A Pediatric Radiology Textbook and Pediatric Radiology Digital Library
Agenesis of Corpus Callosum
Etiology: — Abnormality of ventral induction — Order of growth is genu leads to body leads to splenium (front to back) — Bundles of Probst run front to back instead of crossing midline
Imaging: — Complete agenesis of corpus callosum: Absence of all 4 parts of corpus callosum (rostrum, genu, body, splenium) — Partial agenesis of corpus callosum: Absence of posterior body with or without splenium, short corpus callosum with or without missing parts and with or without abnormal shape, at least one of segments visible, at least one of segments missing and length reduced, interrupted or short corpus callosum — Parallel lateral ventricles on axial images — Viking horn or everted lateral ventricles on coronal images — Colpocephaly — High riding third ventricle — Pericallosal lipoma which arise from persistence and maldifferentiation of meninx primitiva — Intracranial lipomas
DDX: Corpus callosum anomalies — Agenesis – either complete or partial — Hypoplasia – characterized by the presence of a fully formed but thinner corpus callosum — Hyperplasia – characterized by the presence of a fully formed but thick corpus callosum — Dysplasia defined as a corpus callosum with a hump shape
Complications:
Treatment:
Clinical: Associated with Dandy Walker malformation, encephalocele
Radiology Cases of Agenesis of Corpus Callosum
Coronal (left) and sagittal (right) US of the brain show a Viking horn appearance of the anterior horns of the lateral ventricles and absence of the corpus callosum and a large midline cyst.Coronal US of the brain shows a Viking horn deformity of the anterior horns of the lateral ventricles (above left) and parallel bodies of the lateral ventricles (above right). There is mild hydrocephalus present and the third ventricle is high riding. Sagittal US of the brain (below) shows absence of the corpus callosum.Coronal US of the brain shows a Viking horn appearance of the anterior horns of the lateral ventricles (above left) and parallel bodies of the lateral ventricles (above right). Sagittal US of the brain (below) shows absence of the corpus callosum.Sagittal T1 MRI without contrast of the brain shows a small posterior fossa with downward cerebellar tonsil herniation and a small fourth ventricle. There is kinking of the spinal cord at the cervico-medullary junction. There is also agenesis of the body and rostrum of the corpus callosum.
