Response of digital blood pressure to cold provocation in cases with Raynaud phenomena.

: A new diagnostic test of the qualitative and quantitative evaluation of vasospastic disorders is described. It entails measurement of systolic digital artery pressure during successive cooling from 35-5 degrees C. In cases with vasospastic disorders with Raynaud phenomena a significant reduction of systolic blood pressure below 78% of control level is observed and in the most pronounced cases total cessation of flow occurs (critical closing). The test is also a quantitative measure of the degree of vasospasm since the pressure reduction correlates to the clinical degree of vasoconstriction.