Acute disseminated encephalomyelitis in children

Clinical profile of acute disseminated encephalomyelitis in children

AIM

To study the clinical profile of acute disseminated encephalomyelitis (ADEM) in children.

MATERIALS AND METHODS

All children admitted with ADEM during a period of one and a half years were included in the study. The diagnosis of ADEM was made based on the clinical presentation and suggestive MRI findings. All children were treated with intravenous methyl prednisolone, followed by oral prednisolone and followed up for varying periods up to three and a half years.

RESULTS

The sample consisted of 14 children with 11(79%) girls and 3 (21%) boys. The oldest child was 12 years and the youngest was a six-month-old infant. Acute febrile illness preceded the onset of neurological symptoms in 64% of children. The interval between the preceding illness and symptoms of ADEM varied from 7 days to 28 days (mean 12 days). The common presenting symptoms were fever, vomiting, headache, gait disturbance and generalized seizures. Neurological manifestations included altered sensorium, multiple cranial nerve involvement, quadriplegia and paraplegia, dystonia and choreiform movements, nystagmus, bladder involvement (both incontinence and retention), speech defect and double vision. Facial nerve was the most common cranial nerve involved. Psychological manifestations included aggressive behavior, psychotic symptoms and mood changes. One child each had features of acute psychotic episode and depressive episode. All children recovered fully. One child had multiphasic disseminated encephalomyelitis (MDEM) on follow up.

CONCLUSION

Despite the serious neuropsychiatric manifestations, ADEM in children generally has good immediate outcome. Children with ADEM need long-term follow up for cognitive impairments.

Successful renal transplantation after recovery from acute disseminated encephalomyelitis in a child with end-stage renal disease

Acute disseminated encephalomyelitis (ADEM), seen mostly in children, is an acute demyelinating disease, affecting mainly the white matter of brain and spinal cord. We report an unusual case of ADEM in an 11-year old boy with endstage renal disease, who underwent hemopoietic stem cell transplantation prior to renal transplantation. He needed admission to the intensive care unit and required mechanical ventilation. He responded to intravenous injection of steroids and upon recovery, underwent renal transplantation successfully.

Clinical and pharmacological aspects of inflammatory demyelinating diseases in childhood: an update

Inflammatory demyelinating diseases comprise a spectrum of disorders affecting the myelin of the central and peripheral nervous system. These diseases can usually be differentiated on the basis of clinical, radiological, laboratory and pathological findings.

Recent studies have contributed to current awareness that inflammatory demyelinating diseases are not restricted to the adult age group, but are more common in pediatric age than previously believed. Some of pediatric inflammatory demyelinating diseases carry an unfavorable long-term prognosis but appropriate treatments can improve the outcome. The possibility of physical and cognitive disability resulting from these diseases, highlights the urgent need for therapeutic strategies for neurorehabilitation, neuroregeneration, and neurorepair.

This review discusses characteristics of primary demyelinating diseases more frequently observed in childhood, focusing on epidemiology, clinical aspects and treatments.

Human immunodeficiency virus (HIV) infection in a child presenting as acute disseminated encephalomyelitis

Acute disseminated encephalomyelitis is an extremely rare occurrence in human immunodeficiency virus (HIV) infection. We describe an 8-year-old male child who presented with weakness of both lower limbs for 10 days and focal convulsions for 2 days. The child had left, upper motor neuron facial palsy, lower limb hypotonia, and exaggerated deep tendon reflexes. Enzyme-linked immunosorbent assay antibodies for HIV tested positive and the CD4 count was 109 cells/µL. The magnetic resonance imaging (MRI, brain) revealed extensive confluent hyperintensities (on T2-weighted images) in left parietal, right temporal, and right occipital regions of the white matter, and similar signals were seen in right lentiform nucleus and right posterior thalami, suggesting acute disseminated encephalomyelitis. There was transient improvement with intravenous methyl prednisolone. The patient succumbed to the illness. Perinatally transmitted pediatric HIV infection presenting with acute disseminated encephalomyelitis has not yet been reported in the medical literature.

