Antibody-Mediated Autoimmune Encephalitis in Childhood

Two Cases of Pediatric Leucine-Rich Glioma-Inactivated Protein-1 Encephalitis: Clinical Course, Challenges, and Implications

BACKGROUND

Leucine-rich glioma-inactivated protein 1 (LGI-1) encephalitis is a rare form of autoimmune limbic encephalitis. Although relatively well documented in adults, pediatric cases are rare and remain poorly understood.

METHODS

We reviewed two pediatric cases of LGI-1 encephalitis from a single tertiary care facility retrospectively. The detailed analysis included assessment of the initial presentation, clinical progression, diagnostic challenges, treatments, and outcome. To contextualize the differences between pediatric and adult manifestations of disease, we compared these findings with existing literature.

RESULTS

Both cases illustrate the diagnostic challenges faced at initial presentation due to the rarity of this diagnosis in children and the absence of characteristic faciobrachial dystonic seizures, which is common in adults. The constellation of neuropsychiatric symptoms and refractory focal seizures led to a high clinical suspicion for autoimmune encephalitis, therefore, both cases were treated empirically with intravenous methylprednisolone. The diagnosis in both cases was confirmed with positive serum antibody testing, reinforcing that LGI-1 antibodies are more sensitive in the serum rather than the cerebrospinal fluid (CSF). Seizure control and improvement in cognitive symptoms was achieved through a combination of immunotherapy and antiseizure medications.

CONCLUSIONS

This case series underscores the significance of considering LGI-1 encephalitis in the differential diagnosis of pediatric patients exhibiting unexplained neuropsychiatric symptoms and focal seizures and emphasizes the importance of performing both serum and CSF antibody testing. It is necessary to conduct further research to identify the full range of pediatric presentations and to determine the optimal treatment protocol.

Pediatric neuroinflammatory diseases in the intensive care unit

Inflammatory disorders of the central nervous system (CNS) include a wide spectrum of autoimmune, autoinflammatory, and paraneoplastic diseases. While many affected patients require acute hospital admission, a subset may present with severe neurological symptoms requiring intensive care unit (ICU) escalation due to disordered consciousness, respiratory failure, status epilepticus, intracranial hypertension, and/or severe autonomic dysregulation.

Clinical outcome in an infant with anti-NMDA receptor encephalitis: case report and literature review

Anti N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune disease that often presents with various neurological and neuropsychiatric symptoms. Although most reported cases occur in children, only a limited number of studies on children are available. The subject of this case report is an 8-month-old female who presented with fever, vomiting, and seizure. She was diagnosed with encephalitis and treated with acyclovir. After 21 days, she showed irritability, seizure, orolingual-facial dyskinesias, choreodystonic movements, hemiparesis, dysphagia, strabismus, lack of interest in light and objects. Clinical signs, neuroimaging findings, and serum analysis of anti-NMDAR antibodies confirmed the diagnosis of anti-NMDAR encephalitis. After the first line of treatment, she showed full recovery. We update the infants with anti-NMDAR encephalitis in the literature. Clinical outcomes suggest that patients with anti-NMDAR encephalitis are mostly poor in the infants, excluding our case. We propose that early and appropriate treatments are critical for timely diagnosis and rapid improvement.

Psychosis Caused by a Somatic Condition: How to Make the Diagnosis? A Systematic Literature Review

BACKGROUND

First episode of psychosis (FEP) is a clinical condition that usually occurs during adolescence or early adulthood and is often a sign of a future psychiatric disease. However, these symptoms are not specific, and psychosis can be caused by a physical disease in at least 5% of cases. Timely detection of these diseases, the first signs of which may appear in childhood, is of particular importance, as a curable treatment exists in most cases. However, there is no consensus in academic societies to offer recommendations for a comprehensive medical assessment to eliminate somatic causes.

METHODS

We conducted a systematic literature search using a two-fold research strategy to: (1) identify physical diseases that can be differentially diagnosed for psychosis; and (2) determine the paraclinical exams allowing us to exclude these pathologies.

RESULTS

We identified 85 articles describing the autoimmune, metabolic, neurologic, infectious, and genetic differential diagnoses of psychosis. Clinical presentations are described, and a complete list of laboratory and imaging features required to identify and confirm these diseases is provided.

CONCLUSION

This systematic review shows that most differential diagnoses of psychosis should be considered in the case of a FEP and could be identified by providing a systematic checkup with a laboratory test that includes ammonemia, antinuclear and anti-NMDA antibodies, and HIV testing; brain magnetic resonance imaging and lumbar puncture should be considered according to the clinical presentation. Genetic research could be of interest to patients presenting with physical or developmental symptoms associated with psychiatric manifestations.

Retrospective Comparison of Patients Evaluated for Pediatric Autoimmune Encephalitis with Typical and Atypical Premorbid Neuropsychiatric Development

PURPOSE

Patients with neurodevelopmental disorders (NDD) (i.e. autism, developmental delay, early-onset psychiatric or seizure disorders) increasingly seek evaluation of new or exacerbated symptoms concerning for autoimmune encephalitis (AE). Clinical AE evaluation can be challenging in NDD patients with symptom overlap between anti-neuronal autoimmunity and baseline atypical neurodevelopment. This study sought to explore differences in AE features by neurodevelopmental status.

METHODS

This retrospective chart review included 67 children with typical development (TD) or NDD evaluated for AE at the authors' institution. AE diagnosis included seronegative AE or seropositive AE with anti-NMDAR or anti-GAD antibodies. Reported AE clinical domains, symptom onset acuity, and treatment response were compared between three groups: (1) TD children with AE (TD-AE, N = 24); (2) NDD children with AE (NDD-AE, N = 21); and (3) NDD children with a non-AE diagnosis following appropriate workup (NDD-nonAE, N = 22).

