Human Electrophysiological Model to Quantify the CGRP-related Axon Reflex of Trigeminal Afferents

Electrical stimuli via circular electrode array. The electrode array serves as cathode placed above the eyebrow. A surface electrode (anode) will be placed on the temple. Electrical stimuli will be applied via a constant current stimulator. The stimulus intensity for the electrophysiological protocol is adjusted to the 10-fold of the detection threshold. A number of 5 electrical pulses (2 ms, 100 Hertz (Hz)), 10 second intervals.

Stimulation of C-nociceptors with constant current stimulator. Electrodes (placed on the proband's forehead. Stimulation by sine wave pulses of 250 ms duration (4 Hz), intensities inducing a pain intensity of 50/100 on a visual analogue scale from 0-100.