Diagnostic Considerations in Acute Disseminated Encephalomyelitis and the Interface with MOG Antibody

Interpretation: use of autoantibodies in children

Judicious use of autoantibodies in paediatrics can be challenging. Autoimmune conditions can present with a wide range of signs and symptoms, many of which are non-specific. In combination with clinical features and laboratory findings, autoantibodies can facilitate diagnosis and in certain cases inform prognosis. Evidence for use of autoantibodies to guide and monitor treatment is limited. Caution is necessary when interpreting adult studies. We summarise the use of autoantibodies in paediatric practice with a guide on how they may be used.

Neurological complications of influenza vaccination: navigating the spectrum with a focus on acute disseminated encephalomyelitis (ADEM)

Introduction

Acute disseminated encephalomyelitis (ADEM) is a rare neurological disorder characterized by inflammation in the brain and spinal cord. This systematic review aims to investigate the potential association between ADEM and influenza vaccination by analyzing relevant case reports. ADEM is traditionally thought to be a monophasic condition, predominantly affecting children, often following viral illnesses or immunizations. Recent attention has focused on a possible link between ADEM and influenza vaccination, prompting the need for a thorough investigation.

Methods

The systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and the AMSTAR2 (A MeaSurement Tool to Assess systematic Reviews 2) guidelines. Electronic searches were conducted on PubMed, Cochrane Library, and clinicaltrials.gov databases, spanning up to August 2023. Inclusion criteria encompassed full-text articles in English, observational studies, case reports, and case series providing comprehensive details for confirming clinical diagnoses of ADEM following influenza vaccination. Data were extracted, including demographic information, vaccination details, clinical symptoms, diagnostic evaluations, treatment modalities, and outcomes. Quality assessment was performed using the Joanna Briggs Institute (JBI) Critical Appraisal tool.

Results

A total of 23 cases of ADEM following influenza vaccination were identified from 19 included articles. The mean age of affected individuals was 40.2 years (±25.7) with 60.8% being male. Common presenting symptoms included muscle weakness (52.1%), urinary abnormalities (30.4%), altered consciousness (26%), and sensory disturbances (26%). Neurological examination revealed findings such as extensor plantar reflex (positive Babinski sign) in 26%, hyperreflexia in 30.4%, and generalized hyporeflexia in 13% of the cases. Diagnostic evaluations involved MRI, showing multiple hyperintense lesions in cerebral hemispheres (43.4%), subcortex (60.8%), and spinal cord (39.1%). Cerebrospinal fluid analysis indicated elevated white blood cell count in 69.5% of cases, with lymphocytic pleocytosis in 52.1%. Oligoclonal bands were reported positively in 8.6% of cases. Treatment approaches varied, with intravenous methylprednisolone being the most common (39.1%). Out of the 23 cases, two (8.6%) patients had a fatal outcome, while the rest showed clinical improvement with complete or partial resolution of symptoms. Persisting symptoms included numbness in the lower extremities (8.6%) and impaired ability to walk after 10 months (4.3%).

Conclusion

While the association between ADEM and influenza vaccination is rare, healthcare professionals should remain vigilant and consider patients' vaccination history, particularly following an influenza immunization. This systematic review highlights the clinical manifestations, diagnostic tools, treatment approaches, and outcomes of ADEM cases post-influenza vaccination. Further research is essential to understand this association and improve clinical decision-making, ensuring the safety and efficacy of immunization programs.

Anti-Inflammatory and Immunomodulatory Effect of High-Dose Immunoglobulins in Children: From Approved Indications to Off-Label Use

BACKGROUND

The large-scale utilization of immunoglobulins in patients with inborn errors of immunity (IEIs) since 1952 prompted the discovery of their key role at high doses as immunomodulatory and anti-inflammatory therapy, in the treatment of IEI-related immune dysregulation disorders, according to labelled and off-label indications. Recent years have been dominated by a progressive imbalance between the gradual but constant increase in the use of immunoglobulins and their availability, exacerbated by the SARS-CoV-2 pandemic.

