Autoimmune encephalitis: recent updates and emerging challenges. J Clin Neurosci. 2014;21:722-730. [PMID: 24246947 DOI: 10.1016/j.jocn.2013.07.017]

Severe Neurological Manifestation Associated With Coronavirus Disease 2019 in Children During the Omicron Variant-Predominant Period

BACKGROUND

The Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is known to be more infectious and less severe than the other variants. Despite the increasing number of symptomatic patients, severe neurological complications in children with the Omicron variant have been reported rarely, unlike with wild-type or Delta variants. This study aimed to investigate severe neurological complications in children with Omicron variant infection.

METHODS

We conducted a retrospective study of 17 pediatric patients with severe neurological manifestations associated with coronavirus disease 2019 in Korea during the Omicron variant prevalence, from January 1 to April 30, 2022.

RESULTS

Among the 17 patients, 11 had pre-existing neurological disabilities and nine met the criteria for multisystem inflammatory syndrome in children (MIS-C). Four of the five vaccine-eligible patients (12 years and older) were unvaccinated. Severe neurological manifestations included acute necrotizing encephalopathy, acute fulminant cerebral edema, acute disseminated encephalomyelitis, basal ganglia encephalitis, unclassified severe encephalopathy/encephalitis, and refractory status dystonicus. Patients with MIS-C and underlying neurological disabilities had longer median hospital and intensive care unit stays compared with those without these conditions. Five patients survived with new neurological deficits at the one-year follow-up, and three died, all of whom had underlying neurological disabilities.

CONCLUSIONS

This study shows that severe neurological complications in pediatric patients with the Omicron variant of SARS-CoV-2 occur infrequently but may lead to significant morbidity and mortality, especially among those with pre-existing neurological disabilities and unvaccinated individuals. Continued efforts are necessary to prevent and manage such complications in these vulnerable populations.

Sudden unexpected death in epilepsy and ictal asystole in patients with autoimmune encephalitis: a systematic review

OBJECTIVE

As autoimmune encephalitis (AE) often involves the mesial temporal structures which are known to be involved in both sudden unexpected death in epilepsy (SUDEP) and ictal asystole (IA), it may represent a good model to study the physiopathology of these phenomena. Herein, we systematically reviewed the occurrence of SUDEP and IA in AE.

METHODS

We searched 4 databases (MEDLINE, Scopus, Embase, and Web of Science) for studies published between database inception and December 20, 2022, according to the PRISMA guidelines. We selected articles reporting cases of definite/probable/possible/near-SUDEP or IA in patients with possible/definite AE, or with histopathological signs of AE.

RESULTS

Of 230 records assessed, we included 11 cases: 7 SUDEP/near-SUDEP and 4 IA. All patients with IA were female. The median age at AE onset was 30 years (range: 15-65), and the median delay between AE onset and SUDEP was 11 months; 0.9 months for IA. All the patients presented new-onset seizures, and 10/11 also manifested psychiatric, cognitive, or amnesic disorders. In patients with SUDEP, 2/7 were antibody-positive (1 anti-LGI1, 1 anti-GABABR); all IA cases were antibody-positive (3 anti-NMDAR, 1 anti-GAD65). Six patients received steroid bolus, 3 intravenous immunoglobulin, and 3 plasmapheresis. A pacemaker was implanted in 3 patients with IA. The 6 survivors improved after treatment.

DISCUSSION

SUDEP and IA can be linked to AE, suggesting a role of the limbic system in their pathogenesis. IA tends to manifest in female patients with temporal lobe seizures early in AE, highlighting the importance of early diagnosis and treatment.

Autoimmune-mediated encephalitis and mimics: A neuroimaging review

Autoimmune encephalitis is a category of autoantibody-mediated neurological disorders that often presents a diagnostic challenge due to its variable clinical and imaging findings. The purpose of this image-based review is to provide an overview of the major subtypes of autoimmune encephalitis and their associated autoantibodies, discuss their characteristic clinical and imaging features, and highlight several disease processes that may mimic imaging findings of autoimmune encephalitis. A literature search on autoimmune encephalitis was performed and publications from neuroradiology, neurology, and nuclear medicine literature were included. Cases from our institutional database that best exemplify major imaging features were presented.

Basal Ganglia Autoimmune Encephalitis Following Leptospirosis

Basal ganglia encephalitis is a part of the spectrum of autoimmune basal ganglia disorders. We are reporting a child who had a fever with focal seizures followed by behavioral problems, rigidity, bradykinesia, and dystonia. His parkinsonism-like features were increasing day by day up to the level that the child was non-ambulatory. His initial Magnetic Resonance Imaging (MRI) of the brain showed asymmetrical T2 hyperintensities involving both the caudate nuclei and putamina. Later, with progressive symptoms, repeat MRI revealed a swelling and symmetrical signal change in both the caudate nuclei and putamina in the form of T2 and Fluid-attenuated inversion recovery (FLAIR) hyperintensities. In addition, there was T2 hyperintensity involving bilateral substantia nigra. Serum basal ganglia antibody, Leptospira Immunoglobulin M (IgM) antibody was positive, and Cerebrospinal Fluid (CSF) oligoclonal band was positive. So, the child was diagnosed with post-leptospirosis autoimmune basal ganglia encephalitis. He was managed with immunomodulatory agents and significant improvement in the symptoms with mild residual extrapyramidal symptoms were noted.

Severity of Hospitalized Children with Anti-NMDAR Autoimmune Encephalitis

Background: Information on the clinical characteristics and severity of autoimmune encephalitis with antibodies against the N-methyl-d-aspartate receptor (NMDAR) in children is attracting more and more attention in the field of pediatric research. Methods: In this retrospective cohort study, all cases (n = 67) were enrolled from a tertiary children's hospital, from 2017 to 2020. We compared severe cases that received intensive care unit (ICU) care with nonsevere cases that did not receive ICU care and used machine learning algorithm to predict the severity of children, as well as using immunologic and viral nucleic acid tests to identify possible pathogenic triggers. Results: Mean age of children was 8.29 (standard deviation 4.09) years, and 41 (61.19%) were girls. Eleven (16.42%) were admitted to the ICU, and 56 (83.58%) were admitted to neurology ward. Ten individual parameters were statistically significant differences between severe cases and nonsevere cases (P < .05), including headache, abnormal mental behavior or cognitive impairment, seizures, concomitant tumors, sputum/blood pathogens, blood globulin, blood urea nitrogen, blood immunoglobulin G, blood immunoglobulin M, and number of polynucleated cells in cerebrospinal fluid. Random forest regression model presented that the overall prediction power of severity reached 0.806, among which the number of polynucleated cells in cerebrospinal fluid contributed the most. Potential pathogenic causes exhibited that the proportion of mycoplasma was the highest, followed by Epstein-Barr virus. Conclusion: Our findings provided evidence for early identification of autoimmune encephalitis in children, especially in severe cases.

A Prognostic Analysis of the Outcomes in Patients With Anti-γ-Aminobutyric Acid B Receptor Encephalitis

Objective

To evaluate neurological function and its influencing factors in patients with anti-γ -aminobutyric acid B receptor (GABA_BR) encephalitis.