RESULTS

Children with AE had a greater number of reported clinical domains than non-AE children with NDD (p < 0.0001) regardless of baseline developmental status. There were no observed differences in reported domains between TD-AE and NDD-AE groups. Onset acuity differed across the three groups (p = 0.04). No treatment response differences were observed between groups.

CONCLUSION

NDD children with AE had a comparable number of reported clinical domains relative to TD children and a similar treatment response. NDD patients with AE had a greater number of reported clinical domains than their NDD peers without an AE diagnosis. These findings suggest that AE is a multi-domain process in both TD and NDD children.

Clinical spectrum of contactin-associated protein 2 autoimmune encephalitis in children

Objective

Anti-contactin-associated protein 2 (CASPR2)-related autoimmune encephalitis (AE) is more common in adults than in children. Clinical understanding of anti-CASPR2-antibody (Ab)-related AE, diagnosis and treatment standards are lacking in children. Therefore, this retrospective study on clinical symptoms and treatment outcomes in children with anti-CASPR2-Ab-related AE was conducted, to improve the clinical understanding of the disease, its diagnosis and treatment.

Methods

This study retrospectively assessed children with anti-CASPR2-Ab-related AE from January 1, 2020, to June 30, 2022, in the Department of Neurology at Hunan Children's Hospital. Data regarding demographics, clinical symptoms, laboratory examinations, electroencephalography (EEG), imaging, and curative were collected.

Results

Thirteen patients were positive for serum anti-CASPR2-Ab (age at manifestation, 25 months to 13 years old; median, 8.1 years old; male-to-female ratio, 8/5). One patient (P1) had dual Abs, including anti-CASPR2 and anti-N-methyl-D-aspartate receptor Abs; his symptoms were more severe than those of children with anti-CASPR2 Abs alone. The clinical symptoms of the 13 patients with anti-CASPR2 Ab were movement disorders (9/13), consciousness disorders (9/13), abnormal demeanor (8/13), seizures (7/13), language disorders (6/13), fever (6/13), pain (4/13), involuntary exercise (4/13), poor diet (4/13), vomiting (3/13), sleep disorders (3/13), mood disorders (3/13), eczema/itching/redness (2/13), sweating (P8), urinary disorders (P13), and cognitive disorders (P9). No tumors were found in any patient. Additionally, EEG results of six patients were abnormal and imaging findings such as abnormal signals were found in 10 patients. Moreover, all except one patient recovered well after treatment; P1 with overlapping syndrome underwent recovery for more than 2 years. None of the patients who recovered have had a relapse.

Discussion and conclusion

Anti-CASPR2-Ab-related AE has several clinical manifestations. Anti-CASPR2-Ab levels were higher in male patients than in female patients. Moreover, related tumors are relatively rare. Most patients benefit from immunotherapy and have a lower chance of recurrence in the short term. Furthermore, different from patients who had anti-CASPR2-Ab AE alone, those with overlapping syndrome had a severe and complex condition requiring lengthy treatment and rehabilitation. Additional studies are needed to evaluate the long-term prognosis of these patients.

Therapeutic plasma exchange in anti-N-methyl-D-aspartate receptor encephalitis

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is the most commonly identified cause of autoimmune encephalitis. Therapeutic plasma exchange has been increasingly employed to treat this disease. This expansion is a consequence of improved techniques and apheresis instruments, as well as the recognition of its applicability in neurological diseases. However, several aspects of treatment remain incompletely clarified, and treatment strategies are still heterogeneous, especially with regard to therapeutic plasma exchange in anti-NMDAR encephalitis. This review provides an overview of the use of therapeutic plasma exchange including the principle and mechanisms, the evidence, initial time, efficiency and complications in anti-NMDAR encephalitis.

Determination of Clinical, Electrophysiological, and Radiological Characteristics of Pediatric Autoimmune Encephalopathy

Autoimmune encephalopathy (AE) is a group of diseases with subacute onset, that represents a wide clinical spectrum, manifested by complex neuropsychiatric symptoms and signs. In this study, the data of 27 patients diagnosed and followed up in our clinic with the diagnosis of AE between 2011 and 2021 were evaluated retrospectively. Out of 27 patients, 6 were definite seropositive AE, 2 of them met the diagnostic criteria for limbic encephalitis, and the remaining 19 were probable AE. Nowadays, we see AEs with increasing frequency. While there is a generally established approach in the diagnosis and treatment of seropositive patients, there are still hesitations and diagnostic difficulties in seronegative AEs. In this study, clinical, radiological, and prognostic features of definite and probable AE patients diagnosed in a tertiary pediatric neurology clinic were documented. It is thought that pediatric neurologists have an important responsibility to increase awareness about AE in pediatricians. In the future, it is predicted that AE will be diagnosed more frequently with new antibodies and one has to differentiate it from viral encephalitis and neuropsychiatric syndromes and diseases.

Advances in Potential Cerebrospinal Fluid Biomarkers for Autoimmune Encephalitis: A Review

Autoimmune encephalitis (AE) is a severe inflammatory disease of the brain. Patients with AE demonstrate amnesia, seizures, and psychosis. Recent studies have identified numerous associated autoantibodies (e.g., against NMDA receptors (NMDARs), LGI1, etc.) involved in the pathogenesis of AE, and the levels of diagnosis and treatment are thus improved dramatically. However, there are drawbacks of clinical diagnosis and treatment based solely on antibody levels, and thus the application of additional biomarkers is urgently needed. Considering the important role of immune mechanisms in AE development, we summarize the relevant research progress in identifying cerebrospinal fluid (CSF) biomarkers with a focus on cytokines/chemokines, demyelination, and nerve damage.

