Development Of Chronic Pain Syndromes Research Articles

Prevention of chronic postoperative pain syndrome after Lichtenstein hernioplasty

THE OBJECTIVE was to analyze the development of chronic pain syndrome after performing standardized Lichtenstein hernioplasty.METHODS AND MATERIALS. The prospective single-center study was conducted with 40 patients with inguinal hernias (20 patients in the study group and 20 patients in the control group) who underwent Lichtenstein hernioplasty with adherence to standardization criteria and without. The comparative analysis of the early and long-term postoperative periods was performed.RESULTS. When comparing the early and long-term postoperative periods in patients after standardized Lichtenstein hernioplasty, the following data were obtained: pain syndrome according to the Visual Analogue Scale (VAS) was less pronounced after applying standardization criteria (p < 0.001), and statistically significantly lower number of complications (seroma, paresthesia) developed (p=0.045, p=0.019). In the group of patients who underwent standardized Lichtenstein hernioplasty, chronic pain syndrome was not observed in the long-term postoperative period (p < 0.001).CONCLUSIONS. Prevention of chronic postoperative pain syndrome after hernioplasty using the Lichtenstein method is the significant issue. This article emphasizes the importance of considering various factors and implementing preventive strategies to minimize the risk of this complication and ensure optimal surgical outcomes.

An integrated approach to the treatment of acute pain syndrome in military personnel with phantom pain at the hospital stage

Resume. Taking into account the war of the Russian Federation against Ukraine, the problem of adequate pain relief for patients with phantom pain has become relevant, especially at the hospital stage. Effective pain relief for such patients improves their quality of life, so it is of significant socio-economic importance. Objective. To investigate the results of treatment of phantom pain in military personnel at the hospital stage and to develop the basis for a protocol for the treatment of acute phantom pain syndrome in such patients. Materials and methods. The number of military patients who were treated at the Feofaniya Clinical Hospital and participated in the study is not disclosed, as any military losses are a military secret. The number of subjects with phantom pain was 35.7% of the total number of wounded military patients. The intensity of pain was assessed using the visual analogue scale (VAS), the neuropathic pain scale (thes-lanss pain score) and the phantom pain scale Limb deficiency and phantom limb questionnaire. Depression and anxiety in patients were assessed using the Hospital Anxiety and Depression Scale (HADS), PHQ9. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Patients were treated according to the local protocol of Feofania Clinical Hospital. Results. The data of pain intensity scales in military patients with phantom pain before and after treatment at the stage of clinical hospitals showed a decrease in pain intensity in 94 % of patients, improvement in sleep in 92 % of patients and reduction in anxiety and depression in 81 % of patients. Conclusions. Based on these scales, it can be concluded that it is the combined approach to the treatment of phantom pain in the military at the stage of clinical hospitals that can improve the quality of life of military personnel, and in some cases relieve such patients from acute pain, thereby preventing the development of chronic pain syndrome. The developed protocol for the treatment of phantom pain can be recommended for use in other medical institutions in Ukraine. Conclusions. cases relieve such patients from acute pain, thereby preventing the development of chronic pain syndrome. Tcan be recommended for use in other medical institutions in Ukraine

Peripheral nerve injury: molecular pathophysiology and prospects for restorative treatment by means of cell transplantation: a literature review

Peripheral nerve injury (PNI) is a fairly common pathology—PNI accounts for 1-5% of all peacetime injuries and 12% of all combat injuries. This injury leads to disability, the development of chronic pain syndromes and a significant deterioration in the quality of life of the victims. Unfortunately, at present, in the case of the most frequent type of combat trauma — damage to the limbs — PNI treatment is mostly done last, "on the residual principle." Modern means of surgical and conservative treatment of PNI do not provide complete restoration of lost functions, therefore, restorative treatment of PNI is an urgent biomedical problem. The article reviews the currently known molecular mechanisms of various stages of PNI, as well as the plasticity of the central parts of the nervous system on the background of this injury. The main reasons for the limitation of autogenous recovery of functions after a sustained PNI are described — the absence of a relevant spatial organization of regrowth of axons in the area of PNI; post-traumatic death of neurons of spinal nodes and central parts of the nervous system; failure of plastic reconstruction of brain and spinal cord neural networks; irreversibility of atrophy of denervated muscles. Based on this, it was established that the means of restorative treatment of PNI should touch not only the epicenter of PNI, but also the central parts of the nervous system and denervated muscles. Mesenchymal stem cells (MSCs) are well-known means of a positive influence on the the restorative process in the focus of PNI, as well as a source of supportive influence/ strengthening effect and an amplifier of the plasticity of brain neural networks, which makes these cells a promising element of bioengineering treatment of PNI. The effect of MSCs on the central parts of the nervous system in case of PNI remains the least studied. Data from the literature indicate that such an effect can provide support for secondarily affected neurons and stimulate the plastic reorganization of brain networks, i.e., in general, significantly improve the results of restorative treatment of PNI.

