Corpus Callosum - History

In the 18th century, the corpus callosum was considered the site of the soul (Maurice Ptito), and in the early 20th it was assigned the mere role of preventing the cerebral hemispheres from collapsing onto each other

It was only in the 1950's that the corpus callosum, in the pioneering work of Myers and Sperry, was attributed the function of transferal of information between the two hemispheres

This was followed by the development, in the early 1960's, of a surgical intervention aimed at reducing the interhemispheric transmission of abnormal electrical discharges in epileptic patients

Corpus CallosumFrontal Forceps

Commissural fibersShort

Arcuate FibersOccipital forceps

Industium grisium

Medial Longitudinal stria

Lateral Longitudinal stria

Corpus Callosum - Parts

Rostrum

Genu Body

Splenium

Motor

Somatosensory Auditory

Visual200,000,000 Neurons connect each hemisphere

Agenesis of corpus callosum

ACC Clinical

• Partial or complete• Prtial Rostrum is

always missing• Delay in development

at 18-20 weeks to compensate formation of midline structure

• Associated anomalies– Hetrotopias– Lissencephaly, Schizencephaly– Chiari II– Cephalocele– Dandy Walker– Holoporencephaly– Lipomas– Azygous anterior cerebral

artery– Midline facial and skeletal

abnormality– Aicardi Syndrome

ACC - Gross

Coronal section at the level of midbrain

17-year-old female with developmental delays

The corpus callosum, cingulate gyrus, and sulcus are absent or malformed

there is a high-riding third ventricle that is open superiorly to the interhemispheric fissure

The sulci and gyri on the medial hemispheric surface have a radial or "spoke-like" configuration around the third ventricle

Agenesis of corpus callosum

Agenesis of corpus callosum CT

                                   

ACC – MR

ACC

Acardi Syndrome

• Agenesis of corpus callosum (ACC)

• Cortical heterotopia,• Infantile spasm, • Chorioretinopathy, • Mental retardation with

or without associated vertebral anomalies.

• X Linked Recessive