Relationship between vertex potentials and magnitude of pre-pain and pain sensations evoked by electrical skin stimuli.

Vertex potentials evoked by painful and non-painful electrical skin stimuli were recorded in 10 healthy male volunteers. Peak-to-peak amplitudes of the major vertex potential components were compared with subjective rating of the stimuli. While a significant correlation was observed between peak-to-peak amplitudes and stimulus rating following non-painful stimuli, generally no such correlation was present following stimulations above the pain threshold. These findings suggest that vertex potentials elicited by electrical skin stimuli may reflect central processing of non-noxious afferent information rather than of pain-related information.