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.

Approach to the child with coma

Coma and other states of impaired consciousness represent a medical emergency. The potential causes are numerous, and the critical window for diagnosis and effective intervention is often short. The common causes of non-traumatic coma include central nervous system infections, metabolic encephalopathy (hepatic, uremic, diabetic ketoacidosis etc.), intracranial bleed, stroke and status epilepticus. The basic principles of management include 1) Rapid assessment and stabilization, 2) Focussed clinical evaluation to assess depth of coma, localization of lesion in the central nervous system and possible clues to etiology, and 3) Treatment including general and specific measures. Commonly associated problems such as raised intracranial pressure and seizures must be recognized and managed to prevent secondary neurologic injury.

Pediatric multiple sclerosis

BACKGROUND

Pediatric multiple sclerosis (MS), once considered a rare childhood illness, has been increasingly identified as an important childhood acquired neurologic disease requiring early recognition and intervention.

SUMMARY

We present a comprehensive review of the current terminology of acquired central nervous system demyelination in children, pertinent investigations, including magnetic resonance imaging and cerebrospinal fluid cerebrospinal fluid studies, and an approach to the differential diagnosis of pediatric onset MS. In addition, the recent studies exploring the epidemiology and pathobiology will be discussed. Finally, we present an algorithm for the treatment of episodes of demyelination along with chronic immunomodulatory therapeutic options in this patient population.

CONCLUSIONS

Although some similarities exist to adult onset MS, MS onset during childhood and adolescence presents unique diagnostic challenges and requires specialized multidisciplinary care for optimal management. National and international collaborative studies are underway to aid in the understanding of the early and ongoing pathogenesis of MS.

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.

Therapy of multiple sclerosis in children and adolescents

BACKGROUND

Paediatric multiple sclerosis accounts for up to 10% of all MS cases. The initial course of the disease is relapsing-remitting in most children, with a relapse rate generally higher than that observed in adult patients. There is published experience on the use of first-line disease modifying therapies in children with MS. However, about 1/3 of paediatric MS cases do not respond to IFN-beta or glatiramer acetate and continue to develop relapses and disease progression. These patients could be proposed to a second-line treatment.

METHODS

A comprehensive review of the published literature related to pharmacologic treatment of MS in adults and paediatric patients was performed. The recent literature has been extracted for new evidence from controlled trials in adult patients, and open treatment studies and reported expert opinion in paediatric patients.

RESULTS

No disease modifying drug has been approved for the treatment of children and adolescents with MS, although the currently available first-line therapies for adults seem to be safe and well tolerated in this population. Further studies are required to assess the safety and efficacy of second-line treatments in children with MS.

CONCLUSION

The present article constitutes an update of the existing publications regarding treatment of acute events of CNS demyelination in children and adolescents as well as considerations for the use of immunomodulatory therapies.

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.

Acquired demyelinating disorders of childhood in the Western Cape, South Africa

In a retrospective review of patients with acquired demyelinating disorders of the central nervous system, 19 children (0.6%) were identified from the Paediatric Neurology database of 3159 patients; 7 had acute disseminated encephalomyelitis, 1 had Schilder's disease, 5 had multiple sclerosis, and 6 had acute transverse myelitis. The median age of presentation was 83 months, with increased incidence during the summer and winter months. The commonest presentation was hemiparesis. The commonest regions of magnetic resonance imaging (MRI) abnormalities were the deep white matter (68%) and cerebellum (48%).The patients with multiple sclerosis had more monosymptomatic presentations (P < .02), raised cerebrospinal fluid protein (P = .022), and contrast enhancement of lesions (P = .05) compared with the acute disseminated encephalomyelitis group. Neuroepidemiological published surveillances of African children provide no data about these disorders. The prevalence of acquired demyelinating disorders in resource-poor settings is under-estimated because of the large burden of infections and limited access to neuroimaging.

