Is the Central Sensitization Inventory (CSI) associated with quantitative sensory testing (QST)? A systematic review and meta-analysis.

Central sensitization (CS) involves an amplification of neural processing within the central nervous system that can result in widespread pain patterns and hypersensitivity to stimuli. The Central Sensitization Inventory (CSI) and various quantitative sensory testing (QST) methods purport to assess clinical markers of CS. The purpose of this systematic review and meta-analysis was to summarize and quantify the associations between total CSI scores and QST measures from previous studies. A systematic search identified 39 unique studies that were deemed eligible for the systematic review and 33 studies for meta-analyses (with 3314 subjects and 154 effect sizes), including five QST modalities: conditioned pain modulation, temporal summation, pressure pain threshold, heat pain threshold, and cold pain threshold. The meta-analysis yielded statistically significant CSI-QST correlations in total subject samples for all five QST modalities. The strongest associations were identified between CSI scores and pain threshold testing, especially pressure pain threshold, in which 51% of effects sizes, from 29 studies and 3071 subjects, were determined to be in a medium to large range.

Patients with neuropathic pain from lumbosacral radiculopathy demonstrate similar pressure pain thresholds and conditioned pain modulation to those with fibromyalgia.

OBJECTIVE: The purpose of the study was to evaluate pain thresholds, impairment of the endogenous pain modulatory system, and self-reported cognitive-emotional and central sensitization-related symptoms among three subject groups: a rarely studied patient cohort with neuropathic pain from lumbosacral radiculopathy (NPLSR), patients with fibromyalgia (FM) and healthy controls (HC). METHODS: Patient-reported pain-related symptomology was evaluated with psychometricallyvalidated questionnaires. Pressure pain threshold (PPT), heat pain threshold (HPT), and cold pain threshold (CPT) were assessed in the low back and contralateral forearm. Conditioned pain modulation (CPM) was evaluated with a recently introduced methodology that accounts for a standard error of measurement. RESULTS: Compared to the HC subjects, the FM and NPLSR subjects had significantly lower pain thresholds and more CPM impairment. No significant differences in PPT and CPM were observed between the FM and NPLSR groups. Significant group differences were found in self-reported symptoms of depression, anxiety, stress, and central sensitization. Self-reported symptom severity increased in a stair-step fashion, with the HC group scoring lowest and FM group scoring highest. CONCLUSION: The NPLSR group manifested CPM dysfunction and pressure hyperalgesia at similar levels to the FM group, indicating that these two chronic pain syndromes, likely based on different pathophysiological mechanisms, in fact share some common pain processing features. However, though both patient groups demonstrated similarities in pain processing, self-reported cognitive-emotional and central sensitization-related symptom severity was significantly higher in the FM cohort, which distinguished them from the chronic NPLSR cohort.

Influence of Implant Impression Methods, Polymer Materials, and Implant Angulation on the Accuracy of Dental Models.

The paper presents the influence of impression methods, polymer materials, and implant angulation on the accuracy of the definitive working model for the production of implant-supported dental restorations, based on the analysis of results obtained using different impression methods, materials, and parallel and angulated implants. The study findings indicate that all aforementioned factors impact the accuracy of the definitive working model. Specifically, 20° implant angulation in relation to the vertical plane has a greater impact on the impression accuracy compared to parallel implants. The open and splint method in combination with addition silicone, as well as the splint method and polyether combination yielded more accurate results when using implants under 20° angulation compared to other method and material combinations. The splint method in combination with addition silicone resulted in the smallest mean deviations from the center of the parallel implant base compared to other combinations of methods and materials. Analysis results further revealed statistically significant differences in the measured indicators across impression methods, implants, and polymer materials.

Influence of Dimethacrylate Monomer on the Polymerization Efficacy of Resin-Based Dental Cements-FTIR Analysis.

The degree of polymerization for dimethacrylate resin-based materials (BisGMA, TEGDMA, UDMA, HEMA) ranges from 55 to 75%. Literature data indicate that polymerization efficacy depends, among other factors, on the type of methacrylate resin comprising the material. The aim of this study was to evaluate the polymerization efficacy of four dental cement materials characterized by different polymerization mechanisms using FTIR analysis. In the present study, the FTIR method was adopted to analyze the degree of polymerization efficacy of four resin-based dental cement materials, two of which were self-cured and two were dual-cured cements. The IR spectral analysis was performed 24 h after the polymerization of the cementitious material. RelyX ARC cement exhibits the lowest polymerization efficacy (61.3%), while that of Variolink II (85.8%) and Maxcem Elite is the highest (90.1%). Although the efficacy of self-cured cements appears to be superior, the difference is not statistically significant (p = 0.280). Polymerization efficacy largely depends on the chemical structure of the material in terms of the presence of a particular methacrylate resin and less on the polymerization mechanism itself, i.e., whether it is a self-cured or dually cured dental cement. Thus, in clinical practice, cementitious materials with a higher proportion of TEGDMA compared with BisGMA are recommended.

Assessing the Functional Status of Patients with Chronic Pain-Cross Cultural Adaptation and Psychometric Properties of the Serbian Version of the Pain Disability Questionnaire.

