Acute disseminated encephalomyelitis in childhood: epidemiologic, clinical and laboratory features

Fulminant demyelinating diseases

Fulminant demyelinating disease is a heading that covers acute disseminated encephalomyelitis and its variant acute hemorrhagic leukoencephalitis (Hurst disease), severe relapses of multiple sclerosis (MS), variants of MS (tumefactive MS, Marburg variant, Balo concentric sclerosis, myelinoclastic diffuse sclerosis), and neuromyelitis optica-spectrum disorders associated with aquaporin autoimmunity. These categories of inflammatory demyelinating disease often prompt hospital admission and many necessitate intensive care monitoring due to the aggressive nature of the illness and associated neurologic morbidity. In this review, we highlight the discriminating clinical, radiographic, and pathologic features of these disorders. Acute management is often accomplished with use of high-dose intravenous steroids and plasma exchange. Aggressive disease may respond to immunosuppression. Prognosis for recovery varies among the disorders but most patients improve. Factors influencing outcome are also discussed.

Influenza-related postinfectious encephalomyelitis complicated by a perforated peptic ulcer

Influenza virus infection is extremely common and raises global concern due to the increasing prevalence of pandemic H1N1 infection. Influenza may occasionally be associated with neurologic complications and, also, rarely with gastrointestinal complications. Here, we report a rare case complicated with appendicitis, duodenum perforation, and transient delirious behavior after influenza A viral infection in a pediatric patient aged 14 years. The transient delirious behavior could be attributed to postinfectious encephalopathy. The perforated peptic ulcer could have resulted from influenza infection, could have been an adverse event related to oseltamivir administration, or could have been a complication of preceding gastroenteritis. Our case highlights the importance of pediatric healthcare workers to be aware of possible complications arising from both influenza infection and oseltamivir therapy, even though some of these complications may be relatively rare.

Neuroradiological evaluation of demyelinating disease

Central nervous system inflammatory demyelinating disease can affect patients across the life span. Consensus definitions and criteria of all of the different acquired demyelinating diseases that fall on this spectrum have magnetic resonance imaging criteria. The advances of both neuroimaging techniques and important discoveries in immunology have produced an improved understanding of these conditions and classification. Neuroimaging plays a central role in the accurate diagnosis, prognosis, disease monitoring and research efforts that are being undertaken in this disease. This review focuses on the imaging spectrum of acquired demyelinating disease.

Acute disseminated encephalomyelitis following infectious mononucleosis in a toddler

Symptomatic Epstein-Barr virus (EBV) infection complicated by acute disseminated encephalomyelitis (ADEM) in a toddler is rare. Our patient is a 14 month-old boy who presented with listlessness and reduced eye movements nearly 10 days after a prodromal upper respiratory illness that was accompanied by an amoxicillin rash. On examination, the boy appeared drowsy, had a congested throat and a resolving lower extremity rash, but otherwise had a normal neurological examination. Investigation revealed lymphocytosis, mildly elevated liver enzyme and a positive EBV IgM serology. Cerebrospinal fluid analysis showed pleocytosis. Subsequent brain and spine MRI showed demyelinating disease extending from the cerebral peduncles, across the brain stem and down to the mid-thoracic spinal cord. The patient was treated as a case of ADEM and given intravenous methylprednisolone. On outpatient follow-up his symptoms resolved completely in 6 weeks.

Acute demyelinating encephalomyelitis: Clinical characteristics and outcome

Background:

ADEM, although relatively uncommon, is probably under-recognized.

Objectives:

To spotlight the clinical profile and therapeutic outcome of children with ADEM.

Materials and Methods:

This is a prospective study of patients with ADEM who were admitted to the Pediatric Departments in Aladan and Alfarawanya Hospitals in Kuwait, from January 2009 to January 2011. Clinical, microbiological and radiological data were analyzed.

Results:

Of 48 patients presented with acute neurological symptoms and signs, 21 patients fulfilled criteria for ADEM. 80.95% of cases were presenting in winter and spring, 57% of patients had a history of upper respiratory tract illness. The commonest presentations were motor deficits, convulsions and altered consciousness. CSF virology studies showed herpes simplex virus (HSV) and Epstein-Barr virus (EBV) (3 patients) whereas nasal and nasopharyngeal swab showed evidence of influenza H1N1 virus (1 patient). Brain MRI was performed in all patients and revealed multiple hyperintense supratentorial brain lesions on T2/FLAIR images. 85.7% of patients had cortical and/or subcortical white matter lesions which were bilateral and asymmetric in location and size.

Conclusion:

ADEM although rare must be considered in children with acute onset of neurological signs and symptoms and must be distinguished from any acute neurological insult.

Risk of multiple sclerosis after a first demyelinating syndrome in an Australian Paediatric cohort: clinical, radiological features and application of the McDonald 2010 MRI criteria

Background:

The risk of multiple sclerosis (MS) is dependent on multiple variables, including geographical location. There is increasing interest in the early recognition and treatment of MS in children.

Method:

Using univariate and multivariate analysis, we determined the clinical and radiological features that were predictive of MS in 88 children from New South Wales, Australia, with a first acute demyelinating syndrome (ADS) who were followed for a minimum of one year. We tested the McDonald, KIDMUS, Callen and Verhey MRI criteria for paediatric MS.

Results:

After a mean follow-up of 5.2 years, 13/88 (15%) of children had MS. Using multivariate analysis, preceding infection was protective of MS, and corpus callosal lesions, the combined presence of both well and poorly demarcated lesions, and contrast-enhancing lesions on MRI were predictive of MS. The sensitivity and specificity of the respective radiological criteria were McDonald 2005 (69%, 68%), McDonald 2010 (58%, 95%), KIDMUS (8%, 100%), Callen (69%, 85%) and Verhey (62%, 84%). When McDonald 2010 criteria were applied to baseline and serial scans, the sensitivity and specificity was 91% and 93%.

