Reference Values of Current Perception Threshold in Adult Brazilian Cohort

Semmes-Weinstein monofilaments have been widely used to quantify touch sense thresholds. However, it is an instrument of low sensitivity with subjective responses. In the 1980s, a procedure was proposed for the psychophysical assessment of touch sense by sine-wave electric current stimulation. This assessment was based on studies that suggested sinusoidal stimuli of different frequencies would excite sensory systems related to fibers of different diameters, thus increasing the selectivity of the stimulation. This study aims to evaluate and describe the CPT Reference values for the upper limbs nerves of healthy Brazilian subjects using sine-wave electric stimulation. Sixty-five healthy subjects were included, which 36 were male and 29 were female. The mean of age was 45 years (±20).All subjects had the ulnar, median and radial nerves evaluated with a sine-wave electric stimulator (NEUROSTIM) to quantify the Current Perception Threshold (CPT), for the frequencies 1, 250 and 3000 Hz. No statistical differences were found when comparing different limbs on the same patient, neither when comparing genders. There was only significant difference in between groups of different ages for the 1 Hz frequency on the Ulnar nerve, and for the 250 Hz on the Median nerve (p < 0.05). The NEUROSTIM evaluation protocol seems to be effective, objective and able to be replicated for sensory loss evaluation. Having reference values in the CPT of Brazilian adults can help professionals in the clinics to have a better understanding, management and treatment of diseases that affects touch sense, such as leprosy, diabetes and others.