Cavum septi pellucidi and cavum vergae

The septum pellucidum is a non-neural dual membrane structure originating from the medial parts of the cerebral hemispheres. Right and left leaves of the septum are separated by a cavity in fetal life, which gradually becomes thinner and obliterated. Its posterior extension is the cavum vergae. The roof is formed by the corpus callosum and the hippocampal commissure, and posterior and inferior of the septum is formed by the fornix. The midline cavities of the brain are involved in inherited and congenital disorders. Although moderate variations in size are asymptomatic, they are easily picked up by neuroradiological means such as ultrasonography during fetal life. In this way, abnormalities of the cavities may indicate the need for further examinations. The author presents the complex association with pathology in this clinical summary. His past and present work is in the realm of congenital and inherited disorders affecting the morphology of the central nervous system.