Acute disseminated encephalomyelitis: an acute hit against the brain

Eastern equine encephalitis virus: Pathogenesis, immune response, and clinical manifestations

Eastern equine encephalitis virus (EEEV) is a lethal Alphavirus transmitted by Culiseta melanura mosquitoes that primarily cycles between birds. Although rare, infections in humans and horses are associated with high mortality rates and severe neurological effects. Climate change appears to be increasing the spread of this virus. This study aims to provide a comprehensive analysis of EEEV, including its transmission dynamics, pathogenesis, induced host immune response, and long-term impacts on survivors. It also highlights the virus's unique immune evasion strategies that complicate disease management and contribute to severe clinical outcomes, such as encephalitis with fever, convulsions, and coma. Survivors often face chronic cognitive, motor, and psychosocial impairments. Despite these significant public health risks, gaps remain in understanding the molecular mechanisms underlying immune evasion and the long-term neurological sequelae in survivors. By collating current knowledge, this review underscores the urgent need for the development of targeted vaccines and therapeutic interventions to mitigate the growing threat of EEEV, particularly in the context of climate change-driven geographical expansion.

Extracellular vesicles in the pathogenesis of neurotropic viruses

Neurotropic viruses, characterized by their capacity to invade the central nervous system, present a considerable challenge to public health and are responsible for a diverse range of neurological disorders. This group includes a diverse array of viruses, such as herpes simplex virus, varicella zoster virus, poliovirus, enterovirus and Japanese encephalitis virus, among others. Some of these viruses exhibit high neuroinvasiveness and neurovirulence, while others demonstrate weaker neuroinvasive and neurovirulent properties. The clinical manifestations of infections caused by neurotropic viruses can vary significantly, ranging from mild symptoms to severe life-threatening conditions. Extracellular vesicles (EVs) have garnered considerable attention due to their pivotal role in intracellular communication, which modulates the biological activity of target cells via the transport of biomolecules in both health and disease. Investigating EVs in the context of virus infection is crucial for elucidating their potential role contribution to viral pathogenesis. This is because EVs derived from virus-infected cells frequently transfer viral components to uninfected cells. Importantly, EVs released by virus-infected cells have the capacity to traverse the blood-brain barrier (BBB), thereby impacting neuronal activity and inducing neuroinflammation. In this review, we explore the roles of EVs during neurotropic virus infections in either enhancing or inhibiting viral pathogenesis. We will delve into our current comprehension of the molecular mechanisms that underpin these roles, the potential implications for the infected host, and the prospective diagnostic applications that could arise from this understanding.

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.

Clinical, radiological, therapeutic and prognostic differences between MOG-seropositive and MOG-seronegative pediatric acute disseminated encephalomyelitis patients: a retrospective cohort study

Objective

This study aimed to compare the clinical, radiological, therapeutic, and prognostic differences between pediatric patients showing acute disseminated encephalomyelitis (ADEM) with and without myelin oligodendrocyte glycoprotein (MOG) antibodies.

Methods

We retrospectively collected all available data of children diagnosed with ADEM and tested for serum MOG antibodies at the Children's Hospital of Chongqing Medical University from January 2017 to May 2021.

Results

A total of 62 patients were included in our cohort, of which 35 were MOG-seropositive and 27 were MOG-seronegative. MOG-seropositive ADEM children presented with significantly lower rates of seizures (P = 0.038) and cranial nerve (III-XII) palsy (P = 0.003). Isolated leukocytosis in the blood was more common in ADEM children with MOG antibodies (P < 0.001). The two groups showed no significant differences in the distributions and extent of the MRI lesions as well as the appearance of typical/atypical magnetic resonance imaging (MRI) features. MOG-seropositive children were more likely to relapse (P = 0.017) despite having slower oral prednisolone tapering after acute treatments (P = 0.028). In scoring performed on the basis of two neurological function scoring systems, MOG-seropositive children showed milder neurological disability status at onset (P = 0.017 and 0.025, respectively) but showed no difference during follow-up.

Conclusion

In summary, the differences in the clinical manifestations and auxiliary examination findings for MOG-seropositive and MOG-seronegative ADEM children lacked significance and specificity, making early identification difficult. MOG-seropositive children were more likely to relapse and showed slower steroid tapering. Moreover, MOG-seronegative children tended to have more severe neurological impairments at onset with no difference during follow-up.

Central Nervous System Demyelination Following COVID-19 mRNA-Based Vaccination: Two Case Reports and Literature Review

As the world embarks on mass vaccination against SARS-CoV2 to alleviate the spread of this highly contagious novel coronavirus, there are growing anecdotal reports on immune-related neurological complications following immunisation. Similarly, we encountered 2 cases of central nervous system demyelination at our centre with Comirnaty (BNT162b2), a mRNA-based COVID-19 vaccine. Our first patient had typical clinical-radiological manifestations of acute disseminated encephalomyelitis (ADEM) after his COVID-19 vaccination. This was the sixth reported case to date. Our second patient presented with an unusual complaint of trigeminal neuralgia, with an identifiable demyelinating lesion observed in the pons on neuroimaging. Both cases responded well to immunotherapy. However, larger prospective controlled studies and formal registries are much needed to ascertain a possible relationship between COVID-19 vaccines and acute central nervous system demyelination.

