Central sensitivity syndromes: mounting pathophysiologic evidence to link fibromyalgia with other common chronic pain disorders

Cluster subgroups based on overall pressure pain sensitivity and psychosocial factors in chronic musculoskeletal pain: Differences in clinical outcomes

Objective: We aimed to empirically derive psychosocial and pain sensitivity subgroups using cluster analysis within a sample of individuals with chronic musculoskeletal pain (CMP) and to investigate derived subgroups for differences in pain and disability outcomes. Methods: Eighty female participants with CMP answered psychosocial and disability scales and were assessed for pressure pain sensitivity. A cluster analysis was used to derive subgroups, and analysis of variance (ANOVA) was used to investigate differences between subgroups. Results: Psychosocial factors (kinesiophobia, pain catastrophizing, anxiety, and depression) and overall pressure pain threshold (PPT) were entered into the cluster analysis. Three subgroups were empirically derived: cluster 1 (high pain sensitivity and high psychosocial distress; n = 12) characterized by low overall PPT and high psychosocial scores; cluster 2 (high pain sensitivity and intermediate psychosocial distress; n = 39) characterized by low overall PPT and intermediate psychosocial scores; and cluster 3 (low pain sensitivity and low psychosocial distress; n = 29) characterized by high overall PPT and low psychosocial scores compared to the other subgroups. Cluster 1 showed higher values for mean pain intensity (F_(2,77) = 10.58, p < 0.001) compared with cluster 3, and cluster 1 showed higher values for disability (F_(2,77) = 3.81, p = 0.03) compared with both clusters 2 and 3. Conclusions: Only cluster 1 was distinct from cluster 3 according to both pain and disability outcomes. Pain catastrophizing, depression, and anxiety were the psychosocial variables that best differentiated the subgroups. Overall, these results call attention to the importance of considering pain sensitivity and psychosocial variables to obtain a more comprehensive characterization of CMP patients' subtypes.

Association between somatic symptom burden and health-related quality of life in people with chronic low back pain

Depression is a relevant risk factor for low back pain and is associated with the outcomes of low back pain. Depression also often overlaps with somatisation. As previous studies have suggested that somatisation or a higher somatic symptom burden has a role in the outcomes of low back pain, the aim of the present cross-sectional study was to examine whether somatic symptom burden was associated with health-related quality of life in individuals with chronic low back pain independent of depression. We analyzed internet survey data on physical and mental health in Japanese adults aged 20–64 years with chronic low back pain (n = 3,100). Health-related quality of life was assessed using the EuroQol five dimensions (EQ-5D) questionnaire. Somatic symptom burden and depression were assessed using the Somatic Symptom Scale-8 (SSS-8) and the Patient Health Questionnaire-2 (PHQ-2), respectively. SSS-8 score was categorized as no to minimal (0–3), low (4–7), medium (8–11), high (12–15), and very high (16–32). The association between SSS-8 and EQ-5D was examined using linear regression models, adjusting for depression and other covariates, including age, sex, BMI, smoking, marital status, education, exercise, employment, and the number of comorbid diseases. A higher somatic symptom burden was significantly associated with a lower health-related quality of life independent of depression and the number of comorbid diseases (regression coefficient = 0.040 for SSS-8 high vs. very high and 0.218 for non to minimal vs. very high, p trend <0.0001). In conclusion, somatic symptom burden might be important for the health-related quality of life of individuals with chronic low back pain.

As if one pain problem was not enough: prevalence and patterns of coexisting chronic pain conditions and their impact on treatment outcomes

INTRODUCTION

The presence of multiple coexisting chronic pain (CP) conditions (eg, low-back pain and migraines) within patients has received little attention in literature. The goals of this observational longitudinal study were to determine the prevalence of coexisting CP conditions, identify the most frequent ones and patterns of coexistence, investigate the relationships among patients' biopsychosocial characteristics and number of CP conditions, and determine the impact of coexisting CP conditions on treatment response.

PATIENTS AND METHODS

A total of 3,966 patients attending multidisciplinary pain-treatment centers who were enrolled in the Quebec Pain Registry were included. Patients completed self-report and nurse-administered questionnaires before their first visit and 6 months later. Results were analyzed using descriptive statistics, factor and cluster analyses, negative binomials with log-link generalized linear models, and linear mixed-effect models.

