Factors determining the success of radiofrequency denervation in lumbar facet joint pain: a prospective study

Background and aims: Radiofrequency denervation (RF) of the lumbar facet joints has been shown to be effective in well-selected patients. However, long-term success varies between studies. We evaluated the influence of selected psychosocial and constitutional factors on the outcome of RF, expressed as the duration of pain relief. Methods: This prospective observational study included 44 patients who received RF denervations at the University Hospital of Berne. Success was defined as at least 50% pain reduction 7-21days, 6months and 1year after RF therapy. The Cox-regression analysis was performed to evaluate the influence of the following factors on the duration of success: age, sex, depression, work inability and previous surgery. Results: Complete follow-up was available for 41 patients. The success rate 7-21days after the denervation was 76%. It decreased to 32% at 6months and to 22% at 1year. The median success duration was 17weeks (95% CI 10-26). The Cox-regression analysis showed a significant shorter duration of success for patients with depression (hazard ratio [HR] 2.97, 95% CI 1.32-6.65), previous surgery (HR 2.39, 95% CI 1.10-5.21) and number of treated joints (HR 1.95 for each increase in the number of joints, 95% CI 1.14-3.33). In bivariate analyses, only depression was kept to be significant. Conclusions: Depression seems to be related with a short duration of success. Based on these findings, a comprehensive study is warranted to evaluate whether psychosocial factors have to be considered when recruiting patients for radiofrequency denervatio

Reference Values of Conditioned Pain Modulation

BACKGROUND AND AIMS: Endogenous pain modulation can be studied in humans by conditioned pain modulation (CPM): pain induced by a test stimulus is attenuated by a distantly applied noxious conditioning stimulus. The detection of impaired CPM in individual patients is of potential importance to understand the pathophysiology and predict outcomes. However, it requires the availability of reference values. // METHODS: We determined reference values of CPM in 146 pain-free subjects. Pressure and electrical stimulation were the test stimuli. For electrical stimuli, we recorded both pain threshold and threshold for the nociceptive withdrawal reflex. Cold pressor test was the conditioning stimulus. The 5th, 10th and 25th percentiles for the three tests were computed by quantile regression analyses. // RESULTS: The average thresholds increased after the conditioning stimulus for all three tests. However, a subset of subjects displayed a decrease in thresholds during the conditioning stimulus. This produced negative values for most of the computed percentiles. // CONCLUSIONS: This study determined percentile reference values of CPM that can be used to better phenotype patients for clinical and research purposes. The negative value of percentiles suggests that a slightly negative CPM effect can be observed in pain-free volunteers. // IMPLICATIONS: Pain facilitation rather than inhibition during the conditioning stimulus occurs in some pain-free volunteers and may not necessarily represent an abnormal finding

Ultrasound-controlled cryoneurolysis for peripheral mononeuropathies: a retrospective cohort study.

Aim: Cryoneurolysis is a potential therapy for peripheral mononeuropathies, but randomized studies of its effects on the duration of pain reduction are lacking. Methods: This retrospective cohort study evaluated the analgesic effects of cryoneurolysis on patients with refractory peripheral mononeuropathy. We included 24 patients who underwent ultrasound-guided cryoneurolysis between June 2018 and July 2022. The daily maximum pain level was recorded using a numerical rating scale before and 1, 3 and 6 months after the procedure. Results: At 1 month, 54.2% of patients reported pain reduction of at least 30%. This percentage was significantly lower at 3 and 6 months (13.8 and 9.1%, respectively). Conclusion: Our results suggest that repeated cryoneurolysis may be a viable treatment for refractory mononeuropathy. Further investigations are needed

Does Acupuncture Needling Induce Analgesic Effects Comparable to Diffuse Noxious Inhibitory Controls?

Diffuse noxious inhibitory control (DNIC) is described as one possible mechanism of acupuncture analgesia. This study investigated the analgesic effect of acupuncture without stimulation compared to nonpenetrating sham acupuncture (NPSA) and cold-pressor-induced DNIC. Forty-five subjects received each of the three interventions in a randomized order. The analgesic effect was measured using pressure algometry at the second toe before and after each of the interventions. Pressure pain detection threshold (PPDT) rose from 299 kPa (SD 112 kPa) to 364 kPa (SD 144), 353 kPa (SD 135), and 467 kPa (SD 168) after acupuncture, NPSA, and DNIC test, respectively. There was no statistically significant difference between acupuncture and NPSA at any time, but a significantly higher increase of PPDT in the DNIC test compared to acupuncture and NPSA. PPDT decreased after the DNIC test, whereas it remained stable after acupuncture and NPSA. Acupuncture needling at low pain stimulus intensity showed a small analgesic effect which did not significantly differ from placebo response and was significantly less than a DNIC-like effect of a painful noninvasive stimulus

Risk factors for chronic postsurgical pain in visceral surgery: a matched case-control analysis.