Conclusion:

Despite the long follow-up, the risk of MS appears lower in New South Wales children compared to previously reported cohorts. Radiological features are more predictive than clinical features in predicting MS. The McDonald 2010 criteria performed well although the dissemination in time criteria on baseline scans is difficult to apply to children with encephalopathy.

International Pediatric Multiple Sclerosis Study Group criteria for pediatric multiple sclerosis and immune-mediated central nervous system demyelinating disorders: revisions to the 2007 definitions

BACKGROUND

There has been tremendous growth in research in pediatric multiple sclerosis (MS) and immune mediated central nervous system demyelinating disorders since operational definitions for these conditions were first proposed in 2007. Further, the International Pediatric Multiple Sclerosis Study Group (IPMSSG), which proposed the criteria, has expanded substantially in membership and in its international scope.

OBJECTIVE

The purpose of this review is to revise the 2007 definitions in order to incorporate advances in delineating the clinical and neuroradiologic features of these disorders.

METHODS

Through a consensus process, in which input was sought from the 150 members of the Study Group, criteria were drafted, revised and finalized. Final approval was sought through a web survey.

RESULTS

Revised criteria are proposed for pediatric acute disseminated encephalomyelitis, pediatric clinically isolated syndrome, pediatric neuromyelitis optica and pediatric MS. These criteria were approved by 93% or more of the 56 Study Group members who responded to the final survey.

CONCLUSIONS

These definitions are proposed for clinical and research purposes. Their utility will depend on the outcomes of their application in prospective research.

Acute disseminated encephalomyelitis

The advent of magnetic resonance imaging (MRI) has contributed to increase the interest and awareness in childhood white matter disorders. Pediatric inflammatory demyelinating diseases of the central nervous system (CNS) are clinically heterogeneous with respect to their mode of presentation, clinical severity, rate of progression, and prognosis. Acute disseminated encephalomyelitis (ADEM) is an immune-mediated inflammatory disorder of the CNS, typically transitory and self-limiting. The highest incidence of ADEM is observed during childhood. It is characterized by an acute encephalopathy with polyfocal neurological deficits. In the absence of specific biological markers the diagnosis of ADEM is still based on clinical features and MRI evidence of widespread demyelination, after ruling out other possible explanations for an acute encephalopathy. Over the past decade, many retrospective patient studies have focused on clinical and neuroimaging features, in an attempt to define specific diagnostic criteria. The occurrence of relapses in children with ADEM poses diagnostic difficulties in its differentiation from multiple sclerosis (MS) and neuromyelitis optica (NMO). With the widespread use of high-dose steroids, the long-term prognosis of ADEM with regard to functional and cognitive recovery is favorable. This chapter summarizes the available literature on ADEM in children, including the proposed consensus definitions for its monophasic and relapsing variants.

Pediatric Inflammatory Diseases. Part II: Acute Post-Infectious Immune Disorders

Acute post-infectious immune disorders include Acute Disseminated Encephalomyelitis (ADEM) and its variants such as Acute Hemorrhagic Encephalomyelitis (AHEM), acute necrotizing hemorrhagic leukoencephalitis (ANHLE) of Weston Hurst, multiphasic and recurrent ADEM. Acute Necrotizing Encephalopathy of Childhood (ANE or ANEC) represents a dramatic event, consequent to viral infections, especially Influenza-A, and is now considered different from ADEM. ADEM and variants are classically described as uniphasic syndrome occurring in association with an immunization or vaccination (postvaccine encephalomyelitis) or systemic viral infection (parainfectious encephalomyelitis). However, multiphasic forms are not rare. Pathologically, there is perivascular inflammation, edema, and demyelination within the CNS. Clinical features are focal or multifocal neurologic disorder following exposure to virus or receipt of vaccine. The onset of the CNS disorder is usually rapid and include encephalopathy ranging from lethargy to coma, seizures, and focal and multifocal signs reflecting cerebral and spinal cord involvement. The mortality rate is estimated at 10 to 30 percent, with complete recovery rates of 50 percent cited. Poor prognosis is correlated with severity and abruptness of onset of the clinical syndrome. Multifocal CNS lesions are generally evident on MRI that can be similar from those observed in MS.

Acute disseminated encephalomyelitis

Acute disseminated encephalomyelitis is an immune-mediated inflammatory and demyelinating disorder of the central nervous system, commonly preceded by an infection. It principally involves the white matter tracts of the cerebral hemispheres, brainstem, optic nerves, and spinal cord. Acute disseminated encephalomyelitis mainly affects children. Clinically, patients present with multifocal neurologic abnormalities reflecting the widespread involvement in central nervous system. Cerebrospinal fluid may be normal or may show a mild pleocytosis with or without elevated protein levels. Magnetic resonance image (MRI) shows multiple demyelinating lesions. The diagnosis of acute disseminated encephalomyelitis requires both multifocal involvement and encephalopathy by consensus criteria. Acute disseminated encephalomyelitis typically has a monophasic course with a favorable prognosis. Multiphasic forms have been reported, resulting in diagnostic difficulties in distinguishing these cases from multiple sclerosis. In addition, many inflammatory disorders may have a similar presentation with frequent occurrence of encephalopathy and should be considered in the differential diagnosis of acute disseminated encephalomyelitis.

