Sleep disorders in autoimmune encephalitis

Investigating health related quality of life and clinical measures in autoimmune encephalitis: a systematic review

This systematic review sought to understand the types of quality of life or clinical outcome measures currently being utilised for autoimmune encephalitis (AE) patients to determine whether the current measured outcomes accurately represented the full disease burden of AE. This included how the measures were being used (e.g., time point utilised, as an endpoint or as a categorisation method), and what the recorded measures were. The review included all studies that fulfilled the population criteria, which included probable AE. A search conducted on the 24th of June 2024 on PubMed and Embase returned 302 studies that fulfilled the inclusion criteria. Of the 302, the most commonly used measures were the Modified Rankin Scale (mRS) being utilised in 90.07% of studies, followed by Clinical Assessment Scale in Autoimmune Encephalitis (CASE) at 15.56%, Montreal Cognitive Assessment (MoCA) at 7.95%, and finally Mini Mental State Examination (MMSE) at 4.97%. The most common phenotype in the literature was NMDA AE, with 208 studies (68.87%) investigating this cohort. There was significant heterogeneity in the application of measures, such as definitional differences (e.g., a good outcome defined as an mRS of < 1 for some papers, but < 2 for others), utilising measures at differing time points within the disease course of an individual, and the inconsistent reporting of key information, such as comorbidities that may impact the measures being used. This review found the current clinical measures do not holistically encompass the disease burden of AE, with current clinical measures experiencing deficiencies in capturing the effect of AE on sleep and psychosocial function . It is recommended that future studies utilise symptom onset as a standardised time metric, and either a combination of currently available measures, or the creation or validation of new methods to capture disease burden in AE patients.

Neuroimmunology and Sleep

The immune system and sleep are inextricably linked in both health and pathological conditions. Tightly regulated neuroimmune processes are critical for the physiological maintenance of healthy sleep. Reciprocally, sleep disturbances can detrimentally affect immune homeostasis and predispose to increased risk of autoimmune conditions, which themselves are bidirectionally associated with a higher risk of sleep disturbances. Autoimmune diseases of the central nervous system (CNS), particularly conditions that affect neuroanatomical regions involved in sleep homeostasis and nocturnal respiration, are associated with an increased risk sleep disorders that may impact diagnosis, clinical course, and management. This review summarizes the bidirectional relationship between sleep and immunity and highlights several exemplar autoimmune conditions of the CNS that include sleep disorders as a consequence or diagnostic feature of the disorder.

Long-term neurological outcome in patients presenting with encephalitis

BACKGROUND

Advances in encephalitis research have improved the definition and management of encephalitis during the acute phase. Still, little is known about long-term outcomes in different subtypes of encephalitis.

OBJECTIVES

To analyze the prevalence and predictors of long-term clinical outcomes in different subtypes of encephalitis.

METHODS

All patients discharged from a tertiary hub for acute neurology with a confirmed diagnosis of encephalitis were included. Encephalitis were classified into autoimmune (AE), infectious (IE) and of unknown origin (UE) according to guidelines. Long-term neurological sequelae were evaluated using a 16-item questionnaire assessing severity and frequency of neurological symptoms, disability was scored using the expanded Disability status scale (EDSS). Long-term symptoms distribution and predictors were evaluated using univariate and multivariate regression models.

RESULTS

Seventy out 105 survived patients were included (AE n = 30, IE n = 12, UE n = 28). Disability at discharge was worse in AE compared to UE (p = 0.018). Additionally, AE had a higher risk of relapse (n = 8 AE, n = 1 UE, p = 0.001). 36 patients (51,4%) showed significant disability according to EDSS; whereas 72,9% reported a significant neurological long-term sequela, including cognitive deficits (50,0%), depression (41,4%) and numbness (21,0%). Older age and abnormal MRI at onset were the strongest predictors of long-term severe sequelae. independently from the subtype of encephalitis.

DISCUSSIONS

Long-term sequelae are common in encephalitis, and are associated with MRI abnormalities, premorbid disability, and older age at onset. Further longitudinal studies are needed to focus on biological and clinical predictors, to identify patients who might benefit from cognitive and behavioral training after discharge.

Patient-Reported Outcome Measures in NMDA Receptor Encephalitis

BACKGROUND AND OBJECTIVES

The characteristics of persistent long-term symptoms and their contribution to subjective quality of life remain unclear in patients with NMDAR encephalitis. In this study, we aimed to evaluate postacute neuropsychiatric symptoms, subjective cognitive complaints, and disease coping mechanisms and identify predictors of health-related quality of life (HRQoL) after N-methyl-D-aspartate receptor (NMDAR) encephalitis.

METHODS

This cross-sectional observational study investigated patients with NMDAR encephalitis in the postacute phase. Psychometric scales included assessment of neuropsychiatric symptoms (i.e., fatigue, sleep, anxiety, and depressive symptoms), HRQoL, everyday independence, metamemory (i.e., self-rated ability, satisfaction, and use of strategies), and coping strategies (i.e., self-efficacy, disease-related coping, and stress management).

RESULTS

A total of 50 patients (mean age 26.0 ± 10.1 years, 86% female) participated at a median of 4.15 (range 0.3-30.3) years after symptom onset. Patients reported significantly increased levels of anxiety (Beck Anxiety Inventory: 10.5 ± 7.7 [mean ± SD], 95% CI [8.32-12.71], p < 0.001) and depressive (Beck Depression Inventory-II: 11.4 ± 7.7 [9.22-13.62], p = 0.001) symptoms compared with the normative population. Both sleep problems (Pittsburgh Sleep Quality Index: 5.8 ± 3.0 [4.98-6.66], p < 0.001) and motor and cognitive fatigue (Fatigue Scale for Motor and Cognitive Function: 50.5 ± 23.1 [42.5-58.4], p < 0.001) were significantly more prevalent. Moreover, lower self-rated memory ability (Multifactorial Memory Questionnaire score: 54.6 ± 8.5 [52.1-57.1], p = 0.004) was associated with greater reliance on compensatory strategies and memory aids (r = -0.41, p = 0.004). Patients used significantly fewer cognitive coping strategies, such as relativization (11.7 ± 4.7 [10.3-13.1], p = 0.001), while depressive coping prevailed (49.1 ± 15.5 [44.5-53.8], p < 0.001). It is important to note that HRQoL was predicted by self-reported affective symptoms, self-efficacy, and coping behaviors in multivariable regression analyses, but not by acute disease severity or postacute physical disability.

DISCUSSION

Our findings show that persistent neuropsychiatric and subjective cognitive concerns explain a large part of the reduced quality of life in patients with NMDAR encephalitis. These findings have important implications for a patient-centered postacute care and the role of disease coping strategies in the neurorehabilitation of autoimmune encephalitis.

Voltage Gated Ion Channels and Sleep

Ion channels are integral components of the nervous system, playing a pivotal role in shaping membrane potential, neuronal excitability, synaptic transmission and plasticity. Dysfunction in these channels, such as improper expression or localization, can lead to irregular neuronal excitability and synaptic communication, which may manifest as various behavioral abnormalities, including disrupted rest-activity cycles. Research has highlighted the significant impact of voltage gated ion channels on sleep parameters, influencing sleep latency, duration and waveforms. Furthermore, these ion channels have been implicated in the vulnerability to, and the pathogenesis of, several neurological and psychiatric disorders, including epilepsy, autism, schizophrenia, and Alzheimer's disease (AD). In this comprehensive review, we aim to provide a summary of the regulatory role of three predominant types of voltage-gated ion channels-calcium (Ca2+), sodium (Na+), and potassium (K+)-in sleep across species, from flies to mammals. We will also discuss the association of sleep disorders with various human diseases that may arise from the dysfunction of these ion channels, thereby underscoring the potential therapeutic benefits of targeting specific ion channel subtypes for sleep disturbance treatment.

