Influence of the rate of ventricular enlargement on the white matter water content in progressive feline hydrocephalus.
The effectiveness of transependymal absorption of cerebrospinal fluid in hydrocephalus was studied by correlating the measured water content of feline hydrocephalic white matter with the rate of enlargement of the ventricles. Two groups of cats were subjected to opening of either the calvaria or the calvaria and dura before the intracisternal injection of kaolin to obtain two profiles of ventricular enlargement. The water content 1, 2, and 3 mm from the lateral ventricles was measured in each group using the dry/wet weight and microgravimetric techniques after sacrificing the animals in each group at 2, 3, or 6 weeks after inducing hydrocephalus. In the animals with both calvarial and dural opening, the ventricles enlarged rapidly in the first 2 to 3 weeks and then continued to increase but at a slower rate. Concomitant with this early increase of ventricular size was a progressive increase in white matter water content both adjacent to and remote from the ventricles, which continued through 6 weeks. When only the calvaria was opened, ventricular size increased gradually, but continued to increase at a constant rate throughout the 6 weeks. Water content adjacent to the ventricle did not increase until the 3rd week, with little spread to adjacent areas by the 6th week. The central canals of the spinal cord were enlarged in both groups at all sampling levels. Neither increased periventricular water nor dilatation of the central canal was associated with stabilization of ventricular size in these studies. The authors conclude that these pathways are not sufficient to arrest the hydrocephalic process in these models.
D000818:Animals; D001834:Body Water / Q000032:analysis; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry; D002415:Cats; D002552:Cerebral Ventricles / Q000473:pathology; D005110:Extracellular Space / Q000032:analysis*; D006849:Hydrocephalus / Q000134:cerebrospinal fluid / Q000378:metabolism*; D013997:Time Factors