Methods

This was a clinical cohort study of patients diagnosed with anti-GABA_BR encephalitis; long-term follow-up was performed by telephone. Clinical factors associated with prognosis were analyzed, including clinical manifestations, laboratory examinations, imaging features, tumor comorbidities and therapeutic responses.

Results

Twenty-two patients with anti-GABA_BR encephalitis were evaluated (median age: 55 years). Lung cancer was detected in eight patients. All were with serum tumor markers (mainly NSE), and three of them had additional onconeuronal antibodies. The patients with tumors were older than the patients without tumors and more likely to develop status epilepticus (62.5% vs. 14.3%; p = 0.052), central hypoventilation (50% vs. 7.1%; p = 0.039), and hyponatremia (87.5% vs. 14.3%; p = 0.001). The patients with tumors had higher mortality (87.5% vs. 0%; p < 0.05). Although 92.9% of the patients without tumors became functionally independent (mRS ≤2), sequelae of symptomatic seizures, neuropsychiatric symptoms, and cognitive impairment were still observed in 14.3%, 21.4%, and 21.4% of patients, respectively.

Conclusions

(1) Elderly patients with anti-GABA_BR antibodies, especially those with severe symptoms, serum tumor markers, and additional onconeuronal antibodies, should be screened for lung cancer. (2) Anti-GABA_BR encephalitis with tumors has a poor prognosis. (3) Most patients without tumors achieve self-care, but some still experience remaining neurological deficits.

Trends and Developments in the Detection of Pathogens in Central Nervous System Infections: A Bibliometric Study

Introduction

Rapid, sensitive, and specific laboratory assays are critical for the diagnosis and management of central nervous system (CNS) infections. The purpose of this study is to explore the intellectual landscape of research investigating methods for the detection of pathogens in patients with CNS infections and to identify the development trends and research frontier in this field.

Methods

A bibliometric study is conducted by analyzing literature retrieved from the Web of Science (WoS) Core Collection Database for the years 2000 to 2021. CiteSpace software is used for bibliometric analysis and network visualization, including co-citation analysis of references, co-occurrence analysis of keywords, and cooperation network analysis of authors, institutions, and countries/regions.

Results

A total of 2,282 publications are eventually screened, with an upward trend in the number of publications per year. The majority of papers are attributed to the disciplines of MICROBIOLOGY, INFECTIOUS DISEASES, IMMUNOLOGY, NEUROSCIENCES & NEUROLOGY, and VIROLOGY. The co-citation analysis of references shows that recent research has focused on the largest cluster “metagenomic next-generation sequencing”; the results of the analysis of the highest-cited publications and the citation burst of publications reveal that there is a strong interest stimulated in metagenomic next-generation sequencing. The co-occurrence analysis of keywords indicates that “infection”, “pathogen”, “diagnosis”, “gene”, “virus”, “polymerase chain reaction”, “cerebrospinal fluid”, “epidemiology”, and “metagenomic next-generation sequencing” are the main research priorities in the field of pathogen detection for CNS infections, and the keyword with the highest strength of burst is “metagenomic next-generation sequencing”. Collaborative network analysis reveals that the USA, the Centers for Disease Control and Prevention of USA, and XIN WANG and JENNIFER DIEN BARD are the most influential country, institution, and researchers, respectively.

Conclusions

Exploring more advanced laboratory assays to improve the diagnostic accuracy of pathogens is essential for CNS infection research. Metagenomic next-generation sequencing is emerging as a novel useful unbiased approach for diagnosing infectious diseases of the CNS.

Study of Demographic Profile, Etiology, and Clinical Outcome in Patients Admitted With Acute Encephalitis Syndrome From the Western Part of India

Background

Determining the etiology of encephalitis always remains a challenge to clinicians, and also, variables that predict outcome in acute phase settings are not known precisely. The autoimmune causes of acute encephalitis are increasing due to the availability of newer diagnostic markers, whereas earlier studies were primarily focused on infectious causes. We conducted a prospective study to determine the demographic profile, etiological aspect, and in-hospital outcome of patients admitted with acute encephalitis syndrome (AES) in our tertiary care center.

Materials and method

This observational prospective study was carried out at a tertiary care hospital between November 2016 and October 2018. With a sample size of 72, appropriate statistical analysis was done.

Results

The incidence of AES usually escalates during the rainy season, with arboviral etiologies being predominant. The majority of the patients with AES with a likely infectious etiology could not be diagnosed with presently available viral marker studies. Among various clinical variables, a low Glasgow Coma Scale (GCS) score on admission, a high CSF protein value, and diffusion restriction on brain MRI was associated with poor outcome.

Conclusion

Acute encephalitis and encephalitis-related mortality impose a considerable burden on current medical practice. The reported demographics of hospitalized patients with encephalitis may be changing, which are important factors to consider for etiological workup.

Research progress of anti-γ-aminobutyric acid B receptor encephalitis and a case report of paraneoplastic associated encephalitis and treatment analysis

Encephalitis is one of the common diseases in neurology. Early diagnosis and appropriate treatments are essential. Autoimmune encephalitis (AE) generally refers to a type of encephalitis mediated by autoimmune mechanisms. It is gradually considered to be an important cause of reversible encephalitis caused by noninfectious factors. It can occur in children, adolescents, and adults, and is clinically characterized by multifocal or diffuse brain damage such as personality changes, seizures, and cognitive impairment, with an overall good effect of immunotherapy. According to the clinical features of the patients, blood and cerebrospinal fluid tests, neuroelectrophysiology, cranial imaging, treatment and prognosis, AEs can be broadly divided into specific antigen (antibody)-related AEs and nonspecific antigen (or antibody) -related AEs. With the development of AEs research, more and more anti-neuron antibodies have been found, which provides an important reference for the diagnosis and treatment of AEs. Understanding the knowledge about AEs is important to discover new diseases and deepen the understanding of the immunopathological mechanisms of existing central nervous system diseases. Anti-γ-aminobutyric acid B (GABA-B) receptor encephalitis is a type of AE, but this disease is rare in AE, often develop to the clinical manifestations of marginal encephalitis, accompanied by obvious seizures or status epilepticus, Some patients had tumors, mainly small-cell carcinoma, prompt diagnosis, early immunotherapy and, if necessary, tumor treatment resulted in complete or partial neurological improvement in most patients.

Seronegative Autoimmune Basal Ganglia Encephalitis Presenting as Acute Parkinsonism and Refractory Faciobrachial Seizures: A Case Report

Autoimmune basal ganglia encephalitis (BGE) typically presents with acute onset parkinsonism and on imaging is associated with lesions in the basal ganglia. It is associated with chorea and other movement disorders. Seizures are still rare. Various autoantibodies are associated with the development of basal ganglia encephalitis. These autoantibodies are against dopamine D2 receptor (D2R) and N-methyl-D-aspartate receptor (NMDAR). Another paraneoplastic antibody known as anti-recoverin antibodies (Abs) is also associated with basal ganglia encephalitis. We report a case of a 45-year-old male who presented in this hospital with a history of cognitive dysfunction and slowness of activities for eight days and faciobrachial seizures. Magnetic resonance imaging (MRI) of the brain revealed lesions in the putamen and caudate nucleus. Infection and antibody screening were negative. The seizures were refractory to conventional antiepileptics. The patient responded to intravenous immunoglobulin (IVIG) therapy.