Efficacy of Magnesium vs Dexamethasone as an Adjuvant to Ropivacaine in Ultrasound Guided Femoral and Sciatic Nerve Block for Postoperative Analgesia: A Prospective, Double Blinded Randomized Controlled Study

Background: In patients undergoing lower limb orthopaedic surgery, unrelieved post-operative pain not only results in discomfort to the patients but also predispose to the development of chronic pain syndromes. The dawn of ultrasonographic-guided techniques has led to increased interest in femoro-sciatic nerve block (FSNB) for lower limb orthopaedic surgeries. Efficacy of various adjuvants have been studied to prolong the block and analgesia. In recent years, there is growing interest in magnesium sulphate (MgSO4) and dexamethasone as adjuvants to local anaesthetics in nerve blocks. Duration of post-operative analgesia was the primary outcome of our study, whereas the rescue analgesics requirement, VAS scores and haemodynamic parameters and time required for toe movement were the secondary outcomes.
 Methods: Sixty-patients scheduled to undergo below knee orthopaedic surgeries under subarachnoid block were divided into 2 groups: Group RM(n=30) patients received 38 mL of 0.375% Ropivacaine with MgSO4 150 mg in 2 mL NS and Group RD(n=30) patients received 38 mL of 0.375% Ropivacaine with Dexamethasone 8 mg(2mL) to make total drug volume of 40 mL. In all patients, 20 mL of LA solution was injected around femoral nerve and 20 mL around sciatic nerve. The primary outcome was duration of post-op analgesia and secondary being requirement of rescue analgesia and time for toe movement. Mean variables were analysed and compared with unpaired t-test. Proportions were compared with Chi-square test and Fischer-exact test.
 Results: Duration of analgesia was prolonged with Dexamethasone (18.8 ± 7.8) as compared to MgSO4 (8.8 ± 4.2). In regards to early ambulation, MgSO4(6.78 ± 2.25) was a cut above Dexamethasone (16.43 ± 4.56).
 Conclusion: Both MgSO4 or Dexamethasone added to Ropivacaine prolonged the duration of analgesia, decreased requirement of rescue analgesia. Dexamethasone delays requirement of rescue analgesics with better pain scores as compared to MgSO4.

Problems of diagnosis and treatment of chronic pain syndrome in patients with variants of the structure of peripheral nerves. A series of clinical cases

AIM: To assess the presence of variants of the structure of peripheral nerves as possible risk factors for chronic pain syndrome on the example of a series of clinical cases.
 MATERIALS AND METHODS: The systematization and analysis of data from domestic and foreign literature on pathophysiology, clinic, diagnosis and treatment of complex regional pain syndrome has been carried out. Research method: system analysis, presentation of a series of clinical cases.
 RESULTS: A series of clinical cases is presented. The main risk factors for chronic pain syndrome are presented. The conditions and diseases that need to be differentially diagnosed if complex regional pain syndrome is suspected are systematized: tunnel syndromes (carpal tunnel syndrome), diabetic polyneuropathy, HIV polyneuropathy, postherpetic neuralgia, neurogenic claudication/lumbar stenosis, central post-stroke pain, upper thoracic syndrome apertures.
 CONCLUSION: Today, practitioners and neurophysiologists are not sufficiently aware of the existence of interneural anastomoses and features, typical electroneuromyographic signs, as a result of which in most cases the obtained electroneuromyographic data are interpreted erroneously. Variants of the structure of nerves can give an incorrect clinical picture of the condition of peripheral nerves and lead to untimely diagnosis and treatment of chronic pain syndrome, complex regional pain syndrome. Improvements in diagnostic methods, as well as widely introduced high-tech examination methods, in particular electroneuromyography, magnetic resonance imaging and ultrasound, are helping to increase the frequency of detection of abnormalities in the structure of peripheral nerves. In the presented clinical cases, patients had structural variants that gave an incorrect clinical picture of the condition of the peripheral nerves and led to untimely diagnosis and treatment — the development of chronic pain syndrome.

