The latest medical research on Pain Medicine

The research magnet gathers the latest research from around the web, based on your specialty area. Below you will find a sample of some of the most recent articles from reputable medical journals about pain medicine gathered by our medical AI research bot.

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Pain after a motor vehicle crash: The role of socio-demographics, crash characteristics, and peri-traumatic stress symptoms.

Eur J Pain

The vast majority of individuals who come to the emergency department (ED) for care after a motor vehicle collision (MVC) are diagnosed with musculoskeletal strain only and are discharged to home. A significant subset of this population will still develop persistent pain and posttraumatic psychological sequelae may play an important role in pain persistence.

We conducted a multisite longitudinal cohort study of adverse post-traumatic neuropsychiatric sequelae (APNS) among patients seeking emergency department (ED) treatment in the aftermath of a traumatic life experience. We report on a sub-group of patients (n=666) presenting after an MVC, the most common type of trauma and we examine associations of socio-demographic and MVC characteristics, and persistent pain eight weeks after MVC. We also examine the degree to which these associations are related to peritraumatic psychological symptoms and 2-week acute stress reactions using an applied approach.

Eight-week prevalence of persistent moderate or severe pain was high (67.4%) and positively associated with patient sex (female), older age, low socioeconomic status (education and income), and pain severity in the ED. Peritraumatic stress symptoms (distress and dissociation) appear to exert some influence on both acute pain and the transition from acute to persistent pain DISCUSSION AND CONCLUSIONS: The early aftermath of an MVC may be an important time period for intervening to prevent and reduce persistent pain. Substantial variation in mediating pathways across predictors also suggests potential diverse and complex underlying biological and psychological pathogenic processes are at work in the early weeks following trauma.

The first several days after trauma may dictate recovery trajectories. Persistent pain, pain lasting beyond the expected time of recovery, is associated with pain early in the recovery period, but also mediated through other pathways. Future work is needed to understand the complex neurobiological processes in involved in the development of persistent and acute post-traumatic pain.

Internet-delivered acceptance and commitment therapy as microlearning for chronic pain: A randomized controlled trial with 1-year follow-up.

Eur J Pain

Studies of Internet-delivered acceptance and commitment therapy (ACT) for chronic pain have shown small to moderate positive effects for pain interference and pain acceptance. Effects on pain intensity, depression, anxiety and quality of life (QoL) have been less favourable, and improvements for values and sleep are lacking. In this randomized controlled trial iACT - a novel format of Internet-ACT using daily microlearning exercises - was examined for efficacy compared to a waitlist condition.

Adult participants (mean age 49.5 years, pain duration 18.1 years) with diverse chronic pain conditions were recruited via self-referral, and randomized to iACT (n = 57) or waitlist (n = 56). The primary outcome was pain interference. The secondary outcomes were QoL, depression, anxiety, insomnia and pain intensity. The process variables included psychological inflexibility and values. Post-assessments were completed by 88% (n = 100) of participants. Twelve-month follow-up assessments were completed by 65% (iACT only, n = 37). Treatment efficacy was analysed using linear mixed models and an intention-to-treat-approach.

Significant improvements in favour of iACT were seen for pain interference, depression, anxiety, pain intensity and insomnia, as well as process variables psychological inflexibility and values. Between-group effect sizes were large for pain interference (d = 0.99) and pain intensity (d = 1.2), moderate for anxiety and depressive symptoms and small for QoL and insomnia. For the process variables, the between-group effect size was large for psychological inflexibility (d = 1.0) and moderate for values. All improvements were maintained at 1-year follow-up.

The study evaluates a novel behavioral treatment with positive results on pain interference, mood as well as pain intensity for longtime chronic pain sufferers. The innovative format of a digital ACT intervention delivered in short and experiential daily learnings may be a promising way forward.

P2X7-induced nociception in the temporomandibular joint of rats depends on inflammatory mechanisms and C-fibers sensitization.

Eur J Pain

P2X7 receptors are responsible for triggering inflammatory responses contributing to processes of pain in articular tissues. This study aimed to investigate whether the activation of the P2X7 receptor located in the temporomandibular joint (TMJ) tissues induces nociception through an inflammatory mechanisms and/or the activation of C-fibers (small-diameter primary afferents) of rats' TMJ.

The TMJ hypernociception induced by the activation of P2X7 receptor was assessed by measuring the behavioral nociceptive responses. After behavioral experiments, the animals were terminally anaesthetized and periarticular tissues were removed and homogenate for enzyme-linked immunosorbent assay, leukocyte infiltration and Western blotting analysis.

