The posterior end of the corpus callosum is the thickest part, and is termed the splenium (Greek splenion = a bandage).

It overlaps the tela chorioidea of the third ventricle and the midbrain, and ends in a thick, convex, free border.

A sagittal section of the splenium shows that the posterior end of the corpus callosum is acutely bent forward, the upper and lower parts being applied to each other.

Although splenial lesions are rare, they are frequently associated with ischemic infarcts, antiepileptic drug toxicity or abrupt discontinuation, viral encephalitis, and metabolic disturbances.

see Splenium lesion.