Effect of gender on orthodromic sensory nerve action potential amplitude

Objective: Studies in the literature have demonstrated a gender effect on s ensory nerve action potential (SNAP) amplitude for the median and ulnar ner ves by use of the antidromic method of recording. The objective of this stu dy was to determine if performing orthodromic sensory nerve stimulation eli minates the gender bias by removing the finger circumference as a variable. Methods: Fifty-five healthy subjects participated in the study. The mean ag e of the subjects was 37.8 +/- 5.9 yr and 35.3 +/- 5.9 yr for men and women , respectively. Orthodromic sensory nerve conduction studies were performed for the median and ulnar nerves measuring the SNAP amplitude by use of sta ndard electrophysiologic technique. Results: The mean finger circumference of the third digit was 6.5 +/- 0.58 cm for men and 5.9 +/- 0.47 cm for women, and for the fifth digit, it was 5 .6 +/- 0.41 cm for men and 5.3 +/- 0.37 cm for women. The median SNAP ampli tude and their percentiles of 2.5 and 97.5 for the median nerve were 30.0 m uV for men and 28.0 muV for women. For the ulnar nerve, they were 16.5 muV for men and 16.0 muV for women. Conclusion: The study confirmed that orthodromic sensory nerve stimulation did not have any significant effect on SNAP amplitude between men and women .