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 hemorrhage
- Rasmussen encephalitis
- postictal cerebral hemiatrophy
- basal ganglia germinoma 2
- trauma
- infection
- vascular abnormalities (e.g. Sturge-Weber syndrome)
- ischemia
- 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.