Cerebral hemiatrophy has a variety of causes, and is generally associated with seizures and hemiplegia. Causes include:

  • congenital
    • idiopathic (primary)
    • intrauterine vascular injury
  • acquired
    • perinatal intracranial haemorrhage
    • Rasmussen encephaltitis
    • postictal cerebral hemiatrophy
    • basal ganglia germinoma
    • trauma
    • infection
    • vascular abnormalities e.g. Sturge-Weber syndrome
    • ischaemia
    • hypoxia

Radiographic features

The resultant reduction in cerebral volume, if early enough, can lead to changes in the skull, known as Dyke-Davidoff-Masson syndrome.

Changes within the brain parenchyma typically demonstrate:

  • thinning of the grey matter cortex
  • reduced volume of the underlying white matter
  • + / – reduced / abnormal myelination
  • enlargement of the lateral ventricle
  • reduced size of cerebral peduncle (ipsilateral)
  • reduced size of cerebellar hemisphere (contralateral)


Differential diagnosis

A potential pitfall is assuming the ‘small’ side is the abnormality. Thus hemimegalencephaly or gliomatosis cerebri or widespread cortical dysplasia should be considered.