A STUDY OF THE CONGENITAL CLEFTS IN THE CEREBRAL MANTLE

Abstract

Congenital clefts in the cerebral mantle may result from a failure of growth and differentiation of circumscribed areas of the cerebral wall during the first 2 mos. of fetal life. The pathogenesis of these clefts is obscure. They should not be classed with the encephaloclastic porencephalies which result from the necrotizing and scarring processes in the brain often of circulatory origin. The thickness and richly cellular structure of the plate of gray matter in the walls of the clefts and the persistence of myelinated tangential fibers in the piaependymal seam are incompatible with the essentially destructive effects of Venous stasis and of circulatory disturbances. The agenesis of the cerebral wall must occur in the earliest stages of development of the neuraxis, probably before the alar plates of the rostral end of the neural tube were joined and the roof plate of the prosencephalon became closed.