Identification of sensory blockade by somatosensory and pain-induced evoked potentials.

Background: To date, the anesthesia-induced blockade of nociceptive inputs is insufficiently reflected by commercially available electroencephalographic depth-of-anesthesia monitors. The aim of the current study was to evaluate the potential of somatosensory (SSEP) and intracutaneous pain evoked (iSEP) potentials during remifentanil and propofol anesthesia as electroencephalographic indicators of the nociceptive blockade.

Methods: Ten healthy men were investigated in a double-blind crossover design during three sessions with remifentanil, propofol, and placebo administration.

Duration of the cue-to-pain delay increases pain intensity: a combined EEG and MEG study.

Expectation of pain is an important adaptive process enabling individuals to avoid bodily harm. It reflects the linking of past experience and environmental cues with imminent threat. In the present study, we examined changes in perceived pain contingent upon variation of the interval between an auditory cue and a subsequent painful laser stimulus.