Post-Varicella Neurological Complications: A Preliminary Observation from a Tertiary Care Centre of Eastern India

Objectives:

The objective of this study is to analyse detailed clinical presentations, imaging findings, and outcome in a series of 17 cases (n = 17) with neurological complications following acute varicella infection.

Methods:

It is an observational study on the patients who presented to the neurology outpatient department of our institute with neurological abnormalities following acute varicella infection within the last 3 months.

Results:

Neuroimaging, either computed tomography or magnetic resonance imaging, cerebrospinal fluid analysis, electroencephalography and nerve conduction studies were performed in all the patients along with other specialized investigations as per clinical context. The age of presentation varied from childhood to middle age (median age was 23 years) and range of clinical spectrum was also wide. Peripheral nervous system involvement was more common in the form of Guillain–Barré syndrome (29.4%) and isolated lower motor neuron facial nerve palsy (23.5%) compared to central nervous system (CNS) involvement. CNS involvement was documented in the form of ataxia (11.76%), myelopathy (17.6%), stroke (5.88%) and encephalitis (5.88%).

Conclusion:

Chickenpox is a common viral disease and most patients recover without any complication. Although rare, neurological complications following acute varicella infection may have myriad presentations ranging from lower motor neuron facial palsy to life-threatening encephalitis. Compared to other studies, varicella encephalitis and ataxia were not so common in our study group. Response to therapy was uniformly good except in the patients presenting with ataxia. Response was particularly good to central and peripheral demyelinating disorders.

Acute disseminated encephalomyelitis with bilateral optic neuritis following ChAdOx1 COVID-19 vaccination

Background

Acute disseminated encephalomyelitis (ADEM) is a rare immune-mediated inflammatory demyelinating disease of the central nervous system. We report a case of ADEM presenting with bilateral optic neuritis temporally associated with the ChAdOx1 vaccine against SARS-COVID19 virus.

Case presentation

A 36-year-old female presented with bilateral optic neuritis following her first dose of the ChAdOx1 vaccine. Initial MRI Brain showed evidence of demyelination within the subcortical white matter, with no radiological involvement of the optic nerves. Visual evoked potentials were consistent with bilateral optic neuritis which was confirmed radiologically on follow up MRI. She was treated with intravenous steroids with improvement both in symptoms and radiological appearance. A pseudo-relapse occurred which was treated with a further course of intravenous steroids followed by an oral taper. The clinical, radiological and serological results were most consistent with diagnosis of ADEM.

Conclusions

ADEM is an exceedingly rare complication of ChAdOx1 vaccine despite millions of doses. While it is imperative clinicians remain aware of neurological complications of vaccines, the importance of vaccination to control a pandemic should not be undermined.

Measles-Associated CNS Complications: A Review

Measles virus infection is a common infectious disease of childhood, incidence of which is still high in developing countries. Other than the morbidity associated with the acute systemic infection, the measles virus can cause serious fatal neural complications. It can either enter the brain leading to acute encephalitis like primary measles encephalitis and acute post infectious measles encephalomyelitis or it may persist in brain cells (as mutated virus) leading to long-term neurodegenerative diseases like measles inclusion body encephalitis and subacute sclerosing pan encephalitis. The patho-clinical features, treatment, and the outcomes of these complications are different and should be identified in time for early diagnosis and management.

Non-infectious mechanisms of neurological damage due to infection

Infections of the nervous system is a growing aspect of clinical neurology. Accumulating knowledge in early diagnosis, course, therapy and prognosis is enlarging the clinical tools required for effective therapy. Of special importance is the ability to differentiate between proper infections, where anti-microbial agents, when available, should be introduced and used and post infectious conditions where therapy is mainly directed against the host immune system. The two conditions sometimes overlap, a situation that requires the ability to combine clinical skills with the use of laboratory tools such as polymerase chain reaction (PCR), serology, and antigenic detection. In the era of the SARS-CoV-2 pandemic, the need to make this distinction is emphasized as correct diagnosis of post infectious conditions and expedited therapy is important and sometimes lifesaving. We here attempt to present several infectious agents and their possible indirect damage to the nervous system causing in some cases significant neurological deficits. We try to limit our focus on those mechanisms which do not involve the direct tissue damage by the infectious agents but rather are connected to para- and post-infectious mechanisms. We attempt to delineate the features that will enable to tailor the correct diagnosis and following the effective therapy.