Association between inflammatory central nervous system diseases and epilepsy: A retrospective cohort study of 4252 patients in Germany

GOAL

The goal of this study was to analyze the association between inflammatory central nervous system (CNS) diseases and the incidence of epilepsy in patients followed up for up to 10 years in Germany.

METHODS

This retrospective cohort study included adults aged ≥ 18 years who had an initial diagnosis of inflammatory CNS disease (i.e. encephalitis, meningitis or brain abscess) in one of 1229 general practices in Germany between 2005 and 2015 (index date). Patients without inflammatory CNS disease were matched (1:1) to those with inflammatory CNS disease by sex, age, follow-up time after index date, Charlson Comorbidity Index, and practice. The index date for patients without inflammatory CNS disease was a randomly selected visit date between 2005 and 2015. Kaplan-Meier curves and Cox regression analyses were used to assess the association between inflammatory CNS diseases and the incidence of epilepsy.

RESULTS

This study included 2126 individuals with and 2126 patients without inflammatory CNS disease (56.4% women; mean [SD] age 50.0 [12.3] years). Within ten years of the index date, 4.2% of patients with and 1.5% of patients without inflammatory CNS disease had been diagnosed with epilepsy (p < 0.001). This finding was corroborated in the Cox regression analysis, and there was a positive and significant association between inflammatory CNS diseases and epilepsy (HR: 3.82, 95% CI: 2.24-6.52).

CONCLUSIONS

Based on these results, preventive interventions are urgently warranted to reduce the incidence of epilepsy in individuals with a history of inflammatory CNS disease.

Single-cell approaches to investigate B cells and antibodies in autoimmune neurological disorders

Autoimmune neurological disorders, including neuromyelitis optica spectrum disorder, anti-N-methyl-D-aspartate receptor encephalitis, anti-MOG antibody-associated disorders, and myasthenia gravis, are clearly defined by the presence of autoantibodies against neurological antigens. Although these autoantibodies have been heavily studied for their biological activities, given the heterogeneity of polyclonal patient samples, the characteristics of a single antibody cannot be definitively assigned. This review details the findings of polyclonal serum and CSF studies and then explores the advances made by single-cell technologies to the field of antibody-mediated neurological disorders. High-resolution single-cell methods have revealed abnormalities in the tolerance mechanisms of several disorders and provided further insight into the B cells responsible for autoantibody production. Ultimately, several factors, including epitope specificity and binding affinity, finely regulate the pathogenic potential of an autoantibody, and a deeper appreciation of these factors may progress the development of targeted immunotherapies for patients.

Clinical Features and Treatment Outcomes of Seronegative Pediatric Autoimmune Encephalitis

Background and Purpose

New diagnostic criteria for pediatric autoimmune encephalitis (AIE) have been introduced recently. A substantial proportion of cases of pediatric AIE are diagnosed as seronegative based on these criteria, and so the clinical characteristics of this group remain to be investigated.

Methods

This study included 46 pediatric patients younger than 18 years with suspected AIE. Clinical features, laboratory or radiological findings, and treatment outcomes were compared between seronegative and seropositive patients.

Results

Nine (19.6%) of the 46 patients were diagnosed as seropositive AIE. All of the patients with seropositive AIE had anti-N-methyl-D-aspartate receptor antibodies. Commonly identified neuropsychiatric symptoms were altered mental status, cognitive dysfunction, seizure, speech dysfunction, and psychotic disorder in both the seronegative and seropositive groups. Immunotherapy produced favorable treatment outcomes in both the seropositive (n=7, 77.8%) and seronegative (n=35, 94.6%) AIE patients. Treatment outcomes for first-line immunotherapy were better in seronegative AIE than seropositive AIE patients (p=0.003), and hence a smaller proportion of seronegative patients required second-line treatment (p=0.015).

Conclusions

Pediatric seronegative AIE patients showed clinical presentations similar to those of seropositive AIE patients, with favorable treatment outcomes after immunotherapy.

Status epilepticus from GABABR antibody positive encephalitis due to de novo mixed small cell and adenocarcinoma of the prostate

We present a case study of a 67-year-old man who presented with a new onset of recurrent tonic-clonic seizures. He had tested positive to gamma-aminobutyric acid B receptor antibodies in his blood and cerebrospinal fluid, and subsequent CT imaging and transrectal biopsy confirmed the presence of a locally advanced mixed small cell and Gleason 9 adenocarcinoma of the prostate. His seizures remained resistant to treatment with multiple antiepileptic drugs, including sodium valproate, clobazam, topiramate, carbamazepine, phenytoin and lacosamide. He progressed to status epilepticus, which required intravenous immunoglobulin and steroids, followed by plasma exchange 1 week later. The status epilepticus was refractory and required multiple admissions to the intensive care unit.

Early clinical suspicion and treatment in a patient with anti-NMDA receptor encephalitis

Anti-NMDA receptor encephalitis is a complicated disease associated with paraneoplastic syndromes and autoimmune conditions. This case report highlights the importance of early identification and reviews the common clinical manifestations, diagnostic studies, and treatment modalities for this potentially catastrophic disease.

Anti-dopamine D2 receptor antibodies in chronic tic disorders

AIM

To investigate the association between circulating anti-dopamine D2 receptor (D2R) autoantibodies and the exacerbation of tics in children with chronic tic disorders (CTDs).

METHOD

One hundred and thirty-seven children with CTDs (108 males, 29 females; mean age [SD] 10y 0mo [2y 7mo], range 4-16y) were recruited over 18 months. Patients were assessed at baseline, at tic exacerbation, and at 2 months after exacerbation. Serum anti-D2R antibodies were evaluated using a cell-based assay and blinded immunofluorescence microscopy scoring was performed by two raters. The association between visit type and presence of anti-D2R antibodies was measured with McNemar's test and repeated-measure logistic regression models, adjusting for potential demographic and clinical confounders.

RESULTS

At exacerbation, 11 (8%) participants became anti-D2R-positive ('early peri-exacerbation seroconverters'), and nine (6.6%) became anti-D2R-positive at post-exacerbation ('late peri-exacerbation seroconverters'). The anti-D2R antibodies were significantly associated with exacerbations when compared to baseline (McNemar's odds ratio=11, p=0.003) and conditional logistic regression confirmed this association (Z=3.49, p<0.001) after adjustment for demographic and clinical data and use of psychotropic drugs.

INTERPRETATION

There is a potential association between immune mechanisms and the severity course of tics in adolescents with CTDs.