Acute disseminated encephalomyelitis following 2009 H1N1 influenza vaccine

Acute disseminated encephalomyelitis (ADEM) is an immune-mediated inflammatory disorder of the central nervous system. We describe a previously healthy 2-year-old boy with ADEM, who exhibited high fever, lethargy, and recurrent seizures at 25 days after H1N1 influenza vaccination. To our knowledge, there has been only one report of ADEM following the 2009 H1N1 influenza vaccine, although such vaccination is accompanied with optic neuritis apart from this case. Thus, this is the first case of ADEM without optic neuritis, following the 2009 H1N1 influenza vaccination. Although vaccine-associated ADEM remains rare, the increasing number of influenza vaccinations might increase the incidence of ADEM. We still need to pay attention to the occurrence of ADEM and treat patients with steroid therapy.

Isolated brain stem lesion in children: is it acute disseminated encephalomyelitis or not?

Isolated brain stem lesions presenting with acute neurologic findings create a major diagnostic dilemma in children. Although the brain stem is frequently involved in ADEM, solitary brain stem lesions are unusual. We performed a retrospective review in 6 children who presented with an inflammatory lesion confined to the brain stem. Two children were diagnosed with connective tissue disorder, CNS lupus, and localized scleroderma. The etiology could not be determined in 1, and clinical features suggested monophasic demyelination in 3. In these 3 children, initial lesions demonstrated vasogenic edema; all showed dramatic response to high-dose corticosteroids and made a full clinical recovery. Follow-up MRI showed complete resolution of lesions, and none had relapses at >2 years of follow-up. In retrospect, these cases are best regarded as a localized form of ADEM. We conclude that though ADEM is typically a disseminated disease with multifocal lesions, it rarely presents with monofocal demyelination confined to the brain stem.

Treatment of acute disseminated encephalomyelitis

Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disease, characterized by an acute onset of polyfocal central nervous system (CNS) deficits, including encephalopathy, demonstrating multifocal lesions on MRI. ADEM is typically a monophasic disorder, but recurrent and multiphasic courses have been described. Furthermore, an ADEM presentation has been reported in neuromyelitis optica (NMO) and multiple sclerosis (MS), particularly in younger children. CNS infections, other autoimmune diseases, and neurometabolic disorders may mimic ADEM at manifestation. There is no single test confirming the diagnosis of ADEM, and diagnosis is based upon a combination of clinical and radiologic features and exclusion of diseases that resemble ADEM. Therefore, a broad workup including infectious, immunologic, and metabolic tests, as well as a systematic follow-up including MRI, is indicated to establish an accurate diagnosis as a prerequisite for an optimized treatment approach. There is a lack of evidence-based, prospective clinical trial data for the management of ADEM. Empiric antibacterial and antiviral treatment is standard of care until an infectious disease process is ruled out. Based on the presumed autoimmune etiology of ADEM, the common treatment approach consists of intravenous methylprednisolone at a dosage of 20 to 30 mg/kg per day (maximum 1 g/day) for 3 to 5 days, followed by an oral corticosteroid taper of 4 to 6 weeks. In case of insufficient response or contraindications to corticosteroids, intravenous immunoglobulin G (IVIG) at a dosage of 2 g/kg divided over 2 to 5 days is a therapeutic option. For severe or life-threatening cases of ADEM, plasmapheresis should be considered early in the disease course. Decompressive craniectomy has been reported as a life-saving measure for ADEM patients with intracranial hypertension. There is a lack of specific recommendations for the long-term management of recurrent and multiphasic ADEM. In children with relapsing demyelinating events, the diagnosis of a chronic autoimmune CNS disease like MS or NMO should be considered.

Acuted disseminated encephalomyelitis

Acute disseminated encephalomyelitis (ADEM) is a disorder of the central nervous system (CNS) characterized by an acute event, typically with encephalopathy, in which diffuse CNS involvement occurs. It may follow an infectious event and occurs more commonly in young children. Pulse steroid treatment is frequently used to treat ADEM. Although ADEM is typically described as a benign condition, with children generally recovering motor function and resolution of lesions on magnetic resonance imaging (MRI), residual cognitive deficits may occur. This chapter aims to review the clinical features, typical presentation, differential diagnosis, treatment and prognosis of ADEM.

Updated assessment of the prevalence, spectrum and case definition of autoimmune disease

Autoimmune diseases are heterogeneous with regard to prevalence, manifestations, and pathogenesis. The classification of autoimmune diseases has varied over time. Here, we have compiled a comprehensive up-to-date list of the autoimmune diseases, and have reviewed published literature to estimate their prevalence. We identified 81 autoimmune diseases. The overall estimated prevalence is 4.5%, with 2.7% for males and 6.4% for females. For specific diseases, prevalence ranges from 1% to <1/10(6). Considering all diseases in the class, the most common mean age-of-onset was 40-50 years. This list of autoimmune diseases has also yielded information about autoantigens. Forty-five autoimmune diseases have been associated with well-defined autoantigens. Of the diseases with known autoantigens, 33.3% had highly repetitive sequences, 35.6% had coiled-coil arrangements and 57.8% were associated with cellular membranes, which means that based on these structural motifs alone, autoantigens do not appear to be a random sample of the human proteome. Finally, we identified 19 autoimmune diseases that phenocopy diseases arising from germline mutations in the corresponding autoantigen. Collectively, our findings lead to a tentative proposal for criteria for assigning autoimmune pathogenesis to a particular disease.

Multiple sclerosis: neuroprotective alliance of estrogen-progesterone and gender

The potential of 17β-estradiol and progesterone as neuroprotective factors is well-recognized. Persuasive data comes from in vitro and animal models reflecting a wide range of CNS disorders. These studies have endeavored to translate findings into human therapies. Nonetheless, few human studies show promising results. Evidence for neuroprotection was obtained in multiple sclerosis (MS) patients. This chronic inflammatory and demyelinating disease shows a female-to-male gender prevalence and disturbances in sex steroid production. In MS-related animal models, steroids ameliorate symptoms and protect from demyelination and neuronal damage. Both hormones operate in dampening central and brain-intrinsic immune responses and regulating local growth factor supply, oligodendrocyte and astrocyte function. This complex modulation of cell physiology and system stabilization requires the gamut of steroid-dependent signaling pathways. The identification of molecular and cellular targets of sex steroids and the understanding of cell-cell interactions in the pathogenesis will offer promise of novel therapy strategies.