Epidemiology of Demyelinating Diseases in Korean Pediatric Patients

The epidemiology of demyelinating diseases in the Korean pediatric population has not been reported to date. This study aimed to identify the epidemiology of demyelinating diseases in Korean children by using big data. The subjects were children (0-17 years old) diagnosed with acute-disseminated encephalomyelitis, multiple sclerosis, neuromyelitis optica, and Guillain-Barré syndrome enrolled in the Korean Health Insurance Review and Assessment Service (HIRA) from January 2010 to December 2017.Of 1722 enrolled children, 553 (32.1%) had acute-disseminated encephalomyelitis, 170 (9.9%) had multiple sclerosis, 68 (3.9%) had neuromyelitis optica, and 931 (54.1%) had Guillain-Barré syndrome. The male-female ratios were 1.47:1 in acute-disseminated encephalomyelitis, 1.43:1 in Guillain-Barré syndrome, 1:1.66 in multiple sclerosis, and 1:1.62 in neuromyelitis optica. Demyelinating diseases were most prevalent in summer. The prevalence differed by region, with 545 (31.6%) in Seoul and 298 (17.3%) in Gyeonggi. This study is the first to identify the incidence of demyelinating diseases in South Korea.

Adjunctive steroids in adults with encephalitis: a propensity score analysis

OBJECTIVE

Adjuvant steroids have been used for the treatment of encephalitis, although there is limited data regarding its benefit. We described the use and impact of adjunctive steroids on adverse clinical outcomes (ACO) in adults with encephalitis.

METHODS

Retrospective observational study of 230 adults with encephalitis at two tertiary care hospital systems in Houston, Texas, between August 2008 and September 2017. An ACO was assessed at the time of death or discharge and defined as a Glasgow Outcome Scale 1-4. A propensity score analysis was performed.

RESULTS

Out of 230 adult encephalitis patients enrolled, 121 (52.6%) received steroids. Adjunctive steroids were given more frequently to those who had focal neurological deficits (P = 0.01), required mechanical ventilation (MV) (P = 0.01), had intensive care unit admission (P < 0.001), had white matter abnormalities (P = 0.01) or cerebral edema on magnetic resonance imaging of the brain (P = 0.003). An ACO was seen in 135 (58.7%) of patients. The use of adjunctive steroids did not impact ACOs (P = 0.52) on univariate analyses or after propensity score matching. Predictors for an ACO in logistic regression analyses included a Glasgow Coma Score (GCS) < 8, fever, MV, and cerebral edema.

INTERPRETATION

Adjunctive steroids are used more frequently in sicker patients and are not associated with improved clinical outcomes.

Autophagy in white matter disorders of the CNS: mechanisms and therapeutic opportunities

Autophagy is a constitutive process that degrades, recycles and clears damaged proteins or organelles, yet, despite activation of this pathway, abnormal proteins accumulate in neurons in neurodegenerative diseases and in oligodendrocytes in white matter disorders. Here, we discuss the role of autophagy in white matter disorders, including neurotropic infections, inflammatory diseases such as multiple sclerosis, and in hereditary metabolic disorders and acquired toxic‐metabolic disorders. Once triggered due to cell stress, autophagy can enhance cell survival or cell death that may contribute to oligodendrocyte damage and myelin loss in white matter diseases. For some disorders, the mechanisms leading to myelin loss are clear, whereas the aetiological agent and pathological mechanisms are unknown for other myelin disorders, although emerging studies indicate that a common mechanism underlying these disorders is dysregulation of autophagic pathways. In this review we discuss the alterations in the autophagic process in white matter disorders and the potential use of autophagy‐modulating agents as therapeutic approaches in these pathological conditions. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Severe acute disseminated encephalomyelitis complicating measles infection

A 36-year-old man presented with an acute progressive encephalopathy, followed by tetraparesis and was diagnosed with acute disseminated encephalomyelitis (ADEM) complicating infection with measles virus. Despite demonstrating a typical rash and other early symptoms of measles infection, there was uncertainty around the initial diagnosis. Cerebrospinal fluid analysis and MRI of the brain and spinal cord were consistent with severe ADEM. He required treatment on intensive care but responded favourably to immunosuppressive therapy.This case highlights the importance of recognising acute measles infection, familiarity with the neurological complications and the potential for good outcome. Healthcare professionals must continue to play an active role in educating the public on the importance of maintaining herd immunity through universal immunisation.

Neuroinvasive potential of SARS-CoV2 with neuroradiological and neuropathological findings: is the brain a target or a victim?

Coronaviridae family includes pathogen viruses for humans, that lead to clinical conditions with main respiratory involvement; many of these viruses have notoriously a neuroinvasive potential, as demonstrated by published data on SARS-CoV and MERS-CoV epidemics, as well by results obtained in experimental models. During pandemic of coronavirus disease 2019 (COVID-19), it is noticed that the central nervous system involvement represented a truly significant moment in the history of some COVID-19 patients; indeed, clinical and radiological features published in literature regarding COVID-19 disease are consistent with a neurological involvement. It is also known that histopathological data related to SARS-CoV2 infection have been published with considerable delay, which was even greater for neuropathological information. Moreover, many published data are incomplete, and often the lesions described are not directly related to the action of the virus. In this review, we collected the available radiological and neuropathological information, in order to delineate a more complete picture of the relationship between SARS-Cov2 and brain, focusing our attention on the two most important neuroinvasion routes for the virus. We also highlighted what we consider methodological mistakes both in the autopsy procedures and brain study in COVID-19 deaths. We emphasize the need for a complete study of all the organs in case of autopsy. It is important that through this experience, we no longer do the mistake of neglecting the brain.

