ICD-11 classes
08 Diseases of the nervous system
Spinal cord disorders excluding trauma
8B41 — Myelitis
8A42 — Acute disseminated encephalomyelitis

ICD-11 8A42 — Acute disseminated encephalomyelitis

Acute disseminated encephalomyelitis is a demyelinating disorder of the central nervous system. It usually develops after acute viral or bacterial infection or vaccination, with a sudden onset of irritability and lethargy after a prodromal period of 1-4 weeks. Major symptoms include fever, headache, drowsiness, changes in mental status, seizures and coma. Weakness, vomiting, weight loss, stiff neck, ataxia, bilateral optic neuritis and delirium are common. Peripheral nervous system involvement (paralysis of a single limb or hemiplegia) may occur.

The diagnosis includes nothing.

The diagnosis excludes nothing.

Diagnosis with code 8A42 contains 3 clarifying diagnoses:

1. 8A42.0 — Acute haemorrhagic leukoencephalitis
2. 8A42.Y — Other specified acute disseminated encephalomyelitis
3. 8A42.Z — Acute disseminated encephalomyelitis, unspecified

The diagnosis is coded elsewhere:

• Multiple sclerosis or other white matter disorders #6776
• Acute disseminated encephalomyelitis #6802
• Paraneoplastic or autoimmune disorders of the central nervous system, brain or spinal cord #7801
• Acute disseminated encephalomyelitis #7817