REDUCED LOCAL CEREBRAL BLOOD-FLOW IN PERIVENTRICULAR WHITE-MATTER IN EXPERIMENTAL NEONATAL HYDROCEPHALUS - RESTORATION WITH CSF SHUNTING

The extent to which the reduction in CBF occurring in hydrocephalus is a primary or secondary event in the pathogenesis of the brain injury that ensues has not been clearly established. This is particularly tru e in neonatal hydrocephalus, where the disorder is most common, and wh ere timing of the treatment of the developing nervous system is so imp ortant. We investigated the changes in local CBF (1CBF) in an animal m odel of severe progressive neonatal hydrocephalus before and after CSF shunting, Hydrocephalus was induced in 27 1-week-old kittens by percu taneous injection of 0.05 ml of 25% kaolin into the cisterna magna. Fo urteen littermates acted as controls. The 1CBF was measured by C-14-io doantipyrine quantitative autoradiography after 1 week in 15 animals ( 8 hydrocephalic, 7 controls) and after 3 weeks in 26 animals (19 hydro cephalic, 7 controls) following induction of hydrocephalus. Twelve of the 3-week hydrocephalic group received a ventriculoperitoneal shunt 1 0 days following kaolin injection. At 1 week following induction of hy drocephalus, 1CBF was globally reduced in cortical gray matter and whi te matter as well as deep subcortical structures. The maximum reductio n was in the parietal white matter, to 37% of control levels. At 3 wee ks a significant reduction in 1CBF persisted only in the white matter (parietal, occipital, and corpus callosum; average, 42% of control lev els), whereas cortical gray and deep subcortical structures had return ed to normal levels spontaneously. 1CBF was normal in 3-week hydroceph alic shunted animals in all areas. CSF shunting restores the fall in 1 CBF in the periventricular white matter in this model. These findings are consistent with previous studies in the same model demonstrating d erangement of high-energy phosphate metabolism and white matter anaero bic glycolysis with hydrocephalus and resolution with shunting.