Postischemic cutaneous hyperperfusion in the presence of forearm hypoperfusion suggests sympathetic vasomotor...

In Fabry disease, deficiency of alpha-galactosidase A induces glycolipid storage that accounts for neuropathy, renal failure, myocardial infarction and stroke. Vascular crises may be precipitated by stressful conditions. To evaluate pathomechanisms of overall organ versus microvessel perfusion in response to ischemic challenge, we assessed resting and postischemic forearm and skin blood flow in Fabry patients. In 14 Fabry patients and 15 healthy controls, we measured resting and postischemic forearm blood flow by means of venous occlusion plethysmography and superficial index finger skin blood flow using laser Doppler flowmetry. At rest, arterial inflow into the limb was averaged from eight venous occlusion measurements and expressed as % volume change/minute. Postischemic plethysmographic inflow was determined from the peak influx during the first venous occlusion following three minutes of ischemia. Transcutaneous oxygen and carbon dioxide partial pressures at the forearm were monitored continuously. At rest, plethysmographic forearm perfusion was 15% lower in patients than in controls (p < 0.05) while skin blood flow did not differ between patients and controls. After ischemia, forearm hyperperfusion was less pronounced in patients than in controls (p < 0.05), while skin perfusion almost doubled in patients but increased only slightly in controls. Transcutaneous oxygen and carbon dioxide pressures did not differ between both groups. We conclude that the reduced overall limb perfusion at rest and after ischemia is likely to be due to lipid deposition with increased rigidity, decreased distensibility and lowered diameter of the vasculature. The exaggerated skin perfusion after ischemia might be attributable to the small fiber neuropathy of Fabry patients with deficient vasoconstrictor tone and enhanced vasodilatation due to hypersensitivity of denervated intracutaneous nerve fibers towards ischemia.