LA05.1

ICD-11 MMS 2026-01

Megalencephaly

Description

A condition caused by failure of the brain to correctly develop during the antenatal period. This condition is characterised by increased size or weight of an otherwise correctly formed brain. This condition may also present with seizures, motor deficits, mental retardation and mild cognitive impairment.

Index terms

  • Megalencephaly
  • Macrencephaly
  • Macroencephaly
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  • Bilateral megalencephaly
  • Bilateral macrencephaly
  • Bilateral macroencephaly
  • Hemimegalencephaly
  • Unilateral macrencephaly
  • Unilateral macroencephaly
  • Unilateral megalencephaly

Exclusions from above levels

  • LA01 – Encephalocele
  • http://id.who.int/icd/entity/733825440 – Inborn errors of metabolism

Sibling codes

  • LA05.0 – Microcephaly
  • LA05.2 – Holoprosencephaly
  • LA05.3 – Corpus callosum agenesis
  • LA05.4 – Arrhinencephaly
  • LA05.5 – Abnormal neuronal migration
  • LA05.6 – Encephaloclastic disorders
  • LA05.7 – Brain cystic malformations
  • LA05.8 – Colpocephaly
  • LA05.Y – Other specified cerebral structural developmental anomalies
  • LA05.Z – Cerebral structural developmental anomalies, unspecified

Foundation entity

Megalencephaly – http://id.who.int/icd/entity/368780653

Part of: LA05: Cerebral structural developmental anomalies › 20: Developmental anomalies