Contact heat-evoked temporal summation: Tonic versus repetitive-phasic stimulation

Abstract

Temporal summation (TS) is usually evoked by repetitive mechanical or electrical stimuli, and less commonly by tonic heat pain. The present study aimed to examine the TS induction by repetitive-phasic versus tonic heat pain stimuli. Using 27 normal volunteers, we compared the extent of summation by three calculation methods: start-to-end pain rating difference, percent change, and double-logarithmic regression of successive ratings along the stimulation. Subjects were tested twice, and the reliability of each of the paradigms was obtained. In addition, personality factors related to pain catastrophizing and anxiety level were also correlated with the psychophysical results. Both paradigms induced significant TS, with similar increases for the repetitive-phasic and the tonic paradigms, as measured on 0-100 numerical pain scale (from 52.9+/-11.7 to 80.2+/-15.5, p<0.001; and from 38.5+/-13.3 to 75.8+/-18.3, p<0.001, respectively). The extent of summation was significantly correlated between the two paradigms, when calculated by absolute change (r=0.543, p=0.004) and by regression (r=0.438, p=0.025). Session-to-session variability was similar for both paradigms, relatively large, yet not biased. As with other psychophysical parameters, this poses some limitations on TS assessment in individual patients over time. The extent of TS induced by both paradigms was found to be associated with anxiety level and pain catastrophizing. Despite some dissimilarity between the repetitive-phasic and the tonic paradigms, the many similarities suggest that the two represent a similar physiological process, even if not precisely the same. Future clinical applications of these tests will determine the clinical relevance of the TS paradigms presented in this study.

Human Experimental Pain Models for Assessing the Therapeutic Efficacy of Analgesic Drugs

“…Various modalities have been used to induce temporal summation of skin pain: heat (Granot et al, 2006), cold , mechanical pressure (Nie et al, 2006), and electrical stimulation (Arendt- Nielsen et al, 2000c). Temporal and spatial summation evoked experimentally in the skin reflects a central nervous system modulation of the response, and a number of drugs can block these phenomena (Dirks et al, 2002;Hughes et al, 2002;Koppert et al, 2003b).…”

Effect of Static and Dynamic Heat Pain Stimulus Profiles on the Temporal Dynamics and Interdependence of Pain Qualities, Intensity, and Affect

“…In addition to brief repetitive stimuli, prolonged heat pain (or tonic) stimuli have also been used to evoke temporal summation of pain, but the profiles of specific sensations have not been investigated (Granot et al 2006). Moreover, the mechanisms whereby prolonged stimuli evoke temporal summation are not clearly known.…”

“…This mismatch between evoked sensation and nociceptor activity has been ascribed to spinal mechanisms similar to wind-up induced with repetitive heat pain stimuli (Adriaensen et al 1984a;Andrew and Greenspan 1999;LaMotte et al 1984). In addition to spinal mechanisms, repetitive and prolonged stimuli evoke similar responses possibly due to similar temperature dynamics within the skin (Granot et al 2006;Mauderli et al 2003) and thus may engage similar heat transduction mechanisms (Lumpkin and Caterina 2007). Another indication of a similarity between tonic and repetitive stimulation-induced temporal summation was presented by the contrast between profiles of sharp-type and burning sensations.…”

The Role of Resilience and Purpose in Life in Habituation to Heat and Cold Pain

“…Although research has begun to characterize sensitization, especially with regard to temporal summation, 10,20,44 much less work has focused on habituation. Habituation may involve a different time course than sensitization as well as different mechanisms.…”