Cerebral Blood Flow in Healthy Subjects with Different Hypnotizability Scores

Hypnotizability is a cognitive trait associated with differences in the brachial artery flow-mediated dilatation of individuals with high hypnotizability (highs) and low hypnotizability scores (lows). The study investigated possible hypnotizability-related cerebrovascular differences. Among 24 healthy volunteers, the Stanford Hypnotic Susceptibility Scale Form A identified 13 medium-to-lows (med-lows), 11 medium-to-highs (med-highs), and 1 medium hypnotizable. Hypnotizability did not influence the significant changes produced by the trail making task (TMT), mental arithmetic task (MAT), hyperventilation (HVT), and rebreathing (RBT) on heart rate (HR), arterial blood pressure (ABP), and partial pressure of end-tidal CO2 (P-ET CO2), but moderated the correlations between the changes occurring during tasks with respect to basal conditions (A) in ABP and Delta ETCO2 with middle cerebral artery flow velocity (MCAv). In HVT, med-lows exhibited a significant correlation between Delta MCAv and Delta PETCO2, and med-highs showed a significant correlation between Delta ABP and Delta MCAv. Cerebrovascular reactivity (CVR) and conductance (Delta CVCi) were significantly correlated with Delta MCAv only in med-lows during HVT and RBT. For the first time, cerebrovascular reactivity related to hypnotizability was investigated, evidencing different correlations among hemodynamic variables in med-highs and med-lows.