Antibody-negative autoimmune encephalitis as a complication of long-term immune-suppression for liver transplantation

Autoimmune encephalitis is a rare spectrum of disease that can be a complication of chronic immunosuppression. Diagnosis often requires the presence of antineuronal antibodies, but many causative antibodies have not yet been identified. Antibody-negative autoimmune encephalitis (AbNAE) is especially difficult to diagnose and must rely largely on exclusion of other causes. In chronically immune-suppressed transplant recipients, the differential is broad, likely resulting in underdiagnosis and worse outcomes. Here, we present a 58-year-old liver transplant recipient taking tacrolimus for prevention of chronic rejection who presented with 5 days of confusion, lethargy and lightheadedness. He was diagnosed with AbNAE after an extensive workup and recovered fully after high-dose corticosteroids. Our case highlights the importance of recognising the association between chronic immunosuppression and autoimmune encephalitis. Autoimmune encephalitis, even in the absence of characterised antibodies, should be considered when transplant recipients present with central neurologic symptoms.

Anti-NMDA Receptor Encephalitis: Efficacy of Treatment for Male Patients and miRNA Biomarker

BACKGROUND

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is an acute form of encephalitis. Treatments for the anti-NMDA receptor encephalitis usually include steroids, intravenous immunoglobulin, plasma exchange, plasmapheresis, rituximab, cyclophosphamide and tumor resection.

OBJECTIVE

We aimed to compare the efficacy of the treatments including intravenous immunoglobulin, plasma exchange, plasmapheresis, rituximab or cyclophosphamide for male anti- NMDA receptor encephalitis patients without tumor and to discuss potential biomarkers for this disease.

METHOD

The Fisher exact test and the contingency table analysis were used to analyze the treatment efficacy for 43 male and 76 female patients. In addition, a hierarchical tree method was adopted to analyze the difference in the treatment efficacy between male and female patients.

RESULTS

The p-values of testing whether the efficacy rate of plasmapheresis (or plasma exchange) for the male patient is greater than a threshold are significantly different from the pvalues for the other two treatments. In addition, the hierarchical tree method shows that the treatment strategy associating with early recovery is different for male and female patients.

CONCLUSION

The results revealed that the efficacy rate of plasmapheresis (or plasma exchange) is not inferior to that of intravenous immunoglobulin and rituximab (or cyclophosphamide) for male patients without tumor. In addition, B-cell attracting C-X-C motif chemokine 13 (CXCL13) and microRNA let-7b have the potential to be the treatment response biomarkers for anti-NMDA receptor encephalitis. They may not be useful prognostic biomarkers for this encephalitis unless they are not biomarkers for other autoimmune encephalitides.

Novel Surrogate Markers of CNS Inflammation in CSF in the Diagnosis of Autoimmune Encephalitis

Background: Autoimmune encephalitis (AE) is an important cause of refractory epilepsy, rapidly progressive cognitive decline, and unexplained movement disorders in adults. Whilst there is identification of an increasing number of associated autoantibodies, patients remain with a high clinical probability of autoimmune encephalitis but no associated characterized autoantibody. These patients represent a diagnostic and treatment dilemma. Objective: To evaluate routine and novel diagnostic tests of cerebrospinal fluid (CSF) in patients with a high probability of AE to attempt to identify better biomarkers of neuroinflammation. Methods: Over 18 months (2016-2018), adult patients with a high clinical probability of AE were recruited for a pilot cross-sectional explorative study. We also included viral polymerase-chain-reaction (PCR) positive CSF samples and CSF from neurology patients with "non-inflammatory" (NI) diagnoses for comparison. CSF was examined with standard investigations for encephalitis and novel markers (CSF light chains, and cytokines). Results and Conclusions: Thirty-two AE patients were recruited over 18 months. Twenty-one viral controls, 10 NI controls, and five other autoimmune neurological disease controls (AOND) were also included in the analysis. Our study found that conventional markers: presence of CSF monocytosis, oligoclonal bands, anti-neuronal immunofluorescence, and magnetic resonance imaging (MRI) changes could be suggestive of AE, but these investigations were neither sensitive nor specific. Promising novel makers of autoimmune encephalitis were the CSF cytokines IL-21 and IP10 which may provide better delineation between viral infections and autoimmune encephalitis than conventional markers, potentially leading to more immediate diagnosis and management of these patients.

Neuronal Surface Antibody Syndrome: A Review of the Characteristics of the Disease and Its Association with Autoantibodies

Several studies have certified that autoantibodies play an important role in the manifestation of neuromuscular diseases. Scientists have discovered specific neuronal tumor antibodies in patients with typical paraneoplastic neurological disorders. But in some clinical cases, it is not useful to cure this disease with common treatments unless the autoantibodies are addressed. In addition, recent studies have shown a close relationship between certain antibodies and neuronal surface proteins in some special cases. These antibodies, which act on the surface of neurons, mainly include voltage-gated calcium channel (VGKC) antibodies. VGKC antibodies are further divided into several types including anti-leucine-rich glioma inactivated 1 (LGI1), anti-contactin-associated protein-like 2 (Caspr2), anti-N-methyl-D-aspartate receptor (NMDAR), anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR), anti-γ-aminobutyric acid receptor (GABAR), and glycine receptor. For the purpose of this review, cases of clinical studies of autoantibody-associated encephalitis were collected, the key points regarding the pathogenesis were summarized, the clinical manifestation was discussed, and all this information was organized as this review in order to introduce the relationship between autoantibodies and autoimmune encephalitis. Furthermore, it is hoped that it can effectively direct the development of diagnostic and therapeutic approach in the future.

Headache, Delirium or Encephalitis? A Case of Residual Mutism Secondary to Anti-NMDA Receptor Encephalitis

Encephalitis is a heterogeneous syndrome that is diagnosed through clinical assessment and the assistance of laboratory, neuroimaging and electroencephalographic workup. Over the past 10 years, autoimmune encephalitis has been more frequently recognized; however, most reports come from highly specialized hospital settings. Anti-N-methyl-D-aspartate receptor (NDMAR) encephalitis has been associated with paraneoplastic encephalitis syndromes and was first recognized in 2005. We present the case of a 34-year-old male patient who debuted clinically with a headache associated with neuropsychiatric symptoms (i.e., visual and auditory hallucinations, anxiety, aggressiveness) and memory deficits, progressing to autonomic dysfunction (i.e., tachycardia and hypertension), seizures, and stupor with catatonic features. Initially, infectious, metabolic, and toxicological etiologies were excluded; followed by the assessment of immunological and paraneoplastic etiologies, yielding positive IgG levels for anti-NMDAR antibodies. The patient was treated successfully with systemic steroid therapy and therapeutic plasmapheresis, while mutism was the only sequela. Although large case series reporting on paraneoplastic and autoimmune anti-NMDAR encephalitis have been reported in the literature in recent years, this case is of particular importance due to the stepwise differential diagnosis and treatment management procedure that was used in a regional but not highly specialized hospital setting.

A paraneoplastic limbic encephalitis from an anorectal small cell neuroendocrine carcinoma: a case report

BACKGROUND

Paraneoplastic limbic encephalitis (PLE) is a rare autoimmune neurological syndrome observed in cancer patients. PLE is difficult to diagnose and presents a variable response to treatment, depending on the characteristics of the tumor and neuronal autoantibodies.

