|
Definition/Background
Agenesis of the corpus callosum is a rare congenital disorder
in which there is partial or complete absence of the corpus callosum. It is
usually a sporadic occurrence, but is known to be associated with trisomy 18,
trisomy 13, and trisomy 8.
Characteristic
Clinical Features
Signs and symptoms of agenesis of corpus callosum vary greatly
among individuals. Some common characteristics include vision impairment,
delayed milestones, and hypotonia.
Characteristic
Radiologic Findings
Though the diagnosis of agenesis of the corpus callosum can
be easily established on CT studies, MR with its multiplanar capability and
inherently superior soft-tissue resolution is better at demonstrating the
imaging features of agenesis of the corpus callosum.
■ Parallel, nonconverging lateral ventricles, best appreciated
on axial scans
■ High-riding third ventricle, which may be open superiorly to
an inter-hemispheric cyst, best appre-
ciated on coronal images
Sponsored Link
■ Indentation on the medial aspect of the frontal horns by
Probst bundles (longitudinally oriented fiber tracts) resulting in the “Viking
horns” or “bull’s horns” appearance, best appreciated on coronal images
■ Dilated occipital horns (Colpocephaly), best appre-ciated on
axial or coronal images
■ Radial, spokelike orientation of the gyri, best appre-ciated
on sagittal T1WI
Associated findings:
■ Lipoma of the corpus callosum (midline)
■ Azygous anterior cerebral artery
■ Chiai II malformation
■ Migration disorders
■ Cephaloceles (usually midline)
■ Dandy-Walker malformation
■ Holoprosencephaly
■ Median cleft syndrome
Note: Diagnosis of agenesis of corpus callosum can be established
on prenatal sonogram or MRI studies.
The patient is a 42-year-old, with change in mental status.
Axial CT scan demonstrates parallel, nonconverging lateral ventricles. Also noted are dilated occipital horns suggestive of colpocephaly.
Axial CT scan demonstrates high-riding third ventricle.
Reformatted coronal CT scan demonstrates indentation on the medial aspect of the frontal horns by Probst bundles, resulting in “bull’s horns” appearance.
Reformatted mid-sagittal CT scan demonstrates absent corpus callosum. This results in radial, spoke-wheel-like orientation of the gyri. Diagnosis: Agenesis of corpus callosum.
Sponsored Links
|
Labels: Brain, Congenital Anomalies
