Patient handout

Acute Disseminated Encephalomyelitis (ADEM)

PRODUCTION

1. Your condition

This handout is for acute disseminated encephalomyelitis (adem). Your care team identified this based on: post uri/exanthem/vaccination 1-3 wk + encephalopathy + multifocal demyelination — classic pediatric adem (ipmssg 2013 pmid 23572237; tenembaum pmid 12391351).

Other reasons your team may use this plan: encephalopathy — required for adem diagnosis per ipmssg 2013 (pmid 23572237); mri multifocal hyperintense t2/flair lesions — typically large + asymmetric + supratentorial dominant + may enhance; adult-onset adem — rarer; worse prognosis; more likely evolves to ms (hardy pmid 27478954).

2. Your medications

Take these medications exactly as prescribed. Do not stop or change a dose without talking to your provider.

Medication	Starting dose	How	When	What it does
methylprednisolone (pediatric)	30 mg/kg/d IV × 3-5 d (max 1 g/d)	IV	daily × 3-5 d	First-line acute pulse in pediatric ADEM; 70-90% recovery; weight-based dosing capped at 1 g/d (Tenembaum PMID 12391351; Pohl PMID 27572859)
methylprednisolone (adult)	1 g IV daily × 3-5 d	IV	daily × 3-5 d	Adult ADEM dosing same as MS-flare; rarer + worse prognosis (Hardy PMID 27478954)
prednisone (oral taper)	1-2 mg/kg/d PO (pediatric, max 60 mg) × 1-2 wk then taper over 4-6 wk	PO	daily taper	Oral taper after IV pulse; relapse during taper rare in monophasic ADEM but watched

Plan: ADEM acute treatment — IV methylpred + IVIG + PLEX (IPMSSG 2013 PMID 23572237; PMID 22476745)

3. When to call your provider

Contact your care team if any of the following happen:

New event → ED + STAT MRI (MDEM vs MS conversion)
Cognitive regression → developmental specialist + repeat MRI
AED breakthrough → medication adjust
MOG-IgG+ + recurrence → route to neuro.mogad.v1

4. When to seek emergency care

Call 911 or go to the nearest emergency room right away if you have:

Pediatric post-infectious ADEM — URI/exanthem/vaccination 1-3 wk prior + encephalopathy + multifocal demyelination + HSV PCR negative (IPMSSG 2013 PMID 23572237; Tenembaum PMID 12391351)
Adult-onset ADEM — rarer; worse prognosis; more likely evolves to MS (Hardy PMID 27478954)
Post-vaccinal ADEM — very rare; historically rabies / smallpox / influenza vaccines; report to VAERS
MOG-IgG+ pediatric ADEM (~60% pediatric ADEM positive) — route to neuro.mogad.v1 for course classification (Banwell 2023 PMID 36706773)
MDEM — second ADEM event ≥3 mo after first with new lesions on MRI (IPMSSG 2013 PMID 23572237)
ADEM with concurrent or sequential ON (ADEM-ON) — check MOG-IgG (often positive); ophthalmology coordination
ADEM with LETM ≥3 vertebral segments — atypical for classic ADEM; AQP4-IgG MANDATORY (NMOSD pivot) + MOG-IgG
Pediatric severe ADEM with coma / status epilepticus / brainstem-airway compromise → ICU; cyclophosphamide consideration if refractory(life-threatening)
Autoimmune encephalitis (anti-NMDAR / LGI1 / GAD65) — overlap differential with ADEM; AE panel MANDATORY; different chronic management

5. Follow-up

Rehab (PT/OT/SLP); pediatric neuropsych baseline + serial (cognitive + behavioral deficits in 30-50%); ophthalmology if ON; AED management if seizure history; route to neuro.mogad.v1 if MOG-IgG+ + recurrence; surveillance MRI at 3-6-12 mo to classify monophasic vs MDEM; pediatric developmental specialist long-term

6. Sources

Guideline: Krupp / IPMSSG 2013 ADEM diagnostic criteria + Banwell 2023 MOGAD criteria (for MOG-IgG+ ADEM pivot) + Tenembaum 2002 pediatric ADEM natural history + Pohl 2016 long-term outcomes