The Pain Disability Questionnaire (PDQ) has established itself as a leading patient-reported outcome measure for assessing both mental and physical components of pain-related disability. The current study aimed to translate the PDQ into Serbian and validate its psychometric properties. Following a standard translation process, a total of 554 chronic pain patients (average age 55.37 ± 12.72 years; 375 (67.5%) females) completed the PDQ-Serb, Oswestry Disability Index (ODI), Short Form-36 (SF-36), pain intensity rating and a six-minute walk test (6MWT). Responsiveness was examined in a subsample of 141 patients who completed an inpatient rehabilitation program. The internal consistency of the PDQ-Serb was excellent (Cronbach α = 0.92) and test-retest reliability was favorable (ICC = 0.87). Factor analyses found a bifactor model to be the best fit (CFI = 0.97: TLI = 0.96: RMSEA = 0.05; SRMR = 0.03). Statistically significant Pearson's coefficient correlations (p < 0.001) were found between the PDQ-Serb and ODI (r = 0.786), SF-36 Physical Components summary (r = -0.659), SF-36 Mental Components summary (r = -0.493), pain intensity rating (r = 0.572), and 6MWT (r = -0.571). Significant post-treatment improvements following inpatient rehabilitation were found with the PDQ-Serb (p < 0.001; effect size 0.431) and other clinical variables (p < 0.001; effect sizes from 0.367 to 0.536). The PDQ-Serb was shown to be a reliable and valid self-report instrument for the evaluation of pain-related disability.

Correlation of somatization, depression, and chronic pain with clinical findings of the temporomandibular disorders in asymptomatic women.

Objective: The aim of this study was to correlate degree of depression, somatization, and chronic pain in asymptomatic women with clinical findings, using Research Diagnostic Criteria/Temporomandibular disorders (RDC/TMD). Methods: A total of 200 female participants, ages 18-65, filled out a standard RDC/TMD axis II form for the assessment of chronic pain, disability, depression, and non-specific physical symptoms and underwent clinical examination of the temporomandibular joint. Correlation of clinical findings (axis I) and axis II assessment was performed using Spearman's correlation test, with significance set at p < 0.05. Results: There was a significant correlation between depression scores (p < 0.04), chronic pain (p < 0.001), and non-specific physical symptoms without questions about pain (p = 0.008). Discussion: The highest scores on the Graded Chronic Pain Scale were observed in patients with arthralgia, while patients with myofascial pain scored higher on depression and somatization tests.

Establishing Central Sensitization-Related Symptom Severity Subgroups: A Multicountry Study Using the Central Sensitization Inventory.

OBJECTIVES: The goal of this study was to identify central sensitization-related symptom severity subgroups in a large multicountry sample composed of patients with chronic pain and pain-free individuals using the Central Sensitization Inventory (CSI). METHODS: A large, pooled international (N = 8 countries) sample of chronic pain patients plus healthy subjects (total N = 2,620) was randomly divided into two subsamples for cross-validation purposes. First, a hierarchical cluster analysis (HCA) was performed using CSI item-level data as clustering variables (test sample; N = 1,312). Second, a latent profile analysis (LPA) was conducted to confirm the optimal number of CSI clusters (validation sample; N = 1,308). Finally, to promote implementation in real-world clinical practice, we built a free online Central Sensitization Inventory Symptom Severity Calculator. RESULTS: In both HCA (N = 1,219 valid cases) and LPA (N = 1,245 valid cases) analyses, a three-cluster and three-profile solution, respectively, emerged as the most statistically optimal and clinically meaningful. Clusters were labeled as follows: (i) Low Level of CS-Related Symptom Severity, (ii) Medium Level of CS-Related Symptom Severity, and (iii) High Level of CS-Related Symptom Severity. CONCLUSIONS: Our results indicated that a three-cluster solution clearly captured the heterogeneity of the CSI data. The calculator might provide an efficient way of classifying subjects into the cluster groups. Future studies should analyze the extent to which the CSI cluster classification correlates with other patient-reported and objective signs and symptoms of CS in patients with chronic pain, their associations with clinical outcomes, health-related costs, biomarkers, (etc.), and responsiveness to treatment.

Convergent and Discriminant Validity of the Serbian Version of the Central Sensitization Inventory.

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.

Psychometric validation of the Serbian version of the Fear Avoidance Component Scale (FACS).

