Acute Disseminated Encephalomyelitis in Children

Objective. To describe the epidemiologic, clinical, neuroimaging, and laboratory features; treatment; and outcome in a cohort of children with acute disseminated encephalomyelitis (ADEM). Methods. A 6-year retrospective chart review of children with the diagnosis of ADEM was conducted. Results. Eighteen cases were identified. Sixteen patients (88%) presented in either winter or spring. Thirteen children (72%) had a recent upper respiratory tract illness. Patients presented most often with motor deficits (77%) and secondly with altered consciousness (45%). Spinal fluid abnormalities occurred in 70%. Despite rigorous microbiologic testing, a definite microbiologic diagnosis was established only in 1 child with Epstein-Barr virus disease and probable or possible diagnoses in 3 children with Bartonella henselae, Mycoplasma pneumoniae, or rotavirus disease. Brain magnetic resonance imaging identified lesions in the cerebral cortex in 80%, in subcortical white matter in 93%, in periventricular white matter in 60%, in deep gray matter in 47%, and in brainstem in 47% of patients. Eleven patients (61%) were treated with corticosteroids, and 2 were treated with intravenous immunoglobulins. All patients survived. Three patients (17%) had long-term neurologic sequelae. Conclusions. Epidemiologic evidence from this study suggests an infectious cause for ADEM. The agent is most likely a difficult-to-diagnose winter/spring respiratory virus. Magnetic resonance imaging was the neuroimaging study of choice for establishing the diagnosis and for following the course of the disease. Prognosis for survival and outcome was excellent. Recurrent episodes of ADEM must be differentiated from multiple sclerosis. Pediatrics 2002;110:e0–e0. URL: www.pediatrics.org/cgi/ doi/10.1542/peds.; acute disseminated encephalomyelitis, ADEM, encephalitis, postinfectious encephalitis, encephalomyelitis. ABBREVIATIONS. ADEM, acute disseminated encephalomyelitis; CNS, central nervous system; MRI, magnetic resonance imaging; FLAIR, fluid-attenuated inversion recovery; PCR, polymerase chain reaction; EBV, Epstein-Barr virus; Ig, immunoglobulin; TR, repetition time; TE, echo time; NSA, number of signal averages; FOV, field of view; CT, computerized tomography; WBC, white blood cell; CSF, cerebrospinal fluid; IVIG, intravenous gammaglobulin; MS, multiple sclerosis. Acute disseminated encephalomyelitis (ADEM) is considered a monophasic acute demyelinating disorder of the central nervous system (CNS) characterized by diffuse neurologic signs and symptoms coupled with evidence of multifocal lesions of demyelination on neuroimaging. The epidemiology of ADEM has changed since its original description by Lucas1 in the early 18th century. At that time, ADEM commonly followed common childhood infections such as measles, smallpox, and chickenpox and was associated with significant mortality and morbidity. In a series of case reports in 1931 in The Lancet, McAlpine2 described 3 sets of patients with ADEM: 1) postvaccination, 2) after infectious fevers such as in measles, and 3) spontaneous. Those with spontaneous and postvaccination ADEM did well despite the lack of antibiotics, steroids, and intensive care facilities, whereas those with an infectious cause fared poorly. A number of recent reports of ADEM in children have confirmed the observations of McAlpine.3,4 Several articles suggested that improved outcome of ADEM was attributable mainly to the use of steroids; however, evidence for this was mainly anecdotal.5,6 The purpose of the present study was to review ADEM from a single institution with an emphasis on the relationship of clinical features, microbiology, neuroimaging, and treatment to clinical outcome. Eighteen patients with ADEM were identified. Respiratory infections preceded the neurologic presentation in the vast majority. Although in most cases a specific cause could not be identified, the outcome was good regardless of treatment.