The syndrome of the absence of a septum pellucidum with porencephaly.

Two cases of a complex brain malformation including the absence of a septum pellucidum and bilateral porencephaly were reported and compared with Aicardi's cases. The two cases have congenital hemiplegia or double hemiplegia and mental retardation, and one of them has optic atrophy. CT scans revealed the absence of a septum pellucidum and a specific position and shape of the clefts. The syndrome of the absence of a septum pellucidum and porencephaly may represent a specific type of true porencephaly, and the cause must occur before 16 weeks of gestation.