Quantitation of the sweating deficiency in diabetes mellitus

Abstract

This report introduces quantitative tests for the evaluation of sweating and the results obtained in 81 diabetic and 30 control subjects. The tests rely on the ability of pilocarpine, introduced into the skin by iontophoresis, to stimulate sweating from fully or partially innervated sweat glands but not from denervated glands. Many diabetic patients had a reduced number of excitable sweat glands and a low volume of sweat per square centimeter of skin. The results of the sweat tests correlated best with the clinically determined perception of pain from pinprick. The similar degree of involvement of sudomotor axons and pain-conveying axons may be related to the known similarity in size and reinnervation patterns. There was poor correlation of the sweating deficiency with alpha motor conduction velocity and with denervation of foot muscles as determined by the evoked muscle action potential. The number of excitable sweat glands was usually normal if the muscle action potential was above 0.5 mv, and often normal even when a muscle action potential was unobtainable. Every diabetic patient with abnormal sweating and several with normal sweating had reduced heart rate fluctuation during a standard Valsalva maneuver or during slow respiration.

Physiological and immunohistochemical characterization of cisplatin-induced neuropathy in mice

“…21,33 The diameter of the sweat impressions from the three middle toes was measured using a micrometer grid, and used to calculate the volume of the sweat droplets considered to approximate a sphere (volume = 4/3 r 3 ). 22,48 In order to abolish emotional or basal sweating, the distal innervation of the paw was blocked by injecting 0.05 mL of 0.75% bupivacaine at the ankle before the injection of pilocarpine. 49 Pain sensibility was tested by light pricking with a needle at five areas, from the most proximal pad to the tip of the second digit on the plantar aspect of the hindpaw, under a dissecting microscope.…”

Aaem minimonograph #48: Autonomic nervous system testing

“…Since sudomotor innervation is necessary for sweat gland function (they do not follow Cannon's law of denervation hypersensitivity), absent or subnormal responses imply denervation whether or not the stimulation is achieved by axon reflexes or directly. 41,43 Protocol. A variety of methods of sweat imprint tests are summarized in the review by Kennedy.…”

Qdirt

“…1 Sudomotor function can be quantified using the thermoregulatory sweat test, 2 the quantitative sudomotor axon reflex test and the silicone imprint method. 3,4 The thermoregulatory sweat test provides a semi-quantitative, topographic measure of preand postganglionic sudomotor function over the entire body. This technique assesses the function of sudomotor pathways from the hypothalamus to the eccrine sweat gland.…”