The non-selective P2X7 receptor agonist BzATP induced a dose-dependent TMJ nociception, which was blocked by the selective P2X7 receptor antagonist A-438079. The co-administration of the selective β2-adrenoceptor antagonist (ICI-118,551) and the pre-treatment with cyclooxygenase inhibitor indomethacin or with the nonspecific selectin inhibitor Fucoidan significantly reduced BzATP-induced TMJ nociception. BzATP also induced an increase of pro-inflammatory cytokines TNFα, IL-1β, and CINC-1 levels, as well as leukocyte recruitment in TMJ tissue, effects that were reduced by A-438079. Moreover, BzATP-induced TMJ nociception was inhibited in rats neonatal-treated with Capsaicin (depleting C-fibers). Finally, BzATP-induced an increase of TRPV1 expression in TMJ tissue.

These findings suggest that P2X7 receptor activation in TMJ of rats induces nociceptive responses mediated by sympathomimetic amines, prostaglandins, leukocyte migration, and increased levels of pro-inflammatory cytokines. Furthermore, the P2X7 receptor activation induces nociceptive responses dependent on the activation of the primary afferent nociceptors of rats' TMJ.

Safety and Feasibility of Nucleus Accumbens Surgery for Drug Addiction: A Systematic Review.


Substance addiction encompasses the incapacity to discontinue urgent drug use; many severely disabled patients might be considered appropriate candidates for surgery due to the high rates of relapse despite conservative treatment. A crucial finding in the brain of these patients is increased extracellular concentrations of dopamine in the nucleus accumbens (NAcc).

To determine the efficacy and safety of NAcc surgery for the treatment of substance dependence.

Adhering to PRISMA guidelines, we performed a systematic review to identify all original studies in which NAcc surgery was performed to treat relapsing drug addiction with a minimum follow-up of six months. From database inception to April 10, 2020, we searched PubMed, Scopus, and LILACS. Two reviewers independently selected studies and extracted data. The main outcome was the relapse rate. The GRADE methods were applied to evaluate the quality of evidence. This study was registered with PROSPERO CRD42020177054.

Fifteen studies involving 359 participants met inclusion criteria; eight (56%) included NAcc deep brain stimulation (DBS) in 13 patients with addiction for alcohol (N = 6, 46.1%), opioid (N = 4, 30.7%), and nicotine (N = 3, 15.3%); seven studies (N = 346, 44%) performed NAcc radiofrequency (RF) ablation for opioid (N = 334) and alcohol (N = 12) dependence. Relapse rates were 38.4% for DBS and 39% for RF ablation.

Despite available studies reporting a benefit in the treatment of drug addictions with NAcc surgery, this systematic review stresses the need for carefully planned prospective studies in order to further address the efficacy and indications.

Randomized Prospective Study in Patients With Complex Regional Pain Syndrome of the Upper Limb With High-Frequency Spinal Cord Stimulation (10-kHz) and Low-Frequency Spinal Cord Stimulation.


The objective of this prospective randomized study of cases and controls was to evaluate the efficacy of treatment with low-frequency spinal cord stimulation (LF-SCS) and 10 kHz spinal cord stimulation (10-kHz SCS) in patients diagnosed with complex regional pain syndrome type I (CRPS) with upper limb involvement.

Fifty patients were randomized to receive conventional treatment or SCS with a commercially available low-frequency or 10-kHz system. Patients were assessed at 1, 3, 6, and 12 months. The primary endpoint was at 12-months post permanent implantation of the SCS devices. Outcome measures assessed included: Numerical Rating Scale (NRS), 12-Item Short-Format Health Survey (SF-12), Oswestry Disability Index (ODI), Study Sleep Scale medical outcomes (MOS-SS), Douleur Neuropathique 4 questions pain questionnaire (DN4), Patient Global Impression Scale on the impact of treatment improvement (PGI-I), Clinician Global Impression Scale on the impact of improving the patient (CGI-I).

Forty-one patients were finally included in the analysis, 19 patients in the conventional treatment group, 12 in the LF-SCS group, and 10 in the 10-kHz SCS group. At the primary endpoint, patients treated with LF-SCS presented improvements in the NRS and DN4 outcomes around 2.4 and 1.5 times above the minimal clinically important difference (MCID) thresholds. At the primary endpoint, patients treated with 10-kHz SCS presented improvements in the NRS and DN4 outcomes around 2 and 1.4 times above the MCID thresholds.

Patients experienced considerable improvement after SCS. The results show that LF-SCS has very good results when compared with conventional treatment. The results obtained with 10-kHz SCS are encouraging, with the advantages of the absence of paresthesia making it an alternative in the treatment of CRPS.

Deep Brain Stimulation-Related Surgical Site Infections: A Systematic Review and Meta-Analysis.


Over the last decades, the increased use of deep brain stimulation (DBS) has raised concerns about the potential adverse health effects of the treatment. Surgical site infections (SSIs) following an elective surgery remain a major challenge for neurosurgeons. Few studies have examined the prevalence and risk factors of DBS-related complications, particularly focusing on SSIs.