Acute Disseminated Encephalomyelitis: Current Perspectives

Acute disseminated encephalomyelitis (ADEM) is an immune-mediated central nervous system (CNS) disorder, characterized by polyfocal symptoms, encephalopathy and typical magnetic resonance imaging (MRI) findings, that especially affects young children. Advances in understanding CNS neuroimmune disorders as well as the association of myelin oligodendrocyte glycoprotein antibody (MOG-Ab) with both monophasic and recurrent forms of ADEM have led to new insights into its definition, management and outcome. In this review, we aim to provide an update based on current epidemiologic, clinical, radiological and immunopathological aspects and clinical outcome of ADEM.

Epstein-Barr Virus Infection in the Development of Neurological Disorders

Epstein-Barr Virus (EBV) is a ubiquitous human herpesvirus that contributes to the etiology of diverse human cancers and auto-immune diseases. EBV establishes a relatively benign, long-term latent infection in over 90 percent of the adult population. Yet, it also increases risk for certain cancers and auto-immune disorders depending on complex viral, host, and environmental factors that are only partly understood. EBV latent infection is found predominantly in memory B-cells, but the natural infection cycle and pathological aberrations enable EBV to infect numerous other cell types, including oral, nasopharyngeal, and gastric epithelia, B-, T-, and NK-lymphoid cells, myocytes, adipocytes, astrocytes, and neurons. EBV infected cells, free virus, and gene products can also be found in the CNS. In addition to the direct effects of EBV on infected cells and tissue, the effect of chronic EBV infection on the immune system is also thought to contribute to pathogenesis, especially auto-immune disease. Here, we review properties of EBV infection that may shed light on its potential pathogenic role in neurological disorders.

Vaccine-Associated Neurological Adverse Events: A Case Report and Literature Review

Vaccination is an effective strategy to reduce the burden of preventable illness. However, many clinical reports revealed that various vaccinations may associate with neurological disorders, mainly including autoimmune disease, febrile seizure, and vaccine-associated paralytic poliomyelitis (VAPP). Although more and more reports revealed that part of the above post-vaccine neurological disorders is not directly related to vaccination, it may be merely a coincidence. However, these reports may increase the hesitancy on vaccination for the public population and influence the coverage of vaccination. In this report, we described a child with acute flaccid paralysis possibly caused by a poliovirus vaccine. To provide feasible ways to realize or reduce the risk of neurological adverse events caused by vaccines, we further provide a mini-review of the literature of vaccination associated with neurological adverse events. This revealed that oral poliomyelitis vaccine use exclusively and type 2 serotype poliomyelitis vaccine virus were the risk factors for VAPP. The combination vaccine was associated with an increased risk of ADEM and FS following immunization when compared with the administration of vaccines separately. Even though cases have been reported that vaccination may be a trigger of anti-NMDARe and GBS, there is no direct evidence to prove that vaccination increased the risk of GBS and anti-NMDARe.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice - Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Eighth Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating and categorizing indications for the evidence-based use of therapeutic apheresis (TA) in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Eighth Edition of the JCA Special Issue continues to maintain this methodology and rigor in order to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Eighth Edition, like its predecessor, continues to apply the category and grading system definitions in fact sheets. The general layout and concept of a fact sheet that was introduced in the Fourth Edition, has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of TA in a specific disease entity or medical condition. The Eighth Edition comprises 84 fact sheets for relevant diseases and medical conditions, with 157 graded and categorized indications and/or TA modalities. The Eighth Edition of the JCA Special Issue seeks to continue to serve as a key resource that guides the utilization of TA in the treatment of human disease.

Pregnancy-Related Immune Changes and Demyelinating Diseases of the Central Nervous System

Demyelinating diseases of the central nervous system comprise a heterogeneous group of autoimmune disorders characterized by myelin loss with relative sparing of axons occurring on a background of inflammation. Some of the most common demyelinating diseases are multiple sclerosis, acute disseminated encephalomyelitis, and neuromyelitis optica spectrum disorders. Besides showing clinical, radiological, and histopathological features that complicate their diagnosis, demyelinating diseases often involve different immunological processes that produce distinct inflammatory patterns. Evidence of demyelination diseases derives mostly from animal studies of experimental autoimmune encephalomyelitis (EAE), a model that relies on direct antibody–antigen interactions induced by encephalitogenic T cells. Pregnancy is characterized by non-self-recognition, immunomodulatory changes and an altered Th1/Th2 balance, generally considered a Th2-type immunological state that protects the mother from infections. During pregnancy, the immune response of patients with autoimmune disease complicated with pregnancy is different. Immune tolerance in pregnancy may affect the course of some diseases, which may reach remission or be exacerbated. In this review, we summarize current knowledge on the immune status during pregnancy and discuss the relationship between pregnancy-related immune changes and demyelinating diseases of the central nervous system.

