental status, refractory seizures, and/or dysautonomia. Early management in ICU includes prompt initiation of immunotherapy, detection and treatment of seizures, and supportive care with neuromonitoring. In parallel, screening for neoplasm should be systematically performed. Despite severe presentation, epidemiological studies suggest that functional recovery is likely under appropriate therapy, even after prolonged ICU stays.

CONCLUSION

AE and related disorders are increasingly recognized in the ICU population. Critical care physicians should be aware of these conditions and consider them early in the differential diagnosis of patients presenting with unexplained encephalopathy. A multidisciplinary approach is mandatory for diagnosis, ICU management, specific therapy, and prognostication.

Acute Symptomatic Seizures and Risk of Seizure Recurrence in Patients with Anti-NMDAR, Anti-LGI1, and Anti-GABABR Encephalitis

AIMS

To analyze the clinical characteristics of acute symptomatic seizures and predict the risk factors for seizure recurrence in patients with anti-N-methyl-D-aspartate receptor (NMDAR), anti-leucine-rich glioma-inactivated 1 (LGI1), and anti-gamma-aminobutyric acid B receptor (GABABR) encephalitis.

METHODS

In this retrospective study, we included hospitalized patients who had been diagnosed with anti-NMDAR, anti-LGI1, and anti-GABABR encephalitis between November 2014 and April 2021. Binary logistic regression analysis was performed to identify the potential risk factors for seizure recurrence.

RESULTS

In total, 262 patients with anti-NMDAR, anti-LGI1, and anti-GABABR encephalitis were included, 197 (75.2%) of whom presented with acute symptomatic seizures. During follow-up, 42 patients exhibited seizure recurrence. In anti-NMDAR encephalitis, frontal lobe abnormality on brain magnetic resonance imaging, delayed immunotherapy, early seizures, and focal motor onset were associated with seizure recurrence.

CONCLUSIONS

Acute symptomatic seizure is a common clinical feature observed in patients with anti-NMDAR, anti-LGI1, and anti-GABABR encephalitis, with 50% of patients presenting with seizures as an initial symptom. The prognosis of patients with acute symptomatic seizures can be improved after receiving immunotherapy. Nevertheless, a minority of patients will experience seizure recurrence; therefore, restarting immunotherapy is recommended.

Anti-NMDA Receptor Encephalitis Related to Renal Cell Carcinoma: A Case Report

Anti-NMDA receptor (NMDAR) encephalitis is characterized by a well-defined neuropsychiatric syndrome and CSF antibodies against the GluN1 subunit of the NMDAR. 40% of cases are related to underlying tumors, the vast majority ovarian teratomas (94%). We report a case of anti-NMDAR encephalitis associated with renal cell carcinoma (RCC). A 20-year-old female presented to the ED with behavioral changes, involuntary movements, tachycardia, and alternating obtundation with agitation which progressed over 3 weeks. Involuntary movements were severe, requiring intubation and sedation for control, and were accompanied by rhabdomyolysis. Brain MRI showed bilateral mesiotemporal T2/FLAIR hyperintensities. Anti-NMDAR antibodies were present in the serum (1:640) and CSF (1:320). Malignancy screening revealed a renal mass concerning for RCC, which was confirmed upon resection. She was started on high dose IV methylprednisolone and plasmapheresis, followed by rituximab. Lack of response led to escalating immunotherapy with cyclophosphamide. Clinical course was complicated by prolonged ICU admission, prolonged sedation, severe dysautonomia and bacteremia. Improvement began 2 months after immunotherapy, and she was discharged to rehabilitation 100 days after admission with mild neuropsychiatric symptoms. Repeat malignancy screenings, including whole-body imaging and transvaginal ultrasound were consistently negative. Herein, we describe a case of definite anti-NMDAR encephalitis in the setting of newly diagnosed RCC. This case illustrates how tumors other than ovarian teratomas may act as immunological triggers, as well as the complex and prolonged symptomatic and immunosuppressive therapies required in severe presentations of anti-NMDAR encephalitis.