Sleep Disturbances in Autoimmune Neurological Diseases: Mechanisms, Clinical Characteristics, Assessment, and Treatment Strategies

PURPOSE OF REVIEW

Sleep disturbances are a hallmark feature of various autoimmune neurological diseases (AINDs). However, limited awareness of these sleep manifestations exists among clinicians. We provide a comprehensive overview of assessment methods, characteristic sleep disturbances, the impact of specific antibodies on sleep patterns, and treatment strategies for sleep disturbances in AINDs.

RECENT FINDINGS

Research advancements in sleep disturbances in autoimmune neurological disease focus primarily on four areas: mechanisms, clinical characteristics, assessment, and treatment. Regarding mechanisms, animal models for AINDs, particularly those involving specific antibodies like anti-NMDAR, anti-LGI1, and anti-IgLON5, have become more comprehensive. Recent advancements in animal models have led to the establishment of numerous models for AINDs; these models include a wide range of antibodies, including anti-NMDAR, anti-LGI1, and anti-IgLON5. Several studies using these models have revealed common mechanisms underlying sleep disturbances in these diseases. In terms of clinical characteristics, the identification of antibodies associated with recently discovered AINDs has expanded the spectrum of sleep disturbance symptoms observed compared to prior findings. A comprehensive evaluation system for the assessment of sleep disturbances has been established, including questionnaires, polysomnography, functional magnetic resonance imaging, and 18F-FDG PET/CT. Additionally, cardiopulmonary coupling shows promise as a novel assessment tool. Currently, no universally effective treatment exists for sleep disturbances in autoimmune neurological diseases, either through symptomatic treatment or immunosuppressive therapy. Further studies are needed to confirm the efficacy of new therapies and validate the benefits of existing treatments. Sleep disturbances are a hallmark feature of AINDs. Recent advancements have significantly expanded our understanding of their assessment and treatment. However, further studies are needed to address the remaining uncertainties in sleep disturbance management.

Distinctive sleep complaints and polysomnographic findings in antibody subgroups of autoimmune limbic encephalitis

INTRODUCTION

Sleep disturbances are being increasingly recognized in association with autoimmune encephalitis (AIE). We investigated the prevalence of sleep-related symptoms and polysomnographic features of patients with AIE and the long-term outcomes in these patients in a multi-center, prospective study from Turkey.

METHODS

We prospectively evaluated patients with definite AIE in a common database including demographics, AIE-related and sleep-related symptomatology. Maximum and latest modified Rankin scores (mRS) and Liverpool Outcome Score (LOS) were noted.

RESULTS

Of 142 patients, 87 patients (61.3%) fulfilled the criteria for definite AIE (mean age, 46.8+18.8 years; 51.7% women; mean disease duration, 21.0+38.4 months). 78.9% of patients had at least one or more new onset or worsened sleep-related symptomatology: insomnia (55.3%), excessive daytime sleepiness (EDS, 28.0%), sleep apnea (18.7%), REM sleep behavior disorder (RBD, 17.3%), restless legs syndrome (10.7%) and oneiric stupor (9.3%). Sleep efficiency, N3 and REM sleep were decreased and N1 sleep was increased in patients with Ab[+] AIE. LOS points were highest in those with insomnia and sleep apnea, and lowest in those with EDS, RBD and oneiric stupor. RBD and sleep apnea were more common in anti-LG1 Ab[+] group than anti-NMDAR Ab[+] group. Index of periodic leg movements was highest in anti-LG1 Ab[+] group. Patients with EDS and oneiric stupor had more common memory problems. Maximum and latest mRS scores were positively correlated with EDS and oneiric stupor. EDS, RBD and oneiric stupor were negatively correlated with LOS points.

CONCLUSION

Our study emphasizes the presence and importance of early diagnosis of sleep disturbances in AIE in regard to their deteriorative influences on disease prognosis.

Anti-dopamine receptor 2 antibody encephalitis in adults: a case report

BACKGROUND

Anti-dopamine receptor 2 (D2R) antibody encephalitis (D2R encephalitis) is a subtype of autoimmune encephalitis (AE). Lesions in affected patients primarily involve the basal ganglia, resulting in a range of psychiatric and movement disorders. A majority of cases reported to date have impacted children or adolescents, whereas we here describe a case of adult-onset D2R encephalitis.

CASE PRESENTATION

A 30-year-old female patient affected by insomnia, recent memory impairment, bradykinesia, decreased responsivity, increased muscular tone of the extremities, and involuntary shaking of the right limb. Magnetic resonance imaging (MRI) of the basal ganglia did not reveal any notable findings, and both serum and cerebrospinal fluid were positive for antibodies specific for D2R. D2R encephalitis was diagnosed following the exclusion of other diseases. The patient's symptoms improved significantly with immunotherapeutic treatment, and she recovered fully over a 6-month follow-up period.

CONCLUSIONS

D2R is a new form of AE that can develop in adults and can be effectively treated via immunotherapy.

The relationship between sleep and innate immunity

Sleep regulates inflammatory responses, and the innate immune system affects sleep. Interleukin-1 beta, tumor necrosis factor alpha, growth hormone-releasing hormone, prolactin, and nitric oxide are somnogenic substances. Sleep deprivation, such as chronic insomnia or obstructive sleep apnea, affects cytokine production, glial function, natural killer cell activity, and inflammasome function. This review will discuss the relationship between sleep and innate immunity.

REM and NREM Sleep Parasomnia in Anti-NMDA Receptor Encephalitis

OBJECTIVES

Encephalitis with anti-N-methyl-d-aspartate receptor antibodies (anti-NMDARe) is a rare disorder characterized by cognitive impairment, psychosis, seizures, and abnormal movements. Abnormal behaviors during REM sleep have not been described in anti-NMDARe.

METHODS

Patients were monitored by video-polysomnography on a first night followed by multiple sleep latency tests and 18 hours of bed rest.

RESULTS

Two patients with anti-NMDARe developed during the acute and postacute phase parasomnias including REM sleep behavior disorder and continuous finalistic quiet gesturing during a mixed N2/R sleep. The parasomnia disorder was improved by gabapentin and clonazepam.

DISCUSSION

Video-polysomnography avoids misdiagnosing these parasomnia behaviors for seizure or movement disorders and allows adequate treatment.

Potential vicious cycle between postoperative pain and sleep disorders: A bibliometric analysis

Background

Surgical pain affects postoperative sleep quality, and they jointly form a vicious cycle of mutual influence. The cycle of postoperative pain and sleep disorders could lead to delirium, cardiovascular disease, and hyperalgesia, which significantly affect patients' postoperative recovery. Thus, exploring this phenomenon is of great importance for surgical patients, and warrants further investigation.

Objective

By employing bibliometric methods, this study systematically analyzes the publications on postoperative pain-sleep disorders, identifies research trends and field dynamics, and ultimately provides insights for further progress in this research area.

