Vertex potentials evoked by nociceptive laser stimulation of oral mucosa: a comparison of four stimulation paradigms.

A new method for quantitative assessment of oral mucosal nociception and analgesia has been introduced using vertex potentials elicited by nociceptive argon laser stimuli. Four different stimulation paradigms (long, random, warning, and self-triggered) were compared to determine which technique elicited the most reproducible vertex potentials. A warning stimulation paradigm applied on the tongue and hand elicited vertical potentials with smaller amplitudes, lowest intraindividual coefficient of variation (16.5% and 7.9%, respectively), and highest reproducibility. The latency of the major negative peak was not affected significantly by different stimulation paradigms. The high reproducibility of vertical potentials elicited by the warning stimulation may be ascribed to a standardized psychological state of the subjects.