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Objectives: Chronic musculoskeletal pain is associated with decreased parasympathetic and increased sympathetic activity in the autonomic nervous system. The objective of this study was to determine the associations between objective measures of heart rate variability (a measure of autonomic nervous system function), actigraphy (a measure of activity and sleep quality), respiration rates, and subjective patient‐reported outcome measures (PROMs) of central sensitization, kinesiophobia, disability, the effect of pain on sleep, and life quality. Methods: Thirty‐eight study subjects were divided into two subgroups, including low symptoms of central sensitization (n = 18) and high symptoms of central sensitization (n = 20), based on patient‐reported scores on the Central Sensitization Inventory (CSI). Heart rate variability (HRV) and actigraphy measurements were carried out simultaneously in 24 h measurement during wakefulness and sleep. Results: A decrease in HRV during the first 2 h of sleep was stronger in the low CSI subgroup compared to the high CSI subgroup. Otherwise, all other HRV and actigraphy parameters and subjective measures of central sensitization, disability, kinesiophobia, the effect of pain on sleep, and quality of life showed only little associations. Discussion: The high CSI subgroup reported significantly more severe symptoms of disability, kinesiophobia, sleep, and quality of life compared to the low CSI subgroup. However, there were only small and nonsignificant trend in increased sympathetic nervous system activity and poorer sleep quality on the high central sensitization subgroup. Moreover, very little differences in respiratory rates were found between the groups. [ABSTRACT FROM AUTHOR]

Background: Controversy exists with the presence of alterations in descending pain inhibition mechanisms in patients with non‐specific neck pain (NSNP). The aim of the present study was to evaluate the status of conditioned pain modulation CPM, remote pressure pain thresholds (PPT), and psychological factors in a specific subgroup of patients with NSNP such as young adult students. In addition, possible associations between CPM, psychological factors, and pain characteristics were analyzed. Methods: Thirty students with recurrent or chronic NSNP and 30 pain‐free students were included in this cross‐sectional study. The following measures were assessed: CPM, remote PPT, psychological factors (depression, anxiety, pain catastrophizing, and kinesiophobia), pain characteristics (duration, intensity, severity of chronic pain, interference with daily life), and central sensitization inventory (CSI). Results: No significant differences were found in the efficacy of CPM between students with chronic or recurrent NSNP and pain‐free students (β coefficient = −0.67; 95% CI = −1.54, 0.20). However, students with pain showed a significantly higher remote PPT (mean difference = −1.94; 95% CI = −2.71, −1.18). and a greater presence of anxious (mean difference = 6; 95% CI = 2, 9) and depressive symptoms (mean difference = 8.57; 95% CI = 3.97, 13.16). In addition, significant moderate or strong correlations were found between CPM and pain intensity (partial r = 0.41), pain catastrophizing and mean pain intensity (r = 0.37), grade (r = 0.50), and interference of pain (r = 0.57), kinesiophobia and disability (r = 0.38), and depression and CSI (r = 0.39). Conclusions: Young adult students with chronic or recurrent NSNP present remote hyperalgesia and symptoms of depression and anxiety but not dysfunctional CPM. [ABSTRACT FROM AUTHOR]

Background and Purpose: Nociplastic pain due to central sensitization (CS) is common in people suffering from chronic pain, but no clinical practice guideline is available in rehabilitative settings for patients' management. The aim of this study is to achieve expert consensus on physiotherapy competencies in the management of people with nociplastic pain and suspected CS mechanisms. Methods: A web‐based Delphi process was employed. Experts in the rehabilitation field were recruited following pre‐defined eligibility criteria. Following completion of three Delphi rounds, the final list of competencies was generated. Results: In all, 23 participants were recruited. They all completed Round 1 (23/23, 100%), twenty Round 2 and Round 3 (20/23, 87%). Following Round 1, seven areas were identified by the panel as crucial for CS physiotherapy management; 19 competencies out of 40 reached the consensus between experts, and nine additional competencies were added to Round 2 following literary review. Round 2 identified the agreement for all the 29 competencies. During Round 3, all the experts confirmed the final list generated through the consensus process. Discussion: An agreement between experts was found for the final list of competencies that a physiotherapist should implement every time it approaches people with suspected CS mechanisms. Further research is needed to support the clinical utility of our findings and their applicability in daily practice. [ABSTRACT FROM AUTHOR]

Introduction: Exercise is the most recommended treatment for chronic low back pain (CLBP) and is effective in reducing pain, but the mechanisms underlying its effects remain poorly understood. Exercise‐induced hypoalgesia (EIH) may play a role and is thought to be driven by central pain modulation mechanisms. However, EIH appears to be disrupted in many chronic pain conditions and its presence in people with CLBP remains unclear. As people suffering from chronic pain often exhibit psychological factors and central sensitization symptoms influencing pain perception, EIH might be associated with these factors. Objective: The aim of this study is to compare the level of EIH between participants with and without CLBP following back and wrist exercises and to assess the associations between EIH, psychological factors, and symptoms of central sensitization (using the central sensitization inventory ‐ CSI) in CLBP. Method: Twenty‐eight participants with CLBP and 23 without pain were recruited. Pressure pain thresholds (PPT) were measured at 4 sites (2 bony sites = capitate, S1|2 muscle sites = wrist flexors, lumbar erector spinae) before and after each of two exercises (wrist flexion and lumbar extension). Exercise‐induced hypoalgesia was defined as percent change in PPT from pre‐ to post‐exercise. Participants with CLBP also completed questionnaires to measure psychological factors (e.g., kinesiophobia, catastrophizing, anxiety, and self‐efficacy) and symptoms of central sensitization (CSI), and correlations with EIH were calculated. Results: After wrist exercise, EIH measured at the muscle sites was lower in the CLBP group compared with the pain‐free group (p = 0.047) but no differences were found at bony sites (p = 0.49). No significant differences for EIH were observed following back exercise at muscle sites (p = 0.14) or at bony sites (p = 0.65). Exercise‐induced hypoalgesia was not correlated with any psychological factors or with the CSI score. Conclusion: The lower EIH following wrist exercises may represent an alteration in pain modulation control in CLBP. However, psychological factors and central sensitization symptoms may not explain the differences observed. [ABSTRACT FROM AUTHOR]