OBJECTIVES

To provide pragmatic indications for a need-based application of high-dose immunoglobulins in the pediatric context.

SOURCES

A literature search was performed using PubMed, from inception until 1st August 2023, including the following keywords: anti-inflammatory; children; high dose gammaglobulin; high dose immunoglobulin; immune dysregulation; immunomodulation; immunomodulatory; inflammation; intravenous gammaglobulin; intravenous immunoglobulin; off-label; pediatric; subcutaneous gammaglobulin; subcutaneous immunoglobulin. All article types were considered.

IMPLICATIONS

In the light of the current imbalance between gammaglobulins' demand and availability, this review advocates the urgency of a more conscious utilization of this medical product, giving indications about benefits, risks, cost-effectiveness, and administration routes of high-dose immunoglobulins in children with hematologic, neurologic, and inflammatory immune dysregulation disorders, prompting further research towards a responsible employment of gammaglobulins and improving the therapeutical decisional process.

State of the Art: Acute Encephalitis

Encephalitis is a devastating neurologic disease often complicated by prolonged neurologic deficits. Best practices for the management of adult patients include universal testing for a core group of etiologies, including herpes simplex virus (HSV)-1, varicella zoster virus (VZV), enteroviruses, West Nile virus, and anti-N-methyl-D-aspartate receptor (anti-NMDAR) antibody encephalitis. Empiric acyclovir therapy should be started at presentation and in selected cases continued until a second HSV-1 polymerase chain reaction test is negative. Acyclovir dose can be increased for VZV encephalitis. Supportive care is necessary for other viral etiologies. Patients in whom no cause for encephalitis is identified represent a particular challenge. Management includes repeat brain magnetic resonance imaging, imaging for occult malignancy, and empiric immunomodulatory treatment for autoimmune conditions. Next-generation sequencing (NGS) or brain biopsy should be considered. The rapid pace of discovery regarding autoimmune encephalitis and the development of advanced molecular tests such as NGS have improved diagnosis and outcomes. Research priorities include development of novel therapeutics.

Monophasic Acquired Demyelinating Syndromes of the Central Nervous System in Children

Acquired demyelinating syndromes of the central nervous system are immune-mediated demyelinating disorders that can affect the brain, optic nerves, and spinal cord. These disorders have become increasingly recognized in children due to advances in imaging techniques, improvements in diagnostic testing, extensive research into understanding the pathophysiology underlying these disorders, and collaborative multi-institutional efforts to raise awareness of these disorders in children. Moreover, developments in the field of neuroimmunology have allowed us to identify autoantibodies that have presumed causal roles in acquired demyelinating syndromes. Identification of these autoantibodies helps determine clinical course (ie, monophasic vs relapsing course), prognosis, and treatment approach. Acquired demyelinating disorders can affect both children and adults. However, the clinical features, disease course, and treatments are often unique in the pediatric population. Thus, it is important to understand the spectrum of these disorders in children to help provide a timely diagnosis and prompt treatment to achieve optimal outcomes. In this article, the epidemiology, clinical features, diagnosis, treatment, and outcomes of the most common monophasic acquired demyelinating syndromes in children will be reviewed.

Clinical characteristics and associated factors of pediatric acute disseminated encephalomyelitis patients with MOG antibodies: a retrospective study in Hangzhou, China

Background

To explore the clinical characteristics and related factors of children with acute disseminated encephalomyelitis (ADEM) with positive anti-myelin oligodendrocyte glycoprotein (MOG) antibody.

Methods

A retrospective study was conducted and enrolled pediatric ADEM patients who underwent serum MOG antibody detection from May 2017 to August 2020. The patients were divided into two groups: MOG- immunoglobulin G (IgG) positive (n = 35) and MOG-IgG negative (n = 50). We analyzed the clinical characteristics of MOG-IgG-positive ADEM pediatric patients and conducted a comparative analysis between the two groups.

