Fig. 3

Evolution of the spatial distribution of blood pulsation amplitude in the upper arm during capsaicin application. BPA maps for migraine patients are shown in the upper raw (a-c) whereas those for healthy subjects are in the lower raw (d-f). The color scale on the right of each map shows BPA as AC/DC ratio in percent for each distribution, respectively. The moment of PPG recording is shown in the left lower corner of each map with reference to the beginning of capsaicin application