acute disseminated encephalomyelitis (ADEM)

Introduction

also see encephalomyelitis

Etiology

• generally occurs post infection
  • no specific link to infection has been identified
  • typically occurs days to weeks after an infection or vaccination

Epidemiology

• children & young adults

Pathology

• simultaneous multifocal CNS demyelination

Clinical manifestations

• subacute presentation
• monophasic
• moderate to severe symptoms
• headache
• fever*
• seizures, encephalopathy*
• focal neurologic signs*

* differentiating features from multiple sclerosis

Diagnostic procedures

• lumbar puncture (after neuroimaging)
  • CSF analysis
    • lymphocytic pleocytosis (
    • CSF protein and CSF glucose may be normal

Radiology

• neuroimaging
  • magnetic resonance imaging (MRI)
    • multiple areas of demyelination (fluffy appearance)

Differential diagnosis

• multiple sclerosis
• posterior reversible encephalopathy syndrome
  • risk factors: hypertension, preeclampsia, kidney or liver disease, exposure to cytotoxic medications or immunosuppressants, or sepsis
  • recent infection or vaccination are not typical risk factors
• primary CNS lymphoma
  • typically presents with an avidly enhancing brain mass
  • usually occurs in patients > 50 years

Management

• prognosis:
  • generally self-limited, without recurrence

More general terms

• encephalomyelitis

Patient information

acute disseminated encephalomyelitis (ADEM) patient information