A double-blinded, placebo-controlled, randomized study to evaluate the efficacy of perioperative dextromethorphan compared to placebo for the treatment of postoperative pain: a study protocol

BackgroundPain management is a critical component of comprehensive postsurgical care, as it influences patient safety and outcomes, and inadequate control has been associated with the development of chronic pain syndromes. Despite recent improvements, the management of postoperative pain following total knee arthroplasty (TKA) remains a challenge. The use of opioid-sparing, multimodal analgesic regimens has broad support, but there is a paucity of high-quality evidence regarding optimal postoperative protocols and novel approaches are needed. Dextromethorphan stands out among both well-studied and emerging pharmacological adjuncts for postoperative pain due its robust safety profile and unique pharmacology. The purpose of this study is to evaluate the efficacy of multi-dose dextromethorphan for postoperative pain control following TKA.MethodsThis is a single-center, multi-dose, randomized, double-blinded, placebo-controlled trial. A total of 160 participants will be randomized 1:1 to receive either 60 mg oral dextromethorphan hydrobromide preoperatively, as well as 30 mg 8 h and 16 h postoperatively, or matching placebo. Outcome data will be obtained at baseline, during the first 48 h, and the first two follow-up visits. The primary outcome measure will be total opioid consumption at 24 h postoperatively. Secondary outcomes related to pain, function, and quality of life will be evaluated using standard pain scales, the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR) questionnaire, the Patient-Reported Outcomes Measurement Information System (PROMIS-29) questionnaire, and clinical anchors.DiscussionThis study has a number of strengths including adequate power, a randomized controlled design, and an evidence-based dosing schedule. As such, it will provide the most robust evidence to date on dextromethorphan utilization for postoperative pain control following TKA. Limitations include not obtaining serum samples for pharmacokinetic analysis and the single-center study design.Trial registrationThis trial has been registered on the National Institute of Health’s ClinicalTrials.gov (NCT number: NCT05278494). Registered on March 14, 2022.

The dark side of being a pathologist: Unravelling the health hazards.

Pathologists are indispensable to the practice of medicine. Awareness of health hazards among pathologists is a crucial aspect of today's time. Numerous occupational health risks are prevalent which are mostly ignored; for example, the association of microscope use for prolonged durations leading to the development of chronic pain syndromes has been acknowledged for nearly three decades, yet most pathologists are unaware about this hazard until after it transforms into a chronic health issue. The purpose of this study is to learn its prevalence in working pathologists, make them aware of the risks, discuss and encourage them to proactively integrate strategies which are preventive in nature into their daily routine lives. The aim of the study was to analyze the level of risk, knowledge, awareness and biosafety measures taken by the pathologists in their routine daily work life. The study was conducted in a developing country, Northern India, using a standard online 50-item questionnaire enquiring about routine practices. 450 participants were enrolled consisting of 360 pathologists and 90 residents of pathology. Among the 450 enrolled study participants, 84.8% complained of musculoskeletal disorders (MSD), with the neck being the commonest location of pain. Furthermore, 74.8% reported visual refractive errors, among which myopia took the highest place. Work injuries were reported in 60% of participants. Intolerance reactions to chemicals especially formaldehyde was observed in 63.1%. Depression and burnout were reported in 42%. Although knowledge seems to be near adequate, there is a lack of implementation and a noticeable risk of health hazards namely musculoskeletal problems, injuries, visual disorders, and ergonomic issues in routine daily activities of pathologists.