Long-Term Neuropsychological Outcomes of Childhood Onset Acute Disseminated Encephalomyelitis (ADEM): a Meta-Analysis

The long-term neurocognitive prognosis of childhood onset acute disseminated encephalomyelitis (ADEM) is unclear. This review and quantitative synthesis of the available literature examined whether there are long-term impacts of childhood ADEM on neurocognitive functioning. A search of online databases (MEDLINE, EMBASE, EBSCO CINAHL, PsycINFO and the Cochrane Database of Systematic Reviews) from their inception to October 2015 and reference lists identified 13 papers eligible for inclusion in the systematic review; seven of these were eligible for inclusion in meta-analyses. The systematic review indicated that, at a group level there is a positive long-term neuropsychological outcome from childhood onset ADEM. However, despite the apparent absence of long-term negative impacts of ADEM at a group level, at an individual level impairments in the areas of IQ, attention, executive functioning, processing speed, learning and memory, visuospatial skills and internalising symptoms were found in up to 43% of patients when aggregated across the studies. No significant negative effect of ADEM for any of the neuropsychological domains examined was found in meta-analyses. However, the effects for Processing Speed (r mean = -0.296 (CI 95% = -0.605-0.013)) and Internalising symptoms (r mean = 0.242 (CI 95% = -0.014-0.564)) approached significance (p = 0.06), suggesting a trend towards ADEM leading to long-term reduced processing speed and elevated internalising symptoms. Together, our findings suggest that despite a generally positive neurocognitive outcome post childhood ADEM there are a subset of individuals who can suffer from ongoing specific cognitive impairments. Clinical implications and research priorities are discussed.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice-Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Seventh Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating, and categorizing indications for the evidence-based use of therapeutic apheresis in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the Committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Seventh Edition of the JCA Special Issue continues to maintain this methodology and rigor to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Seventh Edition, like its predecessor, has consistently applied the category and grading system definitions in the fact sheets. The general layout and concept of a fact sheet that was used since the fourth edition has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis in a specific disease entity. The Seventh Edition discusses 87 fact sheets (14 new fact sheets since the Sixth Edition) for therapeutic apheresis diseases and medical conditions, with 179 indications, which are separately graded and categorized within the listed fact sheets. Several diseases that are Category IV which have been described in detail in previous editions and do not have significant new evidence since the last publication are summarized in a separate table. The Seventh Edition of the JCA Special Issue serves as a key resource that guides the utilization of therapeutic apheresis in the treatment of human disease. J. Clin. Apheresis 31:149-162, 2016. © 2016 Wiley Periodicals, Inc.

Multiple Sclerosis

Multiple sclerosis (MS) is a chronic disease of the central nervous system (CNS) characterized by loss of motor and sensory function that results from immune-mediated inflammation, demyelination, and subsequent axonal damage.

Clinically, most MS patients experience recurrent episodes (relapses) of neurological impairment, but in most cases (60–80%) the course of the disease eventually becomes chronic and progressive, leading to cumulative motor, sensory, and visual disability, and cognitive deficits.

The course of the disease is largely unpredictable and its clinical presentation is variable, but its predilection for certain parts of the CNS, which includes the optic nerves, the brain stem, cerebellum, and cervical spinal cord, provides a characteristic constellation of signs and symptoms. Several variants of MS have been nowadays defined with variable immunopathogenesis, course and prognosis. Many new treatments targeting the immune system have shown efficacy in preventing the relapses of MS and have been introduced to its management during the last decade.

An Acute Disseminated Encephalomyelitis-Like Illness in the Elderly: Neuroimaging and Neuropathology Findings

INTRODUCTION

Acute disseminated encephalomyelitis (ADEM) is a rare demyelinating disease of the central nervous system (CNS) that classically occurs in children and adolescents. It characteristically presents with acute inflammation, resulting in demyelination, often following an infectious disease. ADEM has been described in adult patients, but the incidence in the adult and especially elderly population is low.

CASES

We describe five older adults (age 57 to 85) who presented with acute neurological symptoms. Three patients presented with an infectious illness preceding the event, 4 patients were encephalopathic, and oligoclonal bands (OCBs) were negative in all tested cases. The clinical scenario and imaging studies suggested alternative diagnoses, such as metastasis, primary CNS tumor, or stroke. Two patients had contrast enhancing lesions, two other patients had lesions with restricted diffusion on diffusion-weighted imaging. Neuropathologic diagnostic from biopsy or autopsy was eventually conclusive, showing perivascular zones of myelin loss with relative axonal sparing in all five cases.

