The syndrome of absence of the septum pellucidum with porencephalies and other developmental defects.

Four children with a complex brain malformation including absence of the septum pellucidum and porencephalies are reported. All patients presented with congenital hemiplegia or diplegia and mild to severe mental retardation. Ocular motor palsy and epilepsy were additional findings in two children. The diagnosis was made by pneumoencephalography (two patients), by CT scan (one patient) or by both techniques ((one patient). The neuroradiological images, especially those obtained by CT scan, are described. Previously reported cases with pathological confirmation are reviewed and compared with the present cases. The nosological situation of this syndrome is discussed in relation with holoprosencephaly and septo-optic dysplasia. We conclude that absence of the septum with porencephaly is a distinct and clinically recognizable syndrome.