Пролонгована паравертебральна аналгезія для знеболювання у хворих після торакотомії

Актуальність. Торакотомія відноситься до одного з найбільш травматичних втручань в хірургії, що супроводжується вираженим гострим болем після операції та розвитком хронічного больового синдрому у віддаленому післяопераційному періоді. Мета дослідження. Порівняти ефективність та безпечність різних методів знеболювання хворих після торакотомії. Матеріали та методи. Після торакотомії 85 хворих було розподілено на три дослідні групи. Знеболювання проводили за допомогою пролонгованої паравертебральної аналгезії (ПВА) (19 хворих) і пролонгованої епідуральної аналгезії (ЕДА) (36 хворих) 0,2% розчином ропівакаїну зі швидкістю 6 мл/год (у паравертебральний або епідуральний простір). У контрольній групі (30 хворих) знеболювання проводилось внутрішньовенною, контрольованою пацієнтом аналгезією розчином морфіну. Як ад’ювантний анальгетик у всіх трьох дослідних групах використовували нестероїдний протизапальний препарат кеторолаку трометамін внутрішньом’язово. У ранньому післяопераційному періоді оцінювали рівень болю в стані спокою та під час фізичного навантаження дихальної мускулатури (виконання спірометрії), показники функції зовнішнього дихання (ФЗД), а також частоту та тип ускладнень застосованих методів знеболювання. У віддаленому післяопераційному періоді оцінювали частоту виникнення хронічного болю. Результати. У групах з пролонгованою ПВА і ЕДА інтенсивність больового синдрому протягом трьох діб післяопераційного періоду за візуальною аналоговою шкалою (ВАШ) у стані спокою була меншою порівняно з контрольною групою. У групі ПВА рівень болю був від 29,1 бала через чотири години після операції до 18,7 бала в кінці третьої доби; у групі ЕДА — від 24,2 до 20,3 бала відповідно; у контрольній групі — від 48,8 до 38,0 бала відповідно. Під час дослідження ФЗД інтенсивність болю в групах ПВА і ЕДА також була нижчою порівняно з контрольною групою і становила 33,8 бала в групі ПВА, 38,7 бала — в групі ЕДА, 61,2 — у контрольній групі. Частоту виникнення хронічного больового синдрому оцінювали через 6 місяців після операції. Було відібрано по 15 хворих із кожної групи. У контрольній групі хронічний больовий синдром розвинувся у 8 хворих (53 %), у групі ЕДА — у 5 хворих (33,3 %), у групі ПВА — у 3 хворих (20 %). Найменша кількість ускладнень і технічних невдач спостерігалась у групі ПВА. Висновки. У групі з пролонгованою ПВА порівняно з пролонгованою ЕДА рівень болю за ВАШ був нижчим, частота випадків хронічного болю меншою, а кількість побічних ефектів мінімальною. Пролонгована паравертебральна блокада у хворих після торакотомії дає змогу ефективно контролювати гострий післяопераційний біль та зменшує розвиток хронічного больового синдрому.

Dopamine-neurotransmission and nociception in zebrafish: An anti-nociceptive role of dopamine receptor drd2a

Dopamine (DA) is an important modulator in nociception and analgesia. Spinal DA receptors are involved in descending modulation of the nociceptive transmission. Genetic variations within DA neurotransmission have been associated with altered pain sensitivity and development of chronic pain syndromes. The variant rs6277 in dopamine receptor 2 a (drd2a) has been associated with a decreased D2 receptor availability and increased nociception. The aim of this study is to further characterize the role of DA neurotransmission in nociception and the anti-nociceptive function of drd2a. The phenotype caused by rs6277 was modelled in zebrafish larvae using morpholino's and the effect on nociception was tested using a validated behavioural assay. The anti-nociceptive role of drd2a was tested using pharmacological intervention of D2 agonist Quinpirole. The experiments demonstrate that a decrease in drd2a expression results in a pro-nociceptive behavioural phenotype (P = 0.016) after a heat stimulus. Furthermore, agonism of drd2a with agonist Quinpirole (0.2 μM) results in dose-dependent anti-nociception (P = 0.035) after a heat stimulus. From these results it is concluded that the dopamine receptor drd2a is involved in anti-nociceptive behaviour in zebrafish. The model allows further screening and testing of genetic variation and treatment involved in nociception.

