CAVUM SEPTI PELLUCIDI AND CAVUM VERGAE IN NORMAL AND DEVELOPMENTALLY DELAYED POPULATIONS

Recent studies have shown that the persistence of the cavum septi pell ucidi beyond the neonatal period is a marker of cerebral dysgenesis. I t has been suggested that the finding of a persistent cavum vergae is also a marker of disturbed brain development. In order to investigate this hypothesis me reviewed 161 brain magnetic resonance imaging scans from normal individuals for the presence of cavum septi pellucidi or cavum vergae, or both. In the 34 prospectively obtained normal adults, there were no individuals with either a cavum septi pellucidi or cavu m vergae. In the ''defined'' normal subjects 3 of 127 individuals (2.4 %) had a cavum septi pellucidi whereas a cavum vergae was noted in 26 of 127 (20.5%). We next reviewed the neuroimaging studies of 249 child ren and adults evaluated for mental retardation or developmental delay . A cavum septi pellucidi was found in 36 of 249 (15.3%) and a cavum v ergae in 48 of 249 (19.3%) of these patients. A cavum septi pellucidi and cavum vergae were found together in 19 of 249 (7.6%). We interpret these data as showing that the cavum septi pellucidi is rarely seen i n normal individuals although the cavum vergae is seen with the same f requency in normal and retarded populations. Thus we conclude that the cavum septi pellucidi selves as a significant marker of cerebral dysf unction manifested by neurodevelopmental abnormalities while the cavum vergae alone does not identify individuals at risk for cognitive dela ys.