Ventricular septa in the neonatal age group: diagnosis and considerations of etiology.

Twenty-four patients with ventricular septa are discussed. Seventeen patients had septa acquired during the neonatal period and seven exhibited septations at birth (cogenital septa). Among the acquired septa, there were true intraventricular septa and septa that originated outside the ventricles but later became part of the ventricular system (pseudosepta). Pseudosepta originate in necrotic, cavitating periventricular white matter that, in temporal sequence, becomes ventricularized. Serial use of cranial sonography provided important information about the pathologic mechanisms that govern the development of septa. Intraventricular hemorrhage and infection are the major causes of true intraventricular septa, while periventricular leukomalacia serves as primary cause of pseudosepta. Sonography is the diagnostic method of choice. Septa are associated with a high incidence (62%) of shunt failure.

Periventricular leukomalacia in combination with intraventricular hemorrhage: sonographic features and sequelae.

Periventricular leukomalacia (PVL) is well recognized as a relatively uncommon yet particularly serious complication of prematurity. Although the sonographic features of PVL have been described, its association with intraventricular hemorrhage (IVH) has not been emphasized. Reviewing 26 consecutive cases of PVL in neonates of 34 weeks or less gestational age, significant associated hemorrhage was found in six (23%). Small quantities of blood were also noted in most of the other 20 infants. Of the six infants with both significant IVH and PVL, five required ventricular shunt and all had particularly poor clinical outcomes. In the neonates who required surgical intervention, rapid ventricular enlargement was accompanied by extensive periventricular cyst formation. Eventually, the septations within the cysts and frequently even the ependyma of superior/posterior lateral ventricles degenerated. Cysts merged imperceptibly with the ventricles giving an appearance that mimicked severe hydrocephalus. This was termed "pseudoventricle formation," as the large intracerebral cerebrospinal fluid spaces are primarily porencephaly and not enlarged ventricles. Response to shunting was minimal by sonography in all five cases and multiple shunt revisions were required in four. Clinical follow-up in children with significant IVH in combination with PVL has shown severe mental retardation and tetraplegia in all cases.