Methods

In this study, we searched the Web of Science database for studies on postoperative pain and sleep disorders from 2013 to 2023, and analyzed the number of publications, journals, authors, institutions, country regions, and keywords by utilizing CiteSpace, VOSviewer, and Bibliometrix.

Results

The 1894 retrieved publications showed a trend of increasing number of publications and correlations between postoperative pain and sleep disorders from 2013 to 2023. The top countries for publications included the USA, China, etc., establishing a global collaborative network centered around the USA, China, and Europe. The top institutions for publications included University of California System, Harvard University, etc. The top authors include Christine Miaskowski, Steven M. Paul, Qiuling Shi, etc. These publications involved multiple disciplines including surgery, neurology, and anesthesiology, and various research funds including NIH, HHS, NSFC, etc. The top journals for publications included the European Archives of Oto-Rhino-Laryngology, etc. Keywords that appear most frequently in this field include "pain", "surgery", "quality of life", "sleep", "depression", and "outcomes". The thematic map indicated that the hot topics in this area include obstructive sleep apnea, tonsillectomy, children, pain, quality of life, and sleep. The undeveloped topics with research potential included postoperative pain, analgesia and dexmedetomidine, breast cancer, fatigue, and lung cancer.

Conclusion

The increased number of publications and correlations between postoperative pain and sleep disorders, and the collaborative network across the USA, China, and Europe indicate a growing global interest in this area. This study also provides valuable insights into the trend of hot topics and frontiers and shows that this is an evolving and dynamic research area.

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.

Interior decorative volatile organic compounds exposure induces sleep disorders through aberrant branched chain amino acid transaminase 2 mediated glutamatergic signaling resulting from a neuroinflammatory cascade

Air pollution has been recognized as a contributing factor to sleep disorders (SD), which have been correlated with an elevated susceptibility to a variety of human diseases. Nevertheless, research has not definitively established a connection between SD and interior decorative volatile organic compounds (ID-VOCs), a significant indoor air pollutant. In this study, we employed a mouse model exposed to ID-VOCs to explore the impacts of ID-VOCs exposure on sleep patterns and the potential underlying mechanism. Of the 23 key compositions of ID-VOCs identified, aromatic hydrocarbons were found to be the most prevalent. Exposure to ID-VOCs in mice resulted in SD, characterized by prolonged wake fullness and decreased sleep during the light period. ID-VOCs exposure triggered neuroinflammatory responses in the suprachiasmatic nucleus (SCN), with microglia activation leading to the overproduction of inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1α (IL-1α), and complement component 1q (C1q), ultimately inducing A1 astrocytes. Consequently, the upregulation of branched chain amino acid transaminase 2 (BCAT2) in A1 astrocytes resulted in elevated extracellular glutamate and disruption of the wake-sleep transition mechanism, which might be the toxicological mechanism of SD caused by ID-VOCs.

Sleep and neuroimmunology: a narrative review

Numerous neuroimmunological disorders present with sleep-related symptoms. The identification of novel autoantibodies introduces new clinical categories in autoimmune diseases of the central nervous system and generates interest in the dynamic interaction between sleep and the immune system. In this review, the complex relationship among sleep, immune regulation, and neuroimmunological disorders was examined with emphasis on the vital role of sleep in modulating immune function and its influence on these conditions, This relationship emphasizes the importance of assessments and management of sleep quality in the treatment approaches for neuroimmunological disorders.

Development of a Composite Score for the Clinical Assessment of Anti-IgLON5 Disease

BACKGROUND AND OBJECTIVES

To develop a composite score to assess the severity of the multiple symptoms present in anti-IgLON5 disease.

METHODS

The anti-IgLON5 disease composite score (ICS) was designed to evaluate 17 symptoms divided into 5 clinical domains (bulbar, sleep, movement disorders, cognition, and others). Each symptom was scored from 0 (absent/normal) to 3 or 6 (severe) depending on the contribution of the symptom to neurologic disability with a maximum ICS of 69. The ICS was tested in patients from 2 cohorts (Barcelona, Spain, and GENERATE, Germany) that included cases personally seen by the authors (internal) and patients whose ICS was obtained from information of questionnaires completed by the referring neurologists (external). Test-retest and interrater reliabilities of the ICS were assessed by the intraclass coefficient (ICC) and the correlation between the ICS and modified Rankin scale (mRS) with the nonparametric Spearman rank coefficient. The Wilcoxon signed rank test was used to compare the ICS at diagnosis of anti-IgLON5 disease and follow-up in a subset of patients with available clinical information.

RESULTS

A total of 86 patients (46 from Barcelona cohort; 40 from GENERATE cohort) were included. The median ICS was 15 (range 2-31). The ICS was higher in the Barcelona cohort than in the German cohort (18 vs 12, p < 0.001), due to higher partial scores in sleep and movement disorder domains. There were no significant differences in the ICS between internal and external patients (15 vs 14, p = 0.96). The ICS correlated with the mRS score (r = 0.429, p < 0.001). Test-retest and interrater reliabilities were excellent with an ICC of 0.997 (95% CI 0.992-0.999) and 0.973 (95% CI 0.925-0.990), respectively. ICS was retested during follow-up in 27 patients, and it was similar to that at diagnosis in 10 clinically stable patients (median ICS at diagnosis 11.5 vs 11.5 at follow-up; p = 1), higher in 8 patients who worsened (12.5 vs 18; p = 0.012), and lower in 9 patients who improved after immunotherapy (14 vs 10; p = 0.007).

DISCUSSION

The ICS is a valid method to assess the extension and severity of the different clinical manifestations of anti-IgLON5 disease.

The relevance of anti-N-methyl-D-aspartate receptor encephalitis for psychiatrists

Psychiatrists are often the first to be consulted in patients with anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. While this disease is rare, psychiatrists need to be aware of its relevant fundamental, clinical and therapeutic aspects. We begin by reviewing the connection between anti-NMDAR encephalitis and the glutamate hypothesis of schizophrenia. Next, we focus on the profile of the patient typically afflicted with this disease. Then, we tackle the limited utility of current diagnostic criteria during the early stage of the disease. After reviewing the psychiatric features, we debate the quest for finding specific psychiatric phenotypes that could facilitate early-stage diagnosis. We conclude by discussing the treatment of psychiatric symptoms and disease outcomes. As follows, this paper presents the relevance of anti-NMDAR encephalitis for psychiatrists.

Neurological, psychiatric, and sleep investigations after treatment of anti-leucine-rich glioma-inactivated protein 1 (LGI1) encephalitis in Spain: a prospective cohort study

BACKGROUND

Anti-leucine-rich glioma-inactivated protein 1 (LGI1) encephalitis is an autoimmune disorder that can be treated with immunotherapy, but the symptoms that remain after treatment have not been well described. We aimed to characterise the clinical features of patients with anti-LGI1 encephalitis for 1 year starting within the first year after initial immunotherapy.

METHODS

For this prospective cohort study, we recruited patients with anti-LGI1 encephalitis as soon as possible after they had received conventional immunotherapy for initial symptoms; patients were recruited from 21 hospitals in Spain. Patients were excluded if they had an interval of more than 1 year since initial immunotherapy, had pre-existing neurodegenerative or psychiatric disorders, or were unable to travel to Hospital Clínic de Barcelona (Barcelona, Spain). Patients visited Hospital Clínic de Barcelona on three occasions-the first at study entry (visit 1), the second 6 months later (visit 2), and the third 12 months after the initial visit (visit 3). They underwent neuropsychiatric and videopolysomnography assessments at each visit. Healthy participants who were matched for age and sex and recruited from Hospital Clínic de Barcelona underwent the same investigations at study entry and at 12 months. Cross-sectional comparisons of clinical features between groups were done with conditional logistic regression, and binary logistic regression was used to assess associations between cognitive outcomes at 12 months and clinical features before initial immunotherapy and at study entry.