A prospective multicenter study of childhood encephalitis in Greece

Encephalitis is associated with significant childhood morbidity and mortality worldwide, however not much is known about the contemporary epidemiology and outcome. In this prospective multicenter pediatric encephalitis study conducted in Greece for 3 years, 42 cases were diagnosed and the presumptively or definitely causative pathogen was identified in 24 (57.1%). Leading pathogens included herpes viruses (10 patients), enteroviruses (6), and Streptococcus pneumoniae (2). No fatalities were observed; however, deficits remained in 5 of 42 (11.9%) children.

Multiple sclerosis and acute disseminated encephalomyelitis diagnosed in children after long-term follow-up: comparison of presenting features

The aim of this study was to compare the characteristics of the first demyelinating event between acute disseminated encephalomyelitis (ADEM) and multiple sclerosis (MS). Children with acute demyelinating disease of the central nervous system and an abnormal brain magnetic resonance image (MRI) were studied. Patients were assigned a final diagnosis after long-term follow-up. Comparisons were made between the MS and ADEM groups. Proposed definitions by the Pediatric MS Study Group were applied to our cohort in retrospect and are discussed. Fifty-two children and adolescents with a documented abnormal brain MRI were identified (24 females, 28 males; mean age 10y 11mo [SD 5y 4mo] range 1y 10mo-19y 7mo). To date, 26 children have been diagnosed with MS, and 24 with ADEM. One child has relapsing neuromyelitis optica and one child has clinically isolated optic neuritis. Follow-up duration was 6 years 8 months in monophasic patients, and 5 years 6 months in relapsing patients. None of the patients with MS had encephalopathy while encephalopathy was present in 42% of patients with ADEM. Cerebrospinal fluid oligoclonal bands, an elevated immunoglobulin and the periventricular perpendicular ovoid lesions correlated with MS outcome. Several clinical characteristics differ between ADEM and MS at first presentation; encephalopathy, when present, strongly suggests the diagnosis of ADEM.

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.

Acute transverse myelitis and acute disseminated encephalomyelitis in childhood: spectrum or separate entities?

The clinical and radiological features of childhood acute transverse myelitis are compared to those of acute disseminated encephalomyelitis with spinal cord involvement in 22 children with acute transverse myelitis and 12 children with acute disseminated encephalomyelitis with spinal cord involvement. Children with acute transverse myelitis were more likely to have a sensory level (55%) and areflexia. Sixty-eight percent of the children with acute transverse myelitis, and 92% of children with acute disseminated encephalomyelitis had longitudinally extensive transverse myelitis. Demyelination was more extensive in acute disseminated encephalomyelitis (mean 15.6 vertebral segments) than in acute transverse myelitis (mean 8.0 vertebral segments). The outcome was normal to good in 82% with acute transverse myelitis and in 100% with acute disseminated encephalomyelitis. Persistent bladder dysfunction was uncommon in both. Poor prognostic factors in acute transverse myelitis are flaccid paraparesis, respiratory failure, and age less than 6 months. These clinical and radiological differences suggest acute transverse myelitis and acute disseminated encephalomyelitis are separate entities.

[Acute disseminated encephalomyelitis]

Acute disseminated encephalomyelitis (ADEM) is an acute widespread autoimmune demyelinating condition, which principally affects the white matter of the brain and spinal cord. It usually follows an infection or vaccination. The typical presentation is that of multifocal neurologic disturbances accompanied by change in mental status. CSF analysis reveals lymphocytic pleocytosis and elevated protein content, but may also yield normal results. MRI is regarded as the diagnostic imaging modality of choice and typically demonstrates involvement of deep cerebral hemispheric and subcortical white matter as well as lesions in the basal ganglia, gray-white junction, diencephalon, brainstem, cerebellum and spinal cord. Unlike multiple sclerosis (MS), ADEM has a monophasic course and a favorable long-term prognosis.

