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Pain Nov 2023Observing someone experience pain relief or exacerbation after an intervention may induce placebo hypoalgesia or nocebo hyperalgesia. Understanding the factors that... (Meta-Analysis)
Meta-Analysis
Observing someone experience pain relief or exacerbation after an intervention may induce placebo hypoalgesia or nocebo hyperalgesia. Understanding the factors that contribute to these effects could help in the development of strategies for optimizing treatment of chronic pain conditions. We systematically reviewed and meta-analyzed the literature on placebo hypoalgesia and nocebo hyperalgesia induced by observational learning (OL). A systematic literature search was conducted in the databases PubMed, PsycINFO, Web of Science, ScienceDirect, PsycARTICLES, Scopus, and Academic Search Ultimate. Twenty-one studies were included in the systematic review, 17 of which were suitable for meta-analysis (18 experiments; n = 764 healthy individuals). The primary end point was the standardized mean difference (SMD) for pain following placebo cues associated during OL with low vs high pain. Observational learning had a small-to-medium effect on pain ratings (SMD 0.44; 95% confidence interval [CI] 0.21-0.68; P < 0.01) and a large effect on pain expectancy (SMD 1.11; 95% CI 0.49-2.04; P < 0.01). The type of observation (in-person vs videotaped) modulated the magnitude of placebo hypoalgesia/nocebo hyperalgesia ( P < 0.01), whereas placebo type did not ( P = 0.23). Finally, OL was more effective when observers' empathic concern (but no other empathy-related factors) was higher ( r = 0.14; 95% CI 0.01-0.27; P = 0.03). Overall, the meta-analysis demonstrates that OL can shape placebo hypoalgesia and nocebo hyperalgesia. More research is needed to identify predictors of these effects and to study them in clinical populations. In the future, OL could be an important tool to help maximize placebo hypoalgesia in clinical settings.
Topics: Humans; Hyperalgesia; Nocebo Effect; Pain; Learning; Pain Perception; Placebo Effect
PubMed: 37326688
DOI: 10.1097/j.pain.0000000000002943 -
Frontiers in Human Neuroscience 2023Deep brain stimulation (DBS) has shown promise in effectively treating chronic pain. This study aimed to assess the efficacy of DBS in this context.
BACKGROUND
Deep brain stimulation (DBS) has shown promise in effectively treating chronic pain. This study aimed to assess the efficacy of DBS in this context.
METHODS
We conducted a systematic literature search using PubMed, Scopus, and Web of Science, following the PRISMA guidelines. A well-constructed search strategy was utilized. Our literature search identified two groups of subjects: one group underwent DBS specifically for chronic pain treatment (DBS-P), while the second group received DBS for other indications (DBS-O), such as Parkinson's disease or dystonia, with pain perception investigated as a secondary outcome in this population. Meta-analysis was performed using R version 4.2.3 software. Heterogeneity was assessed using the tau^2 and I^2 indices, and Cochran's -test was conducted.
RESULTS
The analysis included 966 patients in 43 original research studies with chronic pain who underwent DBS (340 for DBS-P and 625 for DBS-O). Subgroup analysis revealed that DBS-P exhibited a significant effect on chronic pain relief, with a standardized mean difference (SMD) of 1.65 and a 95% confidence interval (CI) of [1.31; 2.00]. Significant heterogeneity was observed among the studies, with an I^2 value of 85.8%. However, no significant difference was found between DBS-P and DBS-O subgroups. Subgroup analyses based on study design, age, pain diseases, and brain targets demonstrated varying levels of evidence for the effectiveness of DBS across different subgroups. Additionally, meta-regression analyses showed no significant relationship between age or pain duration and DBS effectiveness for chronic pain.
CONCLUSION
These findings significantly contribute to the expanding body of knowledge regarding the utility of DBS in the management of chronic pain. The study underscores the importance of conducting further research to enhance treatment outcomes and elucidate patient-specific factors that are associated with treatment response.
