Acute disseminated encephalomyelitis (ADEM) in children: a case report

Case presentation: Female, 2 years old, admitted in emergency with fever and backache, evolving with abnormal sleepiness. At hospital admission, disoriented, ataxic and sleepiness, without signs of meningeal irritation. Encephalitis is suspected and a lumbar puncture was performed. Analysis of cerebrospinal fluid (CSF) excluded infectious causes of central nervous system. Brain magnetic resonance (MRI) shows hypersignal on T2/FLAIR in the pontine tegmentum, extending to the medial aspect of the middle cerebellar peduncles and dentate nuclei. Spine MRI shows alterations suggestive of extensive longitudinal myelitis, with signal alteration at the pons and medulla. Acute disseminated encephalomyelitis (ADEM) is suspected. Treatment with methylprednisolone 30mg/kg/day was performed, showing progressive improvement. Discharged for outpatient follow-up with neuropediatric, physical therapy and prednisolone 1mg/kg/day for 30 days.

Discussion: ADEM is an inflammatory demyelinating disease of the central nervous system (CNS) present in childhood, characterized by encephalopathy and multifocal brain lesions with involvement of the cerebral white matter and spinal cord. It has annual incidence of 5:10.000 children, with a mean age of onset of 3 to 7years. It is a disease that manifests in a genetically susceptible individual, with sudden onset and polysymptomatic presentation, including meningeal signs, fever and encephalopathy, usually preceded by viral infection or recent vaccination. Involves the cortex, as well as lesions in the deep portions of the brain, including the basal ganglia region, brainstem region and cerebellum. ADEM is considered a diagnosis of exclusion, requiring neuroimaging and laboratory studies to exclude other potential diagnosis. MRI is the exam of choice for evaluation. Almost all patients have multiple subcortical lesions, typically bilateral and asymmetrical, characteristic of demyelination. The CSF analysis can be normal, but usually shows inflammatory evidence with pleocytosis and increased protein. Acute therapies include high-dose corticosteroids, plasmapheresis and immunoglobulin. The long-term prognosis is usually favorable, with a recovery over 4 to 6 weeks.

Final comments: ADEM is a demyelinating disease of the CNS, usually presenting itself as a monophasic disorder associated with multifocal neurological symptoms and encephalopathy, preceded by infectious events and can simulate other autoimmune and infectious disorders. Requires early diagnosis and treatment for a good prognosis.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
18 September 2023