FINDINGS

Between May 1, 2019, and Sept 30, 2022, 42 participants agreed to be included in this study. 24 (57%) participants had anti-LGI1 encephalitis (mean age 63 years [SD 12]; 13 [54%] were female and 11 [46%] were male) and 18 (43%) were healthy individuals (mean age 62 years [10]; 11 [61%] were female and seven [39%] were male). At visit 1 (median 88 days [IQR 67-155] from initiation of immunotherapy), all 24 patients had one or more symptoms; 20 (83%) patients had cognitive deficits, 20 (83%) had psychiatric symptoms, 14 (58%) had insomnia, 12 (50%) had rapid eye movement (REM)-sleep behaviour disorder, nine (38%) had faciobrachial dystonic seizures, and seven (29%) had focal onset seizures. Faciobrachial dystonic seizures were unnoticed in four (17%) of 24 patients and focal onset seizures were unnoticed in five (21%) patients. At visit 1, videopolysomnography showed that 19 (79%) patients, but no healthy participants, had disrupted sleep structure (p=0·013); 15 (63%) patients and four (22%) healthy participants had excessive fragmentary myoclonus (p=0·039), and nine (38%) patients, but no healthy participants, had myokymic discharges (p=0·0051). These clinical and videopolysomnographic features led to additional immunotherapy in 15 (63%) of 24 patients, which resulted in improvement of these features in all 15 individuals. However, at visit 3, 13 (65%) of 20 patients continued to have cognitive deficits. Persistent cognitive deficits at visit 3 were associated with no use of rituximab before visit 1 (odds ratio [OR] 4·0, 95% CI 1·5-10·7; p=0·0015), REM sleep without atonia at visit 1 (2·2, 1·2-4·2; p=0·043), and presence of LGI1 antibodies in serum at visit 1 (11·0, 1·1-106·4; p=0·038).

INTERPRETATION

Unsuspected but ongoing clinical and videopolysomnography alterations are common in patients with anti-LGI1 encephalitis during the first year or more after initial immunotherapy. Recognising these alterations is important as they are treatable, can be used as outcome measures in clinical trials, and might influence cognitive outcome.

FUNDING

Fundació La Caixa.

Analysis of the correlation between immune cell characteristics and insomnia: a Mendelian randomization study

Insomnia, recognized as a prevalent sleep disorder, has garnered extensive attention within the realm of public health. Recent studies indicate a close interaction between the immune system and sleep; however, the specific mechanism remains not yet fully understood. Based on the publicly available Genome-Wide Association Study (GWAS) data, we used two-sample Mendelian randomization (MR) analyses to investigate the associations between 731 immune cell traits and insomnia risk. Five MR analysis methods and a comprehensive sensitivity analysis were used to evaluate the reliability of the results. In this study, we identified that 14 immune characteristics among four immune profiles [median fluorescence intensity (MFI), relative cell count (RC), absolute cell count (AC), and morphological parameters (MP)] demonstrated a significant causal association with insomnia. Specifically, eight immune cell characteristics were associated with an increased risk of insomnia, including CD11c+ monocyte% (P < 0.001), CD11c+ HLA DR++ monocyte% (P = 0.004), CD86+ plasmoid dendritic cell (DC) AC (P < 0.001), CD33br HLA DR+ CD14dim AC (P < 0.001), CD8dim AC (P = 0.002), CCR2 on CD14+ CD16- monocyte (P < 0.001), CD39 on monocyte (P < 0.001), and SSC-A on myeloid DC (P < 0.001). Six immune cell characteristics demonstrated protective effects against insomnia, including PB/PC %B cell (P < 0.001), CM CD4+% CD4+ (P < 0.001), T-cell AC (P < 0.001), BAFF-R on IgD- CD38br (P < 0.001), CD16-CD56 on HLA DR+ NK cells (P < 0.001), and CD14 on CD33br HLA DR+ CD14dim (P < 0.001). Our study established the correlation between immune cell characteristics and insomnia, offering a novel theoretical foundation for the concept of sleep-immune cross talk.NEW & NOTEWORTHY This study investigated the association between 731 immune cell characteristics and insomnia using Mendelian randomization, revealing that 14 immune cell characteristics across four groups of immune traits (MFI, RC, AC, and MP) have a significant and causal association with insomnia risk. Our results contribute to the understanding of the sleep-immune cross talk doctrine and offer a new theoretical basis for immune modulation in treating insomnia.

Hypersomnia in anti-glutamic acid decarboxylase 65 (GAD65) associated neurological syndromes: A pilot study

BACKGROUND AND PURPOSE

Despite their detrimental impact on the quality of life in autoimmune encephalitis, sleep disorders have not been investigated in anti-glutamic acid decarboxylase (GAD65) associated neurological syndromes.

METHODS

Six consecutive adult patients diagnosed with anti-GAD65-associated neurological syndromes (four with limbic encephalitis and two with stiff-person syndrome) and 12 healthy controls were enrolled. Participants underwent sleep interviews and sleep studies including night-time video-polysomnography, followed by five daytime multiple sleep latency tests (MSLTs, to assess propensity to fall asleep) and an 18 h bed rest polysomnography (to assess excessive sleep need).

RESULTS

Patients reported the need for daily naps and that their cognition and quality of life were altered by sleepiness, but they had normal scores on the Epworth sleepiness scale. Compared with controls, sleep latencies during the MSLT were shorter in the patient group (median 5.8 min, interquartile range [IQR] 4.5, 6.0 vs. 17.7 min, IQR 16.3, 19.7, p = 0.001), and the arousal index was reduced (2.5/h, IQR 2.3, 3.0 vs. 22.3/h, IQR 13.8, 30.0, p = 0.002), although total sleep time was similar between groups (621 min, IQR 464, 651 vs. 542.5 min, IQR 499, 582, p = 0.51). Remarkably, all six patients had MSLT latencies ≤8 min, indicating severe sleepiness. No parasomnia or sleep-disordered breathing was detected.

CONCLUSION

Central hypersomnia is a relevant characteristic of anti-GAD65-associated neurological syndromes.

Back to the future: encephalitis lethargica as an autoimmune disorder?

More than 100 years after its emergence, the exact pathophysiological mechanisms underlying encephalitis lethargica (EL) are still elusive and awaiting convincing and complete elucidation. This article summarizes arguments proposed over time to support or refute the hypothesis of EL as an autoimmune neuropsychiatric disorder triggered by an infectious process. It also provides a critical evaluation of modern cases labeled as EL and a comprehensive differential diagnosis of autoimmune neurological conditions that could mimic EL. The evidence supporting the autoimmune nature of historical EL is sparse and not entirely convincing. It is possible that autoimmune mechanisms were involved in the pathogenesis of this disease as an idiosyncratic response to a yet unidentified infectious agent in genetically predisposed individuals. Although there has been an increase in the incidence of presumed autoimmune encephalomyelitis since the peak of EL pandemics, most evidence does not support an underlying autoimmune mechanism. There are significant differences between historical and recent EL cases in terms of clinical symptomatology, epidemiology, and neuropathological features, suggesting that they are different entities with only superficial similarity. The term "encephalitis lethargica," still frequently used in the medical literature, should not be used for cases occurring at present in the sporadic form. Historical EL should be kept apart from recent EL, as they differ in important aspects.