Clinical and diagnostic aspects of multiple sclerosis and acute monophasic encephalomyelitis in pediatric patients: a single centre prospective study

OBJECTIVE

The purpose of the study was to compare and contrast the initial presenting demographic, clinical, neuroimaging, and laboratory features in a cohort of children affected from multiple sclerosis (MS) or acute disseminated encephalomyelitis (ADEM).

METHODS

A 12-year prospective study was conducted in 68 pediatric patients (age<or=17 years) who presented with a first episode of central nervous system inflammation suggestive of a demyelinating multifocal pathology. All patients had undergone magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) examination. The mean follow-up period, as at ending on December 31, 2007, was 6.8+/-2.7 years (range 3.2-12.6 years).

RESULTS

At clinical onset, children who developed MS during the follow-up (48 patients; 34 females, 14 males; mean age at onset: 14.4+/-2.5) significantly differed from children affected by ADEM (20 patients; 8 females, 12 males; mean age at onset: 8.1+/-3.8) for the following parameters: prevalence of females affected (female/male ratio: 2.8 versus 0.6, P=0.03); mean age at onset (P<0.001); monosymptomatic onset (73% vs 30%, P=0.002); encephalopathy-like onset (0% vs 50%, P<0.001); presence of oligoclonal IgG bands (IgGOB) in CSF (83% vs 10%, P<0.001); and periventricular (79% vs 20%, P<0.001), brain stem (12.5% vs 60%, P=0.000), and basal ganglia (10% vs 50%, P<0.001) lesions at MRI.

CONCLUSIONS

Our findings depict a pattern of demographic, clinical, neuroimaging, and laboratory findings that can help to distinguish, at clinical onset, children suffering from ADEM from those who will develop MS. Childhood-onset MS seems not to differ from adult-onset MS from both clinical and paraclinical features.

Acute combined central and peripheral nervous system demyelination in children

Reports of acute combined central and peripheral nervous system acquired inflammatory demyelination are rare in children. This study aimed to (1) define the clinical features and prognoses of patients with this entity; and (2) compare these patients with children presenting isolated acute central or peripheral nervous system demyelination. A retrospective chart review of 523 children with central or peripheral nervous system demyelination hospitalized between 1993-2006 was undertaken. Among these, 93 fulfilled criteria (clinical features and positive magnetic resonance imaging or electromyography/nerve conduction studies) for either acute central (n = 37; 39.8%) or peripheral (n = 43; 46%) nervous system demyelination, or a combination of the two (n = 13; 14%). Significant differences between groups were evident for age (median, 10 versus 7 versus 11 years, respectively; P = 0.047), admission to pediatric intensive care unit (8% versus 30% versus 58%, respectively; P = 0.001), length of hospital stay (median, 8 versus 9 versus 29 days, respectively; P < 0.001), treatment with steroids (52% versus 7% versus 75%, respectively; P < 0.001) and immunoglobulins (11% versus 81% versus 75%, respectively; P < 0.001), and poor evolution (3% versus 12% versus 54%, respectively; P = 0.002). This entity in children is not rare, and has a poorer outcome than isolated central or peripheral nervous system demyelination. Assessment is needed for a better understanding of risk factors, etiologies, management, and prognosis.

Disseminated encephalomyelitis in children

The advent of MRI has contributed to increase the interest and awareness in childhood white matter disorders. A major priority is to distinguish transient and self-limited demyelinating syndromes like disseminated encephalomyelitis (DEM), from life-long diseases like multiple sclerosis (MS). However, the term DEM has been inconsistently applied across studies due to the lack of clear clinical and neuroimaging diagnostic criteria. The present review summarizes the available literature on DEM in children, outlines the main clinical and neuroimaging features at presentation, pathogenesis and outcome, and its differentiation from other conditions with acute impact in the CNS. The recently proposed clinical definitions for monophasic disseminated encephalomyelitis and its relapsing variants are discussed, and controversies surrounding the diagnosis of MS in children are addressed.

