The journal of pain : official journal of the American Pain Society
-
Comparative Study
Assessment of self-reported physical activity in patients with chronic pain: development of an abbreviated Roland-Morris disability scale.
The Roland-Morris Disability Scale has been shown to be a reliable and valid measure of disability in persons with chronic pain. A short form with psychometric properties similar to the full scale would have numerous benefits, including decreased patient assessment burden and scoring time. On the basis of data obtained from 993 individuals with chronic pain screened for admission to a multidisciplinary pain management program, an 11-item short form of the Roland scale was developed using procedures and models from item response theory. This short form was found to be a good predictor of the 24-item parent scale and a previously published 18-item short form. The 11-item scale also demonstrated concurrent validity with measures of pain intensity and depression. Item content reflected limitations in specific functional behaviors. ⋯ Brief measures of important pain-related variables can be created using item response theory (IRT). In this study, a reliable and valid 11-item version of the Roland-Morris Disability Scale was created using IRT. Clinicians and researchers might consider using this scale when patient or subject assessment burden is an issue.
-
Comparative Study
Prior pain experience: influence on the observation of experimental pain in men and women.
Research examining perceptions of subjects participating in an experimental pain task has not been widely studied. The primary purpose of this study was to examine the influence of prior experience with the cold pressor on subsequent perceptions of others experiencing this same pain task. Furthermore, to replicate our previous work, we examined how individuals observe experimentally induced pain in male and female participants. Possible interactions between order of cold pressor experience, sex of the viewer, sex of the individual being observed, and characteristics attributed to the individuals in the videos were also analyzed. The sample was composed of 57 participants. They were each randomized to 1 of 2 conditions: (1) participate in cold pressor task before viewing a presentation of 10 video clips (of subjects in cold pressor task), rate videos, and complete battery of questionnaires or (2) cold pressor participation after completion of the same questionnaires, and viewing/rating videos. Participants viewing the videos provided ratings including observed pain and emotional characteristics they attributed to the individuals. These results replicated and extended our previous work by demonstrating a gender bias (ie, a stereotypical belief about an individual on the basis of their sex) in the observation of pain, such that participants rated female subjects as experiencing greater pain intensity when undergoing a cold pressor task compared to male subjects. Furthermore, experiencing the cold pressor before watching the videos increased a participant's pain ratings of observed pain. There were also several significant interactions between cold pressor condition, sex of video participant, sex of viewer, and emotional/behavioral characteristics attributed to the video participant. ⋯ Results of this study demonstrate that prior experience with pain increases accuracy of estimating others' pain. Gender role expectations also influence observer's ratings of pain, and prior experience of pain influences men and women differently.
-
As a method of experimental pain induction, the cold pressor test is thought to mimic the effects of chronic conditions effectively. A survey of previous studies using the cold pressor, however, revealed a lack of standardization and control of water temperature, questioning comparability and reliability. This study reports the influence of temperature on pain tolerance and intensity by using a commercially available circulating water bath. Twenty-six participants (12 men, 14 women) underwent 4 cold pressor trials with temperature order counterbalanced across 1 degrees C, 3 degrees C, 5 degrees C, and 7 degrees C, temperatures representative of the range used in previous literature. After each cold immersion participants rated pain intensity on a visual analogue scale and the McGill Pain Questionnaire. Tolerance times were recorded for each trial. Significant main effects of temperature were found for tolerance time, with higher temperatures resulting in longer times, and pain intensity, with lower temperatures resulting in higher intensities. Gender differences were found, with men tolerating the stimulus for significantly longer than women. It was concluded that small differences in water temperature have a significant effect on pain intensity and tolerance time. The use of cold pressor equipment that ensures a precise constant temperature of circulating water is necessary to ensure comparable and reliable results. ⋯ The cold pressor method of experimental pain induction has been widely used in the evaluation of psychological and physiological pain treatments. This article highlights the need for clear methodologic guidelines for the technique and demonstrates that very minor changes in experimental protocol can produce significant differences.
-
A growing literature has reported significant reductions in pain sensitivity associated with increasing levels of blood pressure. However, most of this research has been limited to casual blood pressure assessments in white men. The present study examined associations between pain reports and ambulatory blood pressure in a sample of African American and white men and women. Possible response bias during pain assessment due to ethnicity and gender was evaluated with individualized pain rating scales. One hundred thirty-five (72 African American and 63 white) men and women underwent 24-hour blood pressure monitoring and arm ischemia pain sensitivity evaluation with both standard verbal rating scales and individually ordered verbal rating scales of intensity and unpleasantness. Lower individualized pain intensity and unpleasantness ratings were associated with higher levels of ambulatory blood pressure. African Americans and women reported higher levels of pain intensity when using the standard verbal rating scale but not when using the individually ordered rating scale. Collectively, these results support previous research relating reduced pain sensitivity with increased blood pressure among men and women. Furthermore, reported differences in pain sensitivity between ethnic groups and genders might in part be associated with variations in response styles to standard pain assessment tools. ⋯ The findings of the present study suggest that, in some instances, different ethnic groups and genders may use the same descriptors to report different levels of pain. In the context of clinical pain assessment, it may be important to consider the possibility that descriptions of painful sensations reflect, in part, demographic characteristics.
-
We present 2 patients with severe and intractable central poststroke pain (CPSP) after right posterolateral thalamic infarcts who were successfully treated with zonisamide. The mechanism of action was presumed to be the suppression of overacting thalamic relay neurons by blockade of low voltage-activated calcium channel or by increasing gamma-aminobutyric acid (GABA) release. Zonisamide can be one of the therapeutic options for severe CPSP and might provide an insight into the pathogenesis of CPSP. ⋯ The blockade of T-type VGCC or the increase in GABA release caused by zonisamide presumably suppresses abnormal activities of thalamic sensory neurons.