European journal of pain : EJP
-
Randomized Controlled Trial
Absence of long-term analgesic effect from a short-term S-ketamine infusion on fibromyalgia pain: a randomized, prospective, double blind, active placebo-controlled trial.
To assess the analgesic efficacy of the N-methyl-D-aspartate receptor antagonist S(+)-ketamine on fibromyalgia pain, the authors performed a randomized double blind, active placebo-controlled trial. Twenty-four fibromyalgia patients were randomized to receive a 30-min intravenous infusion with S(+)-ketamine (total dose 0.5mg/kg, n=12) or the active placebo, midazolam (5mg, n=12). Visual Analogue Pain Scores (VAS) and ketamine plasma samples were obtained for 2.5-h following termination of treatment; pain scores derived from the fibromyalgia impact questionnaire (FIQ) were collected weekly during an 8-week follow-up. ⋯ Side effects as measured by the Bowdle questionnaire (which scores for 13 separate psychedelic symptoms) were mild to moderate in both study groups and declined rapidly, indicating adequate blinding of treatments. Efficacy of ketamine was limited and restricted in duration to its pharmacokinetics. The authors argue that a short-term infusion of ketamine is insufficient to induce long-term analgesic effects in fibromyalgia patients.
-
Randomized Controlled Trial
Differential effects on sensory functions and measures of epidermal nerve fiber density after application of a lidocaine patch (5%) on healthy human skin.
Topical application of lidocaine is an effective approach for treatment of post-herpetic neuralgia and other painful neuropathies. Lidocaine inhibits voltage-gated Na(+) channels and it most likely reduces excitability of cutaneous sensory neurons which can be hyperexcitable or spontaneously active in states of neuropathic pain. However, lidocaine and other local anesthetics also exert a pronounced neurotoxicity and they activate the irritant receptors TRPV1 and TRPA1. ⋯ In conclusion, lidocaine patches seem to have differential effects on sensory modalities in healthy skin. A degeneration of epidermal nerve fibers has previously been demonstrated for patches containing the TRPV1-agonist capsaicin and our findings suggest that this effect might also be relevant for lidocaine patches. These data warrant further studies on molecular mechanisms mediating a relief of neuropathic pain by topical lidocaine.
-
Review
Understanding fear of pain in chronic pain: interoceptive fear conditioning as a novel approach.
The current review deals with interoceptive conditioning as a viable mechanism maintaining fear of pain: The available literature suggests that interoceptive - i.e., internal bodily - sensations may become predictors of pain and will subsequently elicit fear of pain. After a short overview of interoceptive (fear) conditioning and its role in the maintenance of panic disorder, the existing literature on conditioning in the field of pain and fear of pain is reviewed. Next, the authors propose an interoceptive fear conditioning model of fear of pain, suggesting that bodily sensations can function as predictors of pain and as conditioned stimuli become endowed with the capacity to elicit an (anticipatory) fear response. The review concludes with a number of theoretical and clinical considerations, introducing interoceptive exposure as a potentially effective treatment for fear of pain.
-
Despite the increased recognition of paediatric chronic pain, centres for providing appropriate treatment are scarce, and much remains unknown about optimal treatment approaches. The purpose of this study was to investigate effectiveness of multimodal outpatient treatment (MOT) through the examination of treatment pathways and long-term outcomes. ⋯ MOT appears to be beneficial for children with chronic pain. A short intensive intervention (comprising of a total of 2.5-h) can lead to substantial improvements even for severely affected children.
-
Multicenter Study
The association between psychological factors and the development of complex regional pain syndrome type 1 (CRPS1)--a prospective multicenter study.
The objective of this study was to investigate the association between psychological factors and complex regional pain syndrome type 1 (CRPS1). A prospective multicenter cohort study was performed involving the emergency room of three hospitals, and patients age 18years or older, with a single fracture, were included in the study. At baseline (T0), participants completed a questionnaire covering demographic, psychological (Symptom Checklist-90), and medical variables. ⋯ None of the psychological factors predicted the development of CRPS1. The scores on the Symptom Checklist-90 subscales fell into the range of the general population and were, in most cases, average or below average when compared with those of pain patients or psychiatric patients. No empirical evidence supports a diagnosis of CRPS1 patients as psychologically different, and the current results indicate that there is no association between psychological factors and CRPS1.