Effect of anxiety disorder and depression in postoperative pain

Introduction: The aim of this study is to briefly present and to evaluate the elements that show whether the psychological background of the patients, particularly anxiety disorder and depression, are involved in the mechanism of postoperative pain, to examine the mechanisms involved in the intensity of pain and to report the methods used to evaluate and treat pain after a surgical procedure in this vulnerable group of patients. Methods: We performed a literature review of relevant articles, mainly published during the last decade, in MEDLINE database and 15 articles were used. Results: Clinical studies lead us to the conclusion that the intensity of postoperative pain is directly related to the levels of anxiety and to the presence of depression. Undertreatment and delay in managing acute postoperative pain can lead to the development of chronic pain syndromes with consequent negative effects in life and in the level of functionality of patients. A number of neurobiological processes could further explain the effect of psychological factors on pain, especially after surgical procedures. Conclusion: The psychological aspect of acute postoperative pain can be evaluated during the preoperative period, in order to relieve the intense negative psychological experience of pain after surgery, by using pharmacological therapy as well as psychotherapy. It is of great importance to perform psychological monitoring of patients after surgery, since it has been observed that the psychological phenotype of patients is altered during the first postoperative days. Catastrophology is involved in elevated intensity of postoperative pain, therefore the appropriate use of relevant clinical interventions would be beneficial. Psychosocial and psychophysiological evaluation is of great importance in order to detect patients at high risk and to offer individualized management and targeted preventive preoperative planning. The heterogeneity of patient population going to surgery increases the need for further studies which would evaluate appropriate therapeutic regimens, individualized for each special group of patients.

Chronic pelvic pain in women, stages and methods of diagnosis (Literature review)

Usually, women suffering from chronic pelvic pain experience it for some time and do not seek treatment until the pain becomes so severe that it adversely affects a woman’s normal daily functioning, preventing her from maintaining a normal lifestyle and leading to development of chronic pain syndrome. Chronic pelvic pain syndrome is often accompanied by behavioral disorders, cognitive, psychoemotional and sexual disorders, as well as symptoms of dysfunction of the lower urinary and digestive systems, pelvic organs, gynecological dysfunction, which are the result of neurobiological, physiological and sometimes anatomical changes in the body and central nervous system.Often a gynecologist automatically focuses exclusively on gynecological organs, assuming that they are the cause of the problem, but most often the cause of chronic pelvic pain is a group of factors. Disorders of the gastrointestinal, urological, and musculoskeletal systems are at least as common as disorders of the reproductive system in women with chronic pelvic pain. Therefore, diagnostic measures should be aimed at identifying all the causes which requires doctors to take a multidisciplinary approach to the diagnosis and management of chronic pelvic pain. The causes of the problem in most cases can be identified by a thorough history taking and physical examination, which should be more detailed than usual. As a diagnostic tool, it can minimize the need for expensive laboratory testing and imaging or risky surgery. The use of specialized assessment forms and questionnaires for chronic pelvic pain can be important and useful to ensure coverage of all critical points.When planning a diagnostic plan for women with chronic pelvic pain, it is important to consider the key role of the nervous system in the perception of pain. Experiencing pain for a long period of time can change how the brain perceives and processes pain signals, leading to an amplification of pain and cross-organ sensitization.Complicated differential diagnosis often causes the absence of a definitive diagnosis in most patients who complain of chronic pelvic pain. Therefore, during the first visit of the patient, it is sometimes impossible to immediately determine the cause of pain. Because the causes of many disorders associated with chronic pelvic pain have not been identified, most clinicians treat them empirically. Therefore, in the presence of several etio-pathogenetic factors, treatment of only some of them will lead to incomplete relief.The definition of «chronic pelvic pain» can hide many diseases, the detection of which requires the involvement of a multidisciplinary team of gynecologists, urologists, gastroenterologists, nephrologists, vascular surgeons, orthopedists, psychiatrists, psychologists and doctors of other specialties. However, it is mostly gynecologists who are the first to come into contact with this pathology because, in most cases, women who suffer from chronic pelvic pain first turn to them for help. That is why they should be the main members of the multidisciplinary team and take responsibility for its creation. Unfortunately, physicians often lack an interdisciplinary approach to the management of chronic pelvic pain, which complicates comprehensive assessment, diagnosis, and treatment and leads to frustration among women who go from one specialist to another without an adequate solution to their problem.

