Pain
-
As part of a larger longitudinal study, the current analyses characterize the relationship among pain, psychological distress, and physical function after major lower extremity trauma. Structural equation modeling techniques were utilized to analyze data from a prospective 2-year observational study of 327 patients treated at 8 level I trauma centers. Data were gathered at 3, 6, 12, and 24 months after injury. ⋯ The combination of depressive and anxious distress plays an increasingly important role in mediating the impact of pain on physical function as the recovery from lower extremity trauma progresses from early to later stages. Both pain and psychological distress contribute to reduced function during the first year after a serious injury; however, as recovery proceeds, the role of psychological distress in determining function increases. Longitudinal data on patients with severe leg trauma demonstrates that as recovery proceeds, psychological distress plays an increasingly important role in mediating the impact of pain on function.
-
The benefits of transcutaneous electrical nerve stimulation (TENS) for pain relief have not been reliably established, as most systematic reviews find poor methodological quality in many studies. The paradox within the evidence base for TENS is that despite identified sources of bias that may lead to an overestimation of treatment effects, no benefits for TENS can be clearly demonstrated. Conventional assessments of quality assume a single direction of bias, and little work has been undertaken examining other directions of bias. ⋯ We propose criteria for judging directions of bias in future studies of TENS that may be adapted to assess other trials in which implementation fidelity is important, such as other nonpharmacological interventions for pain. Poor implementation fidelity was identified as a significant source of bias in systematic reviews of TENS studies and might explain lack of consistent treatment effects of TENS in pain. Here, criteria for assessing methodology are proposed for use in designing future clinical trials of TENS.
-
"Pain exposure" physical therapy (PEPT) is a new treatment for patients with complex regional pain syndrome type 1 (CRPS-1) that consists of a progressive-loading exercise program and management of pain-avoidance behavior without the use of specific CRPS-1 medication or analgesics. The aim of this study was to investigate primarily whether PEPT could be applied safely in patients with CRPS-1. Twenty patients with CRPS-1 were consecutively enrolled in the study after giving informed consent. ⋯ Three patients initially showed increased vegetative signs but improved in all other CRPS parameters and showed good functional recovery at follow-up. We conclude that PEPT is a safe and effective treatment for patients with CRPS-1. A progressive-loading exercise program and management of pain-avoidance behavior without the use of specific medication ("pain exposure" physical therapy) is safe and effective for patients with complex regional pain syndrome.
-
The important role of operant learning in the development and maintenance of chronic pain is widely recognized. A specific type of reinforcement based on the reduction of painful stimulation when a person's perception changes in the desired direction has been termed intrinsic reinforcement of pain. In the present study, the role of intrinsic operant learning in chronic pain was tested in fibromyalgia (FM) patients with and without comorbid irritable bowel syndrome (IBS) compared with healthy persons. ⋯ Whereas healthy persons learned perceptual changes according the experimental protocol, both patient groups failed to show normal operant perceptual learning: FM patients without IBS demonstrated sensitization learning comparable to that in healthy persons, but unexpectedly these patients learned even more pronounced sensitization in the habituation learning condition, contradicting the experimental protocol; FM patients with IBS demonstrated neither learning of enhanced sensitization nor enhanced habituation; no signs of differential operant learning were observable. Thus, operant perceptual learning was impaired in FM patients; whether learning of both enhanced perceptual sensitization and habituation was impaired depended on the presence of comorbid IBS and could not be explained by other clinical characteristics of the patients such as pain threshold, duration of pain, depressive symptoms, or anxiety. While healthy participants learned sensitization and habituation according to an operant task, FM patients without IBS showed enhanced sensitization and FM with IBS no learning.