Acute disseminated encephalomyelitis: clinical and pathogenesis features

Acute disseminated encephalomyelitis (ADEM) is an immune-mediated disorder of the central nervous system (CNS). Disease typically starts with an abrupt onset of neurologic symptoms and signs within days to weeks after a viral infection or immunization. Neuropathological examination of the CNS in ADEM reveals involvement of white matter, with infiltration of monocytoid cells and perivenous demyelination.

A case of acute disseminated encephalomyelitis in a 12-year-old boy

Acute disseminated encephalomyelitis is an uncommon inflammatory demyelinating disease of the central nervous system. It generally presents after a nonspecific viral infection. We describe a case of a male adolescent who presented to the emergency department with vomiting and lethargy. A review of the pathophysiology and clinical presentation for acute disseminated encephalomyelitis is presented here.

Epstein-Barr virus acute encephalomyelitis in a 13-year-old boy

The association of acute myelopathy and encephalopathy is reported in a 13-year-old boy. Signs and symptoms of infectious mononucleosis, presence of heterophile antibodies, anticapsid antibodies and Epstein-Barr virus DNA detected in cerebrospinal fluid, disclosed a primary or reactivated infection by Epstein-Barr virus. Outcome was rapid and benign with complete clinical recovery in 1 month, after pulse therapy with methylprednisolone. Epstein-Barr virus is a known agent related to acute disseminated encephalomyelitis, by immune mediated mechanisms. However, in this case, cortical involvement in magnetic resonance imaging, short time between infectious mononucleosis and central nervous system manifestations, and the presence of viral DNA in cerebrospinal fluid, raised the possibility of a direct action of the virus in central nervous system. Acute myelopathy associated to Epstein-Barr virus encephalitis has been rarely reported in children.

Serial magnetic resonance imaging and single photon emission computed tomography study of acute disseminated encephalomyelitis patient after Japanese encephalitis vaccination

We report a 5-year-old mentally retarded Japanese boy who developed acute disseminated encephalomyelitis (ADEM) two weeks after Japanese encephalitis vaccination (Beijing strain). He presented sudden status epilepticus, fever, and disturbance of consciousness. Initial neuroradiological findings revealed multifocal cortical swellings without any white matter lesions, suggesting the existence of partial encephalitis or focal status epilepticus. On the follow-up neuroradiological examinations, small white matter lesions were identified as having gradually extended in spite of clinical improvement by methylprednisolone pulse therapy. The cortical involvement became temporarily worse along with the extension and delayed appearance of white matter lesions. Single photon emission computed tomography (SPECT) showed marked hypoperfusion of cerebral blood flow (CBF) in the cortical lesions at both the acute and the recovery period. The serial neuroradiological findings indicated involvement of white matter and gray matter regions at different stages of the illness and a delay between the onset of symptoms and the appearance of ADEM-associated MR imaging of white-matter lesions.

Acute disseminated encephalomyelitis in children: focus on relapsing patients

This study investigated the possible prognostic factors for relapse, and the diagnostic criteria for multiple sclerosis and related disorders, in pediatric acute disseminated encephalomyelitis. The study population comprised 24 Italian children with a mean age at onset of 6.9 years, and a mean follow-up time of 52.8 months (range, 12-180). Clinical, neurophysiologic, spinal-fluid, neuroradiologic, and outcome features were investigated. All patients but 2, who were reclassified as exhibiting clinically isolated syndromes, fulfilled the new classification criteria for acute disseminated encephalomyelitis recently proposed by the International Pediatric Multiple Sclerosis Study Group. Three patients relapsed after 3 months, 2 years, and 8 years, respectively. By the second attack, the diagnosis of multiple sclerosis, as well as of multiphasic disseminated encephalomyelitis, could be rendered using the revised criteria of McDonald et al. Long-term follow-up seemed to confirm a chronic disease course in 2 children. We could not identify features at onset to predict outcomes of patients. However, early in follow-up, the appearance of oligoclonal immunoglobulin G bands in spinal fluid and the persistence of visual-evoked potential abnormalities were associated with poor outcomes.

