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Hemimegalencephaly
Disease definition
Hemimegalencephaly is a rare cerebral malformation characterized by overgrowth of all or part of a cerebral hemisphere, often with ipsilateral severe cortical dysplasia or dysgenesis, white matter hypertrophy and dilated lateral ventricle, presenting in early infancy with progressive hemiparesis, severe psychomotor retardation and intractable seizures. Hemimegalencephaly may be an isolated finding or associated with other syndromes such as angioosteohypertrophic syndrome, epidermal nevus syndrome and Ito hypomelanosis (see these terms). Management includes seizure control by antiepileptic medications and early hemispherectomy.
ORPHA:99802
Classification level: Disorder- Synonym(s):
- Unilateral megalencephaly
- Prevalence: Unknown
- Inheritance: Not applicable
- Age of onset: Infancy
- ICD-10: Q04.5
- OMIM: -
- UMLS: C0431391
- MeSH: -
- GARD: 2637
- MedDRA: -
A summary on this disease is available in Español (2014) Nederlands (2014)
Detailed information
Disease review articles
- Clinical genetics review
- English (2022) - GeneReviews


Additional information
Further information on this disease
Patient-centred resources for this disease
Research activities on this disease
Specialised Social Services
The documents contained in this web site are presented for information purposes only. The material is in no way intended to replace professional medical care by a qualified specialist and should not be used as a basis for diagnosis or treatment.