Genetic risk factors of syndrome pain dysfunction of the temporomandibular joint

Currently, the syndrome of pain dysfunction of the temporomandibular joint is not considered exclusively a local disorder, but rather is considered as a clinical outcome of the combined effect of many factors (local and systemic), which act simultaneously and determine, ultimately, the manifestation of the disease. In the framework of the biopsychosocial concept, a hypothesis has been formulated about the importance of the polymorphism of the COMT and ADRB-2 genes for the development of SDJ TMJs, which make these individuals “vulnerable” to the development of chronic pain syndromes. It was found that a decrease in COMT activity leads to an increase in the level of catecholamimes, in particular, such as adrenaline, which contribute to the formation of persistent pain states by stimulating β2-adrenergic receptors in the peripheral and central nervous system.

Evidence of impaired pain modulation in adolescents with idiopathic scoliosis and chronic back pain

BACKGROUND CONTEXTAlthough 40% of adolescent idiopathic scoliosis (AIS) patients present with chronic back pain, the pathophysiology and underlying pain mechanisms remain poorly understood. We hypothesized that development of chronic pain syndrome in AIS is associated with alterations in pain modulatory mechanisms. PURPOSETo identify the presence of sensitization in nociceptive pathways and to assess the efficacy of the diffuse noxious inhibitory control in patients with AIS presenting with chronic back pain. STUDY DESIGNCross-sectional study. PATIENT SAMPLENinety-four patients diagnosed with AIS and chronic back pain. OUTCOME MEASURESQuantitative sensory testing (QST) assessed pain modulation and self-reported questionnaires were used to assess pain burden and health-related quality of life. METHODSPatients underwent a detailed pain assessment using a standard and validated quantitative sensory testing (QST) protocol. The measurements included mechanical detection thresholds (MDT), pain pressure threshold (PPT), heat pain threshold (HPT), heat tolerance threshold (HTT), and a conditioned pain modulation (CPM) paradigm. Altogether, these tests measured changes in regulation of the neurophysiology underlying the nociceptive processes based on the patient's pain perception. Funding was provided by The Louise and Alan Edwards Foundation and The Shriners Hospitals for Children. RESULTSEfficient pain inhibitory response was observed in 51.1% of patients, while 21.3% and 27.7% had sub-optimal and inefficient CPM, respectively. Temporal summation of pain was observed in 11.7% of patients. Significant correlations were observed between deformity severity and pain pressure thresholds (p=.023) and CPM (p=.017), neuropathic pain scores and pain pressure thresholds (p=.015) and temporal summation of pain (p=.047), and heat temperature threshold and pain intensity (p=.048). CONCLUSIONSChronic back pain has an impact in the quality of life of adolescents with idiopathic scoliosis. We demonstrated a high prevalence of impaired pain modulation in this group. The association between deformity severity and somatosensory dysfunction may suggest that spinal deformity can be a trigger for abnormal neuroplastic changes in this population contributing to chronic pain syndrome.

Genetic Polymorphism of Cytokines as a Predictor of Phenotypic Development of Chronic Pain Syndrome in Cancer Patients

Genetic Polymorphism of Cytokines as a Predictor of Phenotypic Development of Chronic Pain Syndrome in Cancer Patients

P311 The effectiveness of the complex repetitive peripheral magnetic stimulation (rPMS) in treatment of lumbosacral radiculopathy

Objective In the modern society the low back pain (LBP) is the most common cause of temporary disability with estimated life time prevalence as high as 23–80% (Pedisic et al., 2013). LBP with radiculopathy is considered as the most unfavorable prognostic risk factor for the development of chronic pain syndrome and low quality of life (Konstantinou et al., 2013). The aim of this study is to evaluate the short-term efficacy of repetitive peripheral magnetic stimulation (rPMS) in the treatment of lumbosacral radiculopathy. Methods Patients with pain and sensory symptoms resulting from lumbosacral radiculopathy has been enrolled into the study. All patients received conventional drug therapy. A magnetic stimulator MagProO100 (Magventure, Denmark) with CC-coil Cool-125 was used. We assessed the individual motor evoked potential (MEP) thresholds before the rPMS. Treatment consisted of 10 or 15 sessions, each lasting 20 min, with frequency 1 Hz and intensity of stimulus above the MEP threshold. The duration of rPMS treatment depended on the severity of pain syndrome. Patients were evaluated before, immediately after finalizing the rPMS treatment and one month later. Results Fifteen patients (mean age 41.8 ± 14.5 years, 5 men, 10 women) has been included into the study. All participants reported the improvement in the functional status (confirmed by Oswestry questionnaire): 34.4 ± 11.3% before and 17.6 ± 8% at the end of the rPMS course (primary endpoint). The VAS pain level has been decreased by 50% in comparison to the baseline. Reduction of pain and disability remained unchanged for one month after completion of the combined treatment. Conclusion The preliminary results of our study demonstrate that the combination of traditional drug therapy and the rPMS can have positive short-term effects on functional status and pain in patients with lumbosacral radiculopathy. Further investigations are warranted for development of the individualized rPMS treatment algorithm.