Acute childhood encephalitis and encephalopathy associated with influenza: a prospective 11-year review

BACKGROUND

Influenza virus infection has been associated with a variety of neurologic complications. The objective of this study was to evaluate prospectively the role of influenza viruses in acute childhood encephalitis/encephalopathy (ACE).

METHODS

All children admitted to the Hospital for Sick Children, Toronto, during an 11-year period with ACE and evidence of acute influenza virus infection were included. Acute influenza virus infection was defined by detection of the organism in the nasopharynx by direct immunofluorescence microscopy or viral culture and/or by a 4-fold or greater rise in complement fixation titer.

RESULTS

A total of 311 children with ACE were evaluated; evidence of influenza infection was detected in 7% (22 of 311). Eight were excluded from the main analysis because of evidence implicating other potential pathogens. Eleven of the 14 included subjects were <5 years of age. A respiratory prodrome was documented in 93% of subjects. In 64% neurologic manifestations developed within 5 days of onset of respiratory symptoms. Neuroimaging abnormalities were more common in children <2 years of age. Neurologic sequelae occurred in more than one-half of subjects.

CONCLUSIONS

In this prospective registry, influenza virus infection was associated with 5% of ACE cases. The majority of children were <5 years of age and the prevalence of neuroimaging abnormalities was higher in children <2 years of age suggesting that younger children are predisposed to the neurologic complications of influenza. An acute rather than a postinfectious process was suggested by the briefness of the respiratory prodrome in most cases.

Diagnosis of inflammatory demyelination in biopsy specimens: a practical approach

Multiple sclerosis is the most frequent demyelinating disease in adults. It is characterized by demyelination, inflammation, gliosis and a variable loss of axons. Clinically and histologically, it shares features with other demyelinating and/or inflammatory CNS diseases. Diagnosis of an inflammatory demyelinating disease can be challenging, especially in small biopsy specimens. Here, we summarize the histological hallmarks and most important neuropathological differential diagnoses of early MS, and provide practical guidelines for the diagnosis of inflammatory demyelinating diseases.

Multiple sclerosis in children: clinical diagnosis, therapeutic strategies, and future directions

The onset of multiple sclerosis (MS) in childhood poses diagnostic and therapeutic challenges, particularly if the symptoms of the first demyelinating event resemble acute disseminated encephalomyelitis (ADEM). MRI is an invaluable diagnostic tool but it lacks the specificity to distinguish ADEM from the first attack of MS. Advanced MRI techniques might have the required specificity to reveal whether the loss of integrity in non-lesional tissue occurs as a fundamental feature of MS. Although the onset of MS in childhood typically predicts a favourable short-term prognosis, some children are severely disabled, either physically or cognitively, and more than 50% are predicted to enter the secondary-progressive phase of the disease by the age of 30 years. Immunomodulatory therapies for MS and their safe application in children can improve long-term prognosis. Genetic and environmental factors, such as viral infection, might be uniquely amenable to study in paediatric patients with MS. Understanding the immunological consequences of these putative exposures will shed light on the early pathological changes in MS.