Immune mediated diseases and immune modulation in the neurocritical care unit

This chapter will review the spectrum of immune-mediated diseases that affect the nervous system and may result in an admission to the neurological intensive care unit. Immunomodulatory strategies to treat acute exacerbations of neurological diseases caused by aberrant immune responses are discussed, but strategies for long-term immunosuppression are not presented. The recommendations for therapeutic intervention are based on a synthesis of the literature, and include recommendations by the Cochrane Collaborative, the American Academy of Neurology, and other key organizations. References from recent publications are provided for the disorders and therapies in which randomized clinical trials and large evidenced-based reviews do not exist. The chapter concludes with a brief review of the mechanisms of action, dosing, and side effects of commonly used immunosuppressive strategies in the neurocritical care unit.

Acute disseminated encephalomyelitis presenting as fever of unknown origin: case report

Background

Fever of unknown origin (FUO) can be defined as a body temperature higher than 38.3°C on several occasions over more than 3 weeks, the diagnosis of which remains uncertain after 1 week of evaluation. Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disease of the central nervous system with a wide range of clinical manifestations. The highest incidence of ADEM is observed during childhood and it usually occurs following a viral or bacterial infection or, more rarely, following a vaccination, or without a preceding cause.

Case presentation

Here, we describe an atypical case of ADEM that initially manifested as several weeks of FUO in a fifteen years old boy.

Conclusions

This case report suggests a new possible syndromic association between ADEM and FUO, which should be considered in the clinical examination of patients with FUO, especially in the presence of also modest neurologic or neuropsychiatric symptoms.

Idiopathic inflammatory demyelinating disorders of the central nervous system in children

Idiopathic inflammatory demyelinating disorders of the central nervous system usually present with a typical morphologic pattern in adults, with multiple sclerosis as the predominant disorder. However, the variety of disorders in children has an odd range of features that have piqued the interest of researchers. Information concerning this group of diseases, both in vivo and in different age groups, has particularly progressed with the advent of magnetic resonance imaging in the last few decades. In this article, we provide an overview of the applicability of imaging for idiopathic inflammatory demyelinating disorders of the central nervous system in children. In addition to pediatric multiple sclerosis, this review addresses other related disorders, such as acute disseminated encephalomyelitis, pediatric neuromyelitis optica, recurrent optic neuritis, and relapsing transverse myelitis.

Acute disseminated encephalomyelitis following influenza vaccination

INTRODUCTION

Approximately 5% of cases of acute disseminated encephalomyelitis are preceded by vaccination within 1 month prior to symptom onset. This occurs rarely following influenza immunization.

METHODS

Case presentation and literature review.

RESULTS

A 75-year-old woman developed acute disseminated encephalomyelitis within 3 weeks of receiving the seasonal influenza vaccine. The patient subsequently passed away, despite treatment with methylprednisolone and plasma exchange therapy.

CONCLUSIONS

The literature on post-influenza vaccination encephalomyelitis is limited. The majority of published cases had favourable outcomes following treatment with intravenous methylprednisolone. Given the limited number of cases, no incidence estimates have been published.

Complicated features in a young child with influenza B virus pneumonia and co-infection with Stenotrophomonas maltophilia

A 3.5-year-old child with influenza B virus pneumonia developed pneumomediastinum and subcutaneous emphysema on the 3rd day of illness. Bronchoscopy demonstrated obstruction of the left main bronchus by mucopurulent sputum. Culture of the broncho-alveolar lavage yielded Stenotrophomonas maltophilia. After the respiratory complications resolved (11 days), the patient developed neurological symptoms and was diagnosed as acute disseminated encephalomyelitis (ADEM). Stenotrophomonas maltophilia was probably a factor in the development of pneumomediastinum. To our knowledge, this is the first case report of influenza virus infection with Stenotrophomonas maltophilia co-infection associated with spontaneous pneumomediastinum.

Acute disseminated encephalomyelitis that meets modified McDonald criteria for dissemination in space is associated with a high probability of conversion to multiple sclerosis in Taiwanese patients

BACKGROUND

Patients with acute disseminated encephalomyelitis (ADEM) may relapse and some may ultimately convert to multiple sclerosis (MS); however, no criteria that can predict MS conversion are available to date. Our aim was to describe the clinical and magnetic resonance imaging (MRI) features of patients with an initial ADEM attack and evaluate which MRI criteria can predict conversion to MS.

METHODS

We retrospectively reviewed the records of 36 patients diagnosed with ADEM. We determined clinical signs/symptoms, examined the cerebrospinal fluid (CSF), and performed brain MRI scans and compared the findings between patients who did and did not convert to MS.

RESULTS

Clinical signs/symptoms, and CSF analysis show no significant difference between the two groups. The rate of conversion to MS from ADEM in Taiwanese patients is low (11%) after a mean follow-up period of 28.36 months. Modified McDonald criteria were fulfilled in 19/36 patients: 21% (4/19) of those patients developed MS according to Poser criteria subsequently. Of the other patients (17/36) who did not fulfill these criteria, none converted to MS. (log rank test; P=0.027).

CONCLUSIONS

It is difficult to predict from initial clinical presentations to address which patients with ADEM will convert to MS. Patients with ADEM whose brain MRI findings met the modified McDonald criteria may have clinically isolated syndrome because they have a significantly higher probability of conversion to MS. In contrast, patients whose brain MRI findings did not meeting these criteria may be considered as having classic ADEM because they have a lower probability of conversion to MS.

