Fig. 2
Schematic description of the study procedure and representative cases of the CHS and non-CHS groups. (A) Illustration of the recordings (non-CHS patient) of ABP and CBFv signals obtained during the resting status (green box outline) and VM (blue box outline). (Mid left panel) Each shaded green box represents a 5-minute time window for calculating 30 consecutive 10-s averages of ABP and CBFv, obtained for deriving Mxa. (Mid right panel) Graph illustrating the general VM trends in each phase. The red point corresponds to the CBFv at the time when ABP is lowest during VM phase 3, and the green point corresponds to the peak CBFv point. The magnitude difference in CBFv between these two points was defined as VMOI. (B) Representative cases of spontaneous dynamic cerebral autoregulation in the non-CHS group. (The red line indicates the cut-off for discriminating against altered cerebral autoregulation). (C,D) Representative cases of maneuver associated dynamic cerebral autoregulation in the non-CHS group. (Shaded blue: Phase 4 of the VM where the notable overshooting phenomenon is presented) (E) Representative cases of spontaneous dynamic cerebral autoregulation in the CHS group. (F,G) Representative cases of maneuver associated dynamic cerebral autoregulation in the CHS group. (Shaded blue: Diminished overshooting phenomenon is presented). ABP, arterial blood pressure, CBFv, cerebral blood flow velocity, CHS, cerebral hyperperfusion syndrome, Mxa, mean flow index, VM, valsalva maneuver, VMOI, valsalva maneuver overshooting index.