[Acute disseminated encephalomyelitis and severe post-infectious encephalitis]

L’encéphalomyélite aiguë disséminée, acute disseminated encephalomyelitis, (ADEM), est une maladie inflammatoire démyélinisante du système nerveux central (SNC). Également appelée encéphalite post-infectieuse, elle est liée à un mécanisme auto-immun et s’installe typiquement dans les suites d’une infection après un intervalle libre de deux à 30 jours. L’ADEM est caractérisée cliniquement par un tableau d’encéphalopathie aiguë avec signes neurologiques multifocaux. Les patients peuvent nécessiter une admission en réanimation du fait de troubles de la conscience, de crises convulsives ou d’une tétraplégie. L’analyse du liquide céphalorachidien peut montrer une méningite lymphocytaire, mais on ne retrouve pas d’infection évolutive du SNC. Il n’existe pas de marqueur spécifique de la maladie et l’imagerie par résonance magnétique cérébrale est essentielle au diagnostic, permettant de mettre en évidence des lésions multifocales de la substance blanche du SNC sur les séquences T2 et FLAIR. Le traitement de l’ADEM est basé sur les corticoïdes fortes doses, éventuellement associés aux immunoglobulines polyvalentes ou aux échanges plasmatiques. Le pronostic est généralement favorable sous traitement, des récurrences peuvent néanmoins survenir dans l’évolution.

Involvement of morbilliviruses in the pathogenesis of demyelinating disease

Two members of the morbillivirus genus of the family Paramyxoviridae, canine distemper virus (CDV) and measles virus (MV), are well-known for their ability to cause a chronic demyelinating disease of the CNS in their natural hosts, dogs and humans, respectively. Both viruses have been studied for their potential involvement in the neuropathogenesis of the human demyelinating disease multiple sclerosis (MS). Recently, three new members of the morbillivirus genus, phocine distemper virus (PDV), porpoise morbillivirus (PMV) and dolphin morbillivirus (DMV), have been discovered. These viruses have also been shown to induce multifocal demyelinating disease in infected animals. This review focuses on morbillivirus-induced neuropathologies with emphasis on aetiopathogenesis of CNS demyelination. The possible involvement of a morbillivirus in the pathogenesis of multiple sclerosis is discussed.

A medical overview of encephalitis

Encephalitis is uncommon but is a neurological emergency which must be considered in a patient presenting with altered consciousness. Encephalitis is a diffuse inflammatory process of the brain parenchyma associated with evidence of brain dysfunction. The presentation of encephalitis can be acute or chronic. The aetiology of encephalitis can be broadly divided into two major subtypes. (1) Infection-related encephalitis which is a direct consequence of pathogenic viral, bacterial or parasitic agents. Herpes simplex virus (HSV) and varicella-zoster virus (VZV) are the most common cause of acute infectious encephalitis. (2) Autoimmune-mediated encephalitis which is mediated by an aberrant immune response. This can be triggered by a recent viral infection or vaccination. An example of this would be acute disseminated encephalitis (ADEM). This article will focus on the medical management of acute encephalitis. This will involve an extensive overview of the literature reviewing the diagnosis, investigation and treatment of acute viral encephalitis, ADEM and acute haemorrhagic leukoencephalopathy (AHLE). Encephalitis can also present chronically, and some of the different types of chronic encephalitis will be discussed.

IVIG therapy in neurological disorders of childhood

There is growing evidence that intravenous immunoglobulins (IVIG) are effective in some neuroimmunological disorders of childhood. This short review summarizes the evidence-based indications and recommendations of IVIG therapy in these disorders. Despite considerable efforts to define the role and mechanisms of IVIG, more clinical studies are needed to further explore the therapeutic potential of IVIG in childhood diseases of the nervous system and muscle.

Acute disseminated encephalomyelitis: an acute hit against the brain

PURPOSE OF REVIEW

In this review, the possible etiology, clinical characteristics, diagnosis, and treatment of acute disseminated encephalomyelitis (ADEM) are discussed. ADEM is a para- or postinfectious autoimmune demyelinating disease of the central nervous system and has been considered a monophasic disease. The highest incidence of ADEM is observed during childhood.

