Posthemorrhagic hydrocephalus.

Post hemorrhagic hydrocephalus (PHH) can be defined as progressive dilation of the ventricular system that develops as a complication of neonatal intraventricular hemorrhage (IVH). Grading systems exist to quantify IVH but not this secondary ventricular dilation. Cranial ultrasound techniques and measuring methods that allow a uniform, objective grading convention for ventricular enlargement are presented. A biventricular to biparietal ratio (BV:BD) can be measured in the coronal images. A ventricular diameter (VD) can be measured in the sagittal images. Cortical mantle thickness and ventricular size can be measured in the axial images. These measurements allow more precise identification of changes in ventricular size which may have treatment implications. The clinical features of PHH and treatment options are also reviewed. No one treatment modality has proven superior, and neurologic outcome does not correlate with development or resolution of PHH. Better description of parenchymal damage is needed during routine ultrasound studies and development of other modalities to assess parenchymal function need to be developed before the significance of IVH and PHH can be fully understood.