callosal agenesis
A developmental malformation characterized by the complete or partial absence of the corpus callosum, the major white matter tract connecting the cerebral hemispheres.
Full Definition
Callosal agenesis is a congenital brain malformation involving the complete (agenesis) or partial (dysgenesis) absence of the corpus callosum, the largest commissural structure in the brain. This condition occurs during early brain development when the callosal fibers fail to cross the midline, typically between 10-20 weeks of gestation. Callosal agenesis can be isolated or associated with other brain abnormalities and genetic syndromes. Patients may present with developmental delays, intellectual disability, seizures, or may be asymptomatic. The condition is diagnosed through neuroimaging and affects interhemispheric communication.
Usage
Usage note: Distinguish between complete agenesis and partial dysgenesis.
In Context
- "MRI revealed complete callosal agenesis with associated colpocephaly in the newborn patient." — Radiology report
- "The neuropsychological assessment showed deficits in interhemispheric transfer consistent with callosal agenesis." — Clinical evaluation