Results

Thirty-five patients (21 males and 14 females) in the MOG-IgG-positive group with encephalopathy, multifocal neurological symptoms, and typical magnetic resonance imaging (MRI) abnormalities were enrolled. They usually had a favorable outcome, while some suffered from relapse. Compared to the MOG-IgG-negative group, MOG-IgG-positive ADEM patients had a longer disease duration (median: 10 vs. 6 days), more meningeal involvement (31.4% vs. 8%) and frontal lobe involvement (82.8% vs. 68%), higher relapse rates (14.3% vs. 2%), lower serum tumor necrosis factor (1–12.4 pg/ml, median 1.7 vs. 1–34 pg/ml, median 2.2) and interferon-gamma (1–9.4 pg/ml, median 1.3 vs. 1–64 pg/ml, median 3) (P < 0.05, respectively). Multivariate logistic regression analysis showed that the longer disease duration, meningeal involvement and frontal lobe involvement were the correlated factors of patients with ADEM with MOG antibody (P < 0.05).

Conclusions

Our findings provide clinical evidence that MOG-IgG positivity is associated with longer disease duration, meningeal involvement, and frontal lobe involvement.

Clinical Presentation and Outcomes of Acute Disseminated Encephalomyelitis in Adults Worldwide: Systematic Review and Meta-Analysis

Background

Acute disseminated encephalomyelitis (ADEM) is a rare demyelinating disorder that is often misdiagnosed. To improve early diagnosis, we performed a systematic review and meta-analysis of clinical features, outcomes for ADEM in adults.

Methods

The PubMed, Embase, Web of Science and Cochrane Library databases were searched for studies reporting the clinical features of adults with ADEM between January 1990 and May 2021. A random-effects meta-analysis model was used to pool data on clinical features and functional outcomes.

Results

Twelve studies examining 437 adults with ADEM met the inclusion criteria. Overall, the clinical features and diagnostic findings observed in more than two-thirds of the patients were white matter lesions [87.1%, 95% confidence interval (CI)=75-95.6], polyfocal onset (80.5%, 95% CI=50.5-98.9) and pyramidal signs (68.7%, 95% CI =40.0-91.9). The mortality rate was 7.8% (95% CI = 3.3–13.5), and the risk of residual deficits was 47.5% (95% CI = 31.8–63.4).

Conclusions

Adults with ADEM had worse outcomes than children. Clinicians should maintain high clinical suspicion for patients presenting with certain clinical features and diagnostic findings.

Clinical and Magnetic Resonance Imaging Characteristics of Pediatric Acute Disseminating Encephalomyelitis With and Without Antibodies to Myelin Oligodendrocyte Glycoprotein

BACKGROUND

Myelin oligodendrocyte glycoprotein-immunoglobulin G (MOG-IgG)-associated disorders (MOGADs) have been considered as a new inflammatory disease entity of the central nervous system (CNS) and have heterogeneous clinical and imaging presentations. Acute disseminated encephalomyelitis (ADEM) is one of the most important phenotypes. Our research is aimed to compare the clinical and magnetic resonance imaging (MRI) characteristics of ADEM with or without MOG-IgG in pediatric-acquired demyelinating syndromes (ADSs).

METHODS AND RESULTS

We retrospectively reviewed the clinical characteristics, MRI features, and outcomes of pediatric patients with ADSs from March 2017 to February 2021 in our center. MOG-IgG was analyzed by transfected cell-based assay (CBA). Among 46 children with ADEM, 21 children (11 girls and 10 boys) were positive for MOG-IgG. Headache, fever, vomiting, vertigo, ataxia, and decreased muscle strength were common in all enrolled children. No significant difference existed in demographic characteristics, symptoms at an initial episode, or laboratory cerebrospinal fluid (CSF) findings between children with MOG-IgG and children without MOG-IgG. For children with MOG-IgG seropositive ADEM, cerebral MRI showed widespread, poorly demarcated bilateral lesions, especially in cortical and subcortical white matter, and spinal MRI often showed lesions spanning more than three segments. The significant difference in MRI features between the two groups was the presence of lesions in the thalamus and cortical area (p < 0.05). Most children in both groups showed clinical improvement 1 week after immunotherapy and achieved recovery during their hospital stay. Three children with MOG-IgG and four children without MOG-IgG had one or more relapsing courses with median interattack intervals of 4 (range: 1-7) months and 10 (range: 1-24) months, respectively. New clinical symptoms and lesions on cerebral and spinal MRI were found during relapsing courses in two groups. No recurrences were recorded 6-51 months after each patient's last episode.

