Calcarine Fissure

Synonyms

Calcarine sulcus

Definition

The calcarine fissure is a deep sulcus located on the medial surface of the occipital lobe (see Fig. 1). The superior (cuneus) and inferior (lingual gyrus) banks of this sulcus represent the primary cortical projection area for vision. Visual information that is first received in the upper portions of the retina is represented along the upper banks of the fissure (cuneus), while that derived from the lower retina projects to its lower bank. Thus, lesions confined to the upper bank (cuneus) will result in contralateral inferior visual field defects, while damage to the lower bank (lingual gyrus) will produce upper field deficits. Lesions destroying tissue along both the upper and lower banks may result in a contralateral homonymous hemianopia.

Calcarine Fissure, Fig. 1

Mid-sagittal view of the brain (MRI) showing calcarine fissure separating the cuneus and the lingual gyrus of the occipital lobe