CONCLUSION

Each of these patients was found to have pathological findings of acute demyelination on tissue diagnosis, suggesting ADEM or ADEM-like disease. The initial presentation and imaging was pointing toward other diagnoses. Broad differential diagnosis is important, especially for older patients, and pathological proof might be warranted for a conclusive diagnosis.

Acute Disseminated Encephalomyelitis

Acute disseminated encephalomyelitis is a primarily pediatric, immune-mediated disease characterized by demyelination and polyfocal neurologic symptoms that typically occur after a preceding viral infection or recent immunization. This article presents the pathophysiology, diagnostic criteria, and magnetic resonance imaging characteristics of acute disseminated encephalomyelitis. We also present evaluation and management strategies.

Acute Disseminated Encephalomyelitis After Human Parechovirus Infection

BACKGROUND

Acute disseminated encephalomyelitis (ADEM) is an inflammatory, demyelinating disease occurring several weeks after viral infection. Enteroviruses have been described as potential triggers of ADEM, but the closely related parechoviruses have not. The objective of the study is to assess the prevalence and disease presentation of ADEM after parechovirus infection in a syndromic surveillance program for pediatric infection/inflammation of the central nervous system (CNS).

METHODS

The surveillance was conducted at the Charité Department of Pediatrics in Berlin, Germany, from November 2010 to November 2014. All hospitalized children meeting predefined case criteria underwent highly standardized prospective clinical assessments based on the published case definitions, including for ADEM. Stool samples were independently analyzed by enterovirus and parechovirus real-time polymerase chain reaction at the Robert Koch Institute.

RESULTS

Of 105,557 patients screened, 774 (0.7%) fulfilled entry criteria for CNS infection/inflammation, with 114 cases ascertained as ADEM. Parechoviruses were detected in 2.5% of patients with CNS infection/inflammation, including 1 case fulfilling ADEM case criteria with the highest level of diagnostic certainty.

CONCLUSIONS

We report a first case of ADEM after parechovirus infection in a 5-year-old female presenting with acute hemiparesis 2 weeks after a respiratory illness. Parechovirus disease should be included in the differential diagnosis of ADEM.

Two Cases of Acute Disseminated Encephalomyelitis Following Vaccination Against Human Papilloma Virus

We herein present two cases of acute disseminated encephalomyelitis (ADEM) following vaccination against human papilloma virus (HPV). Case 1 experienced diplopia and developed an unstable gait 14 days after a second vaccination of Cervarix. Brain magnetic resonance imaging (MRI) showed an isolated small, demyelinating lesion in the pontine tegmentum. Case 2 experienced a fever and limb dysesthesia 16 days after a second vaccination of Gardasil. Brain MRI revealed hyperintense lesion in the pons with slight edema on a T2-weighted image. Both cases resolved completely. It is important to accumulate further data on confirmed cases of ADEM temporally associated with HPV vaccination.

[Acute disseminated encephalomyelitis in children]

L'encéphalomyélite aiguë disséminée (ADEM) est une maladie inflammatoire, démyélinisante, multifocale intéressant principalement la substance blanche du système nerveux central. Elle est rare mais non exceptionnelle chez l'enfant. Les auteurs rapportent une étude colligeant 9 cas d'ADEM pris en charge au service de Pédiatrie du CHU Hassan II à Fès, sur une période de 4 ans. Il s'agit de cinq garçons et quatre filles; âgés entre 2 ans et 13 ans. Les antécédents (ATCD) d'infection virale sont notés chez quatre patients. La fièvre est constante. Les convulsions sont présentes dans cinq cas et les troubles de conscience dans cinq cas. L'examen neurologique était anormal. L’étude de liquide céphalo-rachidien a révélé une réaction méningée. On ne notait pas de syndrome inflammatoire biologique. L'imagerie par résonance magnétique (IRM) cérébrale a objectivé des lésions en hyper-signal en T2 et T2 FLAIR chez tous les patients. Pour le traitement, des bolus de corticoïdes intraveineux ont été administrés, relayés par une corticothérapie orale et associés à une kinésithérapie motrice et un traitement antiépileptique pour certains patients. L’évolution de nos malades était favorable globalement et on a déploré le décès d'une patiente. L'ADEM est une affection rare du système nerveux central. Les critères diagnostiques sont fondés sur des éléments cliniques et des données d'imagerie. La prise en charge doit être précoce et multidisciplinaire.

Severe post-influenza (H1N1) encephalitis involving pulvinar nuclei in an adult patient

Neurological complications of H1N1 infections are mostly found in children, but rare cases of acute encephalopathy and post-infectious encephalitis such as acute disseminated encephalomyelitis (ADEM) have been described in adults. We report a case of an adult presenting with a progressive and severe encephalopathy that developed after H1N1 respiratory infection resolution. Cerebrospinal fluid (CSF) analysis was normal, including negative PCR for herpes simplex virus, H1N1, influenza B and JC virus, and absent oligoclonal IgG bands in CSF and serum. Initial CT scan was normal, but later MRI showed posterior multifocal leucoencephalopathy with pulvinar sign. The delayed neurological findings together with the ancillary investigation, namely the MRI pattern with both grey and white matter involvement, raised the possibility of a post-infectious process, rather than an acute encephalitis. Despite aggressive immunotherapy, the patient experienced severe neurological sequelae. Early recognition of ADEM manifestations by those dealing with H1N1 infection is important as early immunotherapy may improve the prognosis.