CONCLUSIONS

There was no significant difference in clinical characteristics between ADEM children with MOG-IgG and ADEM children without MOG-IgG. For children with MOG-IgG seropositive ADEM, cerebral MRI showed large, bilateral lesions and spinal MRI often showed lesions spanning more than three segments. Children achieved a favorable outcome regardless of MOG-IgG serostatus.

Weakness, Numbness and Urinary Incontinence in an 11-Year-Old Female

Acute disseminated encephalomyelitis (ADEM) affects the central nervous system (CNS) via a rapid and auto-immune process. It has been associated to viral and bacterial infections, as well as after immunization. Since the beginning of the SARS-CoV-2 (COVID-19) pandemic, reports of COVID 19 infection have been linked to ADEM. We present a case of an 11-year-old female with neurological symptoms during the acute phase of her COVID-19 illness, with MRI changes and positive Myelin Oligodendrocyte Glycoprotein (MOG) antibodies, with clinical presentation consistent of ADEM.

Transient Myelin Oligodendrocyte Glycoprotein Antibody-positive Acute Disseminated Encephalomyelitis Following Influenza A Infection: A Rare Case

Acute disseminated encephalomyelitis (ADEM) is an uncommon disease generally with a preceding history of infectious illness. Here, we report a rare case of ADEM following influenza A infection with transient detection of anti-myelin oligodendrocyte glycoprotein (MOG) antibody in a young male patient who presented with extensive demyelination of brain and spinal cord, likely the result of dysregulated immune response from previous influenza A infection. The patient presented to the emergency with urinary retention and progressive ascending weakness of lower limbs. Magnetic resonance imaging (MRI) of the brain and spinal cord showed multiple ill-defined hyperintensities, suggestive of demyelination. The clinical presentation, MRI findings, cerebrospinal fluid examination, negative anti-aquaporin-4 antibody and metabolic and other viral infectious screening supported the diagnosis of ADEM. The patient had transiently positive anti-MOG antibodies (for 3 months) and was treated with intravenous immunoglobulin followed by oral prednisolone for 3 months. There was a significant recovery in the upper limb weakness and brainstem function. This case highlights the association of anti-MOG antibody with ADEM following viral infections and the need for prolonged follow-up to differentiate between transient antibodies from relapsing MOG antibody disease.

Post-COVID-19 Acute Disseminated Encephalomyelitis in a 17-Month-Old

Neurologic manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in pediatric patients have been reported in the acute and postinfectious stages of coronavirus disease 2019. Acute disseminated encephalomyelitis (ADEM) typically presents in children after a viral illness at a mean age of 3 to 7 years. A total of 60% to 90% of literature-reported pediatric patients with ADEM have minimal to no neurologic deficits at long-term follow-up. We present a 17-month-old developmentally typical girl with parental complaints of irritability, upper extremity weakness, and gait disturbance. She presented to the hospital afebrile and irritable with right-sided nasolabial fold flattening, neck stiffness, left upper extremity rigidity, right upper extremity paresis, bilateral lower extremity hyperreflexia, and truncal ataxia. During her hospital course, she became somnolent with autonomic instability and was transferred to intensive care. Contrasted brain MRI revealed diffuse patchy T2 hyperintensities without contrast enhancement. Nasopharyngeal SARS-CoV-2 polymerase chain reaction and serum antibody testing results were positive. Cerebral spinal fluid analysis was unremarkable. Respiratory viral panel and autoimmune encephalitis and demyelinating disorders panel results were negative. She was started on high-dose methylprednisolone and intravenous immunoglobulin, with improvement in mental status, focal deficits, and ambulation. After hospital discharge, she received inpatient rehabilitation for 2 weeks and at 2 month follow-up had a full neurologic recovery. We report the youngest case of postinfectious ADEM due to SARS-CoV-2 in a toddler. Early recognition of autoimmune and inflammatory complications of SARS-CoV-2 is vital for early aggressive immunomodulatory treatment and, consequently, improved morbidity in these patients.

