title: Individually based measurement of temporal summation evoked by a noxious tonic heat paradigm.
abstract: BACKGROUND
  A model for measuring temporal summation (TS) by tonic noxious stimulation was recently proposed. However, methodological variations between studies make it difficult to reach a consensus regarding the way TS should be applied and calculated. The present study aimed to present a calculation method of TS magnitude produced by a tonic heat model in a large cohort of healthy subjects.
  
  
  METHODS
  Noxious heat stimulation (46.5°C/2 minutes) was applied to the forearm of 154 subjects who continuously rated pain intensity using a computerized visual analog scale. TS was calculated by "mean group" and "individual" approaches.
  
  
  RESULTS
  A "typical" pattern of pain response, characterized by a peak pain followed by a decrease in intensity to a nadir and subsequently a progressive increase in pain scores, was exhibited by 86.4% of the subjects. Using the "mean group" and "individual" calculation approaches, the mean ± standard deviation magnitudes of TS were 31.4±27.5 and 41.0±26.0, respectively (P<0.001). Additionally, using the individualized approach, we identified a different ("atypical") response pattern among the rest of the subjects (13.6%).
  
  
  CONCLUSIONS
  The results support the tonic heat model of TS for future utilization. The individualized TS calculation method seems advantageous since it better reflects individual magnitudes of TS.
authors.affiliation: Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, University of Haifa, Haifa, Israel ; Institute of Pain Medicine, Rambam Health Care Campus, University of Haifa, Haifa, Israel.
authors.forename: Erica
authors.initials: E
authors.lastname: Suzan
authors.affiliation: Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa, Israel.
authors.forename: Joshua
authors.initials: J
authors.lastname: Aviram
authors.affiliation: Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: Roi
authors.initials: R
authors.lastname: Treister
authors.affiliation: Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, University of Haifa, Haifa, Israel ; Institute of Pain Medicine, Rambam Health Care Campus, University of Haifa, Haifa, Israel.
authors.forename: Elon
authors.initials: E
authors.lastname: Eisenberg
authors.affiliation: Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa, Israel.
authors.forename: Dorit
authors.initials: D
authors.lastname: Pud
keywords: healthy volunteers; heat pain; individual differences; pain perception; temporal summation