Purpose: Differentiation of non-haemorrhagic subependymal pseudocysts from subependymal pseudocysts after cerebral haemorrhage in the preterm infant.
Materials and methods: Selective ultrasonographic screening in 2200 neonates and retrospective analysis in 72 infants with subependymal pseudocysts, the full-term infants being analysed from birth, and the preterm infants after the second week of life, thus avoiding the gestational age at which cerebral haemorrhage occurs in the preterm infant.
Results: Three variants of pseudocysts were identified: the caudothalamic germinolysis is a leukomalacic and pseudocystic gliosis. Pseudocysts in the anterior choroid plexus of the lateral ventricle could be distinguished from caudothalamic germinolysis by their location, form and movement. Pseudocysts lateral of the frontal horns are the result of regression of germinal matrix remains.
Conclusion: Differentiation of non-haemorrhagic from post-haemorrhagic germinolysis is necessary to clarify the aetiology and pathogenesis of non-haemorrhagic pseudocysts. Caudothalamic germinolysis possibly is the result of infection with stenotic intima proliferation following vasculitis. The results are thalamostriatal vasculopathy and germinal necrosis. Anterior plexus cysts might be the result of folding faults of the ependyma in the growth period of the choroid plexus. Pseudocysts lateral of the frontal horns should not be mistaken for ventricular ligaments.