[Analysis of the correlations of volume-pressure parameters and visual evoked potentials during disturbances of intracranial volume compensation].

The experiment was carried out on 19 cats with changed intracranial volume-pressure relations by means of an epidural balloon which was inflated to 1.0 ml volume over 60 minutes. The intracranial pressure, the resistance to cerebrospinal fluid resorption, the volume-pressure responses and visual evoked potentials were determined at balloon volumes of 0.3 ml, 0.5 ml, 0.8 ml, 1.0 ml, 1.3 ml, 1.5 ml, 1.8 ml, 2.0 ml and 2.3 ml. It was demonstrated that intracranial pressure is of important informative value only after exhaustion of 63% of the intracranial volume reserve. This value of the volume-pressure responses and resistance to CSF resorption appeared after exhaustion of 28% of this reserve, and the visual evoked potentials were changed after exhaustion of 43% of the reserve. The correlation coefficient between these parameters was high during decompensation. At the time of compensation of the volume the correlation coefficient between the intracranial pressure and the remaining determined parameters was only 0.6.