We systematically searched published literature, up to June 2020, with no language restrictions.

Eligible were studies that examined the prevalence of DBS-related SSIs, as well as studies that examined risk and preventive factors in relation to SSIs. We extracted information on study characteristics, follow-up, exposure and outcome assessment, effect estimate and sample size. Summary odds ratios (sOR) and 95% confidence intervals (CI) were calculated from random-effects meta-analyses; heterogeneity and small-study effects were also assessed.

We identified 66 eligible studies that included 12,258 participants from 27 countries. The summary prevalence of SSIs was estimated at 5.0% (95% CI: 4.0%-6.0%) with higher rates for dystonia (6.5%), as well as for newer indications of DBS, such as epilepsy (9.5%), Tourette syndrome (5.9%) and OCD (4.5%). Similar prevalence rates were found between early-onset and late-onset hardware infections. Among risk and preventive factors, the perioperative implementation of intra-wound vancomycin was associated with statistically significantly lower risk of SSIs (sOR: 0.26, 95% CI: 0.09-0.74). Heterogeneity was nonsignificant in most meta-analyses.

The present study confirms the still high prevalence of SSIs, especially for newer indications of DBS and provides evidence that preventive measures, such as the implementation of topical vancomycin, seem promising in reducing the risk of DBS-related SSIs. Large clinical trials are needed to confirm the efficacy and safety of such measures.

Analgesic and Antibiotic Prescription Pattern among Dentists in Guangzhou: A Cross-Sectional Study.

Pain Res Manag

To assess the rational use of drugs and the pattern of prescribing of analgesics and antibiotics for dental management and the information given by dentists in Guangzhou to their patients about the use of these drugs.

A questionnaire was distributed to 225 dentists working in Guangzhou. The questionnaires consisted of open-ended questions and were given to dentists about analgesic and antibiotic use in dentistry. The questionnaires were analyzed, and absolute frequencies were expressed in the answers to each question. The cases, the analgesics, and the antibiotics recommended by the dentists for each case were determined by the frequency analysis method of descriptive statistics.

Responses to the questionnaire were received from 164 (72.9%) dentists. Paracetamol and diclofenac were the most widely prescribed analgesics. It is also estimated that selective COX-2 inhibitors or opioid analgesics have not been administered by dentists. The antibiotics primarily used for treatment were amoxicillin and metronidazole, and amoxicillin was used for prophylaxis. While more than 80% of dentists indicated that they provided their patients with information on the use of antibiotics, the quality of the information was limited. Patients were primarily instructed by dentists to observe the dosage and dose intervals of the prescription drugs.

The results of the present study demonstrated that dentists most commonly prescribe paracetamol and diclofenac as analgesics, amoxicillin, and metronidazole for the therapy of periodontal, endodontic, and surgical procedures. The results also showed that dentists informed their patients inadequately about analgesic and antibiotic use.

Preoperative cognitive-behavioral therapy for reducing pain catastrophizing and improving pain outcomes after total knee replacement: a randomized clinical trial.

Regional Anesthesia and Pain Medicine (NCT01772329, registration date 21 January 2013).

The study was a randomized controlled trial of patients undergoing elective total knee arthroplasty between January 2013 and March 2020. In phase 1, the change in pain catastrophizing scores (PCS) among 4-week or 8-week telehealth, 4-week in person and no-CBT sessions was compared in 80 patients with a PCS >16. In phase 2, the proportion of subjects that achieved a 3-month decrease in Western Ontario and McMaster Universities Osteoarthritis (WOMAC) pain subscale >4 following 4-week telehealth CBT with no-CBT controls were compared in 80 subjects.

In phase 1, 4-week telehealth CBT had the highest completion rate 17/20 (85%), demonstrated an adjusted median reduction in PCS of -9 (95% CI -1 to -14, p<0.01) compared with no-CBT and was non-inferior to 8-week telehealth CBT at a margin of 2 (p=0.02). In phase 2, 29 of 35 (83%) in the 4-week telehealth CBT and 26 of 33 (79%) subjects in the no-CBT demonstrated a decrease in the WOMAC pain subscale >4 at 3 months, difference 4% (95% CI -18% to 26%, p=0.48), despite a median decrease in the PCS for the 4-week CBT and no-CBT group of -6 (-10 to -2, p=0.02).

Our findings demonstrate that CBT interventions delivered prior to surgery in person or via telehealth can reduced PCS scores; however, this reduction did not lead to improved 3-month pain outcomes.

Effect of peripheral nerve blocks on postanesthesia care unit length of stay in patients undergoing ambulatory surgery: a retrospective cohort study.

Regional Anesthesia and Pain Medicine

Peripheral regional anesthesia and analgesia may increase the efficiency of ambulatory surgical centers by reducing pain and preventing nausea and vomiting, which are important modifiable causes of prolonged postanesthesia care unit (PACU) length of stay. We hypothesized that the use of peripheral nerve blocks (PNB) was associated with shorter PACU length of stay in ambulatory surgery.