A case of acute disseminated encephalomyelitis mimicking leukodystrophy

Acute disseminated encephalomyelitis (ADEM) is a monophasic, immune-mediated demyelinating disorder that can follow immunizations or more often infections including rubeola, rubella, varicella, herpes zoster, mumps, Mycoplasma pneumoniae, or, more commonly, other nonspecific upper respiratory tract infections. Documentation of a preceding illness is not required to make this diagnosis. This report examines the case of a 9-month-old male patient presenting with the features of an acute leukodystrophy following innoculation with the mixed vaccine Pentaxim (Sanofi Pasteur, Lyon- France) while suffering from a lower respiratory tract infection, and who was eventually diagnosed as ADEM. The case is presented as a reminder that ADEM can sometimes be linked to lower respiratory tract infection and vaccination, and that the features in such cases can be confused with leukodystrophy.

Disease course and outcome of acute disseminated encephalomyelitis is more severe in adults than in children

BACKGROUND

Acute disseminated encephalomyelitis (ADEM) affects children more frequently than adults. Current studies investigating ADEM in different age groups are difficult to compare.

OBJECTIVE

To investigate whether the clinical presentation, outcome and disease course of ADEM differ between adults and children.

METHODS

Disease characteristics of 25 adults and 92 children suffering from ADEM between 1988 and 2008 were compared.

RESULTS

The most common presenting symptoms of ADEM in both groups were pyramidal signs and encephalopathy. Ataxia occurred more frequently in children (p  = 0.002). In general, MRI showed ill-defined and large white matter lesions in both groups, whereas periventricular lesions were more prevalent in adults (p = 0.001). In adults, duration of hospitalization was longer (p = 0.002) and intensive care unit (ICU) admission was more frequently required (p = 0.043). Three adults (12%) and one child (1%) died (p = 0.030). Fewer adults had complete motor recovery after their first clinical event (p < 0.001). In 73 patients follow-up time was ≥ 2 years and most of these patients remained monophasic. Although relapses after ADEM can occur, only one adult (5%) and five children (6%) converted to MS.

CONCLUSIONS

The clinical presentations in children and adults share similarities, but the disease course and outcome of ADEM is more severe in adults with respect to hospitalization, ICU admission, recovery and mortality.

Acute disseminated encephalomyelitis: a 10-year cohort study in Thai children

Childhood acute disseminated encephalomyelitis (ADEM) is a demyelinating disease with variable clinical courses and outcomes. Its evolution to multiple sclerosis in Asian children is yet to be determined. Medical records, investigation results and magnetic resonance imaging of brain of Thai children aged less than 15 years with initial diagnosis of ADEM at a referral university hospital in Thailand from January 1997 to December 2006 were reviewed. Clinical course and the outcome were finalized by telephone interview, self-report questionnaire, and/or neurological examination by December 2008. Modified Rankin Score was applied for determination of disability. MRI findings were categorized along with the locations and number of areas of abnormalities shown by T2-weight and FLAIR. 16 patients consisting of 5 boys and 11 girls (age-range 1-14 years, mean 6.9 ± 3.6 years, median 6 years) were identified. Nine patients had cranial nerve dysfunctions including one child with optic neuropathy. One patient died with confirmed pathological diagnosis of ADEM. Among the remaining 15, who were followed from 2 to 10 years (mean 5.8 years), 13 and 3 patients were classified into monophasic ADEM and multiple sclerosis, respectively. Ten of 13 with final diagnosis of ADEM had complete recovery. There was no association between number of lesions or location in the initial MRI and the outcome and final diagnosis. ADEM in Thai children had similar clinical presentation and outcome to previous studies in Western countries. ADEM can occasionally evolve to multiple sclerosis in Thai children as being shown in previous reports from other Asian countries.

Torticollis as the only manifestation of acute disseminated encephalomyelitis

Torticollis can be either congenital or acquired. Acquired torticollis is often the manifestation of an underlying central nervous system disorder. Acute painless torticollis should always raise suspicion of a posterior fossa tumor. Acute disseminated encephalomyelitis is an inflammatory demyelinating disease of the central nervous system involving the subcortical white matter, and to a lesser extent, the gray matter. The illness typically has a monophasic course characterized by a variable combination of fever, headache, meningismus, seizures, spasticity, cranial nerve palsies, ataxia, and psychosis. The course, although often clinically severe, is generally benign with most children making a full recovery. A toddler presenting with subacute painless torticollis as the only manifestation of acute disseminated encephalomyelitis is described. The authors believe the neck twist in this child represented a form of dystonia because of basal ganglia involvement. Torticollis has not been reported as a presenting or only sign of disseminated encephalomyelitis.

Lethal acute demyelinization with encephalo-myelitis as a complication of cured Cushing's disease

Cushing's disease is usually associated with higher mortality rate, especially from cardiovascular causes. Development or exacerbation of autoimmune or inflammatory diseases is known to occur in patients with hypercortisolism after cure. We report for the first time a 34-year old woman with a psychiatric background, who developed four months after the surgical cure of Cushing's disease an acute disseminated encephalomyelitis (ADEM) presenting initially as a psychiatric illness. We hypothesize that the recent correction of hypercortisolism triggered ADEM and that the atypical presentation, responsible for diagnosis delay, led to the death of this patient.

Partial Klüver-Bucy syndrome in a patient with acute disseminated encephalomyelitis

The symptoms of Klüver-Bucy syndrome (KBS) include hyperorality, hypersexuality, visual agnosia, hypermetamorphosis and decreased motor or vocal reaction to fear- or anger-provoking stimuli. This syndrome has been associated with a wide variety of neurodegenerative disorders, as well as traumatic, non-traumatic and infectious brain injuries. We report an 11-year-old boy who developed a fairly classical presentation of KBS, presumably in the setting of post-infectious acute disseminated encephalomyelitis (ADEM). This patient's presentation is a reminder of this rare syndrome and extends the clinical manifestations of ADEM, which is a relatively more common condition.

