Measurement of the pain threshold determined by electrical stimulation and its clinical application

Abstract

Determination of pain thresholds proved to be a suitable method for the detection and definition of disorders of pain sensitivity in patients. Application of electrical current gave reliable, reproducible, and, therefore, quantifiable results. By a pain threshold stimulus Is meant the smallest intensity of an electrical current, expressed in milliamperes, which at a certain frequency and duration of stimulus evokes a pain sensation. Essential to the method is the use of a constant current device, so that the intensity of the stimulating current is independent of skin resistance. Pulse frequency was variable from 0.5 to 1500 cps and impulse duration from 0.01 to 100 msec. The modifying influence of a number of factors was measured, such as location of the stimulus, temperature of the skin, sex, age, attention, training, fatigue, and so on. The method proved valuable for diagnostic purposes in neurological patients.