RECENT FINDINGS

Over the last decade, many cases of multiphasic ADEM have been reported. The occurrence of relapses potentially poses a diagnostic dilemma for the treating physician, as it may be difficult to distinguish multiphasic ADEM from multiple sclerosis (MS). Many retrospective patient studies have thus focused on the clinical and paraclinical features of ADEM and have attempted to define specific diagnostic criteria. Additionally, several experimental models have provided insight with respect to the pathogenic relation of an infectious event and subsequent demyelinating autoimmunity.

SUMMARY

Capitalizing on experience based on a large body of well characterized patient data collected both cross-sectionally and longitudinally, pharmacotherapy has been improved and mortality and comorbidities due to ADEM have been reduced. Unfortunately, the pathogenic events that trigger the initial clinical attack, and possibly pave the way for ongoing relapsing disease, remain unknown. Clinically applicable diagnostic criteria are still lacking.

Paediatric multiple sclerosis and acute disseminated encephalomyelitis in Germany: results of a nationwide survey

The aim of this study was to evaluate the incidence of paediatric multiple sclerosis (MS) and acute disseminated encephalomyelitis (ADEM) in Germany. In a prospective nationwide survey carried out between 1997 and 1999, all registered new cases of paediatric MS and ADEM with an onset before the age of 16 years were evaluated using a standardised questionnaire. A total of 132 patients with suspected or definite MS and 28 patients with an assumed diagnosis of ADEM were reported. Among these, 82% of the MS patients were 10 years of age or older, as opposed to 18% in the ADEM-cohort. The female-to-male ratio was 1.2:1 in the MS-cohort and 0.8:1 in the ADEM-cohort. Manifestation was polysymptomatic in 67% of the MS patients compared to 86% of the ADEM patients. The most frequent primary symptoms in the MS-cohort were cerebellar (44%), sensory (39%) or visual (36%), followed by brainstem (30%), pyramidal (29%) and cerebromental (22%) complaints.

CONCLUSION

The incidence of paediatric MS in Germany is more than fourfold higher than that of paediatric ADEM; in addition, it shows a strikingly different age-distribution. With an estimated minimum of 50 new cases per year, the incidence of paediatric MS in Germany is much more frequent than previously believed.

Acute disseminated encephalomyelitis cohort study: prognostic factors for relapse

To date, there is no available epidemiological study about prognostic factors of acute disseminated encephalomyelitis (ADEM) in children, using a cohort of patients with homogenous inclusion criteria. We aimed to evaluate prognostic factors for relapse after ADEM in children. A total of 132 children from the French National KIDSEP Neuropediatric Cohort (mean age at onset: 6+/-3.3 years; mean follow-up: 5.4+/-3.3 years; lost to follow-up: 10%). ADEM diagnosis was considered in a previously healthy patient acutely presenting more than one neurological deficit, change in mental state and MRI alterations including white matter changes. We used multivariate survival analysis (Cox model) evaluating the prognostic value of baseline clinical, biological and MRI covariates, for the occurrence of a second attack. Twenty-four (18%) of included patients had a second attack. An increased risk of relapse was associated with optic neuritis (hazard ratio, 5.23; 95% CI, 2-13.65), familial history of central nervous system inflammatory demyelination (7.79; 1.54-39.5), Barkhof multiple sclerosis (MS) criteria on MRI (2.52; 1.04-6.12) and no neurological sequelae after first attack (3.79; 1.12-12.85). Clinical and MRI prognostic factors for relapse in ADEM may contribute to an early distinction between monophasic and relapsing disease, which may be related to MS.

Emergency department presentation of acute disseminated encephalomyelitis

Acute disseminated encephalomyelitis is an acute demyelinating disorder of the central nervous system that usually occurs in children and young adults. We report the case of an 8-year-old girl who presented to the emergency department with acutely altered mental status. Standard workup including head computed tomography, lumbar puncture, and routine chemistries was unrevealing. Magnetic resonance imaging revealed findings consistent with acute disseminated encephalomyelitis. Response to treatment with steroids was dramatic. Both the rapidity of onset and resolution of this patient's symptoms are unusual for the course of this disease.