Blood and CSF findings of cellular immunity in anti-NMDAR encephalitis

OBJECTIVES

To investigate the immunopathogenic mechanisms of anti-N-methyl-D-aspartate receptor encephalitis (NMDAR-E) by characterizing the changes of immune cells in both peripheral blood (PB) and cerebrospinal fluid (CSF) of patients with NMDAR-E.

METHODS

Cytology and flow cytometry were used to explore and compare different immunological parameters in PB and CSF of patients with NMDAR-E, viral encephalitis (VE) and healthy volunteers. Moreover, different models were established to assess the possibility of identifying NMDAR-E patients based on PB and CSF parameters.

RESULTS

The neutrophil counts and monocyte-to-lymphocyte ratios (MLR) in PB are higher in NMDAR-E patients than in both VEs and controls (P < 0.001, respectively), while the percentages of CD3 + T, CD4 + T lymphocytes, and the leukocytes count in CSF were lower in NMDAR-Es than in VEs (P < 0.01, respectively). The higher percentages of CD8 + T cells in blood and CSF were both correlated with more severe NMDAR-E (P < 0.05, respectively). The poor neurological status group had significantly higher PB leukocytes but lower CSF leukocyte count (P < 0.05). Longitudinal observations in patients with NMDAR-E showed a decreasing trend of leukocyte count, neutrophils count, neutrophil-to-monocyte ratios (NMR), and neutrophil-to-lymphocyte ratios (NLR) with the gradual recovery of neurological function.

CONCLUSIONS

The expression patterns of T lymphocyte subsets were different in patients with NMDAR-E and viral encephalitis. The changing trends of leukocyte and lymphocyte populations in peripheral blood and cerebrospinal fluid may provide clues for the diagnosis of different types of encephalitides, including NMDARE, and can be used as immunological markers to assess and predict the prognosis.

The T1-weighted/T2-weighted ratio as a biomarker of anti-NMDA receptor encephalitis

BACKGROUND

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis rarely causes visible lesions in conventional MRI, yet advanced imaging detects extensive white matter damage. To improve prognostic capabilities, we evaluate the T1-weighted/T2-weighted (T1w/T2w) ratio, a measure of white matter integrity computable from clinical MRI sequences, in NMDAR encephalitis and examine its associations with cognitive impairment.

METHODS

T1-weighted and T2-weighted MRI were acquired cross-sectionally at 3 Tesla in 53 patients with NMDAR encephalitis (81% women, mean age 29 years) and 53 matched healthy controls. Quantitative and voxel-wise group differences in T1w/T2w ratios and associations with clinical and neuropsychological outcomes were assessed. P-values were false discovery rate (FDR) adjusted where multiple tests were conducted.

RESULTS

Patients with NMDAR encephalitis had significantly lower T1w/T2w ratios across normal appearing white matter (p=0.009, Hedges' g=-0.51), which was associated with worse verbal episodic memory performance (r=0.39, p=0.005, p(FDR)=0.026). White matter integrity loss was observed in the corticospinal tract, superior longitudinal fascicle, optic radiation and callosal body with medium to large effects (Cohen's d=[0.42-1.17]). In addition, patients showed decreased T1w/T2w ratios in the hippocampus (p=0.002, p(FDR)=0.005, Hedges' g=-0.62), amygdala (p=0.002, p(FDR)=0.005, Hedges' g=-0.63) and thalamus (p=0.010, p(FDR)=0.019, Hedges' g=-0.51).

CONCLUSIONS

The T1w/T2w ratio detects microstructural changes in grey and white matter of patients with NMDAR encephalitis that correlate with cognitive performance. Computable from conventional clinical MRI sequences, this measure shows promise in bridging the clinico-radiological dissociation in NMDAR encephalitis and could serve as an imaging outcome measure in clinical trials.

