Data processing
RAP
SECONDARY
ICM + software was used for data preprocessing of the high-resolution recordings prior to statistical analysis. The secondary indices, PRx and RAP were calculated as 5 min window moving Pearson correlation coefficients between 30 consecutive 10-s averages between ABP and ICP, and between intracranial pulse pressure amplitude and ICP, respectively, and updated every minute [Each variable was considered as one average value (for data collected with ICM +) or one single value (for data collected with FluxMed) per each study period and patient.