CASE PRESENTATION

A 64-year-old, Caucasian, non-smoker man presented with a rapidly developing cognitive impairment, personality change, spatial disorientation, and short-term memory loss associated with anorexia and cervical and inguinal lymph nodes. The ¹⁸F-FDG PET scan documented intensely hypermetabolic lymph nodes, which histologically corresponded to a metastasis from a small cell neuroendocrine carcinoma. The brain MRI revealed a high T2-weighted FLAIR signal of the hippocamps, consisted with a PLE. The presence of anti-neuronal Hu antibodies confirmed the diagnosis. The patient underwent plasmapheresis, associated to a systemic chemotherapy resulting in a partial and temporary improvement of the neurological symptoms. Four cycles of intravenous immunoglobulins were also necessary. After six cures of chemotherapy, the lymph node metastases regressed. However, a new anorectal lesion was detected and was histologically confirmed as a primary small cell neuroendocrine carcinoma, which was treated with concomitant chemoradiotherapy. At the end of this treatment, the patient showed a rapid tumor progression leading to his death.

CONCLUSIONS

This case highlights the rare entity, PLE, which is difficult to diagnose and manage. In addition, this is the first published case of PLE associated with an anorectal small cell neuroendocrine carcinoma, which appeared after completion of systemic chemotherapy.

The autoantibody-mediated encephalitides: from clinical observations to molecular pathogenesis

The autoimmune encephalitis (AE) syndromes have been characterised by the detection of autoantibodies in serum and/or cerebrospinal fluid which target the extracellular domains of specific neuroglial antigens. The clinical syndromes have phenotypes which are often highly characteristic of their associated antigen-specific autoantibody. For example, the constellation of psychiatric features and the multi-faceted movement disorder observed in patients with NMDAR antibodies are highly distinctive, as are the faciobrachial dystonic seizures observed in close association with LGI1 antibodies. These typically tight correlations may be conferred by the presence of autoantibodies which can directly access and modulate their antigens in vivo. AE remains an under-recognised clinical syndrome but one where early and accurate detection is critical as prompt initiation of immunotherapy is closely associated with improved outcomes. In this review of a rapidly emerging field, we outline molecular observations with translational value. We focus on contemporary methodologies of autoantibody detection, the evolution and distinctive nature of the clinical phenotypes, generalisable therapeutic paradigms, and finally discuss the likely mechanisms of autoimmunity in these patients which may inform future precision therapies.

Establishing a Pediatric Acute-Onset Neuropsychiatric Syndrome Clinic: Baseline Clinical Features of the Pediatric Acute-Onset Neuropsychiatric Syndrome Cohort at Karolinska Institutet

Objectives: Pediatric acute-onset neuropsychiatric syndrome (PANS) is a descriptive clinical entity defined by the abrupt onset of psychiatric and somatic symptoms leading to significant loss of function. Data on well-characterized PANS patients are limited, biomarkers have yet to be identified, and a solid evidence base to guide treatment is lacking. In this study, we present our experience of a systematic evaluation of the first 45 patients included in a Swedish cohort. Methods: During the period 2014-2018, our clinic received 100 referrals regarding suspected PANS. All patients underwent a standardized psychiatric/medical evaluation by a child/adolescent psychiatrist and a clinical psychologist or a nurse. Those with severe symptoms were also assessed by a pediatric neurologist and a pediatric rheumatologist. Laboratory tests were obtained at different time points in an attempt to capture an active disease state. Results: Of the 100 referrals, 45 met strict PANS criteria and consented to participate in a long-term follow-up study. The median age at intake was 7.2 years (range 3.0-13.1) and 56% were male. Ninety-three percent fulfilled both criteria for acute/atypical onset of PANS symptoms and having had an infection in relation to onset. Sixteen percent had an onset of an autoimmune or inflammatory disorder in temporal relation to the onset of PANS-related symptoms. The most common onset symptoms were obsessive-compulsive disorder (89%), anxiety (78%), and emotional lability (71%). Twenty-four percent had a preexisting autoimmune disease (AD) and 18% a preexisting psychiatric/neuropsychiatric diagnosis. Sixty-four percent of biological relatives had at least one psychiatric disorder and 76% at least one AD or inflammatory disorder. Complement activation (37%), leukopenia (20%), positive antinuclear antibodies (17%), and elevated thyroid antibodies (11%) were the most common laboratory findings. Conclusions: In our PANS cohort, there was a strong indication of an association with AD. Further work is needed to establish whether any of the potential biomarkers identified will be clinically useful. Long-term follow-up of these patients using the Swedish national registers will enable a deeper understanding of the course of this patient group.

Critical Care Management of Anti-N-Methyl-D-Aspartate Receptor Encephalitis

OBJECTIVES

Anti-N-methyl-D-aspartate receptor encephalitis is considered an immune-mediated form of encephalitis with paraneoplastic and nonparaneoplastic forms. Delay in recognition is common and patients typically present to the ICU without a diagnosis or with complications following a delayed diagnosis. The aim of this review is to provide a focused overview for the ICU clinician regarding presentation, diagnosis, and critical care management.

DATA SOURCES, STUDY SELECTION, AND DATA EXTRACTION

PubMed database search with manual review of articles involving anti-N-methyl-D-aspartate receptor encephalitis.

DATA SYNTHESIS

Anti-N-methyl-D-aspartate receptor encephalitis is increasingly encountered in the ICU. The cascade of events initiating anti-N-methyl-D-aspartate receptor antibody formation may involve an infectious trigger particularly in the setting of teratoma. Following a prodrome, most patients develop psychiatric symptoms followed by movement disorder. Classical, psychiatric, and catatonic phenotypes may be distinguished based on the presence and severity of symptoms. Early immunotherapy and low initial cerebrospinal fluid inflammation are independent predictors of positive outcomes in ICU patients. Concomitant organ failure, status epilepticus, and the identification of a tumor did not influence outcome in critically ill patients. Supportive care in the ICU includes management of various manifestations of dyskinesia, status epilepticus, autonomic disorders, and the need for general sedation. Common treatment strategies and limitations are discussed including the emerging role of bortezomib.

CONCLUSIONS

Intensivists should be familiar with the presentation and management of anti-N-methyl-D-aspartate receptor encephalitis. Early diagnosis and immediate implementation of steroids, immunoglobulins, and/or plasmapheresis and immune therapy are associated with a good neurologic outcome although response may be delayed. The selection and timing of second-line immune therapy requires further study.

Clinical Presentation and Outcome in Autoimmune Encephalitis Associated With N-Type Voltage-Gated Calcium Channels in Children

OBJECTIVE

We present the diagnostic and clinical course of the first multicenter case series of pediatric patients with autoimmune encephalitis associated with N-type voltage-gated calcium channel antibodies.

METHODS

Data from 2 university hospitals were retrospectively reviewed and records of 3 patients with autoimmune encephalitis associated with N-type voltage-gated calcium channel antibodies were evaluated.

