A new measuring design for autonomic dysfunction of skin in neuropathies: hyperthermal laser-Doppler flowmetry.

Twenty patients suffering from diabetic neuropathy, 20 patients suffering from alcoholic neuropathy and 20 healthy volunteers within the same age range were studied for the stimulability of microcirculation with a new measuring design. A laser method (laser-Doppler flowmetry) was used to evaluate the increase of the microvascular blood flow of the skin during the hyperthermal phase. It evaluated the degree of increase of microcirculatory blood flow as well as the time from the beginning of hyperthermy to the onset of change in perfusion (the hyperthermal perfusion latency). This was significantly prolonged in both neuropathy groups; the increase of the microvascular blood flow in the diabetic neuropathies was significantly lower than found in alcoholic neuropathies and in healthy volunteers.