8A42

ICD-11 MMS 2026-01

Acute disseminated encephalomyelitis

Description

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.

Exclusions from above levels

  • 05 – Endocrine, nutritional or metabolic diseases
  • 18 – Complications of pregnancy, childbirth and the puerperium
  • 19 – Certain conditions originating in the perinatal period
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  • 22 – Injury, poisoning or certain other consequences of external causes

Child codes

  • 8A42.0 – Acute haemorrhagic leukoencephalitis
  • 8A42.Y – Other specified acute disseminated encephalomyelitis
  • 8A42.Z – Acute disseminated encephalomyelitis, unspecified

Sibling codes

  • 8A40 – Multiple sclerosis
  • 8A41 – Isolated demyelinating syndromes of the central nervous system
  • 8A43 – Neuromyelitis optica
  • 8A44 – Leukodystrophies
  • 8A45 – Secondary white matter disorders
  • 8A46 – Central demyelination of corpus callosum
  • 8A4Y – Other specified multiple sclerosis or other white matter disorders
  • 8A4Z – Multiple sclerosis or other white matter disorders, unspecified

Foundation entity

Acute disseminated encephalomyelitis – http://id.who.int/icd/entity/1390433308

Allowed postcoordination axes

Part of: 08: Diseases of the nervous system