Acute disseminated encephalomyelitis progressing to multiple sclerosis: are infectious triggers involved?

Acute disseminated encephalomyelitis (ADEM) and multiple sclerosis (MS) are demyelinating disorders affecting the central nervous system. An autoimmune aetiology has been proposed for both. ADEM principally affects adolescents following acute infection by a variety of pathogens and has also been reported to occur following vaccination. ADEM typically resolves following medical treatment, whereas MS follows a more relapsing and remitting course. The pathogenesis of MS remains unclear, but it is thought that a combination of infectious and non-infectious environmental factors and host genetics act synergistically to cause disease. A variety of viruses, including Epstein Barr virus, cytomegalovirus, herpes simplex virus and varicella zoster virus, have been implicated as possible infectious triggers. The similar clinical and pathological presentation of ADEM and MS presents a diagnostic challenge for distinguishing ADEM from a first episode of MS. Some cases of ADEM progress to MS for reasons that are not currently clear. This review examines the evidence for infectious agents as triggers for ADEM progressing to MS and suggests potential methods that may facilitate identification of infectious agents that may be responsible for the pathogenesis of ADEM to MS.

Acute disseminated encephalomyelitis: current knowledge and open questions

Acute disseminated encephalomyelitis (ADEM) is usually an acute, multi-focal, and monophasic immune-mediated disease of the central nervous system. The disorder is mainly a condition of the pediatric age group, but neurologists are also involved in the management of adult patients. The lack of defined diagnostic criteria for ADEM underlies the limited understanding of its epidemiology, etiology, pathogenesis, course, prognosis, therapy, as well as the association with, and distinction from, multiple sclerosis. The present review summarizes current knowledge and outlines unanswered questions the answers to which should be eventually provided through a synergistic combination of clinical and basic research.

Measles-induced encephalitis

Encephalitis is the most frequent neurological complication of measles virus infection. This review examines the pathophysiology of measles infection and the presentations, diagnosis and treatment of the four types of measles-induced encephalitis including primary measles encephalitis, acute post-measles encephalitis, measles inclusion body encephalitis and subacute sclerosing panencephalitis. The early symptoms of encephalitis may be non-specific and can be mistakenly attributed to a systemic infection leading to a delay in diagnosis. This review provides a summary of the symptoms that should cause health care workers to suspect measles-induced encephalitis.

Acute disseminated encephalomyelitis with severe neurological outcomes following virosomal seasonal influenza vaccine

Acute disseminated encephalomyelitis (ADEM) is an inflammatory, usually monophasic, immune mediate, demyelinating disease of the central nervous system which involves the white matter. ADEM is more frequent in children and usually occurs after viral infections, but may follow vaccinations, bacterial infections, or may occur without previous events. Only 5% of cases of ADEM are preceded by vaccination within one month prior to symptoms onset. The diagnosis of ADEM requires both multifocal involvement and encephalopathy and specific demyelinating lesions of white matter. Overall prognosis of ADEM patients is often favorable, with full recovery reported in 23% to 100% of patients from pediatric cohorts, and more severe outcome in adult patients. We describe the first case of ADEM occurred few days after administration of virosomal seasonal influenza vaccine. The patient, a 59-year-old caucasic man with unremarkable past medical history presented at admission decreased alertness, 10 days after flu vaccination. During the 2 days following hospitalization, his clinical conditions deteriorated with drowsiness and fever until coma. The magnetic resonance imaging of the brain showed multiple and symmetrical white matter lesions in both cerebellar and cerebral hemispheres, suggesting demyelinating disease with inflammatory activity, compatible with ADEM. The patient was treated with high dose of steroids and intravenous immunoglobulin with relevant sequelae and severe neurological outcomes.

[Acute disseminated encephalomyelitis after rabies vaccination: a case report]

Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disease of the central nervous system. It is a disease whose incidence is not precisely known. The presumed mechanism is demyelination of the immune-mediated central nervous system. There is no pathognomonic clinical presentation in ADEM. The combination of multifocal neurological disorders arising in the aftermath of an infection or vaccination should alert the clinician. We report a case of ADEM in an 8-year-old child occurring after antirabies vaccination. The diagnosis was made by nuclear magnetic resonance imaging (bilateral and multifocal lesions in the subcortical occipitoparietal and frontal left anterior white matter with involvement of U fibers) and a history of antirabies vaccination. The clinical course was marked by the appearance of motor and visual effects.