RESULTS

A third of patients reported coexisting CP conditions. No specific patterns of comorbidities emerged. The presence of coexisting CP conditions was associated with longer pain duration, older age, being female, and poorer quality of life. The presence of more than one CP condition did not have a clinically significant impact on treatment responses.

DISCUSSION

The novelty of the study results relate to the heterogeneity that was found in the patterns of coexistence of CP conditions and the fact that having multiple CP conditions did not clinically impact treatment response. These results highlight the need for future research that examines causes of coexistence among CP conditions across the spectrum of CP, as opposed to focusing on specific conditions, and to examine whether multiple CP conditions impact on additional domains, such as treatment satisfaction. These results highlight the importance of studying the pathophysiological mechanisms underlying the development of coexisting CP conditions, in order eventually to prevent/minimize their occurrence and/or develop optimal treatment and management approaches.

Characterization of migraineurs presenting interictal widespread pressure hyperalgesia identified using a tender point count: a cross-sectional study

BACKGROUND

Migraineurs exhibit pain hypersensitivity throughout the body during and between migraine headaches. Migraine is classified as a central sensitivity syndrome, typified by fibromyalgia showing widespread pressure hyperalgesia determined by a tender point. This study was performed to examine whether: 1) there is a subgroup of episodic migraineurs with widespread pressure hyperalgesia during and between attacks; 2) if such a subgroup exists, what is the prevalence and what is the difference between groups with interictal widespread hyperalgesia and acute allodynia regarding the demographic and clinical characteristics of migraine.

METHODS

This was a cross-sectional study. A total of 176 consecutive episodic migraineurs and 132 age- and sex-matched controls were recruited. The presence of widespread pressure hyperalgesia was investigated using manual tender point survey. To classify a subject's response as widespread pressure hyperalgesia, the cutoff value for responders was defined as the positive tender point count below which 95% of controls responded.

RESULTS

Based on the number of positive tender points in controls, the cutoff value of tender point count for pressure hyperalgesia responders was 7. Of the 176 subjects, interictal widespread pressure hyperalgesia and acute allodynia were observed in 74 (42%) and 115 (65.3%) patients, respectively. Univariate analysis indicated that risk factors associated with interictal widespread pressure hyperalgesia were female gender, younger age at migraine onset, higher frequency of migraine attacks, severe headache impact, cutaneous allodynia and depression. Multivariate logistic regression analysis confirmed that independent risk factors associated with interictal widespread pressure hyperalgesia were female gender, higher frequency of migraine attack and younger age at onset.

CONCLUSION

Interictal widespread pressure hyperalgesia was common (42%) in the episodic migraineurs and was associated with younger age at onset, female gender, and higher frequency of headache, but not duration of migraine illness. Presence of interictal widespread pressure hyperalgesia is assumed to be an indicator of genetic susceptibility to migraine attacks. We expect that a tender point count, as an alternative to quantitative sensory testing, will become useful as a diagnostic indicator of interictal hyperalgesia in migraineurs to predict susceptibility to migraine attacks and to permit tailored treatment.

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.

Use of the Central Sensitization Inventory (CSI) as a treatment outcome measure for patients with chronic spinal pain disorder in a functional restoration program

BACKGROUND CONTEXT

The Central Sensitization Inventory (CSI) is a valid and reliable patient-reported instrument designed to identify patients whose presenting symptoms may be related to central sensitization (CS). Part A of the CSI measures a full array of 25 somatic and emotional symptoms associated with CS, and Part B asks if patients have previously been diagnosed with one or more specific central sensitivity syndromes (CSSs) and related disorders. The CSI has previously been validated in a group of patients with chronic pain who were screened by a trained psychiatrist for specific CSS diagnoses. It is currently unknown if the CSI can be a useful treatment-outcome assessment tool for patients with chronic spinal pain disorder (CSPD) who are not screened for comorbid CSSs. It is known, however, that previous studies have identified CS-related symptoms, and comorbid CSSs, in subsets of patients with CSPDs. Studies have also shown that CS-related symptoms can be influenced by cognitive and psychosocial factors, including abuse history in both childhood and adulthood, sleep disturbance, catastrophic and fear-avoidant cognitions, and symptoms of depression and anxiety.

PURPOSE

This study aimed to evaluate CSI scores, and their associations with other clinically relevant psychosocial variables, in a cohort of patients with CSPD who entered and completed a functional restoration program.

