Agenesis of the Corpus Callosum

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Agenesis of the Corpus Callosum

Last updated on Tuesday, September 9 2008 by jdmiles

Related images:

Septo-optic dysplasia, coronal section through brain at the level of the foramen of Monro
Also known as de Morsier syndrome, septo-optic dysplasia is characterized by abnormalities involving both the septum pellucidum and optic systems. The abnormal tissue within the third ventricle consists of a disorganized amalgam of dysplastic gray and white matter.

Agenesis of the corpus callosum, coronal section through neonatal brain, close-up
The delicate neonatal corpus callosum is easily torn during brain removal. Microscopic confirmation of an uninterrupted transition from leptomeninges to ependymal lining is critical to distinguishing these possibilities.

Agenesis of the corpus callosum, mid sagittal section through brain.
Agenesis of the corpus callosum is typically accompanied by dysplasia involving the cingulate gyrus, usually with a radial arrangement of gyri as pictured here

Agenesis of the corpus callosum, mid sagittal section through brain, close-up
Radial arrangement of the dysplastic cingulate gyri is an expected accompaniment to callosal agenesis.

Agenesis of the corpus callosum, mid sagittal view, close-up
In patients with true callosal agenesis, cingulate gyri are typically dysplastic, as pictured here.

Agenesis of the corpus callosum, mid sagittal section, extreme close-up.
In patients with callosal agenesis, fibers that would have cross the midline instead travel posteriorly along with the fornix, forming Probst's bundle, seen here between the cingulate gyrus and thalamus.

Agenesis of the corpus callosum, coronal section demonstrating Probst bundle
In patients with callosal agenesis, fibers that would have cross the midline instead travel posteriorly along with the fornix, forming Probst's bundle, seen here in cross section superior lateral to the end of the cingulate gyrus.