Fig. 4. (A ) Correlation between onset of complete motor blockade and cerebrospinal fluid (CSF) volume (ρ= 0.42, P = 0.008). (B ) Correlation between onset of complete motor blockade and average CSF velocity (ρ= 0.38, P = 0.015). Although correlation coefficients (ρ) and P values were calculated using Spearman rank correlation, the linear regression lines are presented in these graphs.