RESULTS

The 3 pediatric patients (all female) had symptoms that spanned the clinical spectrum. All 3, however, had regression of expressive language and agitation. Neuroimaging in all 3 patients was normal; electroencephalographic (EEG) findings varied among the 3 patients. Positive titers against the N-type voltage-gated calcium channel antibody were found in their cerebrospinal fluid. Following administration of intravenous immunoglobulin, all 3 had improvement in their core presenting symptoms.

CONCLUSION

Autoimmune encephalitis associated with N-type voltage-gated calcium channel antibodies in the pediatric population presents with a wide clinical spectrum, although expressive language delay and agitation seem to be common symptoms. Treatment with intravenous immunoglobulin improves core symptoms.

Effect of Clozapine on Anti-N-Methyl-D-Aspartate Receptor Encephalitis With Psychiatric Symptoms: A Series of Three Cases

The main clinical manifestations of anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis are acute or subacute seizures, cognition impairment, and psychiatric symptoms. Nowadays, the scheme of antipsychotic therapy for this disease has not been established. This study reports three cases of anti-NMDAR encephalitis with psychiatric symptoms. The anti-NMDAR antibodies in cerebrospinal fluid (CSF) and serum were positive. The psychiatric symptoms still existed after intravenous immunoglobulin (IVIG) treatment; thus, clozapine was used for antipsychotic therapy. Case 1 was a 37-year-old man who suffered from bad mood and suicide behaviors for 1 month. Hallucination and delusion still existed after IVIG treatment and hormone therapy, and the symptoms were relieved when given clozapine for 12 months. Case 2 was a 28-year-old man who was admitted to our hospital due to injuring other people and destructive behaviors for 2 days. He showed irritability, bad temper, declined cognition, and severe delusion of persecution after IVIG treatment and hormone therapy, but the psychiatric symptoms disappeared when given clozapine for 3 months. Case 3 was a 23-year-old man who suffered from headache and babbing for 7 days. Symptoms such as irritability, bad temper, babbing, and injuring other people still existed after IVIG treatment and hormone therapy, but they disappeared when given clozapine for 2 months. Therefore, we suggest that during the treatment of anti-NMDAR encephalitis with psychiatric symptoms, if the anti-NMDAR antibodies in CSF and serum were positive, and psychiatric symptoms could not be controlled after IVIG and hormone therapy, clozapine may work.

Clinical characteristics and factors associated with short-term prognosis in adult patients with autoimmune encephalitis of non-neoplastic etiology

BACKGROUND

Reports that autoimmune encephalitis (AE) is associated with antibodies have increased; however, little is known about the distribution of clinical symptoms, imaging changes, and prognostic factors in patients with AE of non-neoplastic etiology. Accordingly, we evaluated the clinical characteristics and factors associated with short-term prognosis.

METHODS

From January 2016 to June 2018, 31 adult patients were diagnosed with AE of non-neoplastic etiology at Shengjing Hospital of China Medical University and their demographic and clinical characteristics were abstracted. Factors affecting disease severity and predictors of prognosis were analyzed.

RESULTS

Among 31 patients, 19 had anti-NMDAR, 5 had anti-GABABR, and 7 had anti-LGI1 antibody encephalitis. Status epilepticus, ataxia, and cognitive dysfunction were the most common neurological symptoms. Deep white matter (DWM) abnormalities were the most common changes observed on MRI. Logistic regression analysis indicated that conscious disturbance (odds ratio = 11.67, 95%, confidence interval 2.13-64.04; p = 0.005) is an independent factor associated with poor prognosis in AE.

CONCLUSION

The clinical manifestations of AE are diverse; status epilepticus, ataxia, and cognitive dysfunction are most common. The DWM of the brain, rather than the limbic lobe system, was most prone to MR signal abnormalities. Conscious disturbance may be an important predictor of poor short-term prognosis in patients with AE of non-neoplastic etiology.

Multiple Sclerosis and Autoimmune Neurology of the Central Nervous System

Autoimmune disorders of the central nervous system are common and often affect people in the most productive years of their lives. Among primary autoimmune diseases of the central nervous system, multiple sclerosis is most prevalent in the United States. Many other autoantibody-mediated neurologic syndromes have been identified within the past 2 to 3 decades, including neuromyelitis optica and anti-N-methyl-D aspartate receptor encephalitis. Finally, the central nervous system can also be affected by systemic autoimmune diseases such as sarcoidosis. Many of these diseases are treatable when detected early.

Typical clinical and imaging manifestations of encephalitis with anti-γ-aminobutyric acid B receptor antibodies: clinical experience and a literature review

OBJECTIVE

To explore the clinical, imaging, and electroencephalogram (EEG) findings, as well as the treatment and prognosis of five patients with anti-γ-aminobutyric acid B receptor (GABA_BR) encephalitis and review the current literature to gain a deeper understanding and improve the clinical diagnostic ability of the disease.

METHODS

Clinical data such as blood examination, imaging, computed tomography (CT), EEG, and magnetic resonance imaging (MRI) findings from five patients with anti-GABA_BR encephalitis were retrospectively analyzed.

RESULTS

Based on the imaging data, autoimmune encephalitis with anti-GABA_BR antibodies displayed subacute onset of episodic memory loss, seizures, and confusion, in addition to signal changes in the medial temporal lobe and/or hippocampus. Anti-GABA_BR antibodies were found in blood and cerebrospinal fluid (CSF) in all five patients, although the CSF leukocyte count and the levels of protein, sugar, and chloride showed no obvious abnormalities. On MRI, only two patients presented with abnormal signals in the medial temporal lobe and/or hippocampus. The EEG showed a slow wave rhythm in all five patients. After treatment with methylprednisolone pulse therapy combined with antiepileptic treatment, all five patients recovered well, without any complications.

CONCLUSIONS

Autoimmune encephalitis with anti-GABA_BR antibodies may be a severe and refractory disease. Anti-GABA_BR antibodies tested in CSF and serum play a crucial role in the definitive diagnosis and treatment of autoimmune encephalitis. Early treatment is of vital importance to avoid serious complications and neurological sequelae.

Prediction of neutrophil-to-lymphocyte ratio in the diagnosis and progression of autoimmune encephalitis

OBJECTIVE

Autoimmune encephalitis (AIE) is a group of inflammatory disorders of the brain. The severity of AIE vary among individuals and it is always a challenge to predict. In this study, we measured the neutrophil-to-lymphocyte ratio (NLR), a novel potential biomarker of inflammatory status in other inflammatory diseases, in AIE patients and evaluated NLR as a biomarker for monitoring AIE progression.

METHODS

The study participants consisted of 34 newly diagnosed AIE patients and 35 ages and sex-matched healthy controls. Demographic and clinical assessment data were reviewed and abstracted retrospectively. NLR levels were calculated from the peripheral blood tests. The relationship between mRS (the modified Ranking Scale) score and NLR levels, total white blood cells, absolute neutrophil counts and absolute lymphocyte counts were investigated. The performance of NLR in predicting severe AIE was also determined.