Paraneoplastic neurologic syndrome and autoantibody accompaniments of germ cell tumors

Paraneoplastic neurologic syndromes (PNSs) are a group of diseases affecting the central and/or peripheral nervous system caused by immune-mediated processes directed toward antigens with shared expression in tumor and neural tissue. Germ cell tumors (GCTs) are associated with PNSs with varied clinical phenotypes. Early diagnosis of PNS is vital to potentially uncover and treat underlying tumors, improving the chances of recovery, and preventing permanent neurologic complications. In this chapter, we outline the pathophysiology and epidemiology of PNS. We briefly provide a summary of GCTs in males and females. We review the neural-specific autoantibodies and PNSs associated with GCTs and their clinical and radiologic accompaniments. We also provide an overview of the treatment and prognosis of these disorders.

Sleep Disturbances in Autoimmune Neurological Diseases

PURPOSE OF REVIEW

To summarize the current evidence on the associations between autoimmune neurological diseases (e.g., multiple sclerosis, myasthenia gravis) and sleep disturbances (e.g., insomnia, parasomnias), as well as to review the main characteristics of sleep disorders with an immune-related pathophysiology (e.g., narcolepsy, anti-IgLON5 disease).

RECENT FINDINGS

An immune-mediated damage of the areas in the central nervous system that control sleep and wake functions (e.g., hypothalamus, brainstem) can lead to sleep disorders and sleep symptoms. Sleep disturbances are the reason to seek for medical attention in certain neuroimmunological conditions (e.g., narcolepsy, anti-IgLON5 disease) where sleep-related alterations are the main clinical feature. The assessment of sleep-related symptomatology and disorders should be included in the routine evaluation of patients with autoimmune neurological diseases. Clinicians should be aware of the typical clinical presentation of certain neuroimmunological disorders mainly affecting sleep.

A small mature cystic ovarian teratoma associated with anti-NMDA receptor encephalitis and acute respiratory failure: A case report

OBJECTIVE

To report a rare case of anti-N-Methyl-d-aspartate receptor encephalitis (anti-NMDARE) presented by mental and behavioral changes and seizures accompanied with respiratory failure.

CASE REPORT

A 37-year-old multiparous woman was initially presented with abnormal mental behavior and the diagnosis of schizophrenia was made, but the disease progressed rapidly to general convulsion and acute respiratory failure. Although active treatment, including steroids, intravenous immunoglobulins (IVIGs) and plasma exchange was applied, no significant improvement was obtained. Transvaginal ultrasound and pelvic magnetic resonance image (MRI) were arranged and the results showed a suspicious cystic lesion (3 × 2.3 cm) at the right ovary. Laparoscopic unilateral salpingo-oophorectomy was performed and final pathology reported a matured cystic teratoma, suggesting that this patient had anti-NMDARE secondary to ovarian mature teratoma. After surgery, the clinical condition was dramatically improved and she recovered completely without sequelae.

CONCLUSION

Although it is well-known about the relation between anti-NMDARE and ovarian mature teratoma, this small tumor may result in the missing diagnosis. Remind us to consider the possibility of any small ovarian cystic lesion-related anti-NMDARE in women with autoimmune encephalitis.

Clinical features and brain MRI volumetric changes in anti-mGluR5 encephalitis

BACKGROUND

Anti-metabotropic glutamate receptor 5 (mGluR5) encephalitis is a rare and under-recognized autoimmune encephalitis. This study is conducted to characterize its clinical and neuroimaging features.

METHODS

Twenty-nine patients with anti-mGluR5 encephalitis (15 new cases identified in this study and 14 previously reported cases) were included in this study and their clinical features were characterized. Brain MRI volumetric analysis using FreeSurfer software was performed in 9 new patients and compared with 25 healthy controls at both early (≤6 months of onset) and chronic (>1 year of onset) disease stages.

RESULTS

The common clinical manifestations of anti-mGluR5 encephalitis included cognitive deficits (n = 21, 72.4%), behavioral and mood disturbances (n = 20, 69%), seizures (n = 16, 55.2%), and sleep disorder (n = 13, 44.8%). Tumors were observed in 7 patients. Brain MRI T2/FLAIR signal hyperintensities were observed predominantly in mesiotemporal and subcortical regions in 75.9% patients. MRI volumetric analysis demonstrated significant amygdala enlargement in both early and chronic disease stages compared to healthy controls (P < 0.001). Twenty-six patients had complete or partial recovery, one remained stable, one died and one was lost to follow-up.

CONCLUSION

Our findings demonstrated that cognitive impairment, behavioral disturbance, seizures, and sleep disorder are the prominent clinical manifestations of anti-mGluR5 encephalitis. Most patients showed a good prognosis with full recovery, even in the paraneoplastic disease variants. The amygdala enlargement in the early and chronic disease stages is a distinct MRI feature, which exploratively offer a valuable perspective for the study of the disease processes.

Encephalitis: diagnosis, management and recent advances in the field of encephalitides

Encephalitis describes inflammation of the brain parenchyma, typically caused by either an infectious agent or through an autoimmune process which may be postinfectious, paraneoplastic or idiopathic. Patients can present with a combination of fever, alterations in behaviour, personality, cognition and consciousness. They may also exhibit focal neurological deficits, seizures, movement disorders and/or autonomic instability. However, it can sometimes present non-specifically, and this combined with its many causes make it a difficult to manage neurological syndrome. Despite improved treatments in some forms of encephalitides, encephalitis remains a global concern due to its high mortality and morbidity. Prompt diagnosis and administration of specific and supportive management options can lead to better outcomes. Over the last decade, research in encephalitis has led to marked developments in the understanding, diagnosis and management of encephalitis. In parallel, the number of autoimmune encephalitis syndromes has rapidly expanded and clinically characteristic syndromes in association with pathogenic autoantibodies have been defined. By focusing on findings presented at the Encephalitis Society's conference in December 2021, this article reviews the causes, clinical manifestations and management of encephalitis and integrate recent advances and challenges of research into encephalitis.

Idiopathic autoimmune encephalitis with a recurrent course. A case report

We presented a clinical case of idiopathic autoimmune brainstem encephalitis in a 12-year-old female patient. At the onset of the disease, which developed after a respiratory infection, the clinical picture was accompanied by oculomotor and bulbar syndromes. The diagnosis of Bickerstaff brainstem encephalitis was made based on clinical diagnostic criteria and the positive effect of the course of intravenous immunoglobulin therapy. During 3 years of follow-up, there were periods of relapse of the disease, during which symptoms not typical for Bickerstaff stem encephalitis appeared. Against the background of long-term immunosuppressive therapy, there was a long-term remission of about 2 years. The clinical picture, the presence of relapses, the data of additional methods forced to reconsider the diagnosis in favor of idiopathic autoimmune brainstem encephalitis.

