20Developmental anomalies Structural developmental anomalies primarily affecting one body system Structural developmental anomalies of the nervous system LA05Cerebral structural developmental anomalies
LA05.1
category
Megalencephaly
Definition 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.
Also indexed as
Bilateral macrencephaly Bilateral macroencephaly Bilateral megalencephaly Hemimegalencephaly Macrencephaly Macroencephaly Megalencephaly Unilateral macrencephaly Unilateral macroencephaly Unilateral megalencephaly
Nearby in Cerebral structural developmental anomalies
International Classification of Diseases, Eleventh Revision (ICD-11), World Health Organization (WHO) 2019/2021, https://icd.who.int/browse11. Licensed under Creative Commons Attribution-NoDerivatives 3.0 IGO (CC BY-ND 3.0 IGO).
Release 2026-01.
View this entity in the official WHO ICD-11 browser .
This page reproduces WHO classification content for reference. It is not
medical advice and must not be used to diagnose or treat. For coding
decisions, consult the official release and your national coding guidelines.
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