RESULTS

Peripheral NLR level in AIE patients were significantly higher than in healthy controls (p < 0.001). Additionally, median NLR level in patients with severe impairments (using modified Ranking Scale, mRS＞3) was significantly elevated (p < 0.001) compared to patients with mild to moderate impairments (mRS≤3). Spearman correlation analysis indicated that NLR and neutrophil counts were positively associated to mRS score (r = 0.595, p＜0.001 for NLR, and r = 0.392, p = 0.022 for neutrophil counts). While lymphocyte counts were negatively correlated with mRS score (r=-0.522, p = 0.002). Multivariate logistic regression analysis revealed that increased NLR value was an independent risk factor for severe AIE (OR: 2.171, 95% CI: 1.218-3.868, p = 0.009). Furthermore, according to the ROC curve, the best NLR cut-off value to predict severe disease activity of AIE was 4.82, with a sensitivity of 78% and specificity of 88%.

CONCLUSION

Our results suggest that NLR in peripheral blood may be a practical and reliable biomarker to monitor disease progression in patients with AIE.

Three cases of antibody-LGI1 limbic encephalitis and review of literature

PURPOSE

Antibody-LGI1 limbic encephalitis (LGI1-Ab LE) is an anti-neuronal surface antigen-related autoimmune encephalitis. we report three cases of LGI1-Ab LE, describe the characteristics of clinical manifestation, course of evolution, imaging manifestation and treatment outcomes.

METHODS

Data from patients diagnosed with LGI1-Ab LE in the Second Hospital, Hebei Medical University, from June 2016 to July 2017, were retrospectively collected and analyzed. We followed up the patients for 90 days.

RESULTS

Two of the three patients were females, the average age of onset is 53 years old. Epilepsy is the most common clinical manifestations, and one of patients developed faciobrachial dystonic seizures (FBDS), which was recently described as a characteristic feature of LGI1-Ab LE. All patients had cognitive impairment in different degrees and abnormal signal of hippocampus in cranial MRI. All serum LGI1 antibodies were positive, whereas one LGI1 antibodies of CSF were negative. All patients accepted first-line immune therapy and had a good outcome.

CONCLUSION

LGI1-Ab LE, which is an autoimmune disease, is rare clinically and mostly nonparaneoplastic. We suggest that LGI1-Ab LE be considered in any patient with acute or subacute onset, cognitive dysfunction , various types of seizures, accompanied by mental disorders and hyponatremia, MR showed the involvement of the limbic system. It is necessary to have LE-related antibodies tested. Early immunotherapy can significantly improve the patient's overall prognosis. At the same time, we should also pay attention to the possibility of potential tumors.

LGI1 tumor tissue expression and serum autoantibodies in patients with primary malignant glioma

OBJECTIVES

The Leucine-rich glioma inactivated 1 (LGI1) protein is thought to be implicated in malignant progression of glioma tumors, and mutations in the encoding gene, LGI1, cause autosomal dominant lateral temporal epilepsy, a genetic focal epilepsy syndrome. The aim of this study was to investigate the possible involvement of LGI1 in high-grade glioma-associated epilepsy by analyzing its expression in tumor specimens of patients with and without epilepsy and by searching for LGI1 autoantibodies in the sera these patients.

PATIENTS AND METHODS

We examined tumor tissue samples from 24 patients with high-grade gliomas (12 with and 12 without epilepsy) by immunoblot and detected variable amounts of LGI1 in tumor tissues from 9/24 (37%) patients.

RESULTS

LGI1 was detected in 7/12 (58%) patients with epilepsy and in 2/12 (16%) patients without epilepsy (p = 0.0894; Fisher's exact test). Moreover, testing blood sera of five patients for antibodies against LGI1 revealed LGI1 autoantibodies in two patients, both suffering from epilepsy and expressing LGI1 in tumor tissue.

CONCLUSION

Our findings suggest that there may be a preferential expression of LGI1 in high-grade glioma tumors of patients with epilepsy. We also unveil the presence of serum LGI1 autoantibodies in some patients with high-grade gliomas, where they might play an epileptogenic role.

Updates in Refractory Status Epilepticus

Refractory status epilepticus is defined as persistent seizures despite appropriate use of two intravenous medications, one of which is a benzodiazepine. It can be seen in up to 40% of cases of status epilepticus with an acute symptomatic etiology as the most likely cause. New-onset refractory status epilepticus (NORSE) is a recently coined term for refractory status epilepticus where no apparent cause is found after initial testing. A large proportion of NORSE cases are eventually found to have an autoimmune etiology needing immunomodulatory treatment. Management of refractory status epilepticus involves treatment of an underlying etiology in addition to intravenous anesthetics and antiepileptic drugs. Alternative treatment options including diet therapies, electroconvulsive therapy, and surgical resection in case of a focal lesion should be considered. Short-term and long-term outcomes tend to be poor with significant morbidity and mortality with only one-third of patients reaching baseline neurological status.

Prognostic Factors in Anti-Neuronal Antibody Positive Patients

INTRODUCTION

Anti-neuronal antibodies (ANA) are found in paraneoplastic neurological syndrome and autoimmune encephalitis patients. Our aim was to analyze prognostic factors related with ANA seropositivity.

METHODS

Twenty-seven consecutive ANA seropositive patients were included in the study. ANA were detected by immunofluorescent staining, immunoblot and cell-based assay methods. All patients were followed with a standard treatment protocol. Clinical syndromes, tumor types, modified Rankin scores, cranial MRI and oligoclonal band (OCB) findings were recorded. Cases were divided into subgroups due to clinical-laboratory features and ANA types. Prevalence of good prognosis, response to treatment and survival were compared among these subgroups.

RESULTS

Patients showed antibodies to N-methyl-D-aspartate receptor (NMDAR) (6 cases), Hu (6 cases), Ma2 (5 cases), glutamic acid decarboxylase (GAD) (3 cases), Yo (3 cases), amphiphysin (1 case), gamma-amino butyric acid B receptor (GABABR) (1 case), Ri (1 case) and Zic4 (1 case). Associated neurological syndromes were limbic encephalitis (8 cases), subacute cerebellar degeneration (7 cases), brainstem encephalitis (5 cases), subacute sensory neuronopathy (4 cases), stiff-person syndrome (2 cases) and opsoclonus-myoclonus (1 case). A tumor (ductal breast, small cell lung cancer) was detected in six cases at first admission. Six patients died in an average follow-up time of 1.0±1.5 years. Detection of antibodies to extracellular or synaptic target antigens, but not presence of tumor, cranial MRI lesions or OCB, was associated with good prognosis and response to treatment.

CONCLUSION

NMDAR, Hu and Ma2-antibodies were the most prevalent ANA in this first antibody screening study in a Turkish cohort. Antibody type was determined to be the foremost prognostic factor in ANA seropositive cases.