Objectives: The clinical utility of combining the central sensitization (CS) inventory (CSI) with the pressure pain threshold (PPT) in assessing the effect of central sensitization on pain is unknown. This study aimed to investigate the effects of CSI, PPT, and their interaction on pain and the characteristics of clinical symptoms in patients with chronic musculoskeletal pain grouped according to the CSI score and PPT value. Method: A total of 187 participants with chronic musculoskeletal pain were recruited. PPT, brief pain inventory, widespread pain index, pain catastrophizing scale, EuroQol‐5 dimension, and CSI were assessed. Multiple regression analyses were performed using pain intensity and interference scores as dependent variables and the CSI score and PPT value as independent variables. Hierarchical cluster analysis was also performed to classify the participants into subgroups according to the CSI score and PPT value. Following the classification, pain‐related characteristics and health‐related QOL were compared among the subgroups. Results: Multiple regression analyses demonstrated that only the CSI score significantly affected pain intensity and interference. As a result of the cluster analysis, three groups were identified: cluster 1 (n = 61, CSI low/PPT low group), cluster 2 (n = 78, CSI low/PPT high group), and cluster 3 (n = 48, CSI high/PPT low group). The CSI high/PPT low group had a higher incidence of pain‐related symptoms than the CSI low group regardless of the PPT value. Conclusions: Combined CSI and PPT may not fully allow a detailed classification of pain‐related characteristics. The CSI may be clinically more useful for assessing the effect of CS on pain‐related symptoms. [ABSTRACT FROM AUTHOR]

Background: Central sensitization (CS), defined as the amplification of neural signaling within the CNS that elicits pain hypersensitivity, is thought be a characteristic of several chronic pain conditions. Maladaptive body awareness is thought to contribute and maintain CS. Less is known about the relationship between CS and adaptive body awareness. Purpose: This cross‐sectional study investigated relationships among self‐reported adaptive body awareness (Multidimensional Interoceptive Awareness Scale‐2; MAIA‐2), CS‐related symptoms (Central Sensitization Inventory; CSI), and pain intensity and further delineate potential direct and indirect links among these constructs. Methods: Online surveys were administered to 280 individuals with chronic pain reporting elevated CSI scores. Strategic sampling targeted respondents to reflect the 2010 census. Pearson's correlations characterized overall relationship between variables. Multiple regression analyses investigated potential direct links. A path analysis assessed mediational effects of CS‐related symptoms on the relationship between adaptive body awareness and pain intensity. Results: CSI demonstrated strong, inverse correlations with some MAIA‐2 subscales, but positive correlations with others. Higher CSI scores predicted greater pain intensity (b = 0.049, p ≤ 0.001). Two MAIA‐2 subscales, Not‐Distracting (b = −0.56, p ≤ 0.001) and Not‐Worrying (b = −1.17, p ≤ 0.001) were unique predictors of lower CSI. Not‐Distracting (b = −0.05, p = 0.003) and Not‐Worrying (b = −0.06, p = 0.007) uniquely predicted lower pain intensity. CSI completely mediated the relationship between adaptive body awareness and pain intensity [point estimate = −0.04; 95% bootstrap confident intervals (CI) = −0.05 to −0.02]. Conclusions: Findings also support future research to explore causal relationships of variables. Findings suggest that frequency of attention to bodily sensations is distinct from cognitive‐affective appraisal of bodily sensation, and the two distinct higher order processes may have divergent influences on perceived pain and CS‐related symptoms. Results also support future research to explore causal relationships of variables. [ABSTRACT FROM AUTHOR]

A significant proportion of patients do not experience relief from pain during the early postsurgical period after joint arthroplasty and are at risk for developing chronic pain. The objectives of this study were to identify biopsychosocial factors associated with acute postsurgical pain trajectories and with pain intensity and interference after 1, 3, and 12 months. Two hundred ten patients listed for joint arthroplasty filled a presurgical battery of questionnaires assessing presurgical pain intensity, catastrophizing, emotional distress, state anxiety and depression, self‐efficacy, central sensitization, and executive functions. From the day after surgery, they were asked to fill a 7‐day diary, including questions about postsurgical pain and postsurgical state catastrophizing. Finally, they provided data about pain intensity and interference after 1, 3, and 12 months. Predictors of acute pain trajectories were investigated using multilevel growth curve analysis. Results showed that central sensitization was a predictor of the intercept of pain trajectories and daily postsurgical catastrophizing was a significant covariate of pain intensity in the acute phase. Analyses of follow‐up data showed that central sensitization was a predictor of pain intensity and pain interference at 3 and 12 months, that emotional distress was related with pain intensity and interference at 1 month, and with pain interference at 3 months, and that cognitive flexibility was associated with pain interference at 1 month. Assessment of these factors could enable to identify patients at risk for worse outcomes and to plan targeted treatments to be implemented during the patient's inward stay. [ABSTRACT FROM AUTHOR]

Background: Proinflammatory mechanisms are implicated in pain states. Recent research indicates that patients with osteoarthritis (OA) with signs of central sensitization exhibit elevated cerebrospinal fluid (CSF) levels of interferon gamma‐induced protein 10 (IP‐10), Fms‐related tyrosine kinase 1 (Flt‐1), and monocyte chemoattractant protein 1 (MCP‐1). Methods: The current prospective cohort study, including 15 patients with OA, primarily aimed to evaluate associations among alterations in CSF IP‐10, Flt‐1, MCP‐1, and pain sensitization following total hip arthroplasty (THA). Participants provided CSF and blood samples for analysis of 10 proinflammatory mediators, and underwent detailed clinical examination and quantitative sensory testing, immediately preoperative and 18 months after surgery. Results: Neurophysiological measures of pain showed markedly reduced pain sensitivity long‐term postoperative. Increases in remote site pressure pain detection thresholds (PPDTs) and decreased temporal summation indicated partial resolution of previous central sensitization. Compared to preoperative, CSF concentrations of IP‐10 were increased (p = 0.041), whereas neither Flt‐1 (p = 0.112) nor MCP‐1 levels changed (p = 0.650). Compared to preoperative, plasma concentrations of IP‐10 were increased (p = 0.006), whereas interleukin (IL)‐8 was decreased (p = 0.023). Subjects who exhibited increases in arm PPDTs above median showed greater increases in CSF IP‐10 compared to those with PPDT increases below median (p = 0.028). Analyses of plasma IP‐10 and IL‐8 indicated higher levels of peripheral inflammation were linked to decreased pressure pain thresholds (unadjusted β = −0.79, p = 0.006, and β = −118.1, p = 0.014, respectively). Conclusions: THA leads to long‐term decreases in pain sensitivity, indicative of resolution of sensitization processes. Changes in CSF and plasma levels of IP‐10, and plasma IL‐8, may be associated with altered pain phenotype. [ABSTRACT FROM AUTHOR]

