Recently, a self-rating measure for pain perception based on imagined painful daily life situations, the Pain Sensitivity Questionnaire (PSQ), has been developed and shown to correlate with experimentally obtained pain intensity ratings in healthy subjects. Here, we assessed the validity of the PSQ for investigation of general pain perception (ie, pain perception outside the site of clinical pain) in chronic pain patients. PSQ scores were obtained in 134 chronic pain patients and compared to those of 185 healthy control subjects. In a subgroup of 46 chronic pain patients, we performed experimental pain testing outside the clinical pain site, including different modalities (heat, cold, pressure, and pinprick) and different measures (pain thresholds, pain intensity ratings). Results show that PSQ scores were significantly correlated with both experimental pain intensity ratings (Pearson's r=0.71, P<.001) and experimental pain thresholds (r=-0.52, P<.001). In addition, chronic pain patients exhibited significantly elevated PSQ scores as compared to healthy controls, consistent with the generalized increase of experimentally determined pain perception that has repeatedly been reported in chronic pain patients. These results demonstrate that the PSQ constitutes a valid self-rating measure of pain perception outside the clinical pain site in chronic pain patients and might serve as an alternative to experimental assessment of pain perception outside the clinical pain site in situations where experimental pain testing is not feasible.

Pain perception studies in migraine patients have shown trigeminal and peripheral pain facilitation during the migraine attack. We were interested in differences of trigeminal and peripheral pain perception between migraine patients during the migraine interval and healthy subjects. Perception of electrical pain stimulation was measured in 20 migraine subjects outside a migraine attack (10 migraine with aura and 10 migraine without aura) and in 20 healthy subjects. We recorded sensory and pain thresholds, pain ratings after suprathreshold stimulation, and pain rating after two trains of repetitive stimulation (i.e., pain facilitation). Migraine subjects showed a significantly higher pain rating after suprathreshold stimulation in the trigeminal region as compared to healthy subjects (4.8 ± 1.6 versus 3.8 ± 2.2, p < 0.04 after Bonferroni correction) but not in the peripheral region. Furthermore, migraine subjects showed a pain facilitation after repetitive trigeminal stimulation whereas healthy subjects showed a pain habituation. We observed no significant differences between migraine subjects and healthy subjects for all parameters in the peripheral stimulation. Migraine patients with and without aura did not differ in any parameter. All subjects showed decreased sensory and pain thresholds after trigeminal as compared to peripheral stimulation. Migraine subjects show an increased pain perception after trigeminal but not after peripheral pain stimulation as compared to healthy subjects. This phenomenon is probably due to the observed pain facilitation after painful trigeminal stimulation.

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There is evidence for the presence of sensitization of the nociceptive system in subjects with occlusal disharmony. Possibly, deficient inhibition of extratrigeminal and trigeminal pain perception by relaxation might contribute to the development of TMD or other chronic pain disorders.