Peripheral circulation, particularly heat regulation reactions, in patients with amyloidosis and polyneuropathy.

As patients with amyloidosis and polyneuropathy often have signs and symptoms of circulatory disturbances in the extremities, especially the legs, we have examined such patients and controls with oscillometry and digital pulse plethysmography in order to estimate the occurrence of any arterial circulatory insufficiency. No signs of significant obliterative arterial changes were found. Skin temperature was also determined in fingers and toes during body-cooling and at subsequent indirect heating. At low environmental temperature the skin temperature was higher in patients than in controls. In a few patients there was almost no decrease in skin temperature, despite a long period of cooling and a low rectal temperature. Indirect heating elicited a marked increase in the skin temperature of the toes and fingers of the controls. In most patients this reaction was completely absent in the toes and absent or reduced in the fingers. These deviations can be explained by nerve damage caused by amyloid deposition in the nerves. Amyloid deposits in the wall of small blood vessels may be an additional factor. Maximum blood flow in the anterior tibial muscle after combined ischemia and exercise, investigated with radioactive xenon, was reduced in half of the patients.