Introduction: One of the most widely used instruments to identify symptoms that may be related to central sensitization is the Central Sensitization Inventory (CSI). Although this instrument has been translated and validated in Spanish patients with chronic musculoskeletal pain, no psychometric analysis has been carried out in breast cancer survivors. The aim of this study was to perform a psychometric analysis of the Spanish version of the Central Sensitization Inventory (CSI‐Sp) in Spanish breast cancer survivors. Materials and Methods: A validation study was carried out in 183 breast cancer survivors. A psychometric analysis of internal consistency, factor structure, and test‐retest reliability of the CSI‐Sp was performed. Internal consistency was determined using Cronbach's alpha. Test‐retest reliability was evaluated using the Intraclass Correlation Coefficient (ICC) Type 2.1. Exploratory factor analysis was used to determine the internal structure of the questionnaire. Results: The internal consistency was high (α = 0.91). The test‐retest reliability was satisfactory with excellent values (ICC 2.1 = 0.95). The exploratory factor analysis yielded a one factor structure explaining the 33.88% of total variance. Conclusions: The CSI‐Sp has demonstrated to be a psychometrically strong measure for assessing central sensitization symptoms in breast cancer survivors based on internal consistency, test‐retest reliability, and structural validity. Further studies that analyze other measurement properties in different Spanish clinical populations are needed. [ABSTRACT FROM AUTHOR]

Objectives: The goal of the present study was to explore additional evidence of validity of the Serbian version of the Central Sensitization Inventory (CSI), a patient‐reported outcome measure of symptoms that have been found to be associated with central sensitization (CS). The CSI has been found to be psychometrically sound, and has demonstrated evidence of convergent and discriminant validity in numerous published studies and in multiple languages. Methods: CSI data were collected from 399 patients with chronic pain who had various diagnoses and from 146 pain‐free controls. In addition, the patient sample completed a battery of validated patient‐reported outcome measures of sleep problems, cognitive problems, pain catastrophizing, pain‐related fear‐avoidance, decreased quality of life, and decreased perception of social support. Six patient subgroups were formed, with presumably different levels of CS (including those with fibromyalgia, multiple pain sites, and localized pain sites). Results: Significant differences were found in total CSI scores among the controls and patient subgroups. Those with fibromyalgia and multiple pathologies scored highest and the control subjects scored lowest. Other patient‐reported CS‐related symptom dimensions were significantly correlated with total CSI scores. When the patients were divided into CSI severity subgroups (from subclinical to extreme), the severity of these other symptom dimensions increased with the severity of CSI scores. Conclusions: The current study successfully demonstrated additional evidence of the convergent and discriminant validity of the Serbian version of the CSI. [ABSTRACT FROM AUTHOR]

Background: Central sensitization may be present in some patients with hip osteoarthritis (OA), often reflected as widespread pain. We examine the association between pain extent with signs of central sensitization and other clinical and psychological features in patients with hip OA. Methods: Thirty patients with hip OA were recruited for this cross‐sectional observational study. Participants completed pain drawings on a digital tablet, which displayed frontal and dorsal views of the body. The pain extent (%) for each participant was determined by combining the frontal and dorsal pixels shaded and dividing by the total pixels of the body chart area. Participants completed patient‐reported outcome measures to assess for signs and symptoms of central sensitization and psychosocial factors. Quantitative sensory testing including pain pressure thresholds (PPTs) and thermal pressure thresholds was performed at points anatomically local and distant from the hip. Results: Women had significantly greater pain extent (6.71%) than men (2.65%) (z = −2.76, P < 0.01). Across all participants, increased pain extent was significantly associated with higher scores on the Widespread Pain Index (r2 = 0.426, P < 0.05), painDETECT questionnaire (r2 = 0.394, P < 0.05), and Pain Catastrophizing Scale (r2 = 0.413, P < 0.05), and with lower PPTs at the thenar eminence (r2 = −0.410, P < 0.05), vastus lateralis (r2 = −0.530, P < 0.01), vastus medialis (r2 = 0.363, P < 0.05), and greater trochanter (r2 = −0.373, P < 0.05). Conclusions: Greater pain extent was associated with several measures of signs and symptoms of central sensitization in patients with hip OA. These results support the utility of the pain drawing for identifying signs of central sensitization in patients with hip OA. [ABSTRACT FROM AUTHOR]

Background: Musculoskeletal conditions are well documented in inflammatory bowel disease (IBD). However, whether IBD activity influences musculoskeletal pain experiences is uncertain. Central sensitization has been proposed in patients with IBD who are suffering from persistent pain. Identification of central sensitization symptomology using the Central Sensitization Inventory (CSI) has been reported in many pain‐related disorders. Aims of this study were to explore predictive relationships between IBD activity and musculoskeletal pain experiences (severity/interference), and the mediating effects of the CSI. Methods: A cross‐sectional online survey was performed exploring self‐reported musculoskeletal pain in adults with IBD. Survey questionnaires included IBD activity indices, numeric rating scales, PROMIS Pain Interference, and the CSI. Linear regression was used to examine the relationship between active IBD and pain experiences. Simple and serial mediation analyses were used to explore mediation models: independent variable (IBD activity), dependent variables (severity/interference), and mediators (CSI/severity). Results: 208 adults with IBD, 18 to 88 years of age, reported musculoskeletal pain. Regression analysis identified IBD activity as a significant predictor of worse pain severity (R2 = 0.039, P < 0.005) and interference (R2 = 0.067, P < 0.001). Simple mediation showed a significant indirect effect from CSI scores between IBD activity and pain severity. Serial mediation analysis showed a significant indirect effect from CSI scores and pain severity, between IBD activity and pain interference. Conclusion: Active IBD demonstrated a positive association with worse musculoskeletal pain experiences. The CSI demonstrated significant mediation between active IBD and pain severity. Additionally, the CSI and pain severity demonstrated significant mediation between active IBD and pain interference. This suggests that symptoms of central sensitization significantly influence musculoskeletal pain experiences in IBD. [ABSTRACT FROM AUTHOR]

Introduction: Topical capsaicin is commonly employed to experimentally induce central sensitization (CS) in humans. While previous studies have investigated the effect of skin preheating on the sensitizing effect of capsaicin, no studies have compared the synergistic effect of skin preheating on the magnitude of sensitization via topical capsaicin within the first 30 minutes of application. We tested the hypothesis that skin preheating potentiates the sensitizing effect of topical capsaicin by evoking a larger region of secondary hyperalgesia vs. topical capsaicin alone. Methods: Twenty young, healthy subjects each received topical capsaicin (Zostrix HP 0.075%) only (CAP), topical capsaicin with preheating (CAP + HEAT), and topical nonsensitizing placebo cream (CON) in a crossover design. Capsaicin and placebo creams were applied to a 50 cm2 area of the dorsal forearm. The CAP + HEAT session also included a 10‐minute preheating session. Regions of secondary hyperalgesia were assessed using mechanical brush allodynia testing, and skin temperature was assessed via infrared thermography. Outcomes were normalized to baseline and compared at 10, 20, and 30 minutes after cream application. Results: The CAP + HEAT session led to a significantly larger area of secondary hyperalgesia compared to the CAP session as measured by brush allodynia (CON: 0 ± 0 cm; CAP: 2.08 ± 0.45 cm; CAP + HEAT: 3.70 ± 0.46 cm; P < 0.05) and skin temperature (CON: −2.92% ± 0.03%; CAP: −0.63% ± 0.09%; CAP + HEAT: 2.50% ± 0.11%; (of baseline) P < 0.05). Conclusion: Preheating amplifies the sensitizing effect of topical capsaicin within 30 minutes of application. The heat–capsaicin technique may be employed to assess differing magnitudes of CS induction and enables future studies investigating the development and progression of CS in humans. [ABSTRACT FROM AUTHOR]