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

AIMS

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Sleep disorders and polysomnography findings in patients with autoimmune encephalitis

BACKGROUND

Sleep disorders in patients with autoimmune encephalitis (AE) are increasingly reported. Early recognition and treatment have significant importance regarding the potential of sleep disorders' effect on morbidity and even mortality. There are a limited number of studies related to polysomnography (PSG) in these patients. Here, we report the clinical and PSG data of patients with AE and sleep disorders, with a particular interest in sleep-related breathing disorders (SRBD).

METHODS

Seventeen patients with diagnosed AE and acute or subacute onset sleep complaints who underwent video-electroencephalography-PSG recordings in our tertiary center were investigated.

RESULTS

The mean age was 50, with eight females and nine males. The detected antibodies were against leucine-rich glioma-inactivated 1(LGI-1) in 6, anti-contactin-associated protein-2(CASPR2) in 3, voltage-gated potassium channel complex antigens(VGKC) in 1, anti-glycine in 1, dipeptidyl-peptidase-like protein-6(DPPX) in 1, anti-Hu in 1, and anti-amphiphysin in 1. All commercially available and known autoimmune encephalitis-related antibodies were negative in 3 of the patients. Final diagnosis after PSG was circadian rhythm sleep disorder (n = 3), periodic limb movement disorder (n = 3), insomnia (n = 5), central apnea with or without Cheyne-Stokes breathing (CSB) (n = 4), obstructive sleep apnea (OSA) (n = 4), non-rapid eye movement (NREM) and REM parasomnia (n = 8), faciobrachial dystonic seizures (n = 2), and subclinical seizures (n = 1). Sleep microstructure was disrupted in 9, REM periods without atonia occurred in 4, and brief sleep fragments consisting of theta activity interspersed with faster rhythms existed in 7 patients. Nearly half of our patients (47%) had SRBD, and the mean apnea-hypopnea index (AHI) was 14.

CONCLUSIONS

Sleep disorders are frequent and essential components of AEs. Systematic clinical questionnaires and routine PSG assessments would significantly impact the correct diagnosis and proper treatment of SRBD and the overall prognosis of AE.

Anti-leucine-rich glioma inactivated protein 1 encephalitis with sleep disturbance as the first symptom: A case report and review of literature

BACKGROUND

Anti-leucine-rich glioma inactivated protein 1 (anti-LGI1) encephalitis is an infrequent type of autoimmune encephalitis (AE) characterized by acute or subacute cognitive and psychiatric disturbance, facio-brachial dystonic seizures (FBDSs), and hyponatremia. Anti-LGI1 AE has increasingly been considered a primary form of AE. Early identification and treatment of this disease are clearly very important.

CASE SUMMARY

Here, we report that a male patient developed severe anti-LGI1 encephalitis, which was initially misdiagnosed as a sleep disturbance. He was hospitalized for epileptic seizures and typical FBDSs half a month after he developed sleep disturbances. LGI1 antibodies were detected in his cerebrospinal fluid and serum (1:100 and 1:3.2, respectively), which led to the diagnosis of classic anti-LGI1 AE. No obvious abnormality was observed on brain computed tomography images. T2-weighted fluid-attenuated inversion recovery and T2-weighted scans of brain magnetic resonance imaging (MRI) showed slightly elevated signals within the left basal ganglia area. No tumor was detected within the brain of this patient using MRI. After hormone and antiepileptic drug treatment, the patient’s symptoms improved significantly.

CONCLUSION

Anti-LGI1 antibody-associated encephalitis has characteristic clinical manifestations, such as cognitive impairment, psychiatric symptoms, seizures, sleep disorders, hyponatremia, and FBDSs. LGI1 antibodies are present in the serum and/or cerebrospinal fluid, but their production is sensitive to immunosuppressants, and this disease has a relatively good prognosis. In particular, we should be aware of the possibility of anti-LGI1 antibody-associated encephalitis in adolescents with sleep disorders to avoid missed diagnoses and misdiagnoses.

PSYCHIATRIC DISORDERS IN AUTOIMMUNE ENCEPHALITIS - LITERATURE REVIEW

Autoimmune encephalitis (AE) is a non-infectious inflammatory disease caused by the presence of autoantibodies directed against neuronal surface or intracellular antigens. Its incidence in Western countries is about 0.8 per 100,000 people. AE requires differentiation primarily with psychiatric diseases, but it also requires oncological vigilance. On the other hand, in the case of an acute episode of psychosis, differentiation with AE should always be pursued. This paper discusses the most common psychiatric disorders that occur in autoimmune encephalitis.

Sleep disturbances in autoimmune encephalitis

Autoimmune encephalitis is an inflammatory neurological disorder characterized by psychiatric symptoms, cognitive impairment, and focal neurological deficits or seizures. Sleep disturbances are not a major consideration in the diagnosis and treatment of patients with autoimmune encephalitis. Various types of sleep disturbances are frequent, severe, and long-lasting, which can compromise the recovery and quality of life in patients with autoimmune encephalitis. Sleep disorders in patients with autoimmune encephalitis have received limited attention, and the prevalence and pathophysiological mechanisms of sleep disorders remain unclear. Recent studies have suggested that early recognition of specific sleep disturbances may provide clues for diagnosing autoimmune encephalitis. Furthermore, early diagnosis and treatment of sleep disturbances can promote recovery and improve long-term outcomes in patients with autoimmune encephalitis. In this report, we aimed to provide a comprehensive and extensive understanding of the clinical relevance of autoimmune encephalitis and specific related sleep disorders.

Sleep architecture and sleep-disordered breathing in fatal insomnia

STUDY OBJECTIVES

Fatal insomnia (FI) is a rare prion disease severely affecting sleep architecture. Breathing during sleep has not been systematically assessed. Our aim was to characterize the sleep architecture, respiratory patterns, and neuropathologic findings in FI.

METHODS

Eleven consecutive FI patients (ten familial, one sporadic) were examined with video-polysomnography (vPSG) between 2002 and 2017. Wake/sleep stages and respiration were evaluated using a modified scoring system. Postmortem neuropathology was assessed in seven patients.

RESULTS

Median age at onset was 48 years and survival after vPSG was 1 year. All patients had different combinations of breathing disturbances including increased respiratory rate variability (RRV; n = 7), stridor (n = 9), central sleep apnea (CSA) (n = 5), hiccup (n = 6), catathrenia (n = 7), and other expiratory sounds (n = 10). RRV in NREM sleep correlated with ambiguous and solitary nuclei degeneration (r = 0.9, p = 0.008) and reduced survival (r = -0.7, p = 0.037). Two new stages, Subwake1 and Subwake2, present in all patients, were characterized. NREM sleep (conventional or undifferentiated) was identifiable in ten patients but reduced in duration in eight. REM sleep occurred in short segments in nine patients, and their reduced duration correlated with medullary raphe nuclei degeneration (r = -0.9, p = 0.005). Seven patients had REM without atonia. Three vPSG patterns were identified: agitated, with aperiodic, manipulative, and finalistic movements (n = 4); quiet-apneic, with CSA (n = 4); and quiet-non-apneic (n = 3).

CONCLUSIONS

FI patients show frequent breathing alterations, associated with respiratory nuclei damage, and, in addition to NREM sleep distortion, have severe impairment of REM sleep, related with raphe nuclei degeneration. Brainstem impairment is crucial in FI.

