Pain Research and Management
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Acceptance rate22%
Submission to final decision66 days
Acceptance to publication18 days
CiteScore3.100
Journal Citation Indicator0.590
Impact Factor3.037

Article of the Year 2021

Medical Cannabis for Chronic Noncancer Pain: A Systematic Review of Health Care Recommendations

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 Journal profile

Pain Research and Management publishes research focusing on laboratory and clinical findings in the field of pain research and the prevention and management of pain.

 Editor spotlight

Chief Editor Professor Valeriani specialises in clinical neurophysiology with a particular interest in pain and headaches in children and adults, and is currently a neurologist who works at the Bambi Gesu Children’s Hospital in Rome.

 Special Issues

We currently have a number of Special Issues open for submission. Special Issues highlight emerging areas of research within a field, or provide a venue for a deeper investigation into an existing research area.

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Research Article

The Pain Intensity/Quality and Pain Site Association with Muscle Activity and Muscle Activity Distribution in Patients with Chronic Low Back Pain: Using a Generalized Linear Mixed Model Analysis

Background. Pain can alter muscle activity, although it is not clear how pain intensity and site location affect muscle activity. This study aimed to reveal the complex associations among the pain site, pain intensity/quality, muscle activity, and muscle activity distribution. Methods. Electromyographic signals were recorded from above a bilateral lumbar erector spinae muscle with a four-channel electrode in 23 patients with chronic low back pain while they performed a lumbar bending and returning task. We calculated the average value of muscle activity during the extension phase (agonist activity) and the centroid of muscle activity, as well as the distance between the centroid of muscle activity and pain site. We also assessed the pain site and pain intensity/quality by the interview and questionnaire method. A generalized linear mixed model analysis was performed to determine the relationships among pain intensity/quality, pain site, and muscle activity. Results. The results showed that muscle activity during the extension phase was significantly negatively associated with neuropathic pain and “pain caused by light touch.” In addition, the distance between the centroid of muscle activity and pain site during the extension phase was significantly positively associated with intermittent pain, “throbbing pain,” “splitting pain,” “punishing-cruel,” and “pain caused by light touch.” Conclusions. Our findings suggest the existence of a motor adaptation that suppresses muscle activity near the painful area as the pain intensity increases. Furthermore, the present study indicates that the presence or absence of this motor adaptation depended on the pain quality.

Research Article

Advances and Pitfalls of Specialized Pain Care through Public and Private Health Care Providers in Catalonia and the Balearic Islands: A Physician’s Survey

Optimal diagnosis and treatment of pain require a multidisciplinary approach that demands considerable coordination and forethought. A cross-sectional physician survey based on an online questionnaire was carried out to assess the adoption of multidisciplinary working patterns, compare the public and private models, and provide an update on the resources and organization of specialized pain care in Catalonia and the Balearic Islands. Active pain practitioners identified through the Catalan Health Service and Pain Society databases were sent an invitation in December 2020. Of the 321 physicians contacted, 91 (28.3%) answered and 71 provided complete responses (commonly anesthesiologists, representing 92 different sites; some worked at public and private sites). Up to 78.7% reported working in pain management teams, but only 53.5% were regularly involved in teaching or research activities. Thus, the proportion of multidisciplinary sites lies somewhere in-between. Median wait times were significantly shorter and within the recommended standards in private practices (e.g., 15 vs. 90 days in public practices for noncancer patients). In turn, private practices were slightly less staffed and equipped, albeit the differences did not reach statistical significance. Respondents made a median of 530 regular and 30 emergency visits per year, of which 190 involved interventional procedures. They offered a wide range of pharmacological and interventional therapies, although psychotherapy and the most sophisticated procedures were only available in ≤50% of sites. Pain clinicians and facilities are reasonably available in Catalonia, but barely more than half are truly multidisciplinary. Public and private practices differ in some aspects; the latter seems to be more accessible, but it is restricted to patients who can afford it. Compared to previous reports, this update shows both advances and outstanding issues. Multidisciplinary care could be expanded by incorporating more psychologists and some interventional procedures. The public practices should reduce wait times.