Background: Sensitivity‐related trait characteristics involving physical and emotional sensitivities and high trait anxiety personality types have been observed in individuals with nonspecific chronic low back pain (NSCLBP). High trait sensitivity to sensory stimulation combined with interpretation biases based on personality type may contribute to the development of central sensitization (CS) symptoms. To date, there is limited research that has considered both sensitivity levels and personality type in NSCLBP with CS. The purpose of this study was to investigate (1) relationships between trait sensory profiles, trait anxiety, and CS symptoms, and (2) the predictive capacity of sensory profiles, trait anxiety, and personality types on CS symptoms in people with NSCLBP. Methods: This was a cross‐sectional observational study using 4 self‐report measures on adults (N = 165, mean age = 45 ± 12 [standard deviation] years) from physiotherapy clinics in England, Ireland, and New Zealand. Inclusion: NSCLBP > 6 months, age 18 to 64 years, predominant CS pain presentation, no other pathology. Parametric and nonparametric correlation statistics and regression analyses were used. Results: Positive correlations were found between central sensitization inventory (CSI) scores and sensory hypersensitivity profiles and trait anxiety. CSI score increases could be predicted by sensory‐sensitive, low‐registration profiles; trait anxiety scores; and extreme defensive high anxious personality type. Conclusions: Trait sensory hyper‐ and/or hyposensitivity and high trait anxiety–related personality type characteristics predict the extent of CS symptoms in people with NSCLBP. Further investigation is required to establish causality between these characteristics and CS symptoms. [ABSTRACT FROM AUTHOR]

Introduction: The differentiation between acute and chronic pain can be insufficient for appropriate pain management. The aim of this study was to evaluate the prevalence of the predominant pain type (nociceptive, neuropathic, or central sensitization [CS] pain) in breast cancer survivors (BCS) with chronic pain. The secondary aims were to examine (1) differences in health‐related quality of life (HRQoL) between the different pain groups; and (2) the associations between patient‐, disease‐, and treatment‐related factors and the different pain types. Methods: To determine the prevalence of the predominant type of pain, a recently proposed classification system was used. BCS were asked to complete the VAS for pain, Douleur Neuropathique 4 Questionnaire, Margolis Pain Diagram, Central Sensitization Inventory, and Short Form 36 (SF‐36). Results: Ninety‐one BCS participated, among whom 25.3% presented neuropathic pain, 18.7% nociceptive pain, and 15.4% CS pain. Mixed pain was found in 40.6%. A significant intergroup difference in HRQoL was found for SF‐36 "general health" (P = 0.04). The odds for the presence of CS rather than nociceptive pain are 26 times higher in patients exposed to hormone therapy in comparison to the nonexposed (odds ratio 25.95, 95% confidence interval 1.33 to 504.37, P = 0.03). Conclusion: Neuropathic pain is most frequent in BCS. Strong associations were found between CS pain and hormone therapy. [ABSTRACT FROM AUTHOR]

Abstract: Objective: Symptoms of central sensitization (CS) have been described in patients with chronic spinal pain (CSP). Although a gold standard to diagnose CS is lacking, psychophysical pain measures are often used. The Central Sensitization Inventory (CSI) is proposed as an alternative method and indirect tool for the evaluation of CS symptomatology. The aim of the current study was to evaluate the convergent validity of the CSI by investigating the association with psychophysical pain measures and self‐reported measures of current pain intensity, quality of life, disability, and catastrophizing in CSP patients. Methods: One hundred sixteen patients with nonspecific CSP were included in the present study. Patients completed the CSI, were subjected to pressure pain thresholds (PPTs) and a conditioned pain modulation (CPM) paradigm, and completed questionnaires for current pain intensity, quality of life, pain disability, and pain catastrophizing. Results: Higher CSI scores were weakly correlated with lower PPTs (−0.276 ≤ r ≤ −0.237; all P ≤ 0.01) and not with CPM efficacy (r = 0.017; P = 0.858). Higher CSI scores were moderately correlated with higher current pain intensity (r = 0.320; P < 0.001), strongly correlated with lower physical (r = −0.617; P < 0.001) and emotional (r = −0.635; P < 0.001) quality of life, and moderately correlated with higher pain disability (r = 0.472; P < 0.001) and higher pain catastrophizing (r = 0.464; P < 0.001). Conclusion: The CSI was weakly associated with PPTs and not with CPM efficacy in CSP patients. Moderate to strong associations were found with current pain intensity, quality of life, disability, and catastrophizing. The current results illustrate that the CSI does not reflect a direct measure of CS, yet is a representation of general distress, possible originating from CS symptoms. [ABSTRACT FROM AUTHOR]

Abstract: Background and objective: Central sensitization (CS) is a phenomenon associated with several medical diagnoses, including postcancer pain, low back pain, osteoarthritis, whiplash, and fibromyalgia. CS involves an amplification of neural signaling within the central nervous system that results in pain hypersensitivity. The purpose of this systematic review was to gather published studies of a widely used outcome measure (the Central Sensitization Inventory [CSI]), determine the quality of evidence these publications reported, and examine the measurement properties of the CSI. Databases and data treatment: Four databases were searched for publications from 2011 (when the CSI was developed) to July 2017. The Consensus‐Based Standards for the Selection of Health Measurement Instruments (COSMIN) checklist was applied to evaluate methodological quality and risk of bias. In instances when COSMIN did not offer a scoring system for measurement properties, qualitative analyses were performed. Results: Fourteen studies met inclusion criteria. Quality of evidence examined with the COSMIN checklist was determined to be good to excellent for all studies for their respective measurement property reports. Interpretability measures were consistent when publications were analyzed qualitatively, and construct validity was strong when examined alongside other validated measures relating to CS. Conclusions: An assessment of the published measurement studies of the CSI suggest the tool generates reliable and valid data that quantify the severity of several symptoms of CS. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: It has been increasingly recognized that many chronic pain conditions are associated with central sensitization (CS). The Central Sensitization Inventory (CSI) is a potentially useful tool for screening patients whose presenting symptoms are suspected of being related to CS, so that additional diagnostic evaluation can be performed and appropriate treatment can be initiated. The original English version is currently not available in Serbian. Methods: The CSI was translated into Serbian (CSI‐Serb) and then psychometrically evaluated in a sample of 363 chronic pain subjects. Results: The CSI‐Serb showed a high degree of internal consistency (Cronbach's α = 0.909), excellent test‐retest reliability (intraclass correlation coefficient type 2.1 = 0.947), and a significant goodness of fit test result (χ2 = 888.44; P < 0.001). A factor analysis confirmed a 4‐factor solution, as found by the original authors of the CSI, with all items retained. Higher CSI‐Serb scores were associated with higher pain severity and longer pain duration. Total CSI scores distinguished between 3 subject groups with presumably different levels of CS, including fibromyalgia (53.3, SD = 11.2), chronic regional pain only (29.7, SD = 11.6), and a pain‐free control group (20.9, SD = 9.1). Conclusions: The results of the present study indicate strong psychometric properties, including evidence of convergent and discriminant validity, of the CSI‐Serb. These results correspond with those of other translated versions of the CSI that have been psychometrically evaluated and published. Due to the current interest in CS, and its relationship with many chronic pain conditions, it is anticipated that the CSI‐Serb will benefit Serbian‐speaking clinicians in the evaluation of patients with chronic pain conditions. [ABSTRACT FROM AUTHOR]