PURPOSE Chronic postsurgical pain (CPSP) after abdominal visceral surgery is an underestimated long-term complication with relevant impact on health-related quality of life and socioeconomic costs. Early identification of affected patients is important. We aim to identify the incidence and risk factors for CPSP in this patient population. METHODS Retrospective case-control matched analysis including all patients diagnosed with CPSP after visceral surgery in our institution between 2016 and 2019. One-to-two case-control matching was based on operation category (HPB, upper-GI, colorectal, transplantation, bariatric, hernia and others) and date of surgery. Potential risk factors for CPSP were identified using conditional multivariate logistic regression. RESULTS Among a cohort of 3730 patients, 176 (4.7%) were diagnosed with CPSP during the study period and matched to a sample of 352 control patients. Independent risk factors for CPSP were age under 55 years (OR 2.64, CI 1.51-4.61), preexisting chronic pain of any origin (OR 3.42, CI 1.75-6.67), previous abdominal surgery (OR 1.99, CI 1.11-3.57), acute postoperative pain (OR 1.29, CI 1.16-1.44), postoperative use of non-steroidal anti-inflammatory drugs (OR 3.73, OR 1.61-8.65), opioid use on discharge (OR 3.78, CI 2.10-6.80) and length of stay over 3 days (OR 2.60, CI 1.22-5.53). Preoperative Pregabalin intake was protective (OR 0.02, CI 0.002-0.21). CONCLUSION The incidence of CPSP is high and associated with specific risk factors, some of them modifiable. Special attention should be given to sufficient treatment of preexisting chronic pain and acute postoperative pain

Acceptance, Satisfaction, and Preference With Telemedicine During the COVID-19 Pandemic in 2021-2022: Survey Among Patients With Chronic Pain.

BACKGROUND The COVID-19 pandemic has forced many health care providers to make changes in their treatment, with telemedicine being expanded on a large scale. An earlier study investigated the acceptance of telephone calls but did not record satisfaction with treatment or patients' preferences. This warranted a follow-up study to investigate acceptance, satisfaction, and preferences regarding telemedicine, comprising of phone consultations, among health care recipients. OBJECTIVE The primary aim was to assess the acceptance and satisfaction of telemedicine during the subsequent months of 2021-2022, after the initial wave of the COVID-19 pandemic in Switzerland. Furthermore, we aimed to assess patients' preferences and whether these differed in patients who had already experienced telemedicine in the past, as well as correlations between acceptance and satisfaction, pain intensity, general condition, perception of telemedicine, and catastrophizing. Finally, we aimed to investigate whether more governmental restrictions were correlated with higher acceptance. METHODS An anonymous cross-sectional web-based survey was conducted between January 27, 2021, and February 4, 2022, enrolling patients undergoing outpatient pain therapy in a tertiary university clinic. We conducted a descriptive analysis of acceptance and satisfaction with telemedicine and investigated patients' preferences. Further, we conducted a descriptive and correlational analysis of the COVID-19 stringency index. Spearman correlation analysis and a chi-square test for categorical data were used with Cramer V statistic to assess effect sizes. RESULTS Our survey was completed by 60 patients. Telemedicine acceptance and satisfaction were high, with an average score of 7.6 (SD 3.3; on an 11-point Numeric Rating Scale from 0=not at all to 10=completely), and 8.8 (SD 1.8), respectively. Respondents generally preferred on-site consultations to telemedicine (n=35, 58% vs n=24, 40%). A subgroup analysis revealed that respondents who already had received phone consultation, showed a higher preference for telemedicine (n/N=21/42, 50% vs n/N=3/18, 17%; χ22 [N=60]=7.5, P=.02, Cramer V=0.354), as well as those who had been treated for more than 3 months (n/N=17/31, 55% vs n/N=7/29, 24%; χ22 [N=60]=6.5, P=.04, Cramer V=0.329). Acceptance of telemedicine showed a moderate positive correlation with satisfaction (rs{58}=0.41, P<.05), but there were no correlations between the COVID-19 stringency index and the other variables. CONCLUSIONS Despite high acceptance of and satisfaction with telemedicine, patients preferred on-site consultations. Preference for telemedicine was markedly higher in patients who had already received phone consultations or had been treated for longer than 3 months. This highlights the need to convey knowledge of eHealth services to patients and the value of building meaningful relationships with patients at the beginning of treatment. During the COVID-19 pandemic, the modality of patient care should be discussed individually

Guilt is effectively induced by a written auto-biographical essay but not reduced by experimental pain.

