corpus callosum agenesis
Congenital absence of the corpus callosum due to failure of commissural fiber development during embryogenesis.
Full Definition
Corpus callosum agenesis is a congenital malformation characterized by the partial or complete absence of the corpus callosum, the major commissural structure connecting the cerebral hemispheres. This condition results from disrupted development of commissural fibers during the 10th to 20th weeks of gestation. The malformation can occur in isolation or as part of complex syndromes. Associated findings may include colpocephaly (enlargement of posterior horns of lateral ventricles), Probst bundles (aberrant fiber tracts), and cingulate gyrus abnormalities. The condition can be complete (affecting the entire corpus callosum) or partial (typically affecting posterior regions first). Clinical presentation varies widely, from asymptomatic cases to severe developmental delays.
Usage
Usage note: Specify complete versus partial; note associated malformations and syndromic features.
In Context
- "Complete corpus callosum agenesis was identified with associated colpocephaly." — Fetal autopsy report
- "Partial callosal agenesis affected the splenium and posterior body." — Developmental neuropathology case