STUDY DESIGN/SETTING

A retrospective study of prospectively collected data from a cohort study of patients with CSPD, who completed the CSI at admission to, and discharge from, an interdisciplinary function restoration program (FRP) was carried out.

PATIENT SAMPLE

A cohort of 763 patients with CSPD comprised the study sample.

OUTCOME MEASURES

Clinical interviews evaluated mood disorders and abuse history. A series of self-reported measures evaluated comorbid psychosocial symptoms, including pain intensity, pain-related anxiety, depressive symptoms, somatization symptoms, perceived disability, and sleep disturbance, at FRP admission and discharge.

METHODS

Patients were grouped into five severity level groups, from mild to extreme, based on total CSI scores, at FRP admission, and then again at discharge. The FRP included a quantitatively directed and medically supervised exercise process, as well as a multimodal psychosocial disability management component.

RESULTS

The CSI severity groups were strongly associated with Major Depressive Disorder and previous abuse history (p<.01), which are known risk factors for CS-related symptoms and diagnoses. The CSI scores were also strongly associated with patient-reported CSS diagnoses on CSI Part B. The percentage of patients who reported a comorbid CSS diagnosis increased in each higher CSI-severity group, from 11% in the Subclinical group, to 56% in the Extreme group. The CSI severity groups were significantly related to other CS-related patient-reported symptoms, including pain intensity, pain-related anxiety, depressive symptoms, somatization symptoms, perceived disability, and sleep disturbance (p's<.001). The CSI scores, along with all other psychosocial measures, decreased at treatment discharge.

CONCLUSIONS

In the present study, admission CSI scores were highly associated with previous CSS diagnoses, CS-related symptoms, and clinically relevant patient-reported psychosocial variables. All psychosocial variables, as well as scores on the CSI, were significantly improved at FRP discharge. The CSI may have important clinical utility, as a screener and as a treatment outcome measure, for patients with CSPD participating in an interdisciplinary FRP.

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.

Central Sensitization-Based Classification for Temporomandibular Disorders: A Pathogenetic Hypothesis

Dysregulation of Autonomic Nervous System (ANS) and central pain pathways in temporomandibular disorders (TMD) is a growing evidence. Authors include some forms of TMD among central sensitization syndromes (CSS), a group of pathologies characterized by central morphofunctional alterations. Central Sensitization Inventory (CSI) is useful for clinical diagnosis. Clinical examination and CSI cannot identify the central site(s) affected in these diseases. Ultralow frequency transcutaneous electrical nerve stimulation (ULFTENS) is extensively used in TMD and in dental clinical practice, because of its effects on descending pain modulation pathways. The Diagnostic Criteria for TMD (DC/TMD) are the most accurate tool for diagnosis and classification of TMD. However, it includes CSI to investigate central aspects of TMD. Preliminary data on sensory ULFTENS show it is a reliable tool for the study of central and autonomic pathways in TMD. An alternative classification based on the presence of Central Sensitization and on individual response to sensory ULFTENS is proposed. TMD may be classified into 4 groups: (a) TMD with Central Sensitization ULFTENS Responders; (b) TMD with Central Sensitization ULFTENS Nonresponders; (c) TMD without Central Sensitization ULFTENS Responders; (d) TMD without Central Sensitization ULFTENS Nonresponders. This pathogenic classification of TMD may help to differentiate therapy and aetiology.

The Microbiome and Cancer: Implications for Oncology Nursing Science

BACKGROUND

Approximately 1.6 million Americans were diagnosed with cancer in 2014. To combat their disease, many individuals received either curative or palliative treatments that produced undesired symptoms. These symptoms, which often cause significant distress for individuals coping with cancer, may share biologic underpinnings such as epigenetic changes and immune dysregulation. Alterations in the normal flora of the gut may also influence cancer symptoms.

OBJECTIVE

The aim of this review is to describe the emerging role for the gut microbiome in cancer research, especially the potential relationship between the gut microbiome and cancer symptoms.

METHODS

Extant literature was reviewed and synthesized.

RESULTS

The majority of studies linking the gut microbiota and cancer are animal models and focus on the relationship between dysbiosis and colorectal cancer. Emerging evidence supports that the "gut-brain" connection is a plausible mechanism for "psychoneurological" cancer symptoms such as depression, pain, and fatigue.

