Articles: pain-measurement.
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J Clin Psychol Med Settings · Dec 2008
Randomized Controlled TrialFrequent assessment of negative symptoms does not induce depressed mood.
Use of real-time data collection is rapidly expanding in the medical sciences and questions have been raised as to whether frequent ratings of disease symptoms could evoke depressed mood. This study investigated the effect of an intensive momentary assessment protocol on depressed mood. Community rheumatology patients (N = 105) were recruited to participate in a 30-day momentary assessment protocol of pain and fatigue. ⋯ Depression scores were significantly lower following the protocol (p < .001). Whereas 10% of patients shifted into a more depressed category at the end of the protocol, 20% shifted into a less depressed category. These findings suggest frequent assessment of pain and fatigue may not induce depressed mood, and may in some instances be associated with a small reduction in depressed mood.
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Randomized Controlled Trial
A randomized trial of behavioral physical therapy interventions for acute and sub-acute low back pain (NCT00373867).
Psychological factors consistent with fear-avoidance models are associated with the development of chronic low back pain (LBP). As a result, graded activity (GA) and graded exposure (GX) have been suggested as behavioral treatment options. This clinical trial compared the effectiveness of treatment-based classification (TBC) physical therapy alone to TBC augmented with GA or GX for patients with acute and sub-acute LBP. ⋯ GX and TBC were associated with larger reductions in fear-avoidance beliefs at 6 months only. Six-month reduction in disability was associated with reduction in pain intensity, while 6-month reduction in pain intensity was associated with reductions in fear-avoidance beliefs and pain catastrophizing. This trial suggests that supplementing TBC with GA or GX was not effective for improving important outcomes related to the development of chronic LBP.
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Randomized Controlled Trial Multicenter Study
Pregabalin for postherpetic neuralgia: placebo-controlled trial of fixed and flexible dosing regimens on allodynia and time to onset of pain relief.
Time to onset of pain relief and improvement in allodynia in 269 patients with postherpetic neuralgia was examined in a 4-week randomized trial comparing flexibly dosed pregabalin (150-600 mg/d), fixed-dose pregabalin (300 mg/d), and placebo. For each patient with clinically meaningful pain reduction (>or=30%) at end point, onset of pain relief was defined as the first study day on which a patient reported >or=1-point reduction in pain relative to baseline. Average dose achieved was 396 mg/d in the flexible-dose group compared with 295 mg/d in the fixed-dose group. Median pain relief onset times were 3.5 days (flexible-dose), 1.5 days (fixed-dose), and >4 weeks (placebo). Compared with placebo, significantly more patients in both pregabalin treatment groups achieved >or=30% and >or=50% pain reduction at end point. Almost 95% of patients had brush-evoked allodynia, with 68% having moderate to severe allodynia (>or=40/100 mm). At baseline, pain and allodynia were highly correlated. Independent of treatment assignment, improvement in pain and improvement in allodynia were significantly correlated. Allodynia could serve as a useful surrogate outcome measure in future studies. Pregabalin was significantly better than placebo in alleviating allodynia (flexible-dose reduction, 26 mm; fixed-dose, 21 mm; placebo, 12 mm). Discontinuation rates due to adverse events were more frequent in the fixed-dose group. ⋯ A flexible-dose regimen reduces discontinuations, facilitates higher final doses, and results in a slightly greater pain relief. Allodynia (touch-evoked pain) can be of disabling severity and is present in nearly all patients with postherpetic neuralgia. Allodynia severity is correlated with pain severity and improvement in allodynia is correlated with clinical response.
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Randomized Controlled Trial
Learning potentiates neurophysiological and behavioral placebo analgesic responses.
Expectation and conditioning are supposed to be the two main psychological mechanisms for inducing a placebo response. Here, we further investigate the effects of both expectation, which was induced by verbal suggestion alone, and conditioning at the level of N1 and N2-P2 components of CO2 laser-evoked potentials (LEPs) and subjective pain reports. Forty-four healthy volunteers were pseudorandomly assigned to one of three experimental groups: Group 1 was tested with verbal suggestion alone, Group 2 was tested with a conditioning procedure, whereby the intensity of painful stimulation was reduced surreptitiously, so as to make the volunteers believe that the treatment was effective, Group 3 was a control group that allowed us to rule out phenomena of sensitization and/or habituation. ⋯ Conversely, the N2-P2 amplitude changes that were induced by the conditioning procedure were associated with the subjective perception of pain reduction. Compared to natural history, conditioning produced more robust reductions of LEP amplitudes than verbal suggestions alone. Overall, these findings indicate that prior positive experience plays a key role in maximizing both behavioral and neurophysiological placebo responses, emphasizing that the placebo effect is a learning phenomenon which affects the early central nociceptive processing.
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Randomized Controlled Trial
Escitalopram in painful polyneuropathy: a randomized, placebo-controlled, cross-over trial.
Serotonin (5-HT) is involved in pain modulation via descending pathways in the central nervous system. The aim of this study was to test if escitalopram, a selective serotonin reuptake inhibitor (SSRI), would relieve pain in polyneuropathy. The study design was a randomized, double-blind, placebo-controlled cross-over trial. ⋯ Five patients (10.4%) discontinued the study because of adverse effects during escitalopram. This study found a pain-relieving effect of escitalopram in patients with painful polyneuropathy, but a clinically relevant effect was obtained in only few patients. Currently, the drug cannot be recommended as a standard treatment in neuropathic pain.