The journal of pain : official journal of the American Pain Society
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Review Meta Analysis
Botulinum toxin type A for painful temporomandibular disorders: systematic review and meta-analysis.
This systematic review investigated the effectiveness and safety of botulinum toxin type A (BTX-A) for painful temporomandibular disorders. We searched for randomized controlled trials (RCTs) in 10 databases, from inception to February 12, 2019 (MEDLINE, EMBASE, CENTRAL, LILACS, BBO, Web of Science, Scopus, ClinicalTrials.gov, WHO and OpenGrey). We included 12 RCTs that compared BTX-A versus inactive or active interventions. ⋯ PERSPECTIVE: BTX-A for painful temporomandibular disorders appears to be well tolerated. For pain reduction, BTX-A is slightly more effective than placebo only at 1 month; conventional treatment and low-level laser at 1, 6, and 12 months. Low-quality evidence limits the applicability of these findings and precludes recommendations for practice.
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Mechanisms of below-level pain are discoverable as neural adaptations rostral to spinal injury. Accordingly, the strategy of investigations summarized here has been to characterize behavioral and neural responses to below-level stimulation over time following selective lesions of spinal gray and/or white matter. Assessments of human pain and the pain sensitivity of humans and laboratory animals following spinal injury have revealed common disruptions of pain processing. ⋯ Additional questions are raised about demyelination, epileptic discharge, autonomic activation, prolonged activity of C nocireceptive neurons, and thalamocortical plasticity in the generation of below-level pain. PERSPECTIVE: An understanding of mechanisms can direct therapeutic approaches to prevent development of below-level pain or arrest it following spinal cord injury. Among the possibilities covered here are surgical and other means of attenuating gray matter excitotoxicity and ascending propagation of excitatory influences from spinal lesions to thalamocortical systems involved in pain encoding and arousal.
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Randomized Controlled Trial Comparative Study
Therapy Habituation at 12 Months: Spinal Cord Stimulation Versus Dorsal Root Ganglion Stimulation for Complex Regional Pain Syndrome Type I and II.
The ACCURATE randomized, controlled trial compared outcomes of dorsal root ganglion (DRG) stimulation versus tonic spinal cord stimulation (SCS) in 152 subjects with chronic lower extremity pain due to complex regional pain syndrome (CRPS) type I or II. This ACCURATE substudy was designed to evaluate whether therapy habituation occurs with DRG stimulation as compared to SCS through 12-months. A modified intention-to-treat analysis was performed to assess percentage pain relief (PPR) and responder rates at follow-up visits (end-of-trial, 1, 3, 6, 9, 12-months postpermanent implant) for all subjects that completed trial stimulation (DRG:N = 73, SCS:N = 72). ⋯ Trial Registration: The ACCURATE study was registered at ClinicalTrials.gov with Identifier NCT01923285. PERSPECTIVE: This article reports on an ACCURATE substudy, which found that long-term therapy habituation occurred at 12-months with SCS, but not DRG stimulation, in patients with CRPS. The underlying mechanisms of action for these results remain unclear, although several lines of inquiry are proposed.
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Randomized Controlled Trial
The role of heart rate variability in mindfulness-based pain relief.
Mindfulness meditation is a self-regulatory practice premised on sustaining nonreactive awareness of arising sensory events that reliably reduces pain. Yet, the specific analgesic mechanisms supporting mindfulness have not been comprehensively disentangled from the potential nonspecific factors supporting this technique. Increased parasympathetic nervous system (PNS) activity is associated with pain relief corresponding to a number of cognitive manipulations. ⋯ Perspective: Mindfulness has been shown to engage multiple mechanisms to reduce pain. The present study extends on this work to show that higher HRV is associated with mindfulness-induced reductions in pain unpleasantness, but not pain intensity ratings, when compared to sham-mindfulness meditation. These findings warrant further investigation into the mechanisms engaged by mindfulness as compared to placebo.
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Comparative Study
Usefulness of Ramp & Hold Procedures for Testing of Pain Facilitation in Human Participants: Comparisons With Temporal Summation of Second Pain.
Quantitative sensory testing (QST) is used to systematically interrogate normal responding and alterations of nervous system function, including pain-related central sensitization (CS). However, up to now, QST of CS in human subjects has been mostly focused on temporal summation of second pain (TSSP), has been difficult to perform, and has been associated with low reliability. In contrast, slow ramp & hold (RH) procedures are simpler tests of temporal summation and easier to perform. ⋯ The magnitude of short-term CS, determined by aftersensations and wind-down was similar after sensitivity-adjusted TSSP and RH stimuli (P > .05), suggesting that pain facilitation of healthy participants and likely chronic pain patients can not only be tested with TSSP but also with RH procedures. PERSPECTIVE: This article examines the ability of RH procedures to generate similar central sensitivity augmentation than TSSP. The results suggest that RH is similarly well suited as TSSP to explore central pain mechanisms in healthy subjects and most likely also in chronic pain patients.