SYSTEMATIC REVIEW REGISTRATION
https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=428442, identifier CRD42023428442.
PubMed: 38098761
DOI: 10.3389/fnhum.2023.1297894 -
The Cochrane Database of Systematic... Jun 2024Postburn pruritus (itch) is a common and distressing symptom experienced on healing or healed burn or donor site wounds. Topical, systemic, and physical treatments are... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Postburn pruritus (itch) is a common and distressing symptom experienced on healing or healed burn or donor site wounds. Topical, systemic, and physical treatments are available to control postburn pruritus; however, it remains unclear how effective these are.
OBJECTIVES
To assess the effects of interventions for treating postburn pruritus in any care setting.
SEARCH METHODS
In September 2022, we searched the Cochrane Wounds Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE (including In-Process & Other Non-Indexed Citations), Ovid Embase, and EBSCO CINAHL Plus. We also searched clinical trials registries and scanned references of relevant publications to identify eligible trials. There were no restrictions with respect to language, publication date, or study setting.
SELECTION CRITERIA
Randomised controlled trials (RCTs) that enrolled people with postburn pruritus to compare an intervention for postburn pruritus with any other intervention, placebo or sham intervention, or no intervention.
DATA COLLECTION AND ANALYSIS
We used the standard methodological procedures expected by Cochrane. We used GRADE to assess the certainty of the evidence.
MAIN RESULTS
We included 25 RCTs assessing 21 interventions with 1166 randomised participants. These 21 interventions can be grouped into six categories: neuromodulatory agents (such as doxepin, gabapentin, pregabalin, ondansetron), topical therapies (such as CQ-01 hydrogel, silicone gel, enalapril ointment, Provase moisturiser, beeswax and herbal oil cream), physical modalities (such as massage therapy, therapeutic touch, extracorporeal shock wave therapy, enhanced education about silicone gel sheeting), laser scar revision (pulsed dye laser, pulsed high-intensity laser, fractional CO2 laser), electrical stimulation (transcutaneous electrical nerve stimulation, transcranial direct current stimulation), and other therapies (cetirizine/cimetidine combination, lemon balm tea). Most RCTs were conducted at academic hospitals and were at a high risk of performance, attrition, and detection bias. While 24 out of 25 included studies reported change in burn-related pruritus, secondary outcomes such as cost-effectiveness, pain, patient perception, wound healing, and participant health-related quality of life were not reported or were reported incompletely. Neuromodulatory agents versus antihistamines or placebo There is low-certainty evidence that doxepin cream may reduce burn-related pruritus compared with oral antihistamine (mean difference (MD) -2.60 on a 0 to 10 visual analogue scale (VAS), 95% confidence interval (CI) -3.79 to -1.42; 2 studies, 49 participants). A change of 2 points represents a minimal clinically important difference (MCID). Due to very low-certainty evidence, it is uncertain whether doxepin cream impacts the incidence of somnolence as an adverse event compared to oral antihistamine (risk ratio (RR) 0.64, 95% CI 0.32 to 1.25; 1 study, 24 participants). No data were reported on pain in the included study. There is low-certainty evidence that gabapentin may reduce burn-related pruritus compared with cetirizine (MD -2.40 VAS, 95% CI -4.14 to -0.66; 1 study, 40 participants). A change of 2 points represents a MCID. There is low-certainty evidence that gabapentin reduces the incidence of somnolence compared to cetirizine (RR 0.02, 95% CI 0.00 to 0.38; 1 study, 40 participants). No data were reported on pain in the included study. There is low-certainty evidence that pregabalin may result in a reduction in burn-related pruritus intensity compared with cetirizine with pheniramine maleate (MD -0.80 VAS, 95% CI -1.24 to -0.36; 