Landscape of immune infiltration in entorhinal cortex of patients with Alzheimerʼs disease

Alzheimer’s disease (AD) is one of the most common neurodegenerative diseases and manifests as progressive memory loss and cognitive dysfunction. Neuroinflammation plays an important role in the development of Alzheimer’s disease and anti-inflammatory drugs reduce the risk of the disease. However, the immune microenvironment in the brains of patients with Alzheimer’s disease remains unclear, and the mechanisms by which anti-inflammatory drugs improve Alzheimer’s disease have not been clearly elucidated. This study aimed to provide an overview of the immune cell composition in the entorhinal cortex of patients with Alzheimer’s disease based on the transcriptomes and signature genes of different immune cells and to explore potential therapeutic targets based on the relevance of drug targets. Transcriptomics data from the entorhinal cortex tissue, derived from GSE118553, were used to support our study. We compared the immune-related differentially expressed genes (irDEGs) between patients and controls by using the limma R package. The difference in immune cell composition between patients and controls was detected via the xCell algorithm based on the marker genes in immune cells. The correlation between marker genes and immune cells and the interaction between genes and drug targets were evaluated to explore potential therapeutic target genes and drugs. There were 81 irDEGs between patients and controls that participated in several immune-related pathways. xCell analysis showed that most lymphocyte scores decreased in Alzheimer’s disease, including CD4⁺ Tc, CD4⁺ Te, Th1, natural killer (NK), natural killer T (NKT), pro-B cells, eosinophils, and regulatory T cells, except for Th2 cells. In contrast, most myeloid cell scores increased in patients, except in dendritic cells. They included basophils, mast cells, plasma cells, and macrophages. Correlation analysis suggested that 37 genes were associated with these cells involved in innate immunity, of which eight genes were drug targets. Taken together, these results delineate the profile of the immune components of the entorhinal cortex in Alzheimer’s diseases, providing a new perspective on the development and treatment of Alzheimer’s disease.

What respiratory physicians should know about narcolepsy and other hypersomnias

Narcolepsy and related central disorders of hypersomnolence may present to the sleep clinic with excessive daytime sleepiness. A strong clinical suspicion and awareness of the diagnostic clues, such as cataplexy, are essential to avoid unnecessary diagnostic delay. This review provides an overview of the epidemiology, pathophysiology, clinical features, diagnostic criteria and management of narcolepsy and related disorders, including idiopathic hypersomnia, Kleine-Levin syndrome (recurrent episodic hypersomnia) and secondary central disorders of hypersomnolence.

Inositol 1,4,5-trisphosphate receptor type 1 autoantibody (ITPR1-IgG/anti-Sj)-associated autoimmune cerebellar ataxia, encephalitis and peripheral neuropathy: review of the literature

Background

In 2014, we first described novel autoantibodies to the inositol 1,4,5-trisphosphate receptor type 1 (ITPR1-IgG/anti-Sj) in patients with autoimmune cerebellar ataxia (ACA) in this journal. Here, we provide a review of the available literature on ITPR1-IgG/anti-Sj, covering clinical and paraclinical presentation, tumour association, serological findings, and immunopathogenesis.

Methods

Review of the peer-reviewed and PubMed-listed English language literature on ITPR1-IgG/anti-Sj. In addition, we provide an illustrative report on a new patient with ITPR1-IgG-associated encephalitis with cognitive decline and psychosis.

Results

So far, at least 31 patients with serum ITPR1-IgG/anti-Sj have been identified (clinical information available for 21). The most common manifestations were ACA, encephalopathy with seizures, myelopathy, and (radiculo)neuropathy, including autonomic neuropathy. In 45% of cases, an underlying tumour was present, making the condition a facultative paraneoplastic neurological disorder. The neurological syndrome preceded tumour diagnosis in all but one case. In most cases, immunotherapy had only moderate or no effect. The association of ITPR1-IgG/anti-Sj with manifestations other than ACA is corroborated by the case of a 48-year-old woman with high-titre ITPR1-IgG/anti-Sj antibodies and rapid cognitive decline, affecting memory, attention and executive function, and psychotic manifestations, including hallucinations, investigated here in detail. FDG-PET revealed right-temporal glucose hypermetabolism compatible with limbic encephalitis. Interestingly, ITPR1-IgG/anti-Sj mainly belonged to the IgG2 subclass in both serum and cerebrospinal fluid (CSF) in this and further patients, while it was predominantly IgG1 in other patients, including those with more severe outcome, and remained detectable over the entire course of disease. Immunotherapy with intravenous methylprednisolone, plasma exchange, and intravenous immunoglobulins, was repeatedly followed by partial or complete recovery. Long-term treatment with cyclophosphamide was paralleled by relative stabilization, although the patient noted clinical worsening at the end of each treatment cycle.

Conclusions

The spectrum of neurological manifestations associated with ITPR1 autoimmunity is broader than initially thought. Immunotherapy may be effective in some cases. Studies evaluating the frequency of ITPR1-IgG/anti-Sj in patients with cognitive decline and/or psychosis of unknown aetiology are warranted. Tumour screening is essential in patients presenting with ITPR1-IgG/anti-Sj.

Recognizing New-Onset Sleep Disorders in Autoimmune Encephalitis Often Prompt Earlier Diagnosis

SUMMARY

Sleep/wake disorders are common in patients with autoimmune encephalitis, sometimes the most prominent or sole initial symptom, then delaying diagnosis. Sleep/wake disorders in autoimmune encephalitis vary and include severe sleeplessness, hypersomnia, central and/or obstructive sleep apnea, rapid eye movement sleep behavior disorder, indeterminate sleep/wake states, and loss of circadian sleep/wake rhythms. N-methyl- d aspartate receptor encephalitis (NMDAR) is often associated with insomnia, then hypersomnia and sleep-related central hypoventilation. Profound sleeplessness and rapid eye movement sleep behavior disorder are seen in patients with voltage-gated potassium channel-complex antibodies. Fragmented sleep and hypersomnia are common in paraneoplastic syndromes associated with anti-MA protein encephalitis; rapid eye movement sleep behavior disorder in those with antibodies against leucine-rich glioma inactivated protein (LGI1) or contactin-associated protein 2 (CASPR2) antibodies. Antibodies against a cell adhesion protein IGLON5 may result in obstructive sleep apnea, inspiratory stridor, disorganized nonrapid eye movement sleep, and excessive movements and parasomnias fragmenting nonrapid and rapid eye movement sleep. Recognizing a particular sleep/wake disorder is often a presenting or prominent feature in certain autoimmune encephalitis permit for earlier diagnosis. This is important because reduced morbidity and better short- and long-term outcomes are associated with earlier diagnosis and immunotherapies.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Factors predicting neuronal surface antibodies in the elderly with new-onset and unknown seizures

Objective

To investigate risk factors of neuronal surface antibodies (NSAbs) and develop a nomogram that could identify patients at the odds of NSAbs among the elderly (aged 60 years or older) with new‐onset seizures of unknown etiology.

Methods

Clinical data for aged ≥60 years diagnosed with new‐onset seizures of unknown etiology were retrospectively reviewed. A nomogram based on multivariable logistic regression was constructed. Model performance of nomogram was evaluated using area under the curve (AUC), calibration curve, decision curve analysis (DCA), and clinical impact curve (CIC). Meanwhile, it was internally validated by bootstrap validation in current cohort.

