Bilateral involvement and the effect of sympathetic blockade on skin microcirculation in the sympathetic dystrophies

In a recent study we found skin capillary blood cell velocity (CBV) at rest, laser Doppler flux (LDF), and its response to lowering of the hand to be reduced in the dystrophic hand of patients suffering from sympathetic dystrophies. This study confirms these previous findings. Four of the 12 patients investigated felt intermittent pain in the "healthy" hand. Basal CBV, LDF, and reaction during dependency were not impaired in the asymptomatic hand compared with controls. However, during cooling of the contralateral hand CBV and LDF decreased significantly (median 44 and 37.5%) in the control group but neither in the affected nor in the asymptomatic hand among patients. Sympathetic blockade significantly increased both CBV and LDF in the dystrophic hand (median 58 and 20%), but no obvious beneficial symptomatic effect was noted. The lack of response to contralateral cooling in both hands indicates a disturbance of a central nervous mechanism in patients with unilateral sympathetic dystrophies.