Study on the variation and mechanism of diameter of nailfold capillary and its blood flow speed in patient with chronic pain syndrome]

Diameter of nailfold capillaries and their blood flow speed in 90 patients with pain syndrome were measured accurately by using YJD clinical microcirculatory image analyser, and the data obtained were compared with that of 31 normal subjects. The results showed (1) Shortening of capillary loop and slow down of blood flow were revealed in patients no matter where the location of pain was; (2) The disturbance of microcirculation was more prominent in case of chronic pain patient, manifested chiefly as slow down of blood flow speed (0.19 +/- 0.09 mm/s in afferent branch) and increase of loop diameter (15.86 +/- 6.50 microns), as compared with those in normal subjects (0.35 +/- 0.13 mm/s and 14.01 +/- 3.31 microns respectively), the difference were significant, P < 0.01; (3) Typing according to Syndrome Differentiation of TCM, the afferent loop diameter of the Blood Stasis type were 9.23 +/- 1.65 microns, it was significantly different from that of other types; and the blood flow speed of this group was markedly slowing down (0.18 +/- 0.08 mm/s in afferent branch), the change was of significant difference in comparing with normal group, P < 0.01. Authors considered that the mechanism of changes in microcirculation was related to increase of blood viscosity and spasm or diastole of capillaries induced by neurohumoral regulation, and many humoral factors, as histamine, may take part in this procedure.