Anodal Sensory Nerve Action Potentials: From Physiological Understanding To Potential Clinical Applicability

Introduction: Low-intensity electrical stimuli of digital nerves may generate a double peak potential (DPp), composed of a cathodal (caAP) and an anodal (anAP) potential in orthodromic recordings. Methods: We studied the effects on caAP and anAP of stimuli of variable intensity, duration, and frequency. We also applied a conditioning stimulus to study potential differences in recovery time. Results: The anAP was obtained in 33 of 40 healthy subjects (82.5%) and 4 of 20 patients with various types of sensory neuropathies (20%). Changes in stimulus duration and intensity had reciprocal effects on the amplitude of the anAP and the caAP. There were significant differences in recovery time between caAP and anAP after a conditioning stimulus. Conclusion: The caAP and anAP are 2 interdependent waveforms generated by different effects of the same stimulus over axons at the verge of depolarization.