Regional Cerebral Blood Flow and Microangioarchitecture in Feline Hydrocephalus

Oh, Seong Hoon; Choi, Joong Uhn; Lee, Kyu Chang

Abstract

To evaluate the cerebral blood flow in feline hydrocephalic brain, this study was designed to measure the regional cerebral blood flow(rCBF ; frontal and periventricular area) by the hydrogen clearance method and to visualize the vascular morphology such as angioarchitecture, diameter and number of vessels using microfil in different stages of the kaolininduced hydrocephalus. There have been several prior reports about intracraial vascular morphology, using various material such as colloida carbon and microcorrosion casts. But there is none about microfil in normal or hydrocephalic cats. The authors made a first cicrofil model to observe the vascular changes in experimental feline hydrocephalus in the literature. The results were as follows : 1) A reduction of rCBF was detected in the left periventricular area at 2 weeks after kaolin injection. A significant reduction of rCBF was revealed at left periventricular area at 4 weeks after kaolin injection. However, the rCBF of the left frontal cortex was significantly decreased at 4 week after kaolin injection. 2) A reduction in diameter of vessels was detected in the left periventricular area at 2 weeks after kaolin injection. The significant reduction of diameter in the left periventricular area was revealed at 4 weeks after kaolin injection. 3) The vessels of the periventricular area in the control cats were dense but loose in hydrocephalic cats. A reduction in number of vessels was found in the a periventricular area at 1 week after kaolin injection. A reduction in number of vessels was found at 2 weeks after kaolin injection also. And a significant reduction in number of vessels was found at 4 weeks after kaolin injection. 4) The number and caliber of vessels in the frontal cortex were similar between the control and hydrocephelic groups. However, cortical vessels of the control group were straight and parallel and showed the typical 'palisade pattern', whereas some of the hydrocephalic group showed distortion of the cortical vessels. In conclusion, ventricular enlargement causes displacement of primary cerebral arteries, followed by both stretching and a decrease in the caliber of the microvasculature, resulting in diminished cerebral blood flow and tissue destruction. The results suggest that vascular changes playa important role in the production of brain damage in hydrocephalus.