What is the treatment for acute disseminated encephalomyelitis (ADEM)?

Treatment of Acute Disseminated Encephalomyelitis (ADEM)

High-dose intravenous corticosteroids (methylprednisolone, 1 g intravenously daily for 3-5 days) are the first-line treatment for ADEM, followed by an oral corticosteroid taper over 4-6 weeks. 1, 2, 3

First-Line Treatment Options

Corticosteroids

• Methylprednisolone 1 g IV daily for 3-5 days 1, 2
• Follow with oral prednisone taper over 4-6 weeks 3
• Consider adding prednisolone 60-80mg daily for 3-5 days if evidence of significant inflammation, vasculitic component, or cerebral edema 2

Second-Line Options (for patients with inadequate response to corticosteroids)

• Intravenous immunoglobulin (IVIG): 2 g/kg divided over 2-5 days 3

  • IVIG has shown dramatic clinical improvement in steroid-resistant cases 4, 5
  • Clinical improvement typically begins within 5 days of IVIG administration 4

• Plasma exchange (PLEX) 1, 3

  • Should be considered early for severe or life-threatening cases 3
  • Particularly beneficial for patients who respond poorly to corticosteroids 1

Treatment Algorithm

1. Initial Assessment:

   • Confirm diagnosis through MRI with contrast of brain, CSF analysis, and EEG 2
   • Rule out infectious causes before immunosuppressive therapy

2. First-Line Treatment:

   • Start high-dose IV methylprednisolone (1 g/day for 3-5 days) 1, 2
   • Monitor clinical response during treatment

3. Response Assessment (within 5-7 days):

   • If improving: Complete steroid course and transition to oral taper
   • If not improving or worsening: Proceed to second-line therapy

4. Second-Line Treatment (for inadequate response):

   • IVIG 2 g/kg divided over 2-5 days 3, 4
   • OR Plasma exchange, especially for severe cases 1, 3

5. For Refractory Cases:

   • Consider rituximab for cases resistant to standard treatments 6
   • Decompressive craniectomy may be considered as a life-saving measure for patients with intracranial hypertension 3

Special Considerations

• Recurrent or Multiphasic ADEM:

  • Consider alternative diagnoses such as multiple sclerosis or neuromyelitis optica 3, 7
  • Test for myelin oligodendrocyte glycoprotein (MOG) antibodies, as MOG-associated disease can present as ADEM and has potential to be relapsing 7

• Supportive Care:

  • Initiate rehabilitation as soon as the patient is stable 2
  • For declining consciousness, urgent ICU assessment for airway protection and management of raised intracranial pressure 2

Treatment Pitfalls and Caveats

• Delay in initiating immunotherapy can lead to poorer outcomes
• Empiric antibacterial and antiviral treatment should be administered until infectious causes are ruled out 3
• Some patients may deteriorate with corticosteroid treatment; close monitoring is essential 5
• Insufficient duration of oral steroid taper may lead to symptom recurrence
• Long-term follow-up with MRI is important to monitor disease activity and rule out alternative diagnoses

By following this treatment approach, most patients with ADEM show significant improvement, with generally favorable long-term outcomes, although some children may have ongoing neurocognitive sequelae 7.