Faciobrachial Dystonic Seizures as a Sign of Relapse in a Child with LGI-1 Encephalitis

We report an interesting case of a young girl with LGI1-antibody encephalitis who presented at 7 years old with very frequent seizures and severe neurocognitive decline. She responded very well to high dose corticosteroids and intravenous immunoglobulin (IVIG) initially but relapsed after 7 months. The relapse included frequent faciobrachial dystonic seizures (FBDS) that were successfully treated with rituximab. This case report highlights a few important points about LGI1-antibody encephalitis in children to help clinicians recognize this condition early and start prompt treatment with immunosuppressants. Data is lacking about LGI1-antibody encephalitis in children as it is mostly reported in adults. Our patient presented with frequent drug-resistant seizures including FBDS, along with amnesia, confusion, medial temporal lobe involvement, and hyponatremia similar to the presentation in adults. In contrast, none of the patients in the recent systematic review had FBDS or hyponatremia, making our case unique and suggesting variability in clinical presentation in children similar to adults. To our knowledge, FBDS have never been reported in children and our patient was initially misdiagnosed as having Childhood Epilepsy with Centrotemporal spikes. Since receiving rituximab, our patient is seizure-free for 1 year and 9 months and was successfully weaned of topiramate. She is going to school and has normal attention, concentration, memory, and mood. We propose early consideration of rituximab to accelerate recovery and prevent relapse.

Incidence of Childhood Meningoencephalitis in Children With a Suspected Meningoencephalitis in the Netherlands

Supplemental Digital Content is available in the text.

Catatonia with Psychosis in an 8-Year-Old Child: A Case Report and a Literature Review

Objective

We present a narrative review of pediatric catatonia and a case report illustrating the complexity of management of psychosis in a child with catatonia.

Method

The literature search used the text terms pediatric, catatonia, and antipsychotics and the search engines PubMed and EBSCO. All references from peer-reviewed journals were reviewed for treatment strategies specific to management in children who are also psychotic. Findings. This 8-year-old girl presented with psychotic symptoms which were initially treated with antipsychotics and evolved into life-threatening catatonia that was eventually stabilized with a total daily dose of 46 mg of lorazepam. Lower doses led to recurrence. Once catatonia improved, she tolerated combined benzodiazepine and antipsychotic treatment. Long-term maintenance over 5 years required maintenance treatment with both benzodiazepines and antipsychotics to prevent relapse.

Conclusions

The extraordinary doses of benzodiazepines found to be optimal for management of catatonia in this child led to improved alertness and orientation, without evident sedation. Catatonia did not recur with later management of psychosis using neuroleptics when added to lorazepam. The current literature on pediatric catatonia does not provide guidance on dose maintenance or when and if to rechallenge with antipsychotics.

Diagnosis and Management of Suspected Pediatric Autoimmune Encephalitis: A Comprehensive, Multidisciplinary Approach and Review of Literature

Autoimmune encephalitis is an increasingly recognized entity in children. When treated promptly, favorable outcomes are seen in a majority of pediatric patients. However, recognition of autoimmune encephalitis in young patients is challenging. Once autoimmune encephalitis is suspected, additional difficulties exist regarding timing of treatment initiation and duration of treatment, as evidence to guide management of these patients is emerging. Here, we review available literature regarding pediatric autoimmune encephalitis and present our institution's comprehensive approach to the evaluation and management of the disease. These guidelines were developed through an iterative process involving both pediatric neurologists and rheumatologists.

Immunopsychiatry: An Update on Autoimmune Encephalitis for Neuropsychiatrists

INTRODUCTION

Autoimmune encephalitis (AIE) is a group of immune-mediated inflammatory processes of the brain with marked psychiatric features. Although relatively rare, they might offer difficult differential diagnosis with psychiatric conditions, especially catatonia and psychotic syndromes. Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is the most common AIE, presenting with psychiatric syndromes in 90% of cases. The associated psychopathology is complex, pleomorphic and best characterized when there is involvement of a psychiatrist in the assessment.

AREAS COVERED

This text will review the main aspects of AIE to psychiatrists and/or neuropsychiatrists.

EXPERT OPINION

Immune system dysfunction has been implicated in the pathophysiology of psychiatric symptoms and disorders. The use of diagnostic criteria of possible AIE, especially when specific antibodies of AIE are not available, allows early diagnosis and prompt treatment which are associated with better clinical outcomes. The study of the psychiatric aspects of AIE can broaden our knowledge of the underlying mechanisms of various psychiatric manifestations.

Cerebrospinal Fluid Extracellular Vesicles with Distinct Properties in Autoimmune Encephalitis and Herpes Simplex Encephalitis