Research Article

Relative Prevalence and Associated Factors of Complex Regional Pain Syndrome Type I in Patients with Radial Head Fractures Treated with Open Reduction and Internal Fixation: A Cross-Sectional Study

Objective. This cross-sectional study aimed to examine the incidence and associated factors of complex regional pain syndrome type I (CRPS I) in patients who underwent open reduction and internal fixation (ORIF) for radial head fractures. Methods. The study enrolled 601 radial head fracture patients treated with ORIF, 523 of which completed the 1-year follow-up. The incidence of CRPS I in those patients was assessed using the Budapest criteria. Patients were then divided into 2 groups: patients with CRPS I (n = 28) and patients without CRPS I (n = 495). The patients’ demographic and clinical data before the operation were prospectively collected by our team. Independent t-tests and χ2 tests were used as univariate analyses to compare the demographic and clinical data between the two groups. Meanwhile, multivariate regression analysis was conducted to identify the associated risk factors for CRPS I. Results. The incidence of CRPS I in patients with radial head fractures treated with ORIF was 5.5% during the first year following surgery. Significant differences were observed in age, gender, type of trauma, modified Mason Classification, and depressive personality disorders. The logistic regression analysis revealed that the female gender, modified Mason type III fractures, and depressive patients were significantly more likely to develop CRPS I (, 0.023, and 0.025, respectively). Conclusions. The incidence of CRPS I among radial head fracture patients undergoing ORIF was 5.5%. In addition, early detection of CRPS I and providing adequate intervention will likely result in greater benefits for those patients.

Research Article

Antinociceptive Effects and Interaction Mechanisms of Intrathecal Pentazocine and Neostigmine in Two Different Pain Models in Rats

Background. Pentazocine produces a wide variety of actions in the treatment of perioperative analgesia. Neostigmine is a cholinesterase inhibitor used to antagonize the residual effects of muscle relaxants and also produces an analgesic effect. Objectives. To investigate the analgesic effects of intrathecally injected pentazocine and neostigmine and their interaction. Methods. Sprague–Dawley rats were used to test the analgesic effect of pentazocine and neostigmine using the paw formalin pain model and the incision mechanical allodynia model. Pentazocine (3, 10, 30, and 100 μg), neostigmine (0.3, 1, 3, and 10 μg) or a pentazocine-neostigmine mixture were separately injected to evaluate their antinociceptive effects alone on the treatment groups. The corresponding control group received an intrathecal injection containing the same volume of saline. The formalin pain test, or the plantar incision pain behavior test were performed 30 minutes later. Isobolographic analysis was used to evaluate the interaction between pentazocine and neostigmine. Intrathecally administered selective mu-opioid receptor antagonist CTAP, selective kappa-opioid receptor antagonist nor-Binaltorphimine (nor-BNI), nonselective opioid receptor antagonist naloxone, and muscarinic acetylcholine receptor antagonist atropine were also used to test the possible interaction mechanism. These antagonists were used 30 minutes before the pentazocine and neostigmine mixtures which were intrathecally injected. Results. Intrathecally administered pentazocine (3, 10, 30, and 100 μg) and neostigmine (0.3, 1, 3, and 10 μg) alone had a marked dose-related impact on suppressing the biphasic responses in the formalin test. Pentazocine (3, 10, 30, and 100 μg) and neostigmine (0.3, 1, 3, and 10 μg) alone attenuated the mechanical allodynia in a plantar incision model in a dose-dependent manner. Isobolographic analysis revealed that the mixture of intrathecal pentazocine and neostigmine synergistically decreased both phase I and II activity in the formalin test and mechanical allodynia in the plantar incision model. Pretreatment of intrathecally administered nor-BNI, naloxone, atropine, but not CTAP, antagonized the analgesic effect of the pentazocine-neostigmine mixture. Conclusions. All of these results suggest that the combined application of pentazocine and neostigmine is an effective way to relieve pain from formalin and acute incision mechanical allodynia. The synergistic effect between pentazocine and neostigmine is mostly attributed to the kappa-opioid receptor and the cholinergic receptor in the spinal cord.