1 study, 40 participants). A change of 2 points represents a MCID. There is low-certainty evidence that pregabalin reduces the incidence of somnolence compared to cetirizine (RR 0.04, 95% CI 0.00 to 0.69; 1 study, 40 participants). No data were reported on pain in the included study. There is moderate-certainty evidence that ondansetron probably results in a reduction in burn-related pruritus intensity compared with diphenhydramine (MD -0.76 on a 0 to 10 numeric analogue scale (NAS), 95% CI -1.50 to -0.02; 1 study, 38 participants). A change of 2 points represents a MCID. No data were reported on pain and adverse events in the included study. Topical therapies versus relevant comparators There is moderate-certainty evidence that enalapril ointment probably decreases mean burn-related pruritus compared with placebo control (MD -0.70 on a 0 to 4 scoring table for itching, 95% CI -1.04 to -0.36; 1 study, 60 participants). No data were reported on pain and adverse events in the included study. Physical modalities versus relevant comparators Compared with standard care, there is low-certainty evidence that massage may reduce burn-related pruritus (standardised mean difference (SMD) -0.86, 95% CI -1.45 to -0.27; 2 studies, 166 participants) and pain (SMD -1.32, 95% CI -1.66 to -0.98). These SMDs equate to a 4.60-point reduction in pruritus and a 3.74-point reduction in pain on a 10-point VAS. A change of 2 VAS points in itch represents a MCID. No data were reported on adverse events in the included studies. There is low-certainty evidence that extracorporeal shock wave therapy (ESWT) may reduce burn-related pruritus compared with sham stimulation (SMD -1.20, 95% CI -1.65 to -0.75; 2 studies, 91 participants). This equates to a 5.93-point reduction in pruritus on a 22-point 12-item Pruritus Severity Scale. There is low-certainty evidence that ESWT may reduce pain compared with sham stimulation (MD 2.96 on a 0 to 25 pressure pain threshold (PPT), 95% CI 1.76 to 4.16; 1 study, 45 participants). No data were reported on adverse events in the included studies. Laser scar revision versus untreated or placebo controls There is moderate-certainty evidence that pulsed high-intensity laser probably results in a reduction in burn-related pruritus intensity compared with placebo laser (MD -0.51 on a 0 to 1 Itch Severity Scale (ISS), 95% CI -0.64 to -0.38; 1 study, 49 participants). There is moderate-certainty evidence that pulsed high-intensity laser probably reduces pain compared with placebo laser (MD -3.23 VAS, 95% CI -5.41 to -1.05; 1 study, 49 participants). No data were reported on adverse events in the included studies.
AUTHORS' CONCLUSIONS
There is moderate to low-certainty evidence on the effects of 21 interventions. Most studies were small and at a high risk of bias related to blinding and incomplete outcome data. Where there is moderate-certainty evidence, practitioners should consider the applicability of the evidence for their patients.
Topics: Humans; Pruritus; Burns; Randomized Controlled Trials as Topic; Bias; Antipruritics
PubMed: 38837237
DOI: 10.1002/14651858.CD013468.pub2 -
Clinical Oral Investigations Dec 2023To assess whether in animals or patients with ≥ 1 tooth extracted, hyaluronic acid (HyA) application results in superior healing and/or improved complication... (Meta-Analysis)
Meta-Analysis
OBJECTIVES
To assess whether in animals or patients with ≥ 1 tooth extracted, hyaluronic acid (HyA) application results in superior healing and/or improved complication management compared to any other treatment or no treatment.
MATERIALS AND METHODS
Three databases were searched until April 2022. The most relevant eligibility criteria were (1) local application of HyA as adjunct to tooth extraction or as treatment of alveolar osteitis, and (2) reporting of clinical, radiographic, histological, or patient-reported data. New bone formation and/or quality were considered main outcome parameters in preclinical studies, while pain, swelling, and trismus were defined as main outcome parameters in clinical studies.