Clinical study of childhood acute disseminated encephalomyelitis, multiple sclerosis, and acute transverse myelitis in Fukuoka Prefecture, Japan

Acute disseminated encephalomyelitis (ADEM) has recently been studied in several countries owing to the development and wide spread use of imaging technology, but few epidemiological studies of childhood ADEM have been undertaken in Asian countries. To perform a comprehensive survey of ADEM and related diseases in Japanese children, we conducted a multicenter, population-based study on childhood ADEM, multiple sclerosis, and acute isolated transverse myelitis in Fukuoka Prefecture, Japan. We identified 26 children with ADEM, 8 with multiple sclerosis, and 4 with acute transverse myelitis during 5 years between September 1998 and August 2003. The incidence of childhood ADEM under the age of 15 years was 0.64 per 100,000 person-years, mean age at onset was 5.7 years, and male-female ratio was 2.3:1. The prevalence of childhood multiple sclerosis was 1.3 per 100,000 persons. The mean age at onset of multiple sclerosis, 9.3 years, was significantly higher than that of ADEM. Nineteen (73%) and four (15%) patients with ADEM experienced antecedent infectious illnesses and vaccinations, respectively, within 1 month before the onset. Clinical and radiological findings of ADEM revealed that the frequency of seizures, mean white blood cell counts in cerebrospinal fluid, and the frequency of subcortical lesions in Fukuoka study, seemed to be higher than those in previous non-Asian studies. These findings suggest that there are ethnic or geographical differences in the incidence and clinical features of ADEM, and that there might be potent genetic or environmental risk factors for ADEM distinct from those for multiple sclerosis.

Causality in acute encephalitis: defining aetiologies

Defining the causal relationship between a microbe and encephalitis is complex. Over 100 different infectious agents may cause encephalitis, often as one of the rarer manifestations of infection. The gold-standard techniques to detect causative infectious agents in encephalitis in life depend on the study of brain biopsy material; however, in most cases this is not possible. We present the UK perspective on aetiological case definitions for acute encephalitis and extend them to include immune-mediated causes. Expert opinion was primarily used and was supplemented by literature-based methods. Wide usage of these definitions will facilitate comparison between studies and result in a better understanding of the causes of this devastating condition. They provide a framework for regular review and updating as the knowledge base increases both clinically and through improvements in diagnostic methods. The importance of new and emerging pathogens as causes of encephalitis can be assessed against the principles laid out here.

An uncommon illness with a rare presentation: neurosurgical management of ADEM with tumefactive demyelination in children

PURPOSE

This study determined the statewide incidence and prevalence of acute disseminated encephalomyelitis (ADEM) and examined the course of three pediatric patients treated for tumefactive demyelination (TD) at the Blair E. Batson Children's Hospital.

METHODS

Analyses of ICD-9-CM code hospital records and clinical database were conducted.

RESULTS

From 2001 through 2007 the incidence in pediatric patients under 20 years was 0.4/100,000/year, with a prevalence of 8.6/100,000 during 2008. Three patients presented with TD. Case 1 had a 3-week history of ataxia and diplopia; case 2 presented with a sudden onset of coma, while the third child had a 4-month history of increasing lethargy and clumsiness in all extremities. Cerebrospinal fluid examinations were nondiagnostic. MRI examinations revealed asymmetric T2/fluid-attenuated inversion recovery hyperintensity within the pons (case 1), a large heterogenously enhancing temporal lobe mass, with extensive edema (case 2), and multiple small brain lesions with occasional ring enhancement (case 3). In case 1, intralesional MR spectroscopy demonstrated changes consistent with ADEM. Case 2 required intracranial monitoring, and medical treatment to control elevated ICP. Cases 2 and 3 underwent cortical biopsies that revealed ADEM. All three patients improved with corticosteroid therapy. At a minimum of 15 months follow-up, cases 1 and 2 showed resolution of deficits and MRI lesions, while the third patient demonstrated additional MRI lesions and increasing paraparesis.

CONCLUSIONS

These cases demonstrate that appropriate neuroradiological evaluation, treatment of acutely elevated ICP, and brain biopsy can play critical roles in the management of children with undiagnosed ADEM and TD.

Perivenous demyelination: association with clinically defined acute disseminated encephalomyelitis and comparison with pathologically confirmed multiple sclerosis

