Male, 11 days old, full term, with history of myelomeningocele status post repair. Evaluate for anatomic abnormalities and for ventricular size. Complete absence of the corpus callosum is seen. Only rudimentary development of the bodies and frontal horns of the lateral ventricles is noted. There is, however, a prominent midline interhemispheric CSF collection which may communicate with the third ventricle. The left lateral ventricular atrium is slightly prominent while the right is probably within normal limits. The massa intermedia is large. However, there are two discrete cerebral hemispheres with an interhemispheric falx. The pituitary gland appears somewhat elongated in the craniocaudal dimension. The normal posterior pituitary bright spot is seen. Image quality does not allow for accurate assessment of the optic apparatus. The posterior fossa is perhaps slightly crowded. However, the cerebellum neither enwraps the brainstem nor herniates through the tentorium or foramen magnum. No definite tectal beaking is seen.No evidence of restricted diffusion, susceptibility effect or focal parenchymal signal abnormality is seen. Within the limitations of this motion degraded examination, no definite cortical dysplasia is seen. The posterior limbs of the internal capsules and corticospinal tracts do not show clear evidence of myelination which is usually seen in the full-term infant.
Multiple intracranial findings are seen including absence of the corpus callosum, a large massa intermedia and a slightly crowded posterior fossa which, in combination with a history of myelomeningocele, are suggestive of Chiari II malformation. Although the cerebellum does not appear to enwrap the brainstem or herniate out of the posterior fossa, myelomeningocele repair can produce a normalizing effect on some of the cerebellar features of Chiari II. Although not highly suspected, subtle parenchymal abnormalities such as cortical dysplasias may not be detected due to limitations of image quality. However, the possibility of slightly delayed myelination is raised. The left lateral ventricular atrium is at most slightly prominent. However, note is made of a prominent midline interhemispheric CSF space.