Encephalitis mediated by autoantibodies against neuronal antigens and herpes simplex encephalitis (HSE) are seemingly separate causes of encephalopathy in adults. Autoimmune encephalitis (AE) is autoimmune in origin, and herpes simplex encephalitis is infectious. The purpose of this study was to examine the role of cerebrospinal fluid (CSF) exosomes from patients with antibody-positive AE and HSE. Towards this, exosomes were isolated from CSF from 13 patients with anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis, 11 patients with anti-gamma-aminobutyric acid-B (GABAB) receptor encephalitis, 9 patients with anti-leucine-rich glioma-inactivated 1 (LGI1) encephalitis, and 8 patients with anti-contactin-associated protein-like 2 (CASPR2) encephalitis, and 12 control individuals negative of antibodies against neuronal autoantigens. There were ten miRNAs highly expressed in patients with anti-NMDAR encephalitis compared to those in control subjects. Eight miRNAs were found to be lower expressed in anti-NMDAR encephalitis CSF-derived exosomes. Furthermore, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enriched by AE differential expressed exosomic miRNAs demonstrated that AE-related exosomic miRNAs may participate as a feedback regulation in cancer development. In addition, the exosome concentration in CSF of 9 HSE patients was significantly higher compared to those from 9 HSV( −) patients. This observation was consistent with the results that exosome concentration was found to be higher in the animal model which was inoculated intranasally with HSV-1 compared to controls. Furthermore, western blot demonstrated that the subunits of NMDAR, GABA_BR, and AMPAR were detected highly expressed in exosomes derived from sera of HSV-1-treated animal model compared to controls. More importantly, exosomes isolated from CSF of HSE patients contained higher expression levels of two miRNAs encoded by HSV, miR-H2-3p, and miR-H4-3p compared to those from HSV( −) patients. In summary, HSV may trigger brain autoimmunity in HSE by presentation of surface autoantigens via exosomes.

Etiological and Clinical Profile of Acute Nonbacterial Encephalitis in Children: A Single-Center Prospective Study

Encephalitis is a serious neurological syndrome caused by inflammation of the brain. The diagnosis can be challenging and etiology remains unidentified in about half of the pediatric cases. We aimed to investigate demographic, clinical, laboratory, electroencephalographic and neuroimaging findings, and outcome of acute encephalitis of nonbacterial etiology. This prospective study included children hospitalized with the diagnosis of acute encephalitis between 2017 and 2019. Microbiological investigations of the cerebrospinal fluid (CSF) were recorded. All CSF specimens were tested for anti-N methyl D-aspartate receptor (NMDAR) antibodies. In total, 31 children aged 10 months to 17 years (median = 6 years) were included. Pathogens were confirmed in CSF in three patients (9.7%): varicella zoster virus, herpes simplex virus type 1 (HSV-1), and both HSV-1 and NMDAR antibodies. Presenting features included encephalopathy (100%), fever (80.6%), seizure (45.2%), focal neurological signs (29%), and ataxia (19.4%). On clinical follow-up of median 9 (6-24) months, six patients showed neurological deficits: together with two patients who died in hospital, total eight (25.8%) patients were considered to have unfavorable outcome. Need for intubation, receiving immunomodulatory treatment, prolonged hospitalization, and high erythrocyte sedimentation rate at admission were associated with unfavorable outcome. The etiology of encephalitis remains unexplained in the majority of children. HSV-1 is the most frequently detected virus, consistent with the literature. The fact that anti-NMDAR encephalitis was detected in one child suggests autoimmune encephalitis not being rare in our center. The outcome is favorable in the majority while about one-fifth of cases suffer from sequelae.

Neuropsychological Sequelae, Quality of Life and Adaptive Behavior in Children and Adolescents with Anti-NMDAR Encephalitis: A Narrative Review

Anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis is a rare autoimmune illness characterized by a constellation of often severe, but treatable, psychiatric and neurological symptoms. Whereas symptoms such as psychosis and bizarre and abnormal motor behavior are common in adults, pediatric patients typically present with behavioral changes, irritability and sleep dysfunction. The recovery phase is usually slow and may be associated with longstanding adaptive, behavioral and neuropsychological problems. Very few studies explored the cognitive and adaptive sequelae in children with anti-NMDAR encephalitis. The present review article suggests that, although most children and adolescents return to their daily life and previous activities, they may have a low quality of life and show neuropsychological sequelae involving language, memory, especially verbal memory, and attentional resources, even after several months from the hospital discharge. In particular, the available results reveal difficulties in cognitive skills involving executive functions. This impairment is considered the “core” of the cognitive profile of young patients with anti-NMDAR encephalitis. On the other hand, some cognitive skills, such as general intelligence, show good overall recovery over time. Additional neuropsychological research evaluating larger samples, more homogenous methods and longitudinal studies is required.

Age-dependent characteristics and prognostic factors of pediatric anti-N-methyl-d-aspartate receptor encephalitis in a Chinese single-center study

OBJECTIVE

To describe the clinical features and prognosis of pediatric anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis from a single center in northern China.

METHODS

The clinical and laboratory characteristics of hospitalized patients with anti-NMDAR encephalitis, stratified by age, were retrospectively studied. Risk factors including relapse and long-term (follow-up ≥1 year) outcomes were analyzed.

RESULTS

A total of 273 patients were included between November 2011 and December 2019, and the average age of onset was 7.5 ± 4.0 years (0.5-15.8 years). Of them, 159（58.2%） were female, and the proportion of females increased with age. Seizures were the most common initial symptom. Movement disorders（86.1%） and psychiatric（82.4%） symptoms were most frequent in the acute phase. In the acute stage, the incidence of movement disorders decreased with age (χ² = 10.676, p = 0.011), while the proportion of psychiatric symptoms increased with age (χ² = 21.85, p < 0.001) The recurrence rate was 9.6% (24/250). Demyelination was an independent risk factor for relapse (p = 0.006, OR = 5.877, 95% CI: 1.658-20.835). Among the 210 patients who were followed up for more than one year, 28 patients had a poor prognosis (mRS ≥3). Onset age (p = 0.038，OR = 0.844, 95% CI: 0.720-0.991), precursor of viral encephalitis (p = 0.007，OR = 9.876, 95% CI: 1.878-51.940), and ICU admission (p = 0.023，OR = 5.924, 95% CI: 1.280-27.064) significantly affected the prognosis. The mortality rate was 2.9%.

