The relationship of compensated to decompensated hydrocephalus in the cat

✓ The effects of removal of the calvaria and excision of the dura on the development of hydrocephalus was studied in adult cats made hydrocephalic by an intracisternal injection of kaolin. In some animals, the calvaria was removed prior to the induction of experimental hydrocephalus, and in others when the hydrocephalus was compensated. In both groups of cats, the results were similar. Ventricular dilatation was massive, often leaving a cortical mantle less than 1 mm thick. A mean ventricular volume measured in 17 cats was 16.9 ml. Cerebrospinal fluid turnover measured during steady-state ventricular perfusion showed significant increases in formation and decreases in absorption of spinal fluid when compared to that in hydrocephalic cats with intact skulls.