Abstract: Background: Impaired pain inhibitory and enhanced pain facilitatory mechanisms are repeatedly reported in patients with central sensitization pain. However, the exact effects of frequently prescribed opioids on central pain modulation are still unknown. Methods: A randomized, double‐blind, placebo‐controlled cross‐over trial was carried out. Ten chronic fatigue syndrome (CFS)/fibromyalgia (FM) patients, 11 rheumatoid arthritis (RA) patients and 20 controls were randomly allocated to the experimental (10 mg morphine or 0.2 mg/mL Naloxone) and placebo (2 mL Aqua) group. Pressure pain thresholds (PPTs) and temporal summation at the Trapezius and Quadriceps were assessed by algometry. Conditioned pain modulation (CPM) efficacy and deep tissue pain pressure were assessed by adding ischemic occlusion at the opposite upper arm. Results: Deep tissue pain pressure was lower and temporal summation higher in CFS/FM (P = 0.002 respectively P = 0.010) and RA patients (P = 0.011 respectively P = 0.047) compared to controls at baseline. Morphine had only a positive effect on PPTs in both patient groups (P time = 0.034). Accordingly, PPTs increased after placebo (P time = 0.015), and no effects on the other pain parameters were objectified. There were no significant effects of naloxone nor nocebo on PPT, deep tissue pain, temporal summation or CPM in the control group. Conclusions: This study revealed anti‐hyperalgesia effects of morphine in CFS/FM and RA patients. Nevertheless, these effects were comparable to placebo. Besides, neither morphine nor naloxone influenced deep tissue pain, temporal summation or CPM. Therefore, these results suggest that the opioid system is not dominant in (enhanced) bottom‐up sensitization (temporal summation) or (impaired) endogenous pain inhibition (CPM) in patients with CFS/FM or RA. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: Central sensitization (CS) implies increased sensitivity of the nervous system, resulting in increased pain sensitivity as well as widespread pain. Recently, the Central Sensitization Inventory (CSI) was developed to assess symptoms of CS and central sensitivity syndromes. The aim of this study was to examine the convergent validity of the CSI by comparing the outcome to psychosocial factors and clinical features of CS. Methods: In a cross‐sectional explorative study, patients with chronic pain completed multiple questionnaires, including the CSI, Pain Catastrophizing Scale, and Symptom Checklist 90, for psychological distress, duration of pain, intensity of pain, widespread pain, and lateralization of pain. Based on bivariate correlations, relevant predictors of CS were selected and used to fit an exploratory structural equation model (SEM) of CS. Results: In total, 114 patients with chronic pain were included, 56.1% being women. The average pain duration was 88 months. The mean total score on the CSI was 36.09 (15.26). The CSI was strongly related to known contributing and related factors of CS. SEM analysis showed that both psychological distress and widespread pain contributed significantly to the variance in symptoms of CS in patients with chronic pain. Conclusion: In this study, the convergent validity of the CSI was measured with demonstration of a strong relationship between contributing factors and clinical features of CS. These findings of convergent validity, considering former studies of the CSI, underline the use of the questionnaire in the clinical practice. [ABSTRACT FROM AUTHOR]

Introduction: Pain is a major symptom in adolescents with generalized Hypermobility Spectrum Disorder (HSD) or Hypermobile Ehlers-Danlos Syndrome (hEDS) (1). Central sensitization (CS) of pain has been suggested as a possible explanation (2). The aim of this study was to investigate the feasibility of a study protocol investigating features of CS in adolescents with HSD or hEDS for further studies. Introduction: Pain is a major symptom in adolescents with generalized Hypermobility Spectrum Disorder (HSD) or Hypermobile Ehlers-Danlos Syndrome (hEDS) (1). Central sensitization (CS) of pain has been suggested as a possible explanation (2). The aim of this study was to investigate the feasibility of a study protocol investigating features of CS in adolescents with HSD or hEDS for further studies. Results: All three measurements were well tolerated by all participants (patients and control). When measuring endogenous pain modulation through CPM, there were five participants (patients and control), who did not experience pain when immersing their hand in the cold water and as such a CPM reaction was not achieved. Discussion: The test protocols proved to have a good feasibility but there is a need to adapt the protocol to obtain more reliable data in the main study. For example, reduction of the water sample temperature. Process evaluation: One suggestion for improving the study is to add additional measurements for example time required for examinations, time required for completing the questionnaire. [ABSTRACT FROM AUTHOR]

Introduction: Central sensitization is common in knee osteoarthritis patients (KOAP)1. Exercise therapy is suggested to be beneficial by activating endogenous analgesia2. Therefore, this systematic review aims to summarize the basal and/or acute effects of exercises on endogenous analgesia in KOAP. Methods: PubMed, Web of Science, and Embase were systematically searched. If possible, a meta-analysis was performed. Risk of bias was scored using the Cochrane ROB 2.0 or ROBINS-I and strength of evidence was assessed by the GRADE approach. Results: A total of 19 studies were included: 4 studies investigated pain thresholds after an acute bout of exercise; 15 articles focused on basal levels of endogenous analgesia (as measured by pain thresholds (n = 15), -facilitation (n = 3), and -inhibition (n = 2)). A meta-analysis combining 2 studies demonstrated that KOAP did not become more tolerant for pressure pain than healthy controls immediately after resistance training (p > 0.05). Besides that, one study with moderate quality of evidence showed that exercising KOAP had higher pain thresholds than non-exercising KOAP immediately after exercise (p < 0.05). A meta-analysis combining three studies showed that strength training of 6-12 weeks caused a significant increase in pain thresholds in KOAP compared to non-exercising KOAP (p < 0.05). Discussion: Very low quality of evidence proved that strength training of at least 6 weeks is effective in increasing pain thresholds in KOAP. Moderate quality of evidence demonstrated that an acute bout of exercise effectively increases pain thresholds in KOAP. Process evaluation: Literature about this topic is scarce, especially studies investigating pain facilitation (n = 3) and inhibition (n = 1). [ABSTRACT FROM AUTHOR]