Update on Acute Disseminated Encephalomyelitis in Children and Adolescents

Acute disseminated encephalomyelitis (ADEM) is an immune-mediated, inflammatory demyelinating disease of the central nervous system (CNS) that usually affects children and young adults after an infection or vaccination. The presence of several conditions mimicking ADEM, added to the lack of specific biomarkers, makes diagnosis potentially hard. Prompt diagnosis is necessary to start adequate treatment to improve the clinical course and long-term outcome. Because of its heterogeneity in both clinical presentation and course, challenges remain in establishing the most appropriate therapeutic approach in each patient. The aim of this review is to provide an update on management of this disease with a focus on acute treatment and to give suggestions for future research. We showed that there are currently no guidelines that help clinicians manage ADEM and therapeutic decisions are often made on a case-by-case basis. Further studies are necessary to identify clinical, laboratory, and instrumental criteria that could be correlated with outcomes and guide clinicians in choosing when and what treatment should be given in each case.

Management of pediatric post-infectious neurological syndromes

BACKGROUND

Post-Infectious Neurological Syndromes (PINS) are heterogeneous neurological disorders with post or para-infectious onset. PINS diagnosis is complex, mainly related to the absence of any recognized guidelines and a univocal definition.

AIM OF THE STUDY

To elaborate a diagnostic guide for PINS.

MATERIALS AND METHODS

We retrospectively analysed patients younger than 14 years old admitted to Bambino Gesù Children's Hospital in Rome for PINS from December 2005 to March 2018. Scientific literature using PubMed as research platform was analysed: the key words "Post-Infectious Neurological Syndromes" were used.

RESULTS

A polysymptomatic presentation occurred in a percentage of 88% of the children. Motor signs and visual disturbances the most observed symptoms/signs were the most detached, followed by fever, speech disturbances, sleepiness, headache and bradipsychism. Blood investigations are compatible with inflammation, as a prodromal illnesses was documented in most cases. Normal cerebral spinal fluid (CSF) characteristics has been found in the majority of the study population. Magnetic resonance imaging (MRI) was positive for demyelinating lesions. Antibiotics, acyclovir and steroids have been given as treatment.

DISCUSSION

We suggest diagnostic criteria for diagnosis of PINS, considering the following parameters: neurological symptoms, timing of disease onset, blood and CSF laboratory tests, MRI imaging.

CONCLUSIONS

We propose criteria to guide clinician to diagnose PINS as definitive, probable or possible. Further studies are required to validate diagnostic criteria.

Clinical and Neuroimaging Characteristics of Pediatric Acute Disseminating Encephalomyelitis With and Without Antibodies to Myelin Oligodendrocyte Glycoprotein

Objective: To compare the clinical and neuroimaging characteristics of anti-myelin oligodendrocyte glycoprotein antibody (MOG-ab) negative and positive pediatric acute disseminating encephalomyelitis (ADEM) patients.

Methods: Clinical characteristics, neuroimaging features, ancillary examination results, and outcomes of pediatric ADEM patients were retrospectively reviewed between February 2016 and July 2019.

