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

Michal Granot, Yelena Granovsky, Elliot Sprecher, Rony Reuven Nir, David Yarnitsky

Research output: Contribution to journalArticlepeer-review


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.

Original languageEnglish
Pages (from-to)295-305
Number of pages11
Issue number3
StatePublished - Jun 2006

Bibliographical note

Funding Information:
This study was partially funded by a grant from Merck Ltd. and Medoc Ltd.


  • Contact stimuli
  • Heat pain
  • Personality
  • Temporal summation

ASJC Scopus subject areas

  • Clinical Neurology
  • Neurology
  • Anesthesiology and Pain Medicine


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