OBJECTIVE: The Fear Avoidance Components Scale (FACS) is a new patient-reported outcome (PRO) questionnaire designed to comprehensively evaluate fear avoidance (FA) beliefs and attitudes in persons with painful medical conditions. The original English version has demonstrated acceptable psychometric properties, including concurrent and predictive validity. Two factors have been identified: 1. general fear avoidance; and 2. types of activities that are avoided. METHODS: The FACS was first translated into Serbian, and then psychometrically validated. A cohort of 322 chronic musculoskeletal pain subjects completed the FACS-Serb and additional FA-related patient-reported outcome (PRO) measures. Their FACS-Serb scores were then compared to a cohort of 68 acute pain subjects. RESULTS: Test-retest reliability (ICC2,1 = 0.928) and internal consistency for both Factors (Cronbach α 0.904 and 0,880 respectively) were very good. An acceptable fit was found with a confirmatory factor analysis of the 2-factor model found with the original English version of the FACS. Strong associations were found among FACS-Serb scores and other PRO measures of pain catastrophizing, depressive/anxiety symptoms, perceived disability, and pain intensity (p<0.001 for all analyses). FACS-Serb total scores, separate Factor scores, and subjective pain ratings were significantly higher in the chronic vs. acute pain cohorts (p<0.001 for all analyses). CONCLUSIONS: The FACS-Serb demonstrated strong psychometric properties, including strong reliability and internal consistency, criterion validity (through associations with other FA-related PRO measures), and discriminant validity (through comparisons with a separate acute pain cohort). The FACS-Serb appears to be a potentially useful pain-related assessment tool.

Dimensionality and Reliability of the Central Sensitization Inventory in a Pooled Multicountry Sample.

Central sensitization (CS) involves the amplification of neural signaling within the central nervous system, which evokes pain hypersensitivity. The Central Sensitization Inventory (CSI) assesses 25 overlapping health-related symptom dimensions that have been reported to be associated with CS-related disorders. Previous studies have reported satisfactory test-retest reliability and internal consistency, but factor analyses have exhibited conflicting results in different language versions. The purpose of this cross-sectional study was to thoroughly examine the dimensionality and reliability of the CSI, with pooled data from 1,987 individuals, collected in several countries. The principal component analysis suggested that 1 general factor of CS best described the structure. A subsequent confirmatory factor analysis revealed that a bifactor model, which accounted for the covariance among CSI items, with regard to 1 general factor and 4 orthogonal factors, fit the CSI structure better than the unidimensional and the 4-factor models. Additional analyses indicated substantial reliability for the general factor (ie, Cronbach α = .92; ω = .95; and ω hierarchical = .89). Reliability results for the 4 specific factors were considered too low to be used for subscales. The results of this study clearly suggest that only total CSI scores should be used and reported. PERSPECTIVE: As far as we know, this is the first study that has examined the factor structure and reliability of the CSI in a large multicountry sample. The CSI is currently considered the leading self-report measure of CS-related symptoms worldwide.

Cross-Cultural Adaptation and Psychometric Validation of the Serbian Version of the Central Sensitization Inventory.

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.

Factors that predict walking ability with a prosthesis in lower limb amputees.

Introduction: Identification of predictive factors for walking ability with a prosthesis, after lower limb amputation, is very important in order to define patient's potentials and realistic rehabilitation goals, however challenging they are. Objective: The objective of this study was to investigate whether variables determined at the beginning of rehabilitation process are able to predict walking ability at the end of the treatment using support vector machines (SVMs). Methods: This research was designed as a retrospective clinical case series. The outcome was defined as three-leveled ambulation ability. SVMs were used for predicting model forming. Results: The study included 263 patients, average age 60.82 ± 9.27 years. In creating SVM models, eleven variables were included: age, gender, cause of amputation, amputation level, period from amputation to prosthetic rehabilitation, Functional Comorbidity Index (FCI), presence of diabetes, presence of a partner, restriction concerning hip or knee extension, residual limb hip extensor strength, and mobility at admission. Six SVM models were created with four, five, six, eight, 10, and 11 variables, respectively. Genetic algorithm was used as an optimization procedure in order to select the best variables for predicting the level of walking ability. The accuracy of these models ranged from 72.5% to 82.5%. Conclusion: By using SVM model with four variables (age, FCI, level of amputation, and mobility at admission) we are able to predict the level of ambulation with a prosthesis in lower limb amputees with high accuracy.

ASSESSMENT OF QUALITY OF LIFE IN PATIENTS AFTER LOWER LIMB AMPUTATION.

INTRODUCTION: Lower extremity amputation is a surgical procedure resulting in important anatomical, functional, psychological, and social consequences that can influence the quality of life of these patients. The aim of this research was to compare the quality of life of patients with lower extremity amputation and people without amputation taking into account gender differences as well as the amputation level. MATERIAL AND METHODS: The study was designed as a cross-sectional study which included 56 subjects. The patients from the experimental group underwent prosthetic rehabilitation treatment at the Department of Medical Rehabilitation, Clinical Centre of Vojvodina. The experimental group included 28 patients (21 male, 7 female) with lower extremity amputation, their average age being 65.36±13.64. The control group consisted of 28 age and gender matching subjects without amputation. Research ANd Development (RAND) 36--Item Health Survey 1.0 (SF-36) was used to measure the quality of life. RESULTS: The results showed that patients with lower extremity amputation scored lower than the control group on all SF-36 variables (p<0.05). None of the SF-36 variables differed between the genders (p>0.05). Seventeen (61%) patients were with transfemoral, and 11 (39%) with transtibial level of amputation. The patients with transtibial amputations scored higher on physical functioning and general health status variables (p<0.05). CONCLUSION: The patients with lower extremity amputations have numerous limitations compared to the control group, regardless of gender, while the patients with lower level of amputation have a higher level of physical functioning.