CONCLUSIONS

The characteristics of anti-NMDAR encephalitis in children are age-dependent. Early-onset, the precursor of viral encephalitis, and ICU admission may indicate poor prognosis. Demyelination may be a risk factor for recurrence.

Thalamic Lesions in a Toddler with Glutamic Acid Decarboxylase Autoimmune Encephalitis

We present a child with glutamic acid decarboxylase (GAD) autoimmune encephalitis (AE) with bilateral thalamic lesions on magnetic resonance imaging (MRI) of the brain. A healthy 21-month-old girl, after superrefractory status epilepticus (SE) and fever developed dyskinesia and ataxia, which we subsequently diagnosed as GAD AE. She showed remarkable response to treatment with methylprednisolone and intravenous immunoglobulin (IVIg). Following an initial normal MRI of her brain, a further brain imaging showed bilateral thalamic lesions. This is an unusual finding since brain imaging abnormalities, when found in GAD AE, mostly involve the mesial temporal lobe structures. Thalamic lesions in GAD AE have not been reported previously.

Autoimmune encephalitis in a tertiary hospital in the Philippines

BACKGROUND

Autoimmune encephalitis (AE) is an emerging disorder in adults and children. Due to its potentially reversible nature, prompt recognition and intervention are of utmost importance.

OBJECTIVE

To describe the clinical and paraclinical features, as well as treatment outcomes of patients with AE admitted in a Philippine tertiary hospital.

METHODS

Retrospective case series of patients with definite AE.

RESULTS

Eighteen (18) patients were included (12 adults, 6 children), majority of whom had anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis. The median age of onset was 32 (IQR: 10.8) years old and 13 (IQR: 4.8) years old in the adult and pediatric population, respectively. In both age groups, most presented with psychiatric symptoms and normal imaging findings. Cerebrospinal fluid (CSF) pleocytosis was detected in 8/12 (66.7%) adults and 2/6 (33.3%) children, while CSF protein elevation was only seen in 6/12 (50%) adults. Most patients presented with seizures, and the most frequent electroencephalography (EEG) abnormality detected was slow activity (70.5%). A high proportion of patients received high dose steroids, alone (35.3%) or in combination with intravenous immunoglobulin (IVIG, 52.9%). Overall, 66.7% had improved outcomes, mostly seen in the pediatric population.

CONCLUSION

This study highlighted the broad clinical phenotype, as well as the similarities and differences of AE manifestations in adults and children. It demonstrated the limited but supportive role of laboratory investigations in the diagnosis of AE. It also underscored the importance of early intervention in AE and highlighted factors influencing treatment practices and discharge outcomes in the local setting.

Acute manic state with psychotic features in a teenager with autoimmune encephalitis: a case report

Introduction

Autoimmune disorders have become increasingly acknowledged as having a more causative role in encephalitis than previously assumed. Anti-N-methyl-d-aspartate receptor encephalitis seems to be the most prevalent disorder. Symptoms of the neuropsychiatric phase in children and adolescents include abnormal behavior, seizures, and neurologic symptoms. We present a report on a teenage girl with predominantly psychiatric symptoms, highlighting the need for awareness of the disease and multidisciplinary collaboration.

Case presentation

Our patient, a 17-year-old girl of Middle Eastern origin, had no earlier medical history, but a family history of autoimmune disease. One morning, she could not recognize her mother and soon developed increased energy and pressured speech. The condition worsened, with paranoid delusions. In the emergency unit, she ran around speaking incoherently. The condition was interpreted as a full-scale mania. After pediatric clearance, the patient was admitted to the Department of Child and Adolescent Psychiatry. Mood-stabilizing treatment was initiated with second-generation psychotics and lithium, but this brought no improvement. A multidisciplinary discussion was held with physicians from psychiatry and neurology. A lumbar puncture showed N-methyl-d-aspartate receptor antibodies, and autoimmune treatment was initiated. Computed tomography thorax/abdomen revealed a right-sided ovarian tumor. After salpingo-oophorectomy, our patient’s mental status gradually improved, as demonstrated by repeated testing. Seven months post discharge she was in a stable relationship and performing well in school.

Conclusion

This case underlines the importance of collaboration between child and adolescent psychiatry and pediatrics, and gives pointers for timely diagnosis. Manic adolescents who do not respond to mood-stabilizing treatment should be subjected to further consultations and investigations. Psychiatrists and neurologists should develop an integrated approach to the management of brain disorders.

Autoimmune Encephalitis in Tunisia: Report of a Pediatric Cohort

Background

Autoimmune encephalitis (AE) is a rapidly progressive encephalopathy caused by antibodies targeting neurons in the central nervous system generating specific immune responses. It is increasingly recognized in children.

Objective

To describe clinical, neuroimaging, and laboratory features, treatment, and outcome in a cohort of Tunisian children with AE.

Methods

We conducted a retrospective review of the medical records of all children attending the Department of Child and Adolescent Neurology (Tunis) with autoimmune encephalitis between 2004 and 2020. Clinical, neuroimaging, laboratory features, therapeutic data, and outcome were analyzed.

Results

Nineteen children were included in the study (12 girls and 7 boys). The median age at diagnosis was 7.68 years (range: 10 months-13 years). The most frequent manifestations were seizures and behavioral disorders. Eleven cases were diagnosed with anti-NMDA receptor encephalitis, 4 cases with anti-Ma2 encephalitis, 3 cases with anti-GAD encephalitis, and 1 case with anti-SOX1 encephalitis. Brain MRI showed increased T2 and fluid-attenuated inversion recovery (FLAIR) signal of the temporal lobe in 5 patients. Eighteen patients showed improvement following first-line immunotherapy (high-dose corticosteroids, intravenous immunoglobulin). One patient with anti-GAD encephalitis died despite escalating immunotherapy.