CONCLUSIONS

There is compelling evidence that the gut microbiota affects cancer via several mechanisms, including microbial diversity and number, metabolism, and/or immune initiation. However, more research is necessary to elucidate these mechanisms, particularly among a variety of cancers and cancer-related symptoms.

IMPLICATIONS FOR PRACTICE

A better understanding of the role of the gut microbiota in cancer symptoms may lead to the development of targeted individualized interventions affecting the gut microbiota that prevent or ameliorate dysbiosis, thereby reducing symptoms. These interventions may emphasize self-care management strategies essential for wellness, such as diet, nutrition, and stress reduction.

Central Sensitization Inventory as a Predictor of Worse Quality of Life Measures and Increased Length of Stay Following Spinal Fusion

BACKGROUND

Central sensitization is abnormal and intense enhancement of pain mechanism by the central nervous system. Patients with central sensitization may be at higher risk of poor outcomes after spinal fusion. The Central Sensitivity Inventory (CSI) was developed to identify and quantify key symptoms related to central sensitization.

METHODS

In 664 patients who underwent thoracic and/or lumbar fusion, we evaluated retrospectively pretreatment CSI as a predictor of postoperative quality of life measures, length of stay, and discharge status.

RESULTS

Preoperative Pain Disability Questionnaire scores, Patient Health Questionnaire-9 scores, and EuroQol-5 Dimensions index scores were significantly worse in patients with preoperative CSI ≥40 compared with patients with preoperative CSI <40 (P < 0.0001 for all). After adjusting for demographic variables, operation duration, and preoperative health status, preoperative CSI was significantly associated with higher postoperative Pain Disability Questionnaire total score (unadjusted P < 0.001, adjusted P = 0.009), higher postoperative Patient Health Questionnaire-9 score (unadjusted P < 0.001, adjusted P = 0.001), and lower postoperative EuroQol-5 Dimensions index (unadjusted P < 0.001, adjusted P = 0.001). For each 10-unit increase in CSI, average length of stay increased by 6.4% (95% confidence interval 0.4%-12.6%, P = 0.035). The odds of being discharged home after adjusting for confounders was not statistically related to preoperative CSI (P = 0.0709).

CONCLUSIONS

Preoperative CSI was associated with worse quality of life outcomes and increased length of stay after spinal fusions. CSI may be an additional measure in evaluating patients preoperatively to better predict successful spinal fusion outcomes.

Childhood trauma perpetrated by close others, psychiatric dysfunction, and urological symptoms in patients with interstitial cystitis/bladder pain syndrome

BACKGROUND

A psychosocial phenotype of interstitial cystitis/bladder pain syndrome (IC/BPS), a urogenital condition without known organic causes, was proposed. While psychosocial variables, including interpersonal maltreatment and negative affect, were studied in association with IC/BPS, the specificities of the relationships between childhood trauma by close others, psychiatric dysfunctions (negative affect and post-traumatic psychopathology), and urogenital symptoms have not been established.

METHODS

94 IC/BPS patients were recruited together with 47 patients with acute cystitis who served as clinical controls. Standardized scales were used to assess various potentially traumatizing events in childhood and adulthood as well as psychiatric (dissociation and negative affect) and urogenital symptoms.

RESULTS

Among the potentially traumatizing events, those perpetrated by close others during childhood were found to be the most salient features discriminating the IC/BPS group from the control group. When divided into 2 subgroups according to their history of childhood trauma by close others, only IC/BPS patients with childhood trauma by close others had more dissociative and anxiety symptoms compared with the control group. These two subgroups did not differ in urogenital symptom severity.

CONCLUSIONS

Childhood trauma by close others, rather than other types of interpersonal trauma, was a differentiating characteristic in IC/BPS patients, and a childhood trauma related psychosocial phenotype with a distinct clinical profile of dissociation and anxiety proneness was identified. Future studies should investigate whether a distinct set of pathogenic factors exists in IC/BPS patients with a history of childhood trauma by close others, even if this subgroup is not readily differentiated by urogenital symptoms.

