The journal of pain : official journal of the American Pain Society
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Randomized Controlled Trial
Repetitive transcranial magnetic stimulation is efficacious as an add-on to pharmacological therapy in complex regional pain syndrome (CRPS) type I.
Single-session repetitive transcranial magnetic stimulation (rTMS) of the motor cortex (M1) is effective in the treatment of chronic pain patients, but the analgesic effect of repeated sessions is still unknown. We evaluated the effects of rTMS in patients with refractory pain due to complex regional pain syndrome (CRPS) type I. Twenty-three patients presenting CRPS type I of 1 upper limb were treated with the best medical treatment (analgesics and adjuvant medications, physical therapy) plus 10 daily sessions of either real (r-) or sham (s-) 10 Hz rTMS to the motor cortex (M1). Patients were assessed daily and after 1 week and 3 months after the last session using the Visual Analogical Scale (VAS), the McGill Pain Questionnaire (MPQ), the Health Survey-36 (SF-36), and the Hamilton Depression (HDRS). During treatment there was a significant reduction in the VAS scores favoring the r-rTMS group, mean reduction of 4.65 cm (50.9%) against 2.18 cm (24.7%) in the s-rTMS group. The highest reduction occurred at the tenth session and correlated to improvement in the affective and emotional subscores of the MPQ and SF-36. Real rTMS to the M1 produced analgesic effects and positive changes in affective aspects of pain in CRPS patients during the period of stimulation. ⋯ This study shows an efficacy of repetitive sessions of high-frequency rTMS as an add-on therapy to refractory CRPS type I patients. It had a positive effect in different aspects of pain (sensory-discriminative and emotional-affective). It opens the perspective for the clinical use of this technique.
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Randomized Controlled Trial Comparative Study
Preference, expectation, and satisfaction in a clinical trial of behavioral interventions for acute and sub-acute low back pain.
The equivalency of behavioral interventions has led to the consideration of whether patient-related factors influence clinical trial outcomes. The primary purpose of this secondary analysis was to determine if treatment preference and patient expectation were predictors of trial outcomes and if selected patient-satisfaction items were appropriate as outcome measures. Perceived effectiveness, treatment preference, and patient expectation were assessed before random assignment, and patient satisfaction was assessed 6 months later. Patient preference was associated with perceived effectiveness for those with no treatment preference and those preferring graded exposure. Higher patient expectation was associated with higher perceived effectiveness ratings for all treatments in the clinical trial. Patients with no strong treatment preferences had larger 6-month improvements in pain intensity and disability, while patients with higher expectations had lower disability at baseline, 4 weeks, and 6 months. Patient satisfaction rates did not differ based on treatment received. Patient satisfaction was highest with treatment delivery and much lower with treatment effect. Patient satisfaction was uniformly associated with expectations being met, but only satisfaction with treatment effect was associated with lower pain and disability scores. These data support assessment of treatment preference and patient expectation as predictors and patient satisfaction as an outcome measure in low back pain (LBP) clinical trials. ⋯ These data indicate treatment preference potentially impacts rate of improvement for patients with low back pain. Patient expectation did not impact rate of improvement, but those with higher expectations had lower pain and disability scores throughout the trial. Optimal assessment of patient satisfaction should include items that separately consider treatment delivery and effect.
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Randomized Controlled Trial Multicenter Study
A multicenter, randomized, double-blind, controlled dose finding study of NGX-4010, a high-concentration capsaicin patch, for the treatment of postherpetic neuralgia.
Postherpetic neuralgia (PHN) is a painful complication of acute herpes zoster. This multicenter, double-blind, controlled study randomized 299 PHN patients to receive either NGX-4010, a high-concentration capsaicin (8%) patch, or a low-concentration capsaicin (0.04%) control patch for 30, 60, or 90 minutes. The mean percent reductions in NPRS score from baseline to weeks 2 through 8 were significantly greater in the total NGX-4010 group (26.5%, P = .0286) and the 90-minute NGX-4010 group (27.8%, P = .0438) compared to the pooled control group (17.3%). After review of the data suggested a difference between genders in reporting of pain scores and a higher proportion of males (61%) in the 60-minute NGX-4010 group, post hoc gender-stratified analyses were performed and showed that the 60-minute NGX-4010 group also had a significantly larger mean percent reduction in average pain scores (28.0%, P = .0331). Pain reduction in the 30-minute NGX-4010 group, although similar in magnitude to the other doses, was not significantly different from control in either of these analyses. Similar results were observed during weeks 2 through 12. Most treatment-emergent adverse events were application-site specific, transient and mostly mild to moderate in severity. ⋯ This article reports the safety and efficacy of NGX-4010 applied for 3 different durations (30, 60, or 90 minutes) in patients with PHN. The results identified the 60-minute duration as the dose to be evaluated in subsequent studies and identified a gender effect on reported changes in pain.
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Randomized Controlled Trial Comparative Study
Pain and functioning of rheumatoid arthritis patients based on marital status: is a distressed marriage preferable to no marriage?
Relationships may influence adjustment to chronic pain conditions such as rheumatoid arthritis (RA). We examined how both marital status and marital adjustment were related to pain, physical disability, and psychological disability in 255 adults with RA. Among married participants (n = 158), better marital adjustment (assessed using the Locke-Wallace Marital Adjustment Scale) was correlated with less pain and physical and psychological disability (all P values < .05). Married participants were divided into distressed (n = 44) and nondistressed (n = 114) subgroups and compared with unmarried participants (n = 97). Controlling for demographics and disease severity, unmarried participants had higher affective pain (P = .009) and higher psychological disability (P = .02) than only the nondistressed married participants, but unmarried participants did not differ from distressed married participants. These findings suggest that being married in itself is not associated with better health in RA but that being in a well-adjusted or nondistressed marriage is linked with less pain and better functioning. ⋯ This study examined relationships of marital status and marital adjustment to pain and physical and psychological disability in RA. Findings underscore the importance of considering not only marital status but also degree of marital adjustment in RA and may inform clinical interventions in this population.
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Randomized Controlled Trial
High levels of vicarious exposure bias pain judgments.
The present study evaluated the effects of exposure to facial expression of pain, on observers' perceptions of pain expression. Participants were undergraduates shown brief video clips of the facial expressions of shoulder-pain patients displaying no pain or moderate pain. Participants were randomly allocated to either a high preexposure condition in which each clip was preceded by 10 other clips showing strong pain or a no-exposure control. On each test trial, participants indicated whether they thought the person they saw was in pain or not. Data were analyzed using signal detection theory methods. High prior exposure to pain was unrelated to sensitivity to pain expression, but did significantly diminish the likelihood of judging the other to be in pain. Results are discussed in terms of their implications for pain judgments of health-care professionals, adaptation-level theory, and the psychophysical method of selective adaptation. ⋯ This paper provides an experimental demonstration that, when people have large amounts of exposure to others' expressions of pain, their estimation of others' pain is reduced. The findings offer 1 explanation for the widely observed underestimation bias in pain judgments and may suggest ways of changing it.