Decreasing pain in electrical nerve stimulation

Objective Do large stimulation electrodes reduce pain in nerve conduction testing? Methods Fourteen healthy subjects (6 men, 22–42 years) blinded for study design underwent 8 H-reflex studies, using a large (36×36 mm) or a small (6×6 mm) electrode, placed on either the patella or the popliteal fossa; either site could be used for the cathode or the anode. Stimulation intensity was adjusted to obtain M- and H-waves. Intensity and other characteristics of pain were noted, as were M- and H-wave parameters. Results Pain was felt strongest near the smaller electrode when two sizes were used. Large electrodes reduced pain without compromising H- or M-waves. Conclusions Large stimulation electrodes reduce pain. Significance The results apply for tests relying on amplitude measurements.