Chronic Pain in Children and Adolescents: Diagnosis and Treatment of Primary Pain Disorders in Head, Abdomen, Muscles and Joints

Primary pain disorders (formerly "functional pain syndromes") are common, under-diagnosed and under-treated in children and teenagers. This manuscript reviews key aspects which support understanding the development of pediatric chronic pain, points to the current pediatric chronic pain terminology, addresses effective treatment strategies, and discusses the evidence-based use of pharmacology. Common symptoms of an underlying pain vulnerability present in the three most common chronic pain disorders in pediatrics: primary headaches, centrally mediated abdominal pain syndromes, and/or chronic/recurrent musculoskeletal and joint pain. A significant number of children with repeated acute nociceptive pain episodes develop chronic pain in addition to or as a result of their underlying medical condition "chronic-on-acute pain." We provide description of the structure and process of our interdisciplinary, rehabilitative pain clinic in Minneapolis, Minnesota, USA with accompanying data in the treatment of chronic pain symptoms that persist beyond the expected time of healing. An interdisciplinary approach combining (1) rehabilitation; (2) integrative medicine/active mind-body techniques; (3) psychology; and (4) normalizing daily school attendance, sports, social life and sleep will be presented. As a result of restored function, pain improves and commonly resolves. Opioids are not indicated for primary pain disorders, and other medications, with few exceptions, are usually not first-line therapy.

Cross-cultural adaptation and validity of the Spanish central sensitization inventory

PURPOSING

The Central Sensitization Inventory (CSI) is a new patient-reported instrument, which measures symptoms related to Central Sensitivity Syndromes and Central Sensitization. The aim of this study was to translate the CSI into Spanish, and then to perform a psychometric validation, including a factor analysis to reveal the underlying structure.

METHODS

In this two-stage psychometric study participated 395 subjects with various chronic pain conditions and that were recruited from two Primary Care Centres. The CSI was cross-culturally adapted to Spanish through double forward and backward translations. The psychometric properties were then evaluated with analyses of construct validity, factor structure and internal consistency. One subgroup (n = 45) determined test-retest reliability at 7 days.

RESULTS

The Spanish Version of CSI demonstrated high internal consistency (α = 0.872) and test-retest reliability (r = 0.91). Factor structure was one-dimensional and supported construct validity.

CONCLUSIONS

The psychometric properties of the Spanish version were found to be strong, with high test-retest reliability and internal consistency, with similar psychometric properties to the English language version. Unlike the English version, however, a one factor solution was found to be a best fit for the Spanish version.

Myogenic temporomandibular disorders: Clinical systemic comorbidities in a female population sample

BACKGROUND

Myogenic temporomandibular disorders (MTMD) frequently coexist with other clinical conditions in the same individual. In the last decades, several authors have analyzed these comorbidities looking for the origin of this overlapping. Objetives: The aim of this study was to perform a comparative anaylisis between a group of patients with MTMD and a control group of dental patients without dysfunctional pathology to assess whether there are significant differences in the presence of systemic medical comorbidities between the two groups.

MATERIAL AND METHODS

Restrospective epidemiological analysis, based on medical questionnaires in a group of 31 patients, women, aged from 24 to 58 (average 39.96 years), diagnosed with MTMD (Masticatory Myofascial Pain), with a control group with the same number of individuals, gender and age range to evaluate if there is a significant statistical difference in the presence of medical comorbidities in this group of patients with MTMD and if they are in a higher risk of suffering different pathological conditions.

RESULTS

It was found that the group affected by MTMD presented many more associated medical conditions than the control group: health changes during the last year, medical evaluations and treatments, presence of pain, sinus disease, tinnitus, headache, joint pain, ocular disorders, fatigue, dizziness, genitourinary disorders and xerostomia among others; and they were also in a higher risk to suffer other pathological entities as headaches and articular pain.

CONCLUSIONS

These results reinforce our hypothesis that MTMD belong to a group of medical conditions triggered by a loss of equilibrium of the individual's Psycho-Neuro-Endocrine-Immune (PNEI) Axis that produces alterations in the response against external stimuli in some genetically predisposed individuals. It is, therefore, necessary to change the way of diagnosing and managing these individual's medical conditions, being mandatory to look from a more multidisciplinary perspective than the one we are currently offering.

Cross-cultural adaptation and validity of the Spanish central sensitization inventory

Purposing

The Central Sensitization Inventory (CSI) is a new patient-reported instrument, which measures symptoms related to Central Sensitivity Syndromes and Central Sensitization. The aim of this study was to translate the CSI into Spanish, and then to perform a psychometric validation, including a factor analysis to reveal the underlying structure.

