Cerebrospinal fluid flow alterations in the dog with chemical meningitis

Chemical meningitis was induced in eight dogs by insertion of a kaolin-charcoal suspension through a plastic tube. The injected chemical substances were transported by altered cerebrospinal fluid (CSF) flow from the subarachnoid space into the lateral ventricles. If the normal peripheral area of absorption docs not function, the net flow of CSF may be “reversed” by secondary ependymal absorption. Since the kaolin-charcoal suspension enters the ventricular system through the foramina of the fourth ventricle and the aqueduct of Sylvius and causes inflammatory reaction with occlusion, this method does not appear valuable for creating communicating hydrocephalus. Cisternography will detect focal negative filling defects secondary to obliteration of the subarachnoid space. In severe noncommunicating hydrocephalus, less radioactivity over the cerebral cortex was observed. Measurements of the transfer of the radiopharmaceutical from CSF into the blood demonstrated delay in dogs with meningitis.