Applying a Lifespan Developmental Perspective to Chronic Pain: Pediatrics to Geriatrics.

An ideal taxonomy of chronic pain would be applicable to people of all ages. Developmental sciences focus on lifespan developmental approaches, and view the trajectory of processes in the life course from birth to death. In this article we provide a review of lifespan developmental models, describe normal developmental processes that affect pain processing, and identify deviations from those processes that lead to stable individual differences of clinical interest, specifically the development of chronic pain syndromes. The goals of this review were 1) to unify what are currently separate purviews of "pediatric pain," "adult pain," and "geriatric pain," and 2) to generate models so that specific elements of the chronic pain taxonomy might include important developmental considerations. A lifespan developmental model is applied to the forthcoming Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks-American Pain Society Pain Taxonomy to ascertain the degree to which general "adult" descriptions apply to pediatric and geriatric populations, or if age- or development-related considerations need to be invoked.

Sensitization of nociceptive spinal neurons contributes to pain in a transgenic model of sickle cell disease.

Chronic pain is a major characteristic feature of sickle cell disease (SCD). The refractory nature of pain and the development of chronic pain syndromes in many patients with SCD suggest that central neural mechanisms contribute to pain in this disease. We used HbSS-BERK sickle mice, which show chronic features of pain similar to those observed in SCD, and determined whether sensitization of nociceptive neurons in the spinal cord contributes to pain and hyperalgesia in SCD. Electrophysiological recordings of action potential activity were obtained from single identified dorsal horn neurons of the spinal cord in anesthetized mice. Compared with control HbAA-BERK mice, nociceptive dorsal horn neurons in sickle mice exhibited enhanced excitability as evidenced by enlarged receptive fields, increased rate of spontaneous activity, lower mechanical thresholds, enhanced responses to mechanical stimuli, and prolonged afterdischarges following mechanical stimulation. These changes were accompanied by increased phosphorylation of mitogen-activated protein kinases (MAPKs) in the spinal cord that are known to contribute to neuronal hyperexcitability, including c-Jun N-terminal kinase (JNK), p44/p42 extracellular signaling-regulated kinase (ERK), and p38. These findings demonstrate that central sensitization contributes to pain in SCD.

Sensory incongruence leading to hand disownership modulates somatosensory cortical processing

The sense of body ownership is based on integration of multimodal sensory information, including tactile sensation, proprioception, and vision. Distorted body ownership contributes to the development of chronic pain syndromes and possibly symptoms of psychiatric disease. However, the effects of disownership on cortical processing of somatosensory information are unknown. In the present study, we created a “disownership” condition in healthy individuals by manipulating the visual information indicating the location of the subject's own left hand using a mirror box and examined the influence of this disownership on cortical responses to electrical stimulation of the left index finger using magnetoencephalography (MEG). The event-related magnetic field in the right primary somatosensory cortex at approximately 50 msec (M50) after stimulus was enhanced under the disownership condition. The present results suggest that M50 reflects a cortical incongruence detection mechanism involving integration of sensory inputs from visual and proprioceptive systems. This signal may be valuable for future studies of the mechanisms underlying sense of body ownership and the role that disrupted sense of ownership has in neurological disease.