Select topics in neurocritical care

Neurocritical care aims to improve outcomes in patients with life-threatening neurologic illness. The scope of neurocritical care extends beyond the more commonly encountered and important field of cerebrovascular disease, as described previously. This article focuses on neuromuscular, neuroinfectious, and neuroimmunologic conditions that are significant causes of morbidity and mortality in the acutely neurologically ill patient. As understanding continues to increase regarding the physiology of these conditions and the best treatment, rapid identification, triage, and treatment of these patients in the emergency department is paramount.

Cerebrospinal fluid analysis in the context of CNS demyelinating diseases

The central nervous system demyelinating diseases are a group of disorders with different etiologies, characterized by inflammatory lesions that are associated with loss of myelin and eventually axonal damage. In this group the most studied ones are multiple sclerosis (MS), neuromyelitis optic (NMO) and acute disseminated encephalomyelitis (ADEM). The cerebrospinal fluid is essential to differentiate between these different syndromes and to define multiple sclerosis, helping to assess the probability of Clinical Isolated Syndrome turn into multiple sclerosis.

The spectrum of post-vaccination inflammatory CNS demyelinating syndromes

A wide variety of inflammatory diseases temporally associated with the administration of various vaccines, has been reported in the literature. A PubMed search from 1979 to 2013 revealed seventy one (71) documented cases. The most commonly reported vaccinations that were associated with CNS demyelinating diseases included influenza (21 cases), human papilloma virus (HPV) (9 cases), hepatitis A or B (8 cases), rabies (5 cases), measles (5 cases), rubella (5 cases), yellow fever (3 cases), anthrax (2 cases),meningococcus (2 cases) and tetanus (2 cases). The vast majority of post-vaccination CNS demyelinating syndromes, are related to influenza vaccination and this could be attributed to the high percentage of the population that received the vaccine during the HI1N1 epidemia from 2009 to 2012. Usually the symptoms of the CNS demyelinating syndrome appear few days following the immunization (mean: 14.2 days) but there are cases where the clinical presentation was delayed (more than 3 weeks or even up to 5 months post-vaccination) (approximately a third of all the reported cases). In terms of the clinical presentation and the affected CNS areas, there is a great diversity among the reported cases of post-vaccination acute demyelinating syndromes. Optic neuritis was the prominent clinical presentation in 38 cases, multifocal disseminated demyelination in 30, myelitis in 24 and encephalitis in 17. Interestingly in a rather high proportion of the patients (and especially following influenza and human papiloma virus vaccination-HPV) the dominant localizations of demyelination were the optic nerves and the myelon, presenting as optic neuritis and myelitis (with or without additional manifestations of ADEM), reminiscent to neuromyelitic optica (or, more generally, the NMO-spectrum of diseases). Seven patients suffered an NMO-like disease following HPV and we had two similar cases in our Center. One patient with post-vaccination ADEM, subsequently developed NMO. Overall, the risk of a demyelinating CNS disease following vaccination, although non-negligible, is relatively low. The risk of onset or relapse of CNS demyelination following infections against which the vaccines are aimed to protect, is substantially higher and the benefits of vaccinations surpass the potential risks of CNS inflammation. This does not in any way exempt us from“learning” the lessons taught by the reported cases and searching new and safer ways to improve vaccination techniques and increase their safety profile.

The diagnosis of multiple sclerosis and the various related demyelinating syndromes: a critical review

Multiple sclerosis (MS), is a chronic disease of the central nervous system (CNS) characterized by loss of motor and sensory function, that results from immune-mediated inflammation, demyelination and subsequent axonal damage. MS is one of the most common causes of neurological disability in young adults. Several variants of MS (and CNS demyelinating syndromes in general) have been nowadays defined in an effort to increase the diagnostic accuracy, to identify the unique immunopathogenic profile and to tailor treatment in each individual patient. These include the initial events of demyelination defined as clinically or radiologically isolated syndromes (CIS and RIS respectively), acute disseminated encephalomyelitis (ADEM) and its variants (acute hemorrhagic leukoencephalitis-AHL, Marburg variant, and Balo's concentric sclerosis), Schilder's sclerosis, transverse myelitis, neuromyelitis optica (NMO and NMO spectrum of diseases), recurrent isolated optic neuritis and tumefactive demyelination. The differentiation between them is not only a terminological matter but has important implications on their management. For instance, certain patients with MS and prominent immunopathogenetic involvement of B cells and autoantibodies, or with the neuromyelitic variants of demyelination, may not only not respond well but even deteriorate under some of the first-line treatments for MS. The unique clinical and neuroradiological features, along with the immunological biomarkers help to distinguish these cases from classical MS. The use of such immunological and imaging biomarkers, will not only improve the accuracy of diagnosis but also contribute to the identification of the patients with CIS or RIS who, are at greater risk for disability progression (worse prognosis) or, on the contrary, will have a more benign course. This review summarizes in a critical way, the diagnostic criteria (historical and updated) and the definitions/characteristics of MS of the various variants/subtypes of CNS demyelinating syndromes.