Pain
-
Randomized Controlled Trial
Emotional awareness and expression therapy, cognitive-behavioral therapy, and education for fibromyalgia: a cluster-randomized controlled trial.
Patients with fibromyalgia (FM) experience increased lifetime levels of psychosocial adversity, trauma, and emotional conflict. To address these risk factors, we developed emotion awareness and expression therapy (EAET) and tested its benefits against an active control condition, FM education, and the field's gold standard intervention for FM, cognitive behavioral therapy (CBT) for symptom management. Adults with FM (N = 230) formed 40 treatment groups, which were randomized to EAET, CBT, or education and given 8, 90-minute sessions. ⋯ Emotional awareness and expression therapy did not differ from CBT on the primary or most secondary outcomes, but compared to CBT, EAET led to significantly lower FM symptoms (d = 0.35) and widespread pain (d = 0.37) and a higher percentage of patients achieving 50% pain reduction (22.5% vs 8.3%). In summary, an intervention targeting emotional awareness and expression related to psychosocial adversity and conflict was well received, more effective than a basic educational intervention, and had some advantages over CBT on pain. We conclude that EAET should be considered as an additional treatment option for FM.
-
Loss of GABAergic inhibition in pain pathways has been considered to be a key component in the development of chronic pain. In the present study, we intended to examine whether miR-92b-mediated posttranscriptional dysregulation of spinal potassium chloride cotransporter (KCC2) and vesicular γ-aminobutyric acid transporter (VGAT) plays a major role in the development and maintenance of long-term visceral hyperalgesia in neonatal zymosan-treated rats. Neonatal cystitis was induced by transurethral zymosan administration from postnatal (P) days 14 to 16 (protocol 1). ⋯ Intrathecal administration of lentiviral pLSyn-miR-92b-3p sponge (miR-92b-3p inhibitor) upregulated KCC2 and VGAT expression in spinal dorsal horn neurons. In behavioral studies, intrathecal administration of lentiviral miR-92b-3p sponge attenuated an increase in visceromotor responses and referred viscerosomatic hypersensitivity following the induction of cystitis. These findings indicate that miR-92b-3p-mediated posttranscriptional regulation of spinal GABAergic system plays an important role in sensory pathophysiology of zymosan-induced cystitis.
-
Randomized Controlled Trial
Is the rationale more important than deception? A randomized controlled trial of openlabel placebo analgesia.
Research on open-label placebos questions whether deception is a necessary characteristic of placebo effects. Yet, comparisons between open-label and deceptive placebos (DPs) are lacking. We therefore assessed effects of open-label placebos and DPs in comparison with no treatment (NT) with a standardized experimental heat pain paradigm in a randomized controlled trial in healthy participants. ⋯ Our findings reveal that placebos with a plausible rationale are more effective than without a rationale. Even more, open-label placebos did not significantly differ in their effects from DPs. Therefore, we question the ubiquitously assumed necessity of concealment in placebo administration.
-
Different sensory profiles in diabetic distal symmetrical sensory-motor polyneuropathy (DSPN) may be associated with pain and the responsiveness to analgesia. We aimed to characterize sensory phenotypes of patients with painful and painless diabetic neuropathy and to assess demographic, clinical, metabolic, and electrophysiological parameters related to the presence of neuropathic pain in a large cohort of well-defined DSPN subjects. This observational cross-sectional multi-center cohort study (performed as part of the ncRNAPain EU consortium) of 232 subjects with nonpainful (n = 74) and painful (n = 158) DSPN associated with diabetes mellitus of type 1 and 2 (median age 63 years, range 21-87 years; 92 women) comprised detailed history taking, laboratory tests, neurological examination, quantitative sensory testing, nerve conduction studies, and neuropathy severity scores. ⋯ Neuropathic pain was further linked to female sex and higher cognitive appraisal of pain as assessed by the pain catastrophizing scale (P < 0.001), while parameters related to diabetes showed no influence on neuropathic pain with the exception of laboratory signs of nephropathy. This study confirms the value of comprehensive DSPN phenotyping and underlines the importance of the severity of neuropathy for the presence of pain. Different sensory phenotypes might be useful for stratification of patients with painful DSPN for analgesic treatment and drug trials.
-
The mu opioid receptor (MOR) and metabotropic glutamate receptor 5 (mGluR5) are well-established pharmacological targets in the management of chronic pain. Both receptors are expressed in the spinal cord. MMG22, a bivalent ligand containing 2 pharmacophores separated by 22 atoms, which simultaneously activates MOR and antagonizes mGluR5, has been shown to produce potent reversal of tactile hypersensitivity in rodent models of lipopolysaccharide (LPS)-and bone cancer-induced chronic pain. ⋯ Coadministration of oxymorphone and MPEP demonstrated analgesic synergism, an interaction confirmed by isobolographic analysis. This study indicates that in the spared nerve injury-induced model of neuropathic pain, the 2 pharmacophores of the bivalent ligands MMG22 and MMG10 target MOR and mGluR5 as separate receptor monomers. The observed increase in the potency of MMG22 and MMG10, compared with oxymorphone and MPEP, may reflect the synergistic interaction of the 2 pharmacophores of the bivalent ligand acting at their respective separate receptor monomers.