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| CT | T1 sagittal pre gad | T1 coronal pre gad |
Diagnosis: Agenesis of the corpus callosum
Complete agenesis of the corpus callosum has an incidence of 1% - 5% and presents with developmental delay, seizures, or less commonly normal brain function. It is often associated with other CNS anomalies such as hydrocephalus, callosal lipoma, Dandy-Walker complex, Arnold Chiari II malformation, migrational anomalies and holoprosencephaly. Callosal agenesis is also associated with Gorlin, cri du chat, and Aicardi syndromes. In this patient callosal agenesis is associated with frontonasal dysplasia, a rare, autosomal dominant syndrome characterized by hypertelorism, callosal agenesis, broad first digits, split nails, scoliosis and long clavicles. Girls are affected more frequently. If associated with craniosynostosis, the syndrome is termed craniofrontonasal dysplasia.
The corpus callosum may also be partially absent in which case the genu will be present with variable absence of the splenium, rostrum, and body. Complete agenesis of the corpus callosum is characterized by widely spaced, parallel lateral ventricles with relative dilatation of the atria called colpocephaly. Since the corpus callosum is absent, the white matter tracts which would have crossed, instead terminate at the midline producing a medial indentation upon the lateral ventricles termed the bundles of Probst. The cingulate gyrus is also absent which results in a radial, spoke-wheel appearance of the gyri along the interhemispheric fissure. The third ventricle may be elevated connecting to the interhemispheric fissure superiorly with an interhemispheric cyst. Related Cases