Dynamic Contrast-enhanced MRI Quantification of Altered Vascular Permeability in Autoimmune Encephalitis

Background Blood-brain barrier (BBB) permeability change is a possible pathologic mechanism of autoimmune encephalitis. Purpose To evaluate the change in BBB permeability in patients with autoimmune encephalitis as compared with healthy controls by using dynamic contrast-enhanced (DCE) MRI and to explore its predictive value for treatment response in patients. Materials and Methods This single-center retrospective study included consecutive patients with probable or possible autoimmune encephalitis and healthy controls who underwent DCE MRI between April 2020 and May 2021. Automatic volumetric segmentation was performed on three-dimensional T1-weighted images, and volume transfer constant (Ktrans) values were calculated at encephalitis-associated brain regions. Ktrans values were compared between the patients and controls, with adjustment for age and sex with use of a nonparametric approach. The Wilcoxon rank sum test was performed to compare Ktrans values of the good (improvement in modified Rankin Scale [mRS] score of at least two points or achievement of an mRS score of  ≤2) and poor (improvement in mRS score of less than two points and achievement of an mRS score >2) treatment response groups among the patients. Results Thirty-eight patients with autoimmune encephalitis (median age, 38 years [IQR, 29-59 years]; 20 [53%] female) and 17 controls (median age, 71 years [IQR, 63-77 years]; 12 [71%] female) were included. All brain regions showed higher Ktrans values in patients as compared with controls (P < .001). The median difference in Ktrans between the patients and controls was largest in the right parahippocampal gyrus (25.1 × 10-4 min-1 [95% CI: 17.6, 43.4]). Among patients, the poor treatment response group had higher baseline Ktrans values in both cerebellar cortices (P = .03), the left cerebellar cortex (P = .02), right cerebellar cortex (P = .045), left cerebral cortex (P = .045), and left postcentral gyrus (P = .03) than the good treatment response group. Conclusion DCE MRI demonstrated that BBB permeability was increased in all brain regions in patients with autoimmune encephalitis as compared with controls, and baseline Ktrans values were higher in patients with poor treatment response in the cerebellar cortex, left cerebral cortex, and left postcentral gyrus as compared with the good response group. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Filippi and Rocca in this issue.

Longitudinal Disability, Cognitive Impairment, and Mood Symptoms in Patients With Anti-NMDA Receptor Encephalitis

BACKGROUND AND OBJECTIVES

Longitudinal outcomes in anti-NMDA receptor encephalitis (anti-NMDARe) are still not fully understood and may not be adequately captured with the modified Rankin Scale (mRS), often the sole reported outcome. We aim to characterize longitudinal outcomes in anti-NMDARe using multiple outcome measures.

METHODS

This single-center, retrospective, observational study examined outcome measures (mRS and Clinical Assessment Scale in Autoimmune Encephalitis [CASE]) in adults with NMDA receptor-IgG in CSF at short- and long-term follow-ups using linear and logistic regression modeling. Patients with evaluations for cognitive impairment (Montreal Cognitive Assessment/Mini-Mental State Examination), depression (Patient Health Questionnaire-9), and anxiety (General Anxiety Disorder-7) >6 months from symptom onset were correlated with final CASE scores.

RESULTS

Thirty-eight patients (76% female, median disease onset age = 28 years, range = 1-75 years) were included. The majority received first-line immunosuppressants (97%) at a median of 3.9 weeks (interquartile range [IQR] = 2.1-9.7) from symptom onset and 68% received second-line therapies. At baseline, median/mean mRS and CASE were 4 (IQR = 3-5) and 12.9 (SD = 7.2), respectively. At short-term follow-up (median = 10 weeks, IQR = 6-17), factors associated with higher CASE and mRS included dysautonomia, coma/lethargy, seizures/status epilepticus, and intensive care unit admission (p < 0.05). At long-term follow-up (median = 70 weeks, IQR = 51-174), median/mean mRS and CASE were 2 (IQR = 1-3) and 4.4 (SD = 4.2), respectively. Only weakness at symptom onset predicted higher mRS scores (odds ratio = 5.6, 95% confidence interval 1.02-30.9, p = 0.047). Despite both mRS and CASE improving from baseline (p < 0.001), only 9 patients (31%) returned to their premorbid function. Among patients with cognitive and mood evaluations >6 months from onset, moderate-severe cognitive impairment (42%), depression (28%), and anxiety (30%) were frequent. Cognitive and depression measures were associated with final CASE subscores (including memory, language, weakness, and psychiatric).

