splenium

The splenium is the posterior portion of the corpus callosum, the major bundle of nerve fibers that connects the two cerebral hemispheres. It lies at the rear of the corpus callosum and forms its widest, rounded posterior segment.

Anatomy and connections

The splenium contains densely packed myelinated fibers that primarily link the occipital lobes, with connections to parts of the parietal and temporal lobes of the opposite hemisphere. These fibers enable interhemispheric communication for visual processing and higher-order integration of sensory information.

Function

By facilitating transfer of visual and related information between hemispheres, the splenium supports coordinated visuospatial processing, reading, and integration of posterior cortical functions.

Imaging and development

On magnetic resonance imaging, the splenium appears as the posterior, rounded part of the corpus callosum. Developmental anomalies can include splenial hypoplasia or agenesis. In certain conditions, splenial lesions may be seen with diffusion-weighted imaging, including reversible lesions associated with specific infections or metabolic disturbances.

Clinical significance

Damage or disease affecting the splenium can disrupt interhemispheric communication of visual information. Clinically, left splenial involvement with left occipital disease can contribute to alexia without agraphia. Splenial lesions occur in various conditions, such as demyelinating disease, ischemia, infection, or reversible splenial lesion syndromes, making it a region of interest in neuroimaging and neurology.