Conclusion

Diagnosis of autoimmune encephalitis is challenging in children, because of misleading presentations. An early and accurate diagnosis is important to enable proper therapeutic interventions.

Altered microRNAs in cerebrospinal fluid exosomes in paraneoplastic and autoimmune encephalitis: A possible feedback in cancer development

AIMS

The purpose of this study was to examine the role of cerebrospinal fluid (CSF) exosomes from patients with paraneoplastic and autoimmune encephalitis (AE).

MAIN METHODS

Towards this, microRNA profiling in the exosomes which were isolated from cerebrospinal fluid of 12 patients with anti-N-methyl-d-aspartate (NMDA) receptor encephalitis, 12 patients with anti-gamma-aminobutyric acid-B (GABAB) receptor encephalitis, 12 patients with anti-leucine-rich glioma-inactivated 1 (LGI1) encephalitis, and 12 patients with anti-contactin-associated protein-like 2 (CASPR2) encephalitis, and 12 control individuals negative of antibodies against neuronal auto-antigens. Selected findings were validated with quantitative RT-PCR. DIANA-mirPath was chosen for bioinformatic analysis.

KEY FINDINGS

There were ten miRNAs higher expressed in AE patients with anti-NMDAR encephalitis compared to those in healthy controls. Further, eight miRNAs were found to be lower expressed in anti-NMDAR encephalitis CSF derived exosomes. In addition, Endometrial cancer, p53 signaling pathway, Non-small cell lung cancer, Small cell lung cancer, Transcriptional misregulation in cancer, Basal cell carcinoma, Acute myeloid leukemia, Renal cell carcinoma, Colorectal cancer, Choline metabolism in cancer, Melanoma, Pancreatic cancer, Prostate cancer, Ras signaling pathway, Glioma, Pathways in cancer, and Proteoglycans in cancer (all p < 0.01) were significantly enriched in differentially expressed miRNAs.

SIGNIFICANCES

Exosomes expressing specific miRNAs in antibody positive AE may participate as a feedback regulation in cancer development.

Clinical Features, Treatment Strategies, and Outcomes in Hospitalized Children With Immune-Mediated Encephalopathies

BACKGROUND

Autoimmune encephalitis (AE) and acute disseminated encephalomyelitis (ADEM) are immune-mediated brain conditions that can cause substantial neurological sequalae. Data describing the clinical characteristics, treatments, and neurological outcomes for these conditions are needed.

METHODS

This is a single-center retrospective review of children diagnosed with AE or ADEM over a nine-year period with discharge outcomes measured by the Modified Rankin Score.

RESULTS

Seventy-five patients (23 with ADEM and 52 with AE) were identified. Patients with ADEM had a higher percentage of abnormal magnetic resonance imaging findings (100% vs 60.8%; P < 0.001) and a shorter time from symptom onset to diagnosis (6 vs 14 days; P = 0.024). Oligoclonal bands and serum and cerebrospinal fluid inflammatory indices were higher in patients with AE. Nearly all patients received corticosteroids followed by plasmapheresis or intravenous immunoglobulin, and treatment strategies did not differ significantly between groups. Second-line immune therapies were commonly used in patients with AE. Finally, patients with AE had trends toward longer hospital lengths of stay (21 vs 13 days) and a higher percentage of neurological disability at hospital discharge (59.6% vs 34.8%).

CONCLUSIONS

Although patients with ADEM and AE may have similar presenting symptoms, we found significant differences in the frequency of imaging findings, symptom duration, and laboratory and cerebrospinal fluid profiles, which can assist in distinguishing between the diagnoses. Patients in both groups were treated with a combination of immunomodulating therapies, and neurological disability was common at hospital discharge.

Exosomes expressing neuronal autoantigens induced immune response in antibody-positive autoimmune encephalitis

The immunological role of exosomes in autoimmune encephalitis (AE) remains uncharacterized and not examined. In this study we ought to determine whether exosomes are generated in AE and to define the presence of cell surface neuronal autoantigens (autoAgs) in the cargo. Exosomes were isolated from cerebrospinal fluid (CSF) from 12 patients with anti-N-methyl-d-aspartate (NMDA) receptor encephalitis, 8 patients with anti-gamma-aminobutyric acid-B (GABA_B) receptor encephalitis, 8 patients with anti-leucine-rich glioma-inactivated 1 (LGI1) encephalitis, 8 patients with anti-contactin-associated protein-like 2 (CASPR2) encephalitis, 10 patients with anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid 1,2 (AMPA) receptor encephalitis and 30 control individuals negative of antibodies against neuronal autoAgs. Western blot demonstrated that CSF or sera derived exosomes from AE contained specific neuronal autoAgs in protein aggregates, however, control subjects had no detectable levels of these neuronal autoAgs. In addition, development of antibodies against NMDAR, GABA_BR, LGI1, CASPR2, and AMPAR were detected in the sera after 30 days immunization of C57BL/6 J mice with exosomes isolated from antibody positive AE patients; Enzyme-linked immunospot (ELISpot) assay demonstrated increased frequency of neuronal autoAgs-specific IL-17 and IFN-γ in splenocytes from AE derived exosomes immunized mice. We concluded that exosomes expressing neuronal autoAgs were present in CSF from antibody positive AE patients, and we propose these exosomes carrying neuronal autoAgs would play an important role in the immune pathogenesis of autoimmune encephalitis.

