Pain Sensitivity in Acute Inflammatory Pain (PASORI)

Pain is a complex experience influenced by gender and genetics, and, by psychosocial and sensory experiences. Pain sensitivity is thus highly variable between individuals. In the present study we evaluate individuals´ pain perception in response to a number of different pain stimuli in 100 healthy volunteers (50 females and 50 males). The data will allow us to assess pain sensitivity, to predict pain responses and to investigate gender related differences in pain perception. A second aim is to evaluate the robustness of the different pain-tests since the tests are repeated with an interval of 2-4 weeks.

Pain perception is affected by physiological, psychological, existential and demographic factors. In the present study psychophysiological, psychological, genetic and demographic components in pain perception are evaluated in healthy volunteers (n = 100). Psychophysical assessments following induction of a first degree burn injury (47.0 C, 420 s, 12.5 sq.cm, lower leg) include: pain during induction of burn injury thermal thresholds tactile thresholds electrical thresholds areas of secondary hyperalgesia pressure algometric assessments assessment of Diffuse Noxious Inhibitory Control (DNIC) efficiency assessment of (DNIC) using cold pressor test Psychological assessments include: HADS (Hospital Anxiety and Depression Scale) PCS (Pain Catastrophizing Scale) vulnerability score Genetics include: - A118G SNP Demographics include: gender height weight

burn injury, cold pressor test, gender, pain, pain sensitivity, pain prediction, psychometrics, quantitative sensory testing

Inclusion Criteria: healthy psychomotor ability to perform the tests cognitive ability to perform the tests Exclusion Criteria: smoker Body Mass Index > 28 participation in drug studies < 4 weeks prior to inclusion chronic pain chronic intake of analgesics drug or alcohol abuse intake of analgesics < 48 hours prior to study females not on contraceptive therapy (intra-uterine device or p-pill) lesion in the assessment area

Luginbuhl M, Schnider TW, Petersen-Felix S, Arendt-Nielsen L, Zbinden AM. Comparison of five experimental pain tests to measure analgesic effects of alfentanil. Anesthesiology. 2001 Jul;95(1):22-9. doi: 10.1097/00000542-200107000-00009.

Edwards RR, Fillingim RB, Ness TJ. Age-related differences in endogenous pain modulation: a comparison of diffuse noxious inhibitory controls in healthy older and younger adults. Pain. 2003 Jan;101(1-2):155-65. doi: 10.1016/s0304-3959(02)00324-x.

Neziri AY, Scaramozzino P, Andersen OK, Dickenson AH, Arendt-Nielsen L, Curatolo M. Reference values of mechanical and thermal pain tests in a pain-free population. Eur J Pain. 2011 Apr;15(4):376-83. doi: 10.1016/j.ejpain.2010.08.011. Epub 2010 Oct 6.

Neziri AY, Curatolo M, Nuesch E, Scaramozzino P, Andersen OK, Arendt-Nielsen L, Juni P. Factor analysis of responses to thermal, electrical, and mechanical painful stimuli supports the importance of multi-modal pain assessment. Pain. 2011 May;152(5):1146-1155. doi: 10.1016/j.pain.2011.01.047. Epub 2011 Mar 10.

Ravn P, Frederiksen R, Skovsen AP, Christrup LL, Werner MU. Prediction of pain sensitivity in healthy volunteers. J Pain Res. 2012;5:313-26. doi: 10.2147/JPR.S33925. Epub 2012 Aug 29.