Introduction: Patients with persistent physical symptoms (PPS) require an explanation that is acceptable and comprehendible to them. (1) Central sensitization (CS) is an explanatory model for PPS and chronic pain that has been used in physiotherapy and rehabilitation medicine, but, until recently, not by general practitioners (GPs). (2) (3) We explored how GPs used the CS model in their consultations with patients with PPS. Methods: We instructed 33 GPs on how to explain CS to patients with PPS. After 0.5-1.5 years of using the CS model, 26 GPs participated in focus groups and interviews to report and discuss their experiences with CS as an explanatory model. Audio recordings were transcribed and two researchers independently analysed the data. Results: The GPs regarded the CS model as evidence-based, credible and giving recognition to the patient, but on the other hand difficult and time-consuming. They tailored the CS model to their patients' needs and used multiple consultations to explain the model. They reported that the use of the CS model seemed to improve the understanding and acceptance of the symptoms of the patients. Furthermore, patients seemed to become more motivated to accept appropriate therapy. Discussion: GPs who applied the CS model in consultations with patients with PPS, reported that patients seemed to have more understanding. The GPs regarded the model as evidence-based, credible, and giving recognition to the patient, but also as difficult and time-consuming. Process evaluation: GPs were, after a brief training, able to provide explanation with the CS model to their patients with PPS. [ABSTRACT FROM AUTHOR]

Introduction: Complex regional pain syndrome (CRPS) is a chronic pain condition lacking clear understanding of associated pain mechanisms1,2. Thus, the aim of this review is to synthetize existing evidence on the sensory profile and indicators of central sensitization in individuals with CRPS. Methods: Based on a priori published protocol, Embase, Scopus, WoS, PubMed, Cochrane library, Sage, EBSCO host, and ProQuest databases were searched. Eligible studies compared the quantitative sensory testing (QST) outcomes (warm, cold, and mechanical detection thresholds, heat, cold, mechanical, and pressure pain thresholds, wind-up ratio, mechanical pain sensitivity, or presence of allodynia) between individuals with CRPS and healthy controls. Results: Studies included in the quantitative analysis (n = 30) showed a significant loss of warm, cold, and mechanical sensations and gain of heat, cold, mechanical, and pressure pain thresholds (p < 0.05) at the affected region. At contralateral side, there was a significant loss of vibration and mechanical sensations with gain of cold and pressure pain stimuli (p < 0.05). Discussion: Individuals with CRPS have Ipsilateral hypoesthesia and primary hyperalgesia and contralateral vibration and mechanical hypoesthesia and cold and pressure secondary hyperalgesia. Secondary hyperalgesia and contralateral hypoesthesia were considered primary indicators of central mechanisms. Process evaluation: Heterogeneity of the results was solved based on subgroup analysis according to the quality of studies. New treatment strategies should target the central mechanisms involved in CRPS. [ABSTRACT FROM AUTHOR]

Objectives The aim of this study was to create and validate severity levels for the central sensitization inventory ( CSI), a valid and reliable patient-reported outcome instrument designed to identify patients whose presenting symptoms may be related to a central sensitivity syndrome ( CSS; eg, fibromyalgia, chronic fatigue syndrome, irritable bowel syndrome), with a proposed common etiology of central sensitization ( CS). Methods Based on CSI score means and standard deviations from previously published subject samples, the following CSI severity levels were established: subclinical = 0 to 29; mild = 30 to 39; moderate = 40 to 49; severe = 50 to 59; and extreme = 60 to 100. The concurrent validity of the CSI severity levels was then confirmed in a separate chronic pain patient sample (58% with a CSS diagnosis and 42% without) by demonstrating associations between CSI scores and (1) the number of physician-diagnosed CSSs; (2) CSI score distributions in both CSS and non- CSS patient samples; (3) patient-reported history of CSSs; and (4) patient-reported psychosocial measures, which are known to be associated with CSSs. Results Compared to the non- CSS patient subsample, the score distribution of the CSS patient subsample was skewed toward the higher severity ranges. CSI mean scores moved into higher severity levels as the number of individual CSS diagnoses increased. Patients who scored in the extreme CSI severity level were more likely to report previous diagnoses of fibromyalgia, chronic fatigue syndrome, temporomandibular joint disorder, tension/migraine headaches, and anxiety or panic attacks ( P < 0.01). CSI severity levels were also associated with patient-reported depressive symptoms, perceived disability, sleep disturbance, and pain intensity ( P ≤ 0.02). Conclusion This study provides support for these CSI severity levels as a guideline for healthcare providers and researchers in interpreting CSI scores and evaluating treatment responsiveness. [ABSTRACT FROM AUTHOR]

Background Shoulder pain is a common health problem in which changes in shoulder structure cannot always explain the patient's perceived pain. Central sensitization ( CS) might play a role in a subgroup of these patients. Methods The literature was systematically reviewed to address the role of CS in patients with shoulder pain. Electronic databases PubMed and Web of Knowledge were searched for relevant studies. Results Eighteen full-text articles were included, methodological quality was scored, and information was extracted. Studies were clustered on those studying patients with musculoskeletal ( MSK) shoulder pain and those studying patients with hemiplegic shoulder pain ( HSP). In particular, quantitative sensory testing revealed hyperalgesia for pressure pain in the MSK group, whereas these results were inconsistent in patients with HSP. Conditioned pain modulation was reduced in patients with MSK shoulder pain, but functioned normally in the HSP group. Conclusion This review has shown that great progress has been made toward a better understanding of neurophysiologic pain mechanisms in patients with shoulder pain. The presence of generalized mechanical hyperalgesia, allodynia, and impaired conditioned pain modulation in patients with MSK shoulder pain indicates the involvement of the central nervous system. Widespread somatosensory abnormalities observed in patients with HSP could suggest a central origin for their shoulder pain and predispose patients with HSP to develop CS, although results are inconsistent. Additional research is required adopting different assessment methods (especially dynamic methods) to establish the role of CS in patients with shoulder pain. [ABSTRACT FROM AUTHOR]

