Maria Braileanu, BA

A 44-year-old male with a history of absence seizures, migraines, peripheral neuropathy, and multisystem sarcoidosis.


Sagittal MRI demonstrates the absence of the corpus callosum and radially arrayed gyri on T1WI. Axial T1WI, T2WI, and FLAIR sequences reveal parallel and widely spaced lateral ventricles. The frontal horns of the lateral ventricles are abnormally pointy, while the occipital horns are dilated. The findings are consistent with agenesis of the corpus callosum (ACC).




Agenesis of the corpus callosum is a congenital deficit resulting in an absent or abnormal connection between the two cerebral hemispheres. It occurs in 0.5–70 per 10,000 live births and is associated with multiple other neurological and developmental syndromes. Symptomology varies vastly, from minor issues with problem solving and social skills, to severe neurological deficits.

The corpus callosum develops during gestational weeks 8–20, with axons originating from layers I, II/III, V, and VI of the neocortex. Any abnormality in commissural axonal formation, growth, specification, migration, and/or guidance may lead to ACC.

Prenatal ultrasound sonography can be used in the mid-trimester to screen for ACC. The corpus callosum will be absent, with widely spaced parallel lateral ventricles on axial imaging and “trident” lateral ventricles on coronal sections. Prenatal follow-up MRI is warranted as the modality is more sensitive and specific. Head CT or brain MRI is used to diagnose adults. In addition to the aforementioned abnormalities, on sagittal T1WI the gyri may “point” to the third ventricle, and the cingulate gyrus is commonly absent. Relative to myelin, the signal of Probst bundles (aberrant commissural fibers) is usually described as hyper/hypo-intense on T1WI/T2WI sequences, respectively. More recently, the use of diffusion tensor imaging has revealed interesting insights into ACC, such as sigmoid bundles and pathologic plasticity.


Edwards TJ, Sherr EH, Barkovich AJ, Richards LJ. Clinical, genetic and imaging findings identify new causes for corpus callosum development syndromes. 

. 2014;137:1579-1613.

Osborne A. Callosal Dysgenesis. In: Diagnostic Imaging: Brain. 1

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44-year-old male with a history of absence seizures, migraines, peripheral neuropathy, and multisystem sarcoidosis.

Maria Braileanu, BA

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