• Etiology: defective stem cells with abnormal proliferation, migration, organization
  • Imaging: unilateral generalized / focal enlargement of hemisphere + ventricle, dysmyelination, thick cortical ribbon, cortical dysplasia, pachygyria, polymicrogyria, heterotopia, ipsilateral advanced myelination
  • Clinical: associated with epidermal nevus syndrome, Proteus syndrome, Klippel-Trenauny-Weber syndrome, neurofibromatois-1, hypomelanosis of Ito

Radiology Cases of Hemimegalencephaly

MRI of hemimegalencephaly
Axial T2 MRI of the brain shows the left cerebral hemisphere to have diffusely thickening of the cortical ribbon and a decreased amount of white matter.