Research Article

Comparison between Dynamic Stabilization and Instrumented Fusion in the Treatment of Spinal Stenosis with Degenerative Lumbar Scoliosis

Objective. Posterior instrumented fusion is the most widely accepted surgical treatment for spinal stenosis with degenerative lumbar scoliosis (DLS). However, long fusion can affect daily activities due to lumbar stiffness. Dynamic stabilization has been introduced to overcome the drawbacks of fusion in recent years. This study aimed to compare the outcomes of dynamic stabilization (Dynesys system) with posterior instrumented fusion for the management of spinal stenosis with DLS. Methods. This study retrospectively reviewed 65 consecutive patients with spinal stenosis and DLS who were undergoing surgical treatment between January 2013 and December 2017. Among them, 34 patients (Dynesys group) had fenestration decompression and Dynesys stabilization, whereas 31 patients (fusion group) underwent posterior instrumented fusion. Clinical outcomes, radiographic data, and postoperative complications were compared between the two groups. Results. The mean number of fixed segments was 3.6 ± 0.9 in the Dynesys group and 4.2 ± 1.0 in the fusion group. Lower average values of operating time and blood loss were observed in the Dynesys group (). At an average follow-up of 42 months, there were no significant differences in the visual analog scale for the leg pain (VASleg), the scoliosis Cobb’s angle, and the lumbar lordosis between the two groups (). The visual analog scale for back pain (VASback), oswestry disability index (ODI), and lumbar stiffness disability index (LSDI) scores of the Dynesys group were lower compared with the fusion group (). The range of motion (ROM) of implanted segments was significantly higher in the Dynesys group as compared to the fusion group (). The overall complications were less in the Dynesys group, but the difference was not statistically significant (). Conclusion. Both dynamic stabilization and instrumented fusion can improve the clinical outcomes of patients with spinal stenosis and mild DLS. Compared to instrumented fusion, dynamic stabilization has the advantages of less invasion and motion preservation.

Research Article

Differences and Correlations of Anxiety, Sleep Quality, and Pressure-Pain Threshold between Patients with Chronic Low Back Pain and Asymptomatic People

Background. Chronic low back pain (CLBP) is a clinically common and expensive disease. Patients frequently take sick leaves because of pain and dysfunction, and their unpleasant life and work experiences cause psychological depression and anxiety and affect their quality of life. Sleep disturbance is a common problem among patients with low back pain (LBP) with more than 50% complaining about poor sleep quality. This study aimed to explore the correlations between anxiety, sleep quality, and pressure-pain threshold (PPT) and their differences between patients with CLBP and asymptomatic people. Methods. Forty patients with CLBP and 40 asymptomatic people were recruited. Relevant data, including State-Trait Anxiety Inventory, Pittsburgh Sleep Quality Index, and PPT, were individually and independently collected by blinded physiotherapists with a practicing certificate and then statistically analyzed. An independent sample t-test was used to determine the intergroup differences between patients with CLBP and asymptomatic populations. Pearson correlation coefficient was employed for correlation analysis. Results. The CLBP group had significantly higher anxiety scores (41.64 ± 9.88 vs. 36.69 ± 8.31; t = −2.496, ) than the asymptomatic group. A significant difference was found in the total score of the Pittsburgh Sleep Quality Index (6.41 ± 2.43 vs. 5.09 ± 2.18; t = −2.628, ) but not in the trait anxiety (44.00 ± 7.83 vs. 42.67 ± 9.51; t = −0.695, ) of the two groups. State−Trait Anxiety Inventory showed a low to moderate negative correlation with PPT. No remarkable correlation was observed between Pittsburgh Sleep Quality Index and PPT. Conclusions. Patients with CLBP showed considerably worse state anxiety and sleep quality than asymptomatic people; however, no substantial difference in PPT was found between the two groups. The results suggest that in clinical practice, the focus should include pain and related social and psychological factors. CLBP treatment could be considered from multiple perspectives and disciplines.This trial is registered with Chinese Clinical Trial Registry (Trial registration: ChiCTR-TRC-13003701).

Pain Research and Management
 Journal metrics
See full report
Acceptance rate22%
Submission to final decision66 days
Acceptance to publication18 days
CiteScore3.100
Journal Citation Indicator0.590
Impact Factor3.037
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Article of the Year Award: Outstanding research contributions of 2021, as selected by our Chief Editors. Read the winning articles.