Unusual case of anti-N-methyl-D-aspartic acid-receptor (NMDA-R) encephalitis and autoimmune polyglandular syndrome (APS)

Anti-N-methyl-D-aspartic acid-receptor (NMDA-R) encephalitis is a novel disease discovered within the past 10 years. It is an autoimmune disease (AD) that has been associated with other ADs, such as Graves' disease. However, association with autoimmune polyglandular syndromes (APS) has not been previously described. A 58-year-old woman presented with altered mental status and an 8-month history of weight loss, apathy and somnolence. Laboratory evaluation confirmed Graves' disease with thyrotoxicosis and type 1 diabetes mellitus. Despite treatment, she continued to have a fluctuating mental status. Further diagnostic evaluation included an abdominal MRI that showed a cystic lobular left adnexal mass. Serum anti-NMDA-R antibodies were positive, raising concern for NMDA-R encephalitis. Bilateral salpingo-oophorectomy was performed, with pathology consistent with cystadenofibroma. She had a favourable recovery with marked clinical improvement. Anti-NMDA-R antibodies were negative 2 months following surgery. The concomitant occurrence of APS and anti-NMDA-R encephalitis suggests a shared mechanism of autoimmune pathophysiology.

Autoimmune Encephalitis at the Neurological Intensive Care Unit: Etiologies, Reasons for Admission and Survival

Background

Early recognition and treatment of autoimmune encephalitis (AE) has become an essential issue in clinical practice. However, little is known about patients with deteriorating conditions and the need for intensive care treatment. Here, we aimed to characterize underlying aetiologies, clinical symptoms, reasons for intensive care admission, and mortality of critically ill patients with AE.

Methods

We conducted a retrospective chart review of all patients with “definite” or “probable” diagnoses of AE treated at our neurological intensive care unit between 2002 and 2015. We collected and analyzed clinical, paraclinical, laboratory findings and assessed the mortality at last follow-up based on patient records.

Results

Twenty-seven patients [median age 55 years (range 25–87), male = 16] were included. Thirteen (48%) had “definite” AE. The most common reasons for admission were status epilepticus (7/27, 26%) and delirium (4/27, 15%). One-year survival was 82%, all five deceased were male, and 3 (60%) of them had “probable” disease. The non-survivors (median follow-up 1 year) were more likely to have underlying cancer and higher need for respiratory support compared to the survivors (p < 0.041, and p = 0.004, respectively).

Conclusions

Clinical presentations and outcomes in critically ill patients with AE are diverse, and the most common leading cause for intensive care unit admission was status epilepticus. The association of comorbid malignancy and the need for mechanical ventilation with mortality deserves further attention.

Electronic supplementary material

The online version of this article (doi:10.1007/s12028-016-0370-7) contains supplementary material, which is available to authorized users.

Seronegative Paraneoplastic Limbic Encephalitis Associated with Thymoma

Paraneoplastic limbic encephalitis is an autoimmune syndrome characterized by the acute or subacute onset of encephalopathy, memory loss, confusion, temporal lobe seizures, and behavioral and mood changes. Although most patients with paraneoplastic limbic encephalitis have antineuronal antibodies, advances in the field now permit the diagnosis without autoantibody test results. In this case illustrating the new diagnostic criteria, we report a 70-year-old woman who was brought to the emergency room after the acute onset of cognitive impairment, altered mental status, and choreoathetoid movements. Brain magnetic resonance imaging showed hyperintense signals in both temporal lobes, and a chest computed tomogram revealed a thymoma. Because the patient met current diagnostic criteria for autoimmune limbic encephalitis, we were able to start treatment before her antibody tests were processed. The patient received immunotherapy and her tumor was resected. Her choreoathetoid movements disappeared and her other neurologic symptoms improved. Her cerebrospinal fluid proved to be negative for paraneoplastic limbic encephalitis antibodies. Most but not all patients with paraneoplastic limbic encephalitis associated with thymoma have evidence of paraneoplastic antibodies. Prompt management of the underlying malignancy determines whether patients survive and may minimize future cognitive and functional impairment. Practicing neurologists and psychiatrists should be aware of this diagnosis.

Differential diagnosis with other rapid progressive dementias in human prion diseases

Prion diseases are unique in medicine as in humans they occur in sporadic, genetic, and acquired forms. The most common human prion disease is sporadic Creutzfeldt-Jakob disease (CJD), which commonly presents as a rapidly progressive dementia (RPD) with behavioral, cerebellar, extrapyramidal, and some pyramidal features, with the median survival from symptom onset to death of just a few months. Because human prion diseases, as well as other RPDs, are relatively rare, they can be difficult to diagnose, as most clinicians have seen few, if any, cases. Not only can prion diseases mimic many other conditions that present as RPD, but some of those conditions can present similarly to prion disease. In this article, the authors discuss the different etiologic categories of conditions that often present as RPD and also present RPDs that had been misdiagnosed clinically as CJD. Etiologic categories of conditions are presented in order of the mnemonic used for remembering the various categories of RPDs: VITAMINS-D, for vascular, infectious, toxic-metabolic, autoimmune, mitochondrial/metastases, iatrogenic, neurodegenerative, system/seizures/sarcoid, and demyelinating. When relevant, clinical, imaging, or other features of an RPD that overlap with those of CJD are presented.

Treatment strategies for autoimmune encephalitis

Autoimmune encephalitis is one of the most rapidly growing research topics in neurology. Along with discoveries of novel antibodies associated with the disease, clinical experience and outcomes with diverse immunotherapeutic agents in the treatment of autoimmune encephalitis are accumulating. Retrospective observations indicate that early aggressive treatment is associated with better functional outcomes and fewer relapses. Immune response to first-line immunotherapeutic agents (corticosteroids, intravenous immunoglobulin, plasma exchange, and immunoadsorption) is fair, but approximately half or more of patients are administered second-line immunotherapy (rituximab and cyclophosphamide). A small but significant proportion of patients are refractory to all first- and second-line therapies and require further treatment. Although several investigations have shown promising alternatives, the low absolute number of patients involved necessitates more evidence to establish further treatment strategies. In this review, the agents used for first- and second-line immunotherapy are discussed and recent attempts at finding new treatment options are introduced.

Risk Factors for Intensive Care Unit Admission in Patients with Autoimmune Encephalitis

Background

Prevention and early recognition of critical illness in patients with autoimmune encephalitis (AE) is essential to achieve better outcome.

Aim of the study

To evaluate risk factors for intensive care unit (ICU) admission and its prognostic impact in patients with AE.

Patients and methods

A reclassification of patients hospitalized between 2011 and 2016 revealed 17 “definite” and 15 “probable” AE cases. Thirteen patients (41%) developed critical illness and required ICU admission. The underlying conditions were intractable seizures or status epilepticus (54%), altered mental state (39%), and respiratory failure (8%).

Results

ICU admission was associated with longer time from first symptoms to hospitalization (p = 0.046). Regression analysis revealed that anemia on hospital admission and definite diagnosis of AE was associated with a higher risk of acquiring critical illness. At last follow-up after a median of 31 months (range 2.5–52.4), seven patients had died (23%) and 63% had a good outcome [modified Rankin Scale (mRS) 0–3]. Anemia was associated with poor prognosis (p = 0.021), whereas development of critical illness did not impact mortality and functional outcome.

Conclusion

We confirmed the need for ICU care in a subgroup of patients and the prevailing objective is improved seizure control, and definite diagnosis of AE and anemia were identified as risk factors for development of critical illness. However, prognosis was not affected by ICU admission.