Background Two of the most common Quantitative Sensory Techniques ( QST) employed to detect allodynia include mechanical brush allodynia and Semmes-Weinstein monofilaments. However, their relative sensitivity at detecting allodynia is poorly understood. The purpose of this study was to compare the sensitivity of brush allodynia against Semmes-Weinstein monofilament technique for detecting allodynia within regions of secondary hyperalgesia in humans. Methods Twenty subjects (10 males, 10 females; 21.1 ± 0.9 years) were recruited and randomly allocated to allodynia or monofilament groups. Topical capsaicin (Zostrix 0.075%) was applied to a target region defined by C4-C7 dermatomes. Allodynia testing was performed at 0- (baseline) and 10 minutes postcapsaicin. The Semmes-Weinstein group assessed changes in skin sensitivity 8 cm inferior to target region and 2 cm lateral to the spinous process, while brush allodynia was employed to detect the point inferior to the target region where subjects reported changes in skin sensitivity. The distance (cm) from this point to the inferior border of the target region was termed the Allodynia Score. Results Statistically significant increases in the Allodynia Score were observed at 10 minutes postcapsaicin compared to baseline ( P < 0.001). No differences in monofilament scores were observed between 10 minutes postcapsaicin and baseline ( P = 0.125). Brush allodynia also demonstrated superior sensitivity, detecting allodynia in 100% of cases compared to 60% in the Semmes-Weinstein group. Conclusion Brush allodynia is more sensitive than Semmes-Weinstein monofilaments for detecting mechanical allodynia in regions of secondary hyperalgesia. Brush allodynia may be preferred over Semmes-Weinstein monofilaments for clinical applications requiring reliable detection of allodynia. [ABSTRACT FROM AUTHOR]

Objective Chronic musculoskeletal pain is accompanied by central sensitization, which can be determined with quantitative sensory testing ( QST). In this study, we aim to investigate whether central sensitization, as measured by thermal QST, is detectable in community-dwelling elderly individuals suffering from self-reported chronic pain and identify determinants influencing thermal QST measurement analyses and interpretation. Methods In 3,936 participants of the Rotterdam Study, cold and warmth sensitivity and heat pain thresholds were determined using the thermo-sensory analyzer TSA II (Medoc Advanced Medical Systems, Durham, NC, U.S.A.). Using Cox regression, associations were studied with chronic pain and potential determinants (body mass index [ BMI], reaction speed, systolic and diastolic blood pressure, skin color, skin temperature, seasonal influence, depression, anxiety, atopic eczema, age at menarche, years since menopause, hormone replacement therapy ( HRT) use during menopause, and reproductive lifespan). Results In addition to the effect of age and gender on thermal sensitivity, darker skin color and the presence of atopic eczema were associated with higher sensitivity for heat pain. Cold sensitivity and warmth sensitivity thresholds were both influenced by BMI, reaction speed, skin temperature, season, depression, dark skin color, years since menopause, and reproductive lifespan. The presence of chronic pain was associated with 0.2 degrees lower heat pain threshold in all participants, and 0.3 degrees lower in individuals with chronic pain in more than 2 sites. Conclusion Higher sensitivity for heat pain, one feature of central sensitization, is present in community-dwelling elderly with chronic pain. Additional determinants should be considered when analyzing and interpreting QST measurements. [ABSTRACT FROM AUTHOR]

Background Central sensitization plays an important role in the chronic pain experienced by osteoarthritis ( OA) patients. In this prospective observational study, we investigated the influence of the level of preoperative centrally mediated symptoms measured by the Central Sensitization Inventory ( CSI) on pain intensity after total knee arthroplasty ( TKA) for OA. Methods Ninety-eight female OA patients undergoing TKA were enrolled in this study. We assessed CSI scores, pain-related data, and other clinical data preoperatively. All patients received spinal anesthesia and postoperative epidural analgesia. Pain intensity (at rest and on movement) and rescue meperidine requirements were assessed during postoperative days 1 and 2. Also, pain intensity and patient satisfaction were assessed 1 month and 3 months after surgery. After the completion of all postoperative assessments, we separated the study population into a preoperative CSI score ≥40 and <40 group. We assessed pain-related data between the 2 groups at each assessment time. Results Ninety-one patients completed the postoperative assessments (a preoperative CSI ≥40 group; n = 44, CSI <40 group; n = 47). Patients with preoperative CSI ≥40 complained of a greater pain intensity ( P = 0.001) during postoperative days 1 and 2 and required a higher dose of meperidine rescue ( P = 0.003) than those with a preoperative CSI <40. The high CSI score group also showed a less favorable outcome in terms of pain relief on follow-up at 1 month ( P = 0.006) and 3 months ( P = 0.002) after surgery. In multivariate analysis, a preoperative CSI score ≥40 was the strongest determinant with 5.091 of the highest odds ratio (95% CI 1.324 to 19.523, P = 0.016) for predicting a persistent pain 3 months after surgery among demographic and pain-related variables. Conclusions OA patients with high levels of comorbid centrally mediated symptoms showed severe pain and increased analgesic requirements after TKA in the early postoperative period. Moreover, these patients seemed to be at higher risk of persistent pain, and a high CSI score was predictive of low patient satisfaction in terms of pain relief after surgery. [ABSTRACT FROM AUTHOR]

Introduction: Migraine is conceptualized as a continuum, with at the one hand episodic migraine and at the other hand chronic migraine (CM) which is more frequent1. Recent studies support the presence of central sensitization (CS) in migraine patients2,3, but controversial evidence exists about where in the continuum exactly CS appears and which mechanisms are underlying. Therefore this study aims to determine the occurrence and mechanisms of CS within the migraine continuum. Methods: Self-reported and psychophysiological data will be collected from 30 migraine patients and 30 healthy controls. Pain sensitivity will be evaluated using Quantitative Sensory Testing including mechanical and thermal thresholds. Pain facilitation and inhibition will be assessed by using respectively temporal summation and conditioned pain modulation paradigms. Assessments are performed unilateral at the painful side and interictally. Results: Widespread pain and impaired pain facilitation and inhibition are expected to be more pronounced in patients with more migraine days (further along the continuum) than in those with less migraine days. Discussion: This research will show whether signs of CS are present in migraine patients, where in the migraine continuum these symptoms are appearing, and whether impaired pain inhibition and/or facilitation underlie these symptoms. Process evaluation: Data collection is currently going on. Testing patients with CM interictally is a challenge. [ABSTRACT FROM AUTHOR]