Distinction between acute disseminated encephalomyelitis and acute multiple sclerosis is often clinically difficult. Perivenous demyelination is the pathological hallmark of acute disseminated encephalomyelitis, whereas confluent demyelination is the hallmark of acute multiple sclerosis. We investigated whether perivenous demyelination versus confluent demyelination distinguishes acute disseminated encephalomyelitis from multiple sclerosis. Patients with perivenous demyelination (n = 13; median age 43 years, range 5-67) on brain biopsy and/or autopsy, ascertained retrospectively, were compared with a cohort with confluent demyelination only (n = 91; 84% multiple sclerosis, 16% isolated syndrome at follow-up; median age 39 years, range 10-69). Clinical presentation, course and the International Paediatric Multiple Sclerosis Study Group clinical criteria for acute disseminated encephalomyelitis were assessed in both cohorts. Among the perivenous demyelination cohort, 10 patients had only perivenous demyelination and three also had confluent demyelination. All but one patient with perivenous demyelination only had a monophasic course, whereas two of three with both types had a relapsing course. The perivenous demyelination cohort was more likely than the confluent demyelination cohort to present with encephalopathy (P < 0.001), depressed level of consciousness (P < 0.001), headache (P < 0.001), meningismus (P = 0.04), cerebrospinal fluid pleocytosis (P = 0.04) or multifocal enhancing magnetic resonance imaging lesions (P < 0.001). A distinct pattern of cortical microglial activation and aggregation without associated cortical demyelination was found among six perivenous demyelination patients, all of whom had encephalopathy and four of whom had depressed level of consciousness. This pattern of cortical pathology was not observed in the confluent demyelination cohort, even in one patient with depressed level of consciousness. Clinical criteria were 80% sensitive and 91% specific for pathologically defined acute disseminated encephalomyelitis (perivenous demyelination), but misdiagnosed acute disseminated encephalomyelitis among 9% of patients with confluent demyelination and multiple sclerosis diagnosis at last follow-up. Perivenous demyelination is associated with meningoencephalopathic presentations and a monophasic course. Depressed level of consciousness is a more specific clinical criterion for pathologically confirmed acute disseminated encephalomyelitis than encephalopathy, which over-diagnosed acute disseminated encephalomyelitis among multiple sclerosis patients. A distinct pattern of cortical microglial activation without cortical demyelination may be the pathological correlate of depressed level of consciousness in acute disseminated encephalomyelitis. Although pathological evidence of perivenous demyelination may be superior to clinical criteria for diagnosing acute disseminated encephalomyelitis, the co-occurrence of perivenous and confluent demyelination in some individuals suggests pathogenic overlap between acute disseminated encephalomyelitis and multiple sclerosis and misclassification even with biopsy.

Encefalomielite acuta disseminata

L’encefalomielite acuta disseminata (EMAD) è una malattia infiammatoria autoimmune che coinvolge il cervello e il midollo spinale. Descritta soprattutto nel bambino, generalmente fa seguito a un episodio infettivo o a una vaccinazione, ma può essere idiopatica. La sua presentazione clinica comprende un’encefalopatia acuta associata a segni e a sintomi neurologici multifocali. La sua diagnosi si basa sulla clinica e sulla risonanza magnetica, che rivela lesioni multifocali della sostanza bianca in ipersegnale T2 mal delimitate, della stessa età, che prendono il gadolinio e possono anche riguardare il talamo e i nuclei della base. Il liquor può mostrare un’iperlinfocitosi con iperproteinorrachia e, a volte, la presenza di bande oligoclonali transitorie. La sua prognosi è piuttosto favorevole, passato l’episodio monofasico, con un trattamento specifico. È quindi fondamentale escludere fino dall’inizio le sue molte diagnosi differenziali. Il trattamento dell’EMAD, di prima scelta, consiste in boli di corticosteroidi endovenosi a forti dosi. In caso di insuccesso bisogna ricorrere agli scambi plasmatici o alle immunoglobuline endovenose. Anche se, di solito, è monofasica, possono verificarsi altri episodi che fanno allora pensare a un’EMAD multifasica. Tuttavia, in alcuni casi queste nuove poussées sono una modalità di esordio di un’autentica sclerosi multipla.

1H-MRS for the diagnosis of acute disseminated encephalomyelitis: insight into the acute-disease stage

BACKGROUND

Acute disseminated encephalomyelitis (ADEM) is a demyelinating disorder of the central nervous system (CNS). Differentiating ADEM from other inflammatory disorders, such as multiple sclerosis, is not always conclusive using conventional MRI.

OBJECTIVE

To evaluate longitudinal magnetic resonance spectroscopy (MRS) changes that distinguish ADEM from other inflammatory disorders.

MATERIALS AND METHODS

MRI/MRS scans were performed in seven patients with ADEM during the acute and chronic phases of the disease.

RESULTS

Partial recovery was detected between the acute and chronic phases in choline/creatine ratio. Major elevation of lipids and reduction in myo-inositol/creatine ratio was detected in all patients during the acute phase, followed by a reduction in lipids peak and elevation above normal in myo-inositol/creatine ratio during the chronic phase.

CONCLUSION

Consistent and unique MRS changes in metabolite ratios between the acute and chronic presentations of the disease were found. To the best of our knowledge, these patterns have not been described in other inflammatory disorders and might assist in the early diagnosis of ADEM.

Human metapneumovirus associated with central nervous system infection in children

BACKGROUND

Human metapneumovirus (hMPV) is an established pathogen of the respiratory tract of children and adults. hMPV is related to other paramyxoviruses known to cause encephalitis. Reports suggest that hMPV may cause disease of the central nervous system (CNS).

METHODS

Two groups of patients were studied. The first group consisted of children between birth and 18 years from whom nasal scrapings were obtained between January 2004 and October 2005. hMPV RNA amplification by PCR was done and records were reviewed for clinical and demographic data. The second group consisted of patients with encephalitis referred to the California Encephalitis Project (CEP) for comprehensive diagnostic testing between November 2004 and June 2006.

RESULTS

In group 1, 1474 specimens were examined for hMPV RNA. Sixty-three evaluable patients were infected with hMPV of whom 4 (6.3%) had seizures, compared with 145 patients infected with RSV of whom 1 had seizures (0.7%, P = 0.031). Comparing respiratory syncytial virus (RSV) and hMPV infections, there was no significant difference in the occurrence of fever. All children with hMPV infections and seizures were hospitalized and 3 were intubated because of status epilepticus. Group 2 consisted of 205 pediatric cases referred to CEP between November 2004 and June 2006 who had hMPV testing done. hMPV was detected in nasopharyngeal swabs of 5 patients. Neither hMPV RNA nor antihMPV specific IgM were detectable in the CSF from the 5 patients for whom CSF was available.

CONCLUSION

Nine cases of CNS illness temporally associated with the presence of hMPV nucleic acid in the upper airway are described. Compared with children infected with RSV, children with hMPV were significantly more likely to have had a seizure. Our data, in conjunction with previously reported cases suggest that hMPV may be associated with a spectrum of CNS disease ranging from febrile seizures to severe, fatal encephalitis.