CSF studies which ultimately led to the possible diagnosis of anti-NMDAR encephalitis

A 17-year-old man with no significant medical history presented with new-onset seizure activity and altered mental status manifesting as bizarre behaviour, which included rapid pressured and tangential speech, psychomotor agitation, insomnia and delusions. He also had autonomic dysregulation, manifested in labile blood pressures. He had been recently discharged from his first psychiatric hospitalisation. Many studies were performed, including electroencephalogram (EEG), head CT, laboratory work, urine drug screen and lumbar puncture with cerebral spinal fluid studies, which ultimately led to the diagnosis of anti-N-methyl-D-aspartate receptor (NMDAR) autoimmune encephalitis. He was treated with five rounds of plasmapheresis with complete resolution of his altered mental status. This case highlights the importance of being familiar with the presentation of anti-NMDAR autoimmune encephalitis, especially in cases of new-onset mental status changes with psychotic like symptoms, seizure-like activity and autonomic dysregulation as early detection and treatment improves chances of good prognosis with return to baseline cognitive function.

Serum matrix metallopeptidase-9 and tissue inhibitor of metalloproteinase-1 levels in autoimmune encephalitis

OBJECTIVE

Some pediatric patients with autoimmune encephalitis (AE) experience sequelae in spite of immunotherapy. In this study, we aimed to evaluate the association of serum matrix metallopeptidase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels with the neurological prognosis of AE.

METHODS

We retrospectively included 13 patients with AE who had been referred to Saitama Children's Medical Center from February 2011 to May 2019. We compared serum MMP-9 levels, TIMP-1 levels, and MMP-9/TIMP-1 ratio in the acute period (within 30 days from the onset of AE) and subacute period (30-day period following the acute period). We also compared these biomarker levels between patients with (group A) and without sequelae (group B). Sequelae were evaluated at discharge or the last visit.

RESULTS

Group A (median age, 7.8 years; range, 5.3-10.7 years) and group B (median age, 13.3 years; range, 11.1-15.4 years) had 6 patients each; 1 patient was excluded because the time of AE onset was unknown. In the acute period, there were no significant differences in MMP-9 levels, TIMP-1 levels, and MMP-9/TIMP-1 ratio between groups A and B. In the subacute period, serum MMP-9/TIMP-1 ratio was higher in group A than in group B (p < 0.01). There were no significant differences in MMP-9 and TIMP-1 levels between groups A and B.

CONCLUSIONS

Patients with sequelae of AE showed a high MMP-9/TIMP-1 ratio in the subacute period. Our study demonstrates that elevation of serum MMP-9/TIMP-1 ratio in the subacute period may be a predictive factor of sequelae of AE.

Medical Etiologies of Secondary Psychosis in Children and Adolescents

This is an updated review of child and adolescent somatic disorders associated with psychosis/psychotic symptoms, organized into neurologic, infectious, genetic, inborn errors of metabolism, autoimmune, rheumatologic, endocrine, nutritional, metabolic, and iatrogenic categories. When possible clinical manifestations or types of psychotic symptoms and proposed neuropathogenesis causing the neuropsychiatric symptoms are included. In some cases, the psychiatric symptoms may be the first presentation of the disease. The authors hope that this review will aid child and adolescent psychiatrists in considering alternative etiologies of youth presenting with psychosis and encourage appropriate physical examination, history, and further work-up when suspected.

Clinical Features, Treatment, and Outcomes Among Chinese Children With Anti-methyl-D-aspartate Receptor (Anti-NMDAR) Encephalitis

Objective: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is the most common form of autoimmune encephalitis in pediatric patients. In this study, we aimed to investigate the clinical features and long-term outcomes of pediatric patients with anti-NMDAR encephalitis in China.

Methods: We conducted a retrospective study of children (age range: 0–18 years) with anti-NMDAR encephalitis treated at Children's Hospital of Fudan University between July 2015 and November 2018. Demographic characteristics, clinical features, treatment, and outcomes were reviewed.

Results: Thirty-four patients with anti-NMDAR encephalitis were enrolled (age range: 5 months to 14 years; median age: 7 years; female: 18). The median follow- up duration was 20 months (range: 6–39 months). Eighteen (52.9%) patients initially presented with seizures and 10 (29.4%) with abnormal (psychiatric) behaviors or cognitive dysfunction. Thirty (88.2%) patients exhibited more than two symptoms during the disease course. No neoplasms were detected. Twelve (35.2%) patients had abnormal cerebrospinal fluid (CSF) findings, including leukocytosis, and increased protein concentration. Eighteen (52.9%) patients exhibited normal brain MRI findings. Electroencephalography revealed abnormal background activity in 27 (79.4%) patients, and epileptiform discharges in 16 (47.0%) patients prior to immunotherapy. All patients received first-line immunotherapy, with 30 (88.2%) and four (11.8%) patients achieving good (Modified Rankin Scale [mRS] score of 0–2) and poor outcomes (mRS score of 3–5), respectively. Initial mRS scores differed significantly between the good and poor outcome groups. Fourteen out of 18 patients (77.7%) with seizures accepted anti-epileptic drug (AED) administration, and seizure freedom was achieved in 12 out of 14 (85.7%) patients at the last follow-up. Ten of these 12 (83.3%) patients withdrew from AED treatment within 1 year.

Conclusions: Most patients achieved seizure freedom, so long-term use of AEDs may not be necessary for pediatric patients with anti-NMDAR encephalitis. Among our patients, 83.3% were sensitive to first-line immunotherapy and achieved good outcomes. Higher mRS scores before immunotherapy predicted poor outcomes, highlighting the need for a comprehensive assessment of patients with anti-NMDAR encephalitis.