RESULTS
Five preclinical and 22 clinical studies (1062 patients at final evaluation) were included. In preclinical trials, HyA was applied into the extraction socket. Although a positive effect of HyA was seen in all individual studies on bone formation, this effect was not confirmed by meta-analysis. In clinical studies, HyA was applied into the extraction socket or used as spray or mouthwash. HyA application after non-surgical extraction of normally erupted teeth may have a positive effect on soft tissue healing. Based on meta-analyses, HyA application after surgical removal of lower third molars (LM3) resulted in significant reduction in pain perception 7 days postoperatively compared to either no additional wound manipulation or the application of a placebo/carrier. Early post-operative pain, trismus, and extent of swelling were unaffected.
CONCLUSIONS
HyA application may have a positive effect in pain reduction after LM3 removal, but not after extraction of normally erupted teeth.
CLINICAL RELEVANCE
HyA application may have a positive effect in pain reduction after surgical LM3 removal, but it does not seem to have any impact on other complications or after extraction of normally erupted teeth. Furthermore, it seems not to reduce post-extraction alveolar ridge modeling, even though preclinical studies show enhanced bone formation.
Topics: Humans; Animals; Tooth Socket; Hyaluronic Acid; Trismus; Dry Socket; Tooth Extraction; Molar, Third; Pain
PubMed: 37963982
DOI: 10.1007/s00784-023-05227-4 -
Psychonomic Bulletin & Review Mar 2024We conducted a systematic review investigating the influence of visual perspective and body ownership (BO) on vicarious brain resonance and vicarious sensations during... (Review)
Review
We conducted a systematic review investigating the influence of visual perspective and body ownership (BO) on vicarious brain resonance and vicarious sensations during the observation of pain and touch. Indeed, the way in which brain reactivity and the phenomenological experience can be modulated by blurring the bodily boundaries of self-other distinction is still unclear. We screened Scopus and WebOfScience, and identified 31 articles, published from 2000 to 2022. Results show that assuming an egocentric perspective enhances vicarious resonance and vicarious sensations. Studies on synaesthetes suggest that vicarious conscious experiences are associated with an increased tendency to embody fake body parts, even in the absence of congruent multisensory stimulation. Moreover, immersive virtual reality studies show that the type of embodied virtual body can affect high-order sensations such as appropriateness, unpleasantness, and erogeneity, associated with the touched body part and the toucher's social identity. We conclude that perspective plays a key role in the resonance with others' pain and touch, and full-BO over virtual avatars allows investigation of complex aspects of pain and touch perception which would not be possible in reality.
PubMed: 38429591
DOI: 10.3758/s13423-024-02477-5 -
Pain Feb 2024Despite being widely assumed, the worsening impact of unpredictability on pain perception remains unclear because of conflicting empirical evidence, and a lack of...
Despite being widely assumed, the worsening impact of unpredictability on pain perception remains unclear because of conflicting empirical evidence, and a lack of systematic integration of past research findings. To fill this gap, we conducted a systematic review and meta-analysis focusing on the effect of unpredictability on pain perception. We also conducted meta-regression analyses to examine the moderating effect of several moderators associated with pain and unpredictability: stimulus duration, calibrated stimulus pain intensity, pain intensity expectation, controllability, anticipation delay, state and trait negative affectivity, sex/gender and age of the participants, type of unpredictability (intensity, onset, duration, location), and method of pain induction (thermal, electrical, mechanical pressure, mechanical distention). We included 73 experimental studies with adult volunteers manipulating the (un)predictability of painful stimuli and measuring perceived pain intensity and pain unpleasantness in predictable and unpredictable contexts. Because there are insufficient studies with patients, we focused on healthy volunteers. Our results did not reveal any effect of unpredictability on pain perception. However, several significant moderators were found, ie, targeted stimulus pain intensity, expected pain intensity, and state negative affectivity. Trait negative affectivity and uncontrollability showed no significant effect, presumably because of the low number of included studies. Thus, further investigation is necessary to clearly determine their role in unpredictable pain perception.
PubMed: 38422488
DOI: 10.1097/j.pain.0000000000003199 -
General Psychiatry 2023Non-suicidal self-injury (NSSI) is a frequent and prominent phenomenon in major depressive disorder (MDD). Even though its prevalence and risk factors are relatively...
BACKGROUND
Non-suicidal self-injury (NSSI) is a frequent and prominent phenomenon in major depressive disorder (MDD). Even though its prevalence and risk factors are relatively well understood, the potential mechanisms of NSSI in MDD remain elusive.
AIMS
To review present evidence related to the potential mechanisms of NSSI in MDD.
METHODS
According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines, articles for this systematic review were searched on Medline (through PubMed), Embase (through Elsevier), PsycINFO (through OVID) and Web of Science databases for English articles, as well as China National Knowledge Infrastructure (CNKI), SinoMed, Wanfang Data, and the Chongqing VIP Chinese Science and Technology Periodical (VIP) Databases for Chinese articles published from the date of inception to 2 August 2022. Two researchers (BW, HZ) independently screened studies based on inclusion and exclusion criteria and assessed their quality.
RESULTS
A total of 25 157 studies were searched. Only 25 of them were ultimately included, containing 3336 subjects (1535 patients with MDD and NSSI, 1403 patients with MDD without NSSI and 398 HCs). Included studies were divided into 6 categories: psychosocial factors (11 studies), neuroimaging (8 studies), stress and hypothalamic-pituitary-adrenal (HPA) axis (2 studies), pain perception (1 study), electroencephalogram (EEG) (2 studies) and epigenetics (1 study).
CONCLUSIONS
This systematic review indicates that patients with MDD and NSSI might have specific psychosocial factors, aberrant brain functions and neurochemical metabolisms, HPA axis dysfunctions, abnormal pain perceptions and epigenetic alterations.
PubMed: 37655114
DOI: 10.1136/gpsych-2022-100946 -
Langenbeck's Archives of Surgery Aug 2023Patients undergoing medical procedures often experience pain and anxiety. These periprocedural outcomes can be overcome by providing a distraction using virtual reality... (Meta-Analysis)
Meta-Analysis
PURPOSE
Patients undergoing medical procedures often experience pain and anxiety. These periprocedural outcomes can be overcome by providing a distraction using virtual reality (VR), decreasing their perception. VR has proved effective in reducing pediatric pain and anxiety; however, limited studies have confirmed its effectiveness in adults. We performed a systematic review and meta-analysis on the effectiveness of VR, as opposed to standard care, in reducing periprocedural pain and anxiety in adults.
METHODS
A systematic search of randomized controlled trials was conducted using the databases of MEDLINE, Cochrane CENTRAL, and Scopus. Trials involving patients (> 18 years) undergoing elective medical procedures conducted with or without local anesthesia and participating in VR therapy were included. Primary outcomes were pre-procedural anxiety, post-procedural anxiety, and intra-procedural pain. Pre-procedural pain, post-procedural pain, and intra-procedural anxiety were secondary outcomes.
RESULTS
Data from 10 studies shortlisted for inclusion revealed no significant association between the use of VR and lower pre-procedural anxiety compared to standard care (p > 0.05) (SMD = -0.02, 95% CI = -0.18 - 0.14, P = 0.81) but demonstrated that the use of VR was significantly associated with a reduction in post-procedural anxiety (SMD = -0.73, 95% CI = -1.08 - -0.39, P < 0.0001), intra-procedural pain (SMD = -0.61, 95% CI = -1.18 - -0.04, P = 0.04), and post-procedural pain (SMD = -0.25, 95% CI = -0.44 - -0.05, P = 0.01).
CONCLUSION
The use of VR caused a significant reduction in post-procedural anxiety, intra-procedural pain, and post-procedural pain in adults undergoing medical procedures, although the findings were insignificant concerning pre-procedural anxiety.
Topics: Child; Humans; Adult; Pain, Procedural; Anxiety; Pain Management; Virtual Reality; Anesthesia, Local
PubMed: 37556082
DOI: 10.1007/s00423-023-03046-5 -
Journal of Pain Research 2024This systematic review aims to assess the use and perception of "Western" medical acupuncture-based on conventional biomedical mechanisms and evidence-based medicine for...
PURPOSE
This systematic review aims to assess the use and perception of "Western" medical acupuncture-based on conventional biomedical mechanisms and evidence-based medicine for diagnosis and needle placement-for pain management among athletes and their healthcare providers.
METHODS
A systematic review is reported based on the PRISMA guidelines. PubMed, Web of Science, SPORTDiscus, Allied and Complementary Medicine databases, and Google Scholar were searched (search: from database inception to July 2023). Two authors independently conducted multi-stage screening, data extraction, and quality assessment. The outcomes of interest were prevalence of acupuncture prescriptions by healthcare professionals, prevalence of acupuncture use by athletes, and perceptions related to acupuncture effectiveness among healthcare professionals and athletes. Only studies wherein "Western" medical acupuncture was used for pain management were included.
RESULTS
Our review included 11 observational studies and clinical trials. The prevalence of "Western" medical acupuncture prescription varied from 15.4% (UK) to 58.4% (US) among sports medicine healthcare professionals. Prevalence of acupuncture use among athletes ranged from 2.2% among college athletes in Palestine to 61% among professional football players in the Netherlands. Acupuncture was used for managing delayed-onset of soreness and pain due to various types of musculoskeletal injuries. Both athletes and their healthcare providers reported positive perceptions of acupuncture.
CONCLUSION
Our systematic review identifies a notable research gap in evaluating the practice and perception of "Western" medical acupuncture among healthcare professionals and athletes. Our findings suggest that "Western" medical acupuncture is not only prescribed by sport medicine professionals and used by athletes for diverse musculoskeletal pains but is also generally perceived positively for its effectiveness. Given the positive clinical experience of health professionals, athletes' favorable perception, and acupuncture's well-established safety profile, acupuncture should be given serious consideration-as a complementary approach-in the overall management of pain.
REGISTRATION
Open Science Framework (https://osf.io/qb9gc).
PubMed: 38292755
DOI: 10.2147/JPR.S441869 -
BMC Neurology Nov 2023Fibromyalgia (FM) is a chronic pain condition that affects millions of people worldwide. Transcranial Direct Current Stimulation (tDCS) is a non-invasive brain... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Fibromyalgia (FM) is a chronic pain condition that affects millions of people worldwide. Transcranial Direct Current Stimulation (tDCS) is a non-invasive brain stimulation technique that has shown promise as a potential treatment for FM by modulating pain perception and reducing symptoms, such as fatigue and depression. We aimed to systematically review studies that assess the effect of tDCS on pain reduction in FM patients.
METHODS
Seven electronic databases (PubMed, Scopus, Embase, PsycINFO, Web of Science, Cochrane, and CINAHL Complete) were searched for records in English. Studies that measured the effect of tDCS on pain intensity in FM patients were included. The Cochrane Collaboration's tool was used to assess the quality of the included studies. A random-effect model was preferred, and statistical analysis was performed by Stata software version 17.
RESULTS
Twenty studies were included for qualitative, and eleven for quantitative analysis. Out of 664 patients included in the study, 443 were in the stimulation group. The left M1 area was the most common stimulation target (n = 12), and 2 mA was the most common stimulation amplitude (n = 19). The analysis showed that active tDCS significantly reduced pain intensity in FM patients in comparison to the sham group (SMD= -1.55; 95% CI -2.10, -0.99); also, no publication bias was noted.
CONCLUSION
Our systematic review highlights the potential effect of tDCS on the reduction of pain intensity in FM patients. Additionally, this current evidence could suggest that tDCS applied at an intensity of 2mA to the left M1 is the most effective strategy.
Topics: Humans; Transcranial Direct Current Stimulation; Fibromyalgia; Pain Measurement; Transcranial Magnetic Stimulation; Chronic Pain
PubMed: 37919664
DOI: 10.1186/s12883-023-03445-7