Impact of Wait times on Spinal Cord Stimulation Therapy Outcomes

Presently, the long-term success rate of spinal cord stimulation (SCS) ranges from 47% to 74%. SCS efficacy is inversely proportional to the passage of time between development of chronic pain syndrome and time of implantation. To improve outcomes, implantation should be performed early. This study identifies sources of delay and offers suggestions for improvement. A retrospective analysis of 437 SCS patients examines delays to accessing SCS at various points in the referral stream, from initial diagnosis, family physician, and various specialist treatments, to implantation. Analysis of variance evaluated the effect of age, sex, treating specialty, and their interactions on implantation delay. A multiple linear regression model was developed to assess factors contributing to implantation delay. From time of onset of chronic pain to implantation, patients endured a delay of 65.4±2.04months. Initial physician contact occurred at a mean of 3.4±0.12months after development of pain syndrome. Family physicians managed cases for 11.9±0.45months and various specialists for an additional 39.8±1.22months. Neurosurgeons were quickest to refer to an implant physician (average wait-time 32.28± 2.64months), while orthopedic surgeons and nonimplanting anesthesiologists took the longest, contributing to wait times of 51.60±5.04months and 58.08±5.76months, respectively. Once the decision for implantation was made, the implanting physician required 3.31±0.09months to organize the procedure. A gradual decline in wait times was observed from 1980 to present. To improve SCS success rates, physicians involved in the treatment for chronic pain should refer these cases early to an implant physician once failure of medical management becomes apparent.

Guest Editorial: Perioperative Pain Management in Orthopaedic Surgery: Editorial Comment

Postoperative pain ranks at or near the top of the list of concerns for patients following orthopaedic surgery. Once considered little more than a nuisance, the symptom of pain has now reached the status of a “vital sign” [13]. Frequent assessment of a patient's pain is widely mandated by societies, its successful treatment judged by consumer groups, and evaluated as a measure to potentially guide reimbursement by government agencies [11]. This environment has accelerated perioperative pain-related research, resulting in a better understanding of its nature. Importantly, the last decade has seen a widespread acknowledgement that inadequately treated pain may be associated with a number of adverse outcomes, including the development of chronic pain, incomplete rehabilitation, and prolonged length of hospitalization [1, 4]. This realization has sparked innovations in the treatment of perioperative pain, including the development of protocols using a variety of techniques such as neuraxial, peripheral nerve [6] and local infiltration blocks [2] with or without catheters, as well as the development of novel intravenous, oral and local additive drugs and delivery systems [3, 7, 14]. Despite these innovations, no single intervention targeting one pain pathway has provided the “perfect result.” Therefore, more clinicians are promoting a combination of approaches targeting different steps in the pain cascade, widely known as “multimodal pain management” [10]. Over the years, a migration of the target area for pain control from the central nervous system to the actual site of surgery has occurred, with the goal to reduce unwanted side effects and complications of previous techniques. Although occupying an important role in perioperative pain management, reliance on opiod-based systemic medications is waning in light of frequently high rates of side effects, such as nausea, drowsiness and respiratory depression. These side effects hinder expedient and efficient rehabilitation [9]. Neuraxial techniques, such as epidural analgesia, addressed many of these concerns—gaining popularity among some practitioners and institutions in the process. Unfortunately, the advent of potent anticoagulants and the associated risk of hematoma formation has limited this approach [12]. Facilitated by the widespread use of ultrasound, peripheral nerve blocks are seen by many as an alternative to epidurals in the setting of potent anticoagulant use. However, peripheral nerve blocks are not without downsides. They are often accompanied by negative effects on motor strength and possibly rehabilitation. Trying to avoid the latter, some orthopaedic surgeons have promoted the use of periarticular injections or intraarticular infusions. Questions regarding the effectiveness and safety profiles of these treatments are still being investigated [15]. In light of these questions, clinicians and researchers continue to investigate the role of nonpharmacologic interventions on pain outcomes, and the impact pain management strategies may have beyond the alleviation of acute discomfort (Fig. 1).Fig. 1: Dr. Stavros G. Memtsoudis is shown.In this context, researchers are currently investigating the correlation between the impact of various acute pain management strategies and patient morbidity, mortality and the development of chronic pain syndromes. Previously elusive links between acute pain, its treatment and the immune system even have lead to investigations on the effect on cancer recurrence [5, 8]. Although perioperative pain management research has progressed, the collaboration between researchers and clinicians will continue to be vital for sharing new information and achieving further improvements. Embracing the notion that appropriate management of acute pain may influence long-term outcomes and survival in some orthopaedic populations should provide enough impetus to fuel future investment in this line of research for a long time to come.