Results

Of 147 patients included in final analysis, 68 (46.3%) had NSAbs‐mediated encephalitis. Six factors were identified: duration of seizures less than 3 months (OR:14.259; 95% CI: 4.480–45.386), focal‐onset seizures (OR:12.457; 95% CI: 2.710–57.261), psychiatric deficits (OR:10.063; 95% CI: 3.231–31.343), sleep disorders (OR:3.091; 95% CI: 1.011–9.454), hyponatremia (OR:6.252; 95% CI: 1.445–27.043), and medial temporal lobe (MTL) lesions on MRI (OR:4.102; 95% CI: 1.382–12.169). The nomogram had a good discrimination with an AUC of 0.916 and with a corrected AUC of 0.881 after the bootstrapping validation, our model also exhibited a better predictive performance than scoring systems commonly used clinically. Additionally, the calibration curve showed that predicted NSAbs‐positive rates of nomogram were closely aligned with actual observed results. Moreover, the nomogram achieved well on clinical utility by using the DCA and CIC.

Interpretation

Our nomogram may provide a convenient and useful tool for identifying the elderly with new‐onset seizures of unknown etiology who are at risk of NSAbs‐mediated encephalitis, which would allow these patients receive earlier immunotherapy.

Anti-LGI1 encephalitis recurring 3 years after the first episode: a case report

Background

Patients with antibodies against leucine-rich glioma-inactivated 1 (LGI1) present with limbic encephalitis, which is clinically characterized by a subacute disturbance of memory and behavior, often experience seizures. Most patients have a monophasic course, often with hyponatremia.

Case presentation

Herein, we report a 67-year-old Japanese male presenting with involuntary neck movement, abnormal behavior and apraxia. He was disoriented to time and place and occasionally unable to follow directions. Laboratory tests revealed the patient had hyponatremia (131 mEq/L). Cerebrospinal fluid (CSF) analysis showed that the cell count (1/μL) and protein content (33 mg/dL) were in the normal ranges. Electroencephalography showed transient theta bursts in the right frontal lobe. Magnetic resonance imaging (MRI) of the brain demonstrated hyperintensities in the medial temporal lobe and basal forebrain on fluid-attenuated inversion recovery (FLAIR) without gadolinium enhancement. Anti-voltage-gated potassium channel (Anti-VGKC) complex antibodies were below the reference level for limbic encephalitis. Although the diagnosis was unknown, intravenous methylprednisolone therapy was effective. Three years later, the patient began to speak incoherently and became disoriented to time. FLAIR MRI of the brain revealed recurrence in the left medial temporal lobe. The patient’s serum sodium level was 131 mEq/L. After intravenous methylprednisolone therapy, he regained alertness. A CSF sample stored at the time of the first attack was assayed and the patient was found to be LGI1-positive and CASPR-2-negative, and the diagnosis of anti-LGI1 encephalitis was made.

Conclusions

Monitoring serum sodium levels and the preserved samples from the first episode were useful for diagnosis.

Understanding and management of anti-N-methyl-D-aspartate receptor encephalitis from a child psychiatry perspective: report of five cases

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a rare autoimmune entity in psychiatry literature that occurs when antibodies attack NMDA-type glutamate receptors in the brain. Principle clinical features include a neurological domain such as seizure, orofacial dyskinesia, dystonia, and choreic-like movements of extremities. Also the psychiatric manifestations of this form of encephalitis may vary from psychotic-like symptoms to mood symptoms like depression or mania. Herein we report on five female child cases diagnosed with anti-NMDAR encephalitis, presented with both neurological and psychiatric clinical picture, and highlight the trajectory of disorder from a psychiatric perspective.

Contemporary advances in antibody-mediated encephalitis: anti-LGI1 and anti-Caspr2 antibody (Ab)-mediated encephalitides

Encephalitides with antibodies directed against leucine-rich glioma-inactivated 1 (LGI1) and contactin-associated protein-like 2 (Caspr2) represent two increasingly well characterised forms of autoimmune encephalitis. Both share overlapping and distinct clinical features, are mediated by autoantibodies directed against differing proteins complexed with voltage-gated potassium channels, with unique genetic predisposition identified to date. Herein we summarise disease mechanisms, clinical features, treatment considerations, prognostic factors and clinical outcomes regarding these disorders.

Clinical Features and Therapeutic Effects of Anti-leucine-rich Glioma Inactivated 1 Encephalitis: A Systematic Review

Background: Clinical presentations and treatment programs about anti-leucine-rich glioma inactivated 1 (LGI1) encephalitis still remain incompletely understood. Objective: This study analyzed the clinical features and therapeutic effects of anti-LGI1 encephalitis. Methods: PubMed, EMBASE, and the Cochrane Library were searched to identify published English and Chinese articles until April 2021. Data were extracted, analyzed, and recorded in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Results: A total of 80 publications detailing 485 subjects matched our inclusion criteria. Short-term memory loss (75.22%), faciobrachial dystonic seizures (FBDS) (52.53%), other seizures excluding FBDS (68.48%), psychiatric symptoms (57.67%), and sleep disturbances (34.30%) were the most frequently described symptoms in anti-LGI1 encephalitis. Hyponatremia (54.90%) was the most common hematologic examination change. The risk of incidence rate of malignant tumors was higher than in healthy people. The positive rate of anti-LGI1 in serum (99.79%) was higher than CSF (77.38%). Steroids (93.02%), IVIG (87.50%), and combined use (96.67%) all had a high remission rate in the initial visit. A total of 35 of 215 cases relapsed, of which 6/35 (17.14%) did not use first-line treatment, and 21 (60.00%) did not maintain long-term treatment. Plasma exchange (PE) could be combined in severe patients, immunosuppressant could be used for refractory patients or for recurrence and using an anti-epileptic drug to control seizures may benefit cognition. Conclusions: Short-term memory loss, FBDS, psychiatric symptoms, and hyponatremia were key features in identifying anti-LGI1 encephalitis. Serum and CSF antibody tests should be considered in diagnosis criteria. Steroids with IVIG should be recommended, PE was combined for use in severe patients, immunosuppressant therapy might improve outcomes if recurrence or progression occurred, and control seizures might benefit cognition. The useful ways to reduce relapse rate were early identification, clear diagnosis, rapid treatment, and maintaining long-term treatment. The follow-up advice was suggested according to the research of paraneoplastic syndrome, and concern about tumors was vital as well.

Contemporary advances in anti-NMDAR antibody (Ab)-mediated encephalitis

The study of antibody (Ab)-mediated encephalitis has advanced dramatically since the discovery of antibodies directed against the N-methyl-D-aspartate receptor (NMDAR) in association with a unique neuro-psychiatric syndrome, over a decade-and-a-half ago. Anti-NMDAR Ab-mediated encephalitis now represents the most well characterised form of autoimmune encephalitis. The disease most commonly manifests in young women, but all ages and both sexes can be affected. Autoantibodies may arise in the context of two well-recognised disease triggers in a proportion of patients, and ultimately facilitate NMDAR displacement from synapses. Various CSF cytokines, chemokines, and other molecules have been explored as candidate biomarkers but are limited in sensitivity and specificity. The clinical spectrum is diverse, with evolution and a combination of neuro-psychiatric abnormalities at disease nadir common. Anti-NMDAR Ab-mediated encephalitis is immunotherapy responsive, and a near-majority ultimately acquire a broadly favourable clinical outcome. The diagnosis, and more particularly, the management of the disease can still hold considerable challenges. Moreover, well-defined biomarkers remain elusive. The present review will therefore delineate pathogenic and clinical advances to date in anti-NMDAR antibody-mediated encephalitis.