Introduction: Up to 37% of lumbar radiculopathy patients experience residual pain and disability following lumbar discectomy. Although it is assumed that dysfunctional pain processing may play a mechanistic role in symptom persistence, research in this area is lacking. Therefore, this study will evaluate pain processing in lumbar radiculopathy patients prior to and 3 months following lumbar discectomy. Methods: Lumbar radiculopathy patients (n = 122) scheduled for discectomy will be recruited through Flemish hospitals. At follow-up, patients with =1.5/10 average pain intensity on a visual analogue scale and <20% improvement on the Oswestry Disability Index will be categorized as having residual complaints. These will be compared to matched patients without residual complaints and pain-free controls. Pain sensitivity will be evaluated using Quantitative Sensory Testing including thermal, mechanical, and electrical perception and pain thresholds. Spinal modulation will be assessed using nociceptive flexion reflex thresholds; pain facilitation by the presence of psychocognitive factors through questionnaires and temporal summation of mechanical stimuli and the NFR; and pain inhibition using a conditioned pain modulation paradigm. Results: Not applicable. Discussion: We hypothesize that pre-operative pain characteristics are predictive of residual complaints and that patients with residual complaints exhibit dysfunctional pain processing compared to individuals without residual complaints as expressed by impaired pain inhibition and enhanced spinal modulation, pain sensitivity and facilitation. The findings will provide the potential to identify patients at risk of poor surgical outcome and explore treatment strategies according to dysfunctions in pain processing. Process evaluation: Currently recruiting and completing ethical committee applications for multicentric recruitment. [ABSTRACT FROM AUTHOR]

Central sensitization (CS) has been proposed as a common pathophysiological mechanism to explain related syndromes for which no specific organic cause can be found. The term 'central sensitivity syndrome (CSS)' has been proposed to describe these poorly understood disorders related to CS. The goal of this investigation was to develop the Central Sensitization Inventory (CSI), which identifies key symptoms associated with CSSs and quantifies the degree of these symptoms. The utility of the CSI, to differentiate among different types of chronic pain patients who presumably have different levels of CS impairment, was then evaluated. Study 1 demonstrated strong psychometric properties (test-retest reliability = 0.817; Cronbach's alpha = 0.879) of the CSI in a cohort of normative subjects. A factor analysis (including both normative and chronic pain subjects) yielded 4 major factors (all related to somatic and emotional symptoms), accounting for 53.4% of the variance in the dataset. In Study 2, the CSI was administered to 4 groups: fibromyalgia (FM); chronic widespread pain without FM; work-related regional chronic low back pain (CLBP); and normative control group. Analyses revealed that the patients with FM reported the highest CSI scores and the normative population the lowest ( P < 0.05). Analyses also demonstrated that the prevalence of previously diagnosed CSSs and related disorders was highest in the FM group and lowest in the normative group ( P < 0.001). Taken together, these 2 studies demonstrate the psychometric strength, clinical utility, and the initial construct validity of the CSI in evaluating CS-related clinical symptoms in chronic pain populations. ▪ [ABSTRACT FROM AUTHOR]

▪ Abstract This review summarizes the present and emerging knowledge base on the pathophysiology, diagnosis, and management of fibromyalgia. Epidemiology: Fibromyalgia is the most common chronic pain syndrome encountered in general medicine and rheumatology. Historically, contemporary concepts of fibromyalgia have evolved in terms of its clinical description and parallel advances in the understanding of its pathophysiology. Pathophysiology: A generally accepted paradigm postulates that fibromyalgia is the clinical expression of a rheumatologic disorder in which the associated pain is driven primarily by central sensitization and possibly through changes in several neuronal systems but not necessarily reliant on peripheral processes. Management: Several agents, including serotonin-norepinephrine reuptake inhibitors (ie, duloxetine and milnacipran), opioids (ie, tramadol), and the α2-δ ligand pregabalin, which recently received U.S. regulatory approval for the treatment of fibromyalgia, have been evaluated in clinical trials, demonstrating benefit in terms of pain reduction and improvement in core symptoms (ie, fatigue and sleep disturbance). The European League Against Rheumatism has developed updated guidelines for the management of fibromyalgia. ▪ [ABSTRACT FROM AUTHOR]

▪ Abstract: Injury to the ilioinguinal nerve commonly follows during lower abdominal and pelvic surgery, especially with inguinal hernia repair, appendectomy, and hysterectomy. Other potential causes include low abdominal blunt trauma, iliac crest bone graft, psoas abscess, Pott's disease, and prolonged wearing of abdominally constrictive clothing. The actual incidence of ilioinguinal neuralgia is uncertain, as reported percentage ranges between 12% and 62%. Prompt and accurate diagnosis is critical, and appropritate treatments range from conservative pharmacologic management with nonopioid (eg, gabapentin, topiramate) as well as opioid agents, to surgical neurectomy of the proximal portion of the ilioinguinal nerve. Pharmacological treatment is frequently unsuccessful (particularly if delayed) and while surgery is successful in approximately 73% of cases, it can result in problematic paresthesias, and pain may continue to persist in some patients. Thus, minimally invasive techniques, such as peripheral nerve stimulation, may be viable in those patients who are refractory to pharmacological management, as an option to surgery, and who have not gained satisfactory pain relief through surgical intervention. We present three cases of successful pain control of ilioinguinal neuralgia with peripheral nerve stimulation. These cases demonstrate the potential benefits of neurostimulation including durable effective pain relief and decreased use of medication. Putative mechanisms of effect(s) and caveats for continued research to inform prudent employment of this technique are presented. ▪ [ABSTRACT FROM AUTHOR]

Objective: To describe the treatment of an intractable complex regional pain syndrome I (CRPS-I) patient with anesthetic doses of ketamine supplemented with midazolam. Methods: A patient presented with a rapidly progressing contiguous spread of CRPS from a severe ligamentous wrist injury. Standard pharmacological and interventional therapy successively failed to halt the spread of CRPS from the wrist to the entire right arm. Her pain was unmanageable with all standard therapy. As a last treatment option, the patient was transferred to the intensive care unit and treated on a compassionate care basis with anesthetic doses of ketamine in gradually increasing (3–5 mg/kg/h) doses in conjunction with midazolam over a period of 5 days. Results: On the second day of the ketamine and midazolam infusion, edema, and discoloration began to resolve and increased spontaneous movement was noted. On day 6, symptoms completely resolved and infusions were tapered. The patient emerged from anesthesia completely free of pain and associated CRPS signs and symptoms. The patient has maintained this complete remission from CRPS for 8 years now. Conclusions: In a patient with severe spreading and refractory CRPS, a complete and long-term remission from CRPS has been obtained utilizing ketamine and midazolam in anesthetic doses. This intensive care procedure has very serious risks but no severe complications occurred. The psychiatric side effects of ketamine were successfully managed with the concomitant use of midazolam and resolved within 1 month of treatment. This case report illustrates the effectiveness and safety of high-dose ketamine in a patient with generalized, refractory CRPS. [ABSTRACT FROM AUTHOR]