Introduction The aim of the present study was (1) to validate the method of guilt-induction by means of a written auto-biographical essay and (2) to test whether experimental pain is apt to alleviate the mental burden of guilt, a concept receiving support from both empirical research and clinical observation. Methods Three independent groups of healthy male participants were recruited. Group allocation was not randomized but within group pain/sham administration was counterbalanced over the two test-days. Groups were tested in the following consecutive order: Group A: guilt induction, heat-pain/sham, N = 59; Group B: guilt induction, cold-pressure-pain/sham, N = 43; Group C: emotionally neutral induction, heat-pain/sham, N = 39. Guilt was induced on both test-days in group A and B before pain/sham administration. Visual analog scale (VAS) guilt ratings immediately after pain/sham stimulation served as the primary outcome. In a control group C the identical heat-pain experiment was performed like in group A but a neutral emotional state was induced. Results A consistently strong overall effect of guilt-induction (heat-pain: p < 0.001, effect size r = 0.71; CPT-pain p < 0.001, r = 0.67) was found when compared to the control-condition (p = 0.25, r = 0.08). As expected, heat- and cold-pressure-stimuli were highly painful in all groups (p < 0.0001, r = 0.89). However, previous research supporting the hypothesis that pain is apt to reduce guilt was not replicated. Conclusion Although guilt-induction was highly effective on both test-days no impact of pain on behavioral guilt-ratings in healthy individuals could be identified. Guilt induction per se did not depend on the order of testing. The result questions previous experimental work on the impact of pain on moral emotions

Efficacy and safety of acupuncture for chronic pain caused by gonarthrosis: A study protocol of an ongoing multi-centre randomised controlled clinical trial [ISRCTN27450856]

BACKGROUND: Controlled clinical trials produced contradictory results with respect to a specific analgesic effect of acupuncture. There is a lack of large multi-centre acupuncture trials. The German Acupuncture Trial represents the largest multi-centre study of acupuncture in the treatment of chronic pain caused by gonarthrosis up to now. METHODS: 900 patients will be randomised to three treatment arms. One group receives verum acupuncture, the second sham acupuncture, and the third conservative standard therapy. The trial protocol is described with eligibility criteria, detailed information on the treatment definition, blinding, endpoints, safety evaluation, statistical methods, sample size determination, monitoring, legal aspects, and the current status of the trial. DISCUSSION: A critical discussion is given regarding the considerations about standardisation of the acupuncture treatment, the choice of the control group, and the blinding of patients and observers

[Diagnostic and therapeutic nerve blocks in pain therapy]

Abstract. Nerve blocks are not only performed in anaesthesiology to enable surgery, but also in pain therapy to diagnose and treat localised pain. For diagnostic purposes a minimal dose of local anaesthetic is applied directly to the nerve. Ultrasound has recently become the most precise and practicable tool to localise the nerve. When the effect of the block lasts as long as the predicted duration of the local anaesthetic, this confirms that the blocked nerve conducts the pain. In such cases, repetitive therapeutic blocks with local anaesthetics can be used to desensitise the nerve. A structural lesion of the nerve caused by heat (radiofrequency ablation), cold (cryoneurolysis) or even surgical nerve dissection can lead to long-term pain reduction. However, there is only weak evidence supporting these therapies and a relevant risk of pain due to deafferentation, and depending on the nerve, there could be persistent motor or sensitivity disturbances. Any intervention in humans includes placebo and nocebo effects. Those effects should be taken into consideration by asking the patient about previous experiences and their expectations for the intervention. The knowledge of placebo and nocebo effects can then be used to make the patient more comfortable during the procedure, to improve therapeutic effects and to reduce side effects. Problematic psychosocial factors and signs of centralised sensitivity should be evaluated in advance in order to consider withholding the use of interventional procedures in sensitised patients