Understanding Childhood Neuroimmune Diseases of the Central Nervous System

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

Imaging of Childhood Inflammatory Brain Diseases

Brain has been considered as an immune-privileged site for centuries owing to the presence of blood-brain barrier, absent lymphatic drainage, and antigen-presenting cells. However, the present prevailing concept is of immune surveillance where brain is continuously surveyed by immune cells. However, the presence of immune cells in central nervous system (CNS) brings the risk of inflammation and autoimmunity involving both T and B cell mediated pathways. These mechanisms form the underlying pathology in a wide spectrum of pediatric CNS diseases manifesting as acquired neurological deficits. Overlapping, heterogenous, and ambiguous clinical features often delays the diagnosis. Although not always pathognomonic, magnetic resonance imaging can be an important biomarker leading to early diagnosis, prognostication, and systematic follow-up pf these diseases. This review describes the spectrum of different pediatric inflammatory disorders and their pertinent imaging features illustrated with clinical examples.

Th17 cells were recruited and accumulated in the cerebrospinal fluid and correlated with the poor prognosis of anti-NMDAR encephalitis

Anti-N-methyl-D-aspartate-receptor (NMDAR) encephalitis is an autoimmune disorder characterized by memory deficits, psychiatric symptoms, and autonomic instability. The lack of suitable biomarkers targeting anti-NMDAR encephalitis makes the immunotherapy and prognosis challenging. In this study, we found that the Th17 cells were significantly accumulated in the cerebrospinal fluid (CSF) of anti-NMDAR encephalitis patients than that of control individuals. The concentration of the cytokines and chemokines including interleukin (IL)-1β, IL-17, IL-6, and CXCL-13 were significantly increased in the CSF of anti-NMDAR encephalitis patients. IL-6 and IL-17 were found to promote the differentiation of CD4+ T cells into Th17 lineage. The chemotaxis assay showed that CCL20 and CCL22 play essential roles in the migration of Th17 cells. Notably, the correlation between the expression of IL-17 and the outcome of anti-NMDAR encephalitis patients was analyzed. The data showed that high level of IL-17 was significantly correlated with the limited response to the treatment and relapse of anti-NMDAR encephalitis patients. Our results suggested the potential important involvement of IL-17 in anti-NMDAR encephalitis.

Anti-NMDA receptor encephalitis in a toddler: A diagnostic challenge

Anti N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune disorder and is considered to be one of the most common causes of encephalitis in children. Despite the fact that around half of all reported cases are of children, the number of studies that report infants and toddlers is very small. Furthermore, reports on children from the Middle East particularly are extremely rare.

We report a 21-month-old Jordanian female toddler with NMDAR encephalitis, who initially presented with behavioral changes and some autistic features. She presented a diagnostic challenge due to a concurrent urinary tract infection and gastroenteritis. Multiple investigations were conducted and she was treated with methylprednisolone and intravenous immunoglobulin (IVIg) empirically as well as plasma exchange and rituximab once the diagnosis was confirmed. Her condition improved gradually. We discuss her clinical picture and the diagnostic challenges within this age group; we also review the current related literature.

Evaluation and Management of Autoimmune Encephalitis: A Clinical Overview for the Practicing Child Psychiatrist

Medical conditions that present with psychiatric symptoms are becoming increasingly well-recognized in response to the emergence of the field of neuroimmunology. As the availability of testing for novel antineuronal antibodies has increased, so too has the clinical awareness of this diagnostic spectrum. Psychiatrists may have little exposure to this area of expertise, yet may be called on to assist in the diagnosis and treatment of patients with complex neuropsychiatric syndromes secondary to autoimmune encephalitis. This article summarizes the evaluation and management of patients with autoimmune encephalitis and describes emerging patterns in phenotype recognition.

Psychoneuroimmunology of mental disorders

The immune system is a key element in the organism's defence system and participates in the maintenance of homeostasis. There is growing interest in the aetiopathogenic and prognostic implications of the immune system in mental disorders, as previous studies suggest the existence of a dysregulation of the immune response and a pro-inflammatory state in patients with mental disorders, as well as an increased prevalence of neuropsychiatric symptoms in patients suffering from autoimmune diseases or receiving immune treatments. This study aims to conduct a narrative review of the scientific literature on the role of Psychoneuroimmunology in mental disorders, with special focus on diagnostic, prognostic and therapeutic issues. The development of this body of knowledge may bring in the future important advances in the vulnerability, aetiopathogenic mechanisms, diagnosis and treatment of some mental disorders.

Neurological Complications of Rheumatic Disease

Rheumatic disease represents a broad spectrum of systemic conditions manifested by multisystem involvement and mediated by autoimmunity and inflammation. Their neurological complications may occur at any point in the disease process and are diagnostically challenging. For years central nervous system (CNS) was considered as a system uniquely protected from effects of the immune system because of the blood-brain barrier. Indeed, under physiological conditions immune access to CNS is tightly regulated. Over the past decade, new scientific discoveries highlighted pathways by which immune and neurological systems interact, including a variety of mechanisms controlling permeability of blood-brain barrier, and specific roles that CD4⁺ and CD8⁺ T-lymphocytes play in initiation of specific adaptive immune response to neural specific antigens. This leads to release of proinflammatory cytokines (interleukin 1, interleukin 6, and tumor necrosis factor alpha). In addition, B-cells involved in CNS inflammation produce antibodies against membrane bound and soluble antigens. This article describes specific neurological manifestations of the most common autoimmune rheumatic disorders.