Methods

In this two-stage psychometric study participated 395 subjects with various chronic pain conditions and that were recruited from two Primary Care Centres. The CSI was cross-culturally adapted to Spanish through double forward and backward translations. The psychometric properties were then evaluated with analyses of construct validity, factor structure and internal consistency. One subgroup (n = 45) determined test-retest reliability at 7 days.

Results

The Spanish Version of CSI demonstrated high internal consistency (α = 0.872) and test-retest reliability (r = 0.91). Factor structure was one-dimensional and supported construct validity.

Conclusions

The psychometric properties of the Spanish version were found to be strong, with high test-retest reliability and internal consistency, with similar psychometric properties to the English language version. Unlike the English version, however, a one factor solution was found to be a best fit for the Spanish version.

Fibromyalgia: Timely diagnosis and treatment options

Fibromyalgia can be challenging to diagnose and treat, and patients often feel isolated and misunderstood. Surveys of patients with fibromyalgia suggest that patients would benefit from greater understanding and acceptance. NPs can provide this support and play a prominent role in helping patients manage their fibromyalgia.

Opioid Use in Fibromyalgia: A Cautionary Tale

Multiple pharmacotherapies are available for the treatment of fibromyalgia (FM), including opioid analgesics. We postulate that the mechanism of action of traditional opioids predicts their lack of efficacy in FM. Literature searches of the MEDLINE and Cochrane Library databases were conducted using the search term opioid AND fibromyalgia to identify relevant articles, with no date limitations set. Citation lists in returned articles and personal archives of references were also examined for additional relevant items, and articles were selected based on the expert opinions of the authors. We found no evidence from clinical trials that opioids are effective for the treatment of FM. Observational studies have found that patients with FM receiving opioids have poorer outcomes than patients receiving nonopioids, and FM guidelines recommend against the use of opioid analgesics. Despite this, and despite the availability of alternative Food and Drug Administration-approved pharmacotherapies and the efficacy of nonpharmacologic therapies, opioids are commonly used in the treatment of FM. Factors associated with opioid use include female sex; geographic variation; psychological factors; a history of opioid use, misuse, or abuse; and patient or physician preference. The long-term use of opioid analgesics is of particular concern in the United States given the ongoing public health emergency relating to excess prescription opioid consumption. The continued use of opioids to treat FM despite a proven lack of efficacy, lack of support from treatment guidelines, and the availability of approved pharmacotherapy options provides a cautionary tale for their use in other chronic pain conditions.

Genome-wide expression profiling in the peripheral blood of patients with fibromyalgia

OBJECTIVES

Fibromyalgia (FM) is a common pain disorder characterized by nociceptive dysregulation. The basic biology of FM is poorly understood. Herein we have used agnostic gene expression as a potential probe for informing its underlying biology and the development of a proof-of-concept diagnostic gene expression signature.

METHODS

We analyzed RNA expression in 70 FM patients and 70 healthy controls. The isolated RNA was amplified and hybridized to Affymetrix® Human Gene 1.1 ST Peg arrays. The data was analyzed using Partek Genomics Suite version 6.6.

RESULTS

Fibromyalgia patients exhibited a differential expression of 421 genes (p<0.001), several relevant to pathways for pain processing, such as glutamine/glutamate signaling and axonal development. There was also an upregulation of several inflammatory pathways and downregulation of pathways related to hypersensitivity and allergy. Using rigorous diagnostic modeling strategies, we show "locked" gene signatures discovered on Training and Test cohorts, that have a mean Area Under the Curve (AUC) of 0.81 on randomized, independent external data cohorts. Lastly, we identified a subset of 10 probesets that provided a diagnostic sensitivity for FM of 95% and a specificity of 96%. We also show that the signatures for FM were very specific to FM rather than common FM comorbidities.

CONCLUSIONS

These findings provide new insights relevant to the pathogenesis of FM, and provide several testable hypotheses that warrant further exploration and also establish the foundation for a first blood-based molecular signature in FM that needs to be validated in larger cohorts of patients.

Clinical Characteristics of Dry Eye Patients With Chronic Pain Syndromes

PURPOSE

To investigate clinical characteristics of dry eye disease (DED) patients with a chronic pain syndrome.

DESIGN

Cross-sectional study.