Pediatric multiple sclerosis

Pediatric multiple sclerosis (MS) accounts for up to 5% of all MS cases. Work conducted over the past 5 years has provided new information about the treatment, pathogenesis, demographics, and natural history of this disorder. Genetic and environmental factors seem to exert critical influences on its development. Clinical, MRI and laboratory data from prepubertal and postpubertal children suggest differences between the immune response and/or CNS environment in younger compared with older children and adults with MS. Randomized, controlled treatment trials for pediatric MS have not yet been performed, but therapies used in adult MS have been evaluated in this population, and their use seems to be safe. This article provides a comprehensive review of current knowledge regarding pediatric MS, highlighting new advances in the field.

A child with difficulty swallowing

Difficulty swallowing is a common presenting complaint among children seen in the emergency department. We report a case of a male child who presented with difficulty swallowing as the first manifestation of acute disseminated encephalomyelitis and review the pathogenesis and clinical manifestations of this disease. Acute disseminated encephalomyelitis is typically a monophasic, postinfectious, demyelinating disease that presents most often with encephalopathy and acute or subacute, multifocal neurologic deficits. The case demonstrates the importance of considering alternate diagnoses when presented with a patient having a common symptom for which evaluation does not provide a plausible cause.

Retinal nerve fiber thickness in inflammatory demyelinating diseases of childhood onset

PURPOSE

To evaluate retinal nerve fiber layer thickness (RNFLT) using optical coherence tomography (OCT) in children with acquired demyelinating diseases.

METHODS

This is a cross-sectional study of patients seen between 2006-2008 at the Pediatric MS Center of the Jacobs Neurological Institute. Consensus definitions for pediatric demyelinating disease were followed. All children received OCT testing and assessment of visual acuity (VA) using Snellen and low contrast letter acuity (LCLA) charts.

RESULTS

Thirty-eight children diagnosed with acquired demyelinating disease, 15 healthy controls, and five children with other neurological disorders (OND) were included. Average RNFLT in healthy controls was 107 +/- 12 microm(n = 30) versus 108 +/- 5 microm (n = 10) in OND controls. In children with multiple sclerosis, average RNFLT +/- SD was 99 +/- 14 microm in unaffected (n = 24) versus 83 +/- 12 micromin eyes affected by optic neuritis ("affected eyes") (n = 10). Average RNFLT in children with acute disseminated encephalomyelitis and transverse myelitis was 102 +/- 15 microm in unaffected (n = 18) versus 67 +/- 17 microm in affected eyes (n = 6). In children with optic neuritis (ON), average RNFLT +/- SD was 97 +/- 13 microm in unaffected (n = 5) versus 89 +/- 12 microm in affected eyes (n = 9). Differences between children with demyelinating disease and controls and between ON and nonON eyes were statistically significant (P < 0.001). Bivariate correlations of RNFLT with LCLA (P = 0.002) and VA (P < 0.001) were significant.

CONCLUSIONS

OCT may be a valuable tool for the assessment and monitoring of anterior optic pathway dysfunction in children with demyelinating diseases.

Evaluation of the cases with acute disseminated encephalomyelitis

OBJECTIVE

We aimed to describe the epidemiologic, clinical, laboratory features, neuroimaging, treatment, and outcome of children with acute disseminated encephalomyelitis in a cohort study.

METHODS

In this study, twelve children who were diagnosed as acute disseminated encephalomyelitis were reviewed retrospectively. All of the cases were reevaluated with systemic and neurological examinations, serologic tests, cerebrospinal fluid investigations, magnetic resonance imaging.

RESULT

Their age ranged between 2.5 and 16 years. Five of the cases had initial infections. Patients presented most often with motor deficits (75%), secondly with loss of conscious (33%), and seizures (33%). Spinal fluid abnormalities occurred in 41.6%. Cranial, and spinal magnetic resonance imaging (MRI) revealed hyperintense signal changes mainly in basal ganglia and thalamus (58%), cortical and subcortical areas (33) in T2 weighted images. Myelitis was determined in two cases. Six patients were treated with steroid, and 3 were treated with intravenous immunoglobulin. Ten patients recovered completely. We observed relapse in one case and recurrence in two cases. These cases responded well to high dose intravenous prednisolone followed by oral prednisolone for 6 months.

CONCLUSION

Outlook recovery is generally good in acute disseminated encephalomyelitis. Recurrence and neurological deficits are rarely seen. Early treatment of prednisolone is one of the most important factors to determine the prognosis in this disease.

Post-infectious encephalitis in adults: diagnosis and management

Many important central nervous system (CNS) syndromes can develop following microbial infections. The most severe forms of post-infectious encephalitis include acute disseminated encephalomyelitis (ADEM), acute hemorrhagic leukoencephalitis and Bickerstaff's brainstem encephalitis. ADEM is an inflammatory demyelinating disorder of the CNS. It typically follows a minor infection with a 2–30 days latency period and is thought to be immune-mediated. It is clinically characterized by the acute onset of focal neurological signs and encephalopathy. Patients can require intensive care unit admission because of coma, seizures or tetraplegia. Cerebrospinal fluid analysis usually shows lymphocytic pleocytosis but, unlike viral or bacterial encephalitis, no evidence of direct CNS infection is found. There are no biologic markers of the disease and cerebral magnetic resonance imaging is essential to diagnosis, detecting diffuse or multifocal asymmetrical lesions throughout the white matter on T2- and FLAIR-weighted sequences. High-dose intravenous steroids are accepted as first-line therapy and beneficial effects of plasma exchanges and intravenous immunoglobulins have also been reported. Outcome of ADEM is usually favorable but recurrent or multiphasic forms have been described.