Results: Among 37 pediatric ADEM patients, 24 patients (11 girls and 13 boys) fulfilled the inclusion criteria. The median age was 72 (range 19–156) months, and the median follow-up duration was 20 (range 12–48) months. Children with ADEM and MOG-abs presented with increased ataxia, reduced bladder/rectum dysfunction, and paralysis compared to children without MOG-abs. An important finding was that no significant differences existed in age at symptom onset, sex ratio, time from immunotherapy to clinical improvement and clinical recovery, or modified Rankin Scale (mRS) at the last follow-up. More typical cerebral MRI lesions were detected in patients with ADEM and MOG-abs than in children without MOG-abs [11/12 (91.7%) vs. 8/12 (66.7%)]. Cerebellar lesions were higher in ADEM patients with MOG-abs (7/12, 58.3%) than in those without MOG-abs (2/12, 16.7%). While seven children had abnormal spinal MRI findings (7/12, 58.3%) and five had longitudinally extensive transverse myelitis (LETM) (5/12, 41.7%) per group, the coexistence of spinal dysfunction and abnormal spinal MRI was lower in ADEM with MOG-abs (2/12, 16.7%) than in children without MOG-abs (7/12, 58.3%). Clinical improvement was achieved 1 week after immunotherapy. Most children in both groups achieved clinical recovery within 3 months after immunotherapy, although two (16.7%) patients with ADEM and MOG-abs had persistent neurological sequelae at the last follow-up.

Conclusion: MOG-abs-positive ADEM is a major subtype of pediatric ADEM. Ataxia is the most common clinical presentation in pediatric ADEM and MOG-abs. Children with ADEM and MOG-abs have similar patterns of lesions characterized by large, bilateral, widespread lesions, as well as more cerebellar lesions than children without MOG-abs. Most spinal lesions were subclinical in pediatric ADEM with MOG-abs. A favorable prognosis can be achieved for pediatric ADEM regardless of the MOG-abs status. However, some patients with MOG-abs are likely to have more severe neurological sequelae.

Molecular Biomarkers in Multiple Sclerosis and Its Related Disorders: A Critical Review

Multiple sclerosis (MS) is a chronic autoimmune disease affecting the central nervous system (CNS) which can lead to severe disability. Several diseases can mimic the clinical manifestations of MS. This can often lead to a prolonged period that involves numerous tests and investigations before a definitive diagnosis is reached. As well as the possibility of misdiagnosis. Molecular biomarkers can play a unique role in this regard. Molecular biomarkers offer a unique view into the CNS disorders. They help us understand the pathophysiology of disease as well as guiding our diagnostic, therapeutic, and prognostic approaches in CNS disorders. This review highlights the most prominent molecular biomarkers found in the literature with respect to MS and its related disorders. Based on numerous recent clinical and experimental studies, we demonstrate that several molecular biomarkers could very well aid us in differentiating MS from its related disorders. The implications of this work will hopefully serve clinicians and researchers alike, who regularly deal with MS and its related disorders.

A Probable Case of Recurrent Bickerstaff Brainstem Encephalitis With Fulminant Course in a Pediatric Patient

INTRODUCTION

Bickerstaff brainstem encephalitis is a rare, often postinfectious, syndrome characterized by the clinical triad of ophthalmoplegia, ataxia, and altered consciousness. Here, we present a probable case of recurrent, pediatric Bickerstaff encephalitis, whereby the patient acutely developed loss of consciousness and eventually brain death despite optimal management.

CASE REPORT

A 3-year-old male patient initially presented to the emergency department with progressive ataxia, following history of upper respiratory tract infection. He deteriorated within 12 hours of hospitalization, requiring cardiopulmonary resuscitation. The patient had decreased consciousness thereafter, showing minimal signs of brain activity. He was then deemed to be suffering a second episode of Bickerstaff encephalitis, the first being a year prior, and intravenous immunoglobulins were administered immediately. Magnetic resonance imaging of the brain on day 2 of admission showed signs of diffuse, bilateral encephalitis in the brainstem, thalami, and basal ganglia. Brain death was confirmed on day 11 of admission, following 2 brain death examinations.

CONCLUSION

Although Bickerstaff brainstem encephalitis tends to involve the brainstem, outcomes of brain death have been rarely reported, even more so in the pediatric age group. This case report sheds light on, possibly, the first reported fatality of Bickerstaff encephalitis among children.