METHODS

Four hundred twenty-five patients of a tertiary care DED patient cohort in the Netherlands were included. Chronic pain syndromes irritable bowel syndrome, chronic pelvic pain, and fibromyalgia were assessed by questionnaires. Outcome variables were the Ocular Surface Disease Index (OSDI) symptom questionnaire, tear osmolarity, Schirmer test, tear breakup time, conjunctival hyperemia, staining of the cornea and conjunctiva, and amount of mucus. Outcomes were cross-sectionally compared between DED patients with a chronic pain syndrome and those without.

RESULTS

A total of 74 out of 425 DED patients (17%) had at least 1 chronic pain syndrome. The total symptom score was significantly higher in DED patients with a chronic pain syndrome than in those without (45.8 vs 33.8, P < .0005). Moreover, patients with a chronic pain syndrome scored higher on every single subscale of the 12-item OSDI symptom questionnaire. However, ocular signs were similar or even less severe in these patients. Similarly, in 64 DED patients from the population-based cohort TwinsUK, patients with a chronic pain syndrome (n = 24, 38%) had higher subscale and total (34.1 vs 14.4, P = .001) symptom scores.

CONCLUSION

In DED patients, chronic pain syndromes are common and are associated with increased severity of DED symptoms across all domains of the OSDI, even though objective ocular surface signs are no worse. In clinical practice, more awareness of chronic pain syndromes might help in understanding the discrepancy between signs and symptoms in DED.

Risk of associated conditions in relatives of subjects with interstitial cystitis

OBJECTIVES

Urological chronic pelvic pain syndrome includes interstitial cystitis/painful bladder syndrome (IC/PBS), a chronic bladder pain condition of unknown etiology. Interstitial cystitis/painful bladder syndrome can co-occur with a number of associated conditions such as irritable bowel syndrome and fibromyalgia. The purpose of this study was to estimate the heritability of approximately 20 associated conditions in first-degree relatives (and if appropriate, second- and third-degree relatives) of patients with IC/PBS to identify shared genetic contributions for the disease combinations.

METHODS

We used the Utah Population Database, a unique population-based genealogical database that has been linked to electronic health records for the University of Utah Health Sciences Center back in 1994. Interstitial cystitis/painful bladder syndrome probands were identified by the International Classification of Diseases, Ninth Revision code for chronic interstitial cystitis and had genealogy information for 12 of their 14 immediate ancestors. We calculated excess risk of an associated condition in relatives of patients with IC/PBS using relative risk estimates.

RESULTS

We identified 248 IC/PBS probands. We found that 2 associated conditions, myalgia and myositis/unspecified (fibromyalgia) as well as constipation, were in significant excess in the patients with IC/PBS themselves, their first-degree relatives, and their second-degree relatives. The excess risk among relatives between IC/PBS and these associated conditions also held in the converse direction. Excess risk of IC/PBS was observed in the first- and second-degree relatives in probands with myalgia and myositis/unspecified (fibromyalgia) and in probands with constipation.

CONCLUSIONS

These results suggest that myalgia and myositis/unspecified (fibromyalgia) as well as constipation are likely to share underlying genetic factors with IC/PBS.

Neuropathic Ocular Pain due to Dry Eye is Associated with Multiple Comorbid Chronic Pain Syndromes

Recent data show that dry eye (DE) susceptibility and other chronic pain syndromes (CPS) such as chronic widespread pain, irritable bowel syndrome, and pelvic pain, might share common heritable factors. Previously, we showed that DE patients described more severe symptoms and tended to report features of neuropathic ocular pain (NOP). We hypothesized that patients with a greater number of CPS would have a different DE phenotype compared with those with fewer CPS. We recruited a cohort of 154 DE patients from the Miami Veterans Affairs Hospital and defined high and low CPS groups using cluster analysis. In addition to worse nonocular pain complaints and higher post-traumatic stress disorder and depression scores (P < .01), we found that the high CPS group reported more severe neuropathic type DE symptoms compared with the low CPS group, including worse ocular pain assessed via 3 different pain scales (P < .05), with similar objective corneal DE signs. To our knowledge, this was the first study to show that DE patients who manifest a greater number of comorbid CPS reported more severe DE symptoms and features of NOP. These findings provided further evidence that NOP might represent a central pain disorder, and that shared mechanistic factors might underlie vulnerability to some