Heterotopia

  • Etiology: Abnormality of neuronal migration with island of gray matter in abnormal location in white matter and can be anywhere from subcortical to periventricular in location
  • Imaging:
    — Subependymal nodules have gray matter signal
    — Line ventricular walls and protrude into ventricle
    — Unilateral or bilateral
    — Large or small
    — Diffuse or regional
    — May be contiguous – usually thick and along most of lateral ventricl
    — May be noncontiguous – resembles pearls on a string
    — Unilateral nodular heterotopia can have subcortical heterotopia
    — Associated abnormalities involve corpus callosum
  • DDX:
  • Complications:
  • Treatment:
  • Clinical: Seizures

Radiology Cases of Heterotopia

MRI of heterotopia
Axial (left) and coronal (right) T2 MRI without contrast of the brain shows multiple subependymal nodules along the lateral wall of the left lateral ventricle that have signal characteristics similar to those of gray matter. Similar lesions were found in the right lateral ventricle on images that did not contain artifact from the right parietal VP shunt.