DISCUSSION

Multiple clinical factors influenced short-term outcomes, but only onset weakness influenced long-term mRS, highlighting that mRS is predominantly affected by global motor function. Although mRS and CASE improved over time for most patients, these outcome measures did not capture the full extent of long-term functional impairment in terms of mood, cognition, and the ability to return to premorbid function. This emphasizes the need for increased utilization of more nuanced cognitive and mood outcome measures.

Ovarian teratoma-associated anti-NMDA receptor encephalitis with severe features

Anti-N-methyl-D-aspartame receptor (NMDAR) encephalitis is an uncommon clinical entity for the general intensivist or neurologist. Diagnosis can be made by the presence of cerebrospinal fluid IgG antibody against the GluNR1 and GluNR2 subunits of the NMDAR. We present a case of anti-NMDAR encephalitis in a young woman with an ovarian teratoma treated with surgical resection and multiple immunomodulatory therapies.

Canadian Consensus Guidelines for the Diagnosis and Treatment of Autoimmune Encephalitis in Adults

Autoimmune encephalitis is increasingly recognized as a neurologic cause of acute mental status changes with similar prevalence to infectious encephalitis. Despite rising awareness, approaches to diagnosis remain inconsistent and evidence for optimal treatment is limited. The following Canadian guidelines represent a consensus and evidence (where available) based approach to both the diagnosis and treatment of adult patients with autoimmune encephalitis. The guidelines were developed using a modified RAND process and included input from specialists in autoimmune neurology, neuropsychiatry and infectious diseases. These guidelines are targeted at front line clinicians and were created to provide a pragmatic and practical approach to managing such patients in the acute setting.

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

OBJECTIVE

To investigate the associations between brain magnetic resonance imaging (MRI) changes and clinical profiles in children with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis.

METHODS

Clinical data and brain MRI results of children diagnosed with anti-NMDAR encephalitis in Guangzhou Women and Children's Medical Center from October 2014 to June 2022 were retrospectively studied.

RESULTS

A total of 143 children (Male: female 54:89) were enrolled, with a mean onset age of 6.8 years (6.8 ± 3.1). 40.6 % (58/143) of patients had abnormal initial brain MRI. Lesions in temporal lobe (34.5 %, 20/58) and frontal lobe (25.9 %, 15/58) were relatively common. Children with abnormal initial brain MRI were prone to have fever (P = 0.023), dystonia (P = 0.037), positive MOG antibodies (P = 0.015), higher cerebrospinal fluid (CSF) white blood cell count (WBC) (P = 0.019) and to receive rituximab treatment (P = 0.037). There were no significant differences in modified Rankin Scale (mRS) scores before immunotherapy, after immunotherapy and at last follow-up between the normal initial brain MRI group and abnormal group. No initial brain MRI changes were found to be associated with relapses. Brain MRI was reviewed in 72 patients at last follow-up with a median follow-up time of 25.5 months and 48.6 % (35/72) of patients had abnormal brain MRI. The mRS score of the group with normal brain MRI at last follow-up was significantly lower than that of the abnormal group.

CONCLUSIONS

About 40.0 % of children with anti-NMDAR encephalitis had abnormal initial brain MRI. Initial brain MRI was associated with certain clinical profiles, but not with relapse and prognosis. Around half of patients had abnormal brain MRI at last follow-up and were prone to have higher mRS score.

Electroconvulsive therapy for catatonia in anti-NMDA receptor encephalitis: A case series

BACKGROUND

Anti-NMDAR encephalitis is the most common cause of immune-mediated catatonia.

CASE SERIES

Three females presented with neuropsychiatric symptoms and were empirically treated with first-line immunotherapy and ovarian teratoma resection for suspected autoimmune encephalitis, preceding diagnostic confirmation via NMDAR antibody positivity. They required escalating large doses of benzodiazepines for refractory malignant catatonia resulting in ICU level care. ECT treatments were initiated, and patients were gradually noted to have clinical improvement as was measured by the Bush-Francis Catatonia Rating Scale.

CONCLUSIONS

Clinicians should recognize catatonia among patients with suspected anti-NMDAR encephalitis and consider the early implementation of ECT into treatment algorithms.