#166: DEMystifying ADEM

January 28, 2026 | By Sam Masur

Audio

In this episode, Dr. Janetta Arellano (Children’s Hospital of Orange County) joins us to take a deep dive into ADEM. We discuss the key features, diagnostic approach, and management of ADEM, with important pearls for distinguishing it from other neurologic emergencies.

Acute Disseminated Encephalomyelitis (ADEM) Pearls

1. For patients coming in with acute neurological symptoms prompt neuroimaging (MRI preferred) will help narrow our differential diagnosis 
2. Prompt diagnosis and early treatment of ADEM will help prevent relapses and improve outcomes
3. Even in the outpatient setting, always keep an open mind about other diagnoses especially if the course deviates from expected recovery.

ADEM Notes 

Pathophysiology 

Acute Disseminated Encephalomyelitis is an autoimmune demyelinating disease of the central nervous symptom, occurring most commonly after a viral infection, presenting with multifocal neurologic deficits and encephalopathy. 

1. Triggering Event – Viral Infection triggers immune response against the antigen to the infection itself
2. Molecular Mimicry – Antigen can share structural similarities to myelin protein and the immune system cross-reacts with the CNS myelin
3. Immune Activation – T-cells infiltrate the CNS resulting in cytokine release and B-cells producing antibodies leading to inflammation and demyelination

Immune Based Demyelinating Disorder Breakdown 

Presentation

Encephalopathy is required for diagnosis of ADEM – can range from irritability, confusion, Level of consciousness changes. This can also be presented with ataxia and autonomic symptoms as well. (Hardy et.al., 2016)

Differential Diagnosis

Presentation is similar to other concerning neurological conditions that need to be further assessed and ruled out 

• CNS infection (encephalitis/meningitis)
• Increased ICP 
• Vascular – stroke or vasculitis
• Other autoimmune demyelinating diseases (see above)
• Malignancy

Work-up

Further Physical Exam Findings

• Vital signs – Fever, Signs of Dysautonomia, Vital signs suggestive of Increased ICP (Hypertension, Bradycardia)
• Mental Status changes
• Meningeal Signs – Neck stiffness, positive Kernig, Brudzinski sign
• Focal neurologic deficits on thorough neurological exam 
• Gait Disturbance – Is there weakness, ataxia
• Cerebellar signs and symptoms

Investigations 

MRI Brain (and spine depending on the patient) with and without contrast is ideal – can be challenging in younger kids who require sedation. While waiting for this, can prioritize CT head non-contrast.

Findings for ADEM on MRI:

Bilateral T2 Flair hyperintensity in white and grey matter. 
Serum Studies:

• CBC
• Electrolytes 
• Inflammatory markers (ESR, CRP, PCT)
• Anti-MOG IgG – for more confirmatory testing for ADEM by MOGAD

CSF studies from High Volume Lumbar puncture (15-20 cc):

• Opening and closing pressure
• Cell count with differential
• Protein
• Glucose 
• CSF culture
• Meningoencephalitis panel (PCR of multiple organisms)
• Oligoclonal bands 

In ADEM, there may be a mild lymphocytic predominance on cell count and mild protein elevation on CSF. 

Diagnostic Criteria for ADEM

As per the International Pediatric Multiple Sclerosis Study Group (IPMSSG) the diagnostic criteria for ADEM includes:

• First polyfocal CNS event – multifocal neurological changes
• Encephalopathy not explained by fever or metabolic issues
• Large poorly demarcated T2 lesions primarily in the white matter
• No previous MRI findings (Monophasic) (Krupp et. al., 2013)

Treatment

First line treatment: High dose corticosteroids – Methylprednisolone 30mg/kg max 1g for 3-5 days
Improvement is based on clinical symptoms – Repeat neuroimaging early on may not be helpful. 

After an inpatient steroid course, patients are sent home on steroid taper to prevent recurrence of symptoms. 

General taper: 2mg/kg/day with max of 60mg per day, and start weaning weekly for a total of 4 weeks. 

Second line treatment: 

• IVIG – if no improvement on corticosteroids or contraindication to steroid use 
• Plasma exchange – if very serious disease – on a ventilator in the ICU. This results in more immediate response.

Disparities in Care 

• Disparities in access to care – Rural or underserved populations with no children’s hospitals, pediatric neurologists or neuroimaging requiring sedation.
• Language Barriers – limited English proficiency and gaps even when using interpreter systems.
• Provider level of comfort – generally less common so symptoms are usually attributed to infections, toxins, or psychiatric diagnoses leading to delays.

Prognosis

Prognosis with treatment is good with prompt treatment. Most patients recover within weeks to months. 20% of patients may have mild residual deficits – attention issues, subtle motor deficits. Follow-up MRI 3-6 months later shows improvement or resolution of lesions. 

Prognosis without treatment may lead to relapse, especially with the MOG positive treatments. 

After discharge from the hospital, there should be a follow-up with the neurologist 4-6 weeks after discharge to monitor neurologic recovery, school performance. Can consider repeating MRI 3-6 months after treatment to assess improvement. If there is residual deficits, referring them to therapy. 

Goal

Listeners will explain the basic pathophysiology, diagnosis, and management of ADEM to improve both inpatient emergent care and outpatient follow-up. 

Learning Objectives

After listening to this episode listeners will…  

1. recognize the key clinical features of ADEM, including red flags in history and physical examination that should prompt urgent evaluation.
2. differentiate ADEM from other causes of acute neurologic symptoms in children, such as infection, stroke, and other immune-mediated demyelinating disorders.
3. describe the recommended diagnostic workup for suspected ADEM, including characteristic MRI and cerebrospinal fluid findings.
4. outline the initial management, escalation of therapy, and expected prognosis for children diagnosed with ADEM.

Disclosures

Dr. Arellano reports no relevant financial disclosures. The Cribsiders report no relevant financial disclosures. 

Citation

Venkataraman  V, Arellano J, Berk J, Chiu C, Masur S. “#166: DEMystifying ADEM”. The Cribsiders Pediatric Podcast. https:/www.thecribsiders.com/ Jan 28, 2025.