In this retrospective cohort study, we analyzed data from adult ambulatory surgical cases, in which PNB was a viable anesthetic option (ie, was routinely performed for these procedures), at an academic medical center between 2008 and 2018. We assessed the association between the use of PNB and the primary endpoint of PACU length of stay. As key secondary endpoint, we compared intraoperative opioid doses. Analyses were adjusted for patient demographics, comorbidities and intraoperative factors.

A total of 57 040 cases were analyzed, of whom 13 648 (23.9%) received a PNB. The use of PNB was associated with shorter PACU length of stay (a decrease of 7.3 min, 95% CI 6.1 to 8.6, p<0.001). This association was most pronounced in surgeries of long duration (decrease of 11.2 min, 95% CI 9.0 to 13.4) and in patients undergoing leg and ankle procedures (decrease of 15.1 min, 95% CI 5.5 to 24.6). Intraoperative opioid doses were significantly lower in patients receiving a nerve block (decrease of 9.40 mg oral morphine equivalents, 95% CI 8.34 to 10.46, p<0.001).

The use of PNB significantly reduced PACU length of stay in ambulatory surgical patients, which may in part be attributed to lower intraoperative opioid requirements.

Efficacy and safety of caudal dexmedetomidine in pediatric infra-umbilical surgery: a meta-analysis and trial-sequential analysis of randomized controlled trials.

Regional Anesthesia and Pain Medicine

Dexmedetomidine is used as a local-anesthetics adjuvant in caudal block to prolong analgesia in pediatric infra-umbilical surgery.

We evaluated the analgesic efficacy and safety of the addition of caudal dexmedetomidine to local anesthetics (vs local anesthetics alone) in pediatric infra-umbilical surgery.

We searched 10 databases for randomized controlled trials (RCTs) of pediatric patients undergoing infra-umbilical surgery, comparing caudal block with and without dexmedetomidine as local anesthetic adjuvant. We performed a frequentist random-effects meta-analysis (R statistical package). We analyzed continuous outcomes as a ratio of means (ROM) and dichotomous data as relative risk (RR), along with 95% CI. We included 19 RCTs (n=1190 pediatric patients) in the meta-analysis. The primary outcome was duration of analgesia (defined as 'the time from caudal injection to the time at which the study-specific pain score was greater than a cut-off threshold').

Data from 19 included RCTs (n=1190) suggested that compared with control (mean duration 346 min), the addition of caudal dexmedetomidine significantly prolonged the duration of analgesia (ratio of means 2.14, 95% CI 1.83 to 2.49, p<0.001; 'moderate' evidence). Trial-sequential analysis showed adequate 'information size' for the primary outcome. Caudal dexmedetomidine also reduced the number of analgesic administrations ('low' evidence), total acetaminophen dose ('moderate' evidence) and the risk of emergence delirium ('moderate' evidence). There were no significant differences in adverse effects such as hypotension, bradycardia, post-operative nausea and vomiting, urinary retention and respiratory depression.

Our results suggest that the addition of dexmedetomidine to local anesthetic in caudal block significantly improves the duration of analgesia and reduces the analgesic requirements, while maintaining a similar risk-profile compared with local anesthetic alone. Further data on neurological safety are needed.

The Management of Sciatica by Acupuncture: An Expert Consensus Using the Improved Delphi Survey.

Journal of Pain

Acupuncture therapy is an effective non-drug therapy for sciatica, but it has not yet formed an effective treatment strategy and recommendations. Our objective was to establish an expert consensus on acupuncture treatment of sciatica for clinical guidance based on the improved Delphi survey.

A group of 80 clinical specialists was invited to participate in two rounds of semi-open clinical issue investigation. At the same time, the PubMed, Embase, and Cochrane Library databases were searched for systematic reviews on acupuncture treatment of sciatica, and the quality of evidence was evaluated. Then the three-round Delphi survey was undertaken with 30 experts based on the clinical issue investigation and systematic reviews.

In round 1 of the Delphi survey, the experts evaluated 17 items identified from the results of the clinical investigation and literature review. The criterion for achieving consensus was a threshold of 80% agreement. After the three-round Delphi survey, 16 items (94.12%) achieved consensus, including 5 domains: the principle of acupuncture treatment for sciatica; the "dose" of acupuncture; the clinical effects of acupuncture; the adverse effects, and others.

This Delphi survey achieved an expert consensus on key items in the management of sciatica for acupuncture, which provides the current opinions in China. We trust that these treatment recommendations may facilitate their implementation in the future.

The nonlinear increase of pain in distance-based and area-based spatial summation.


When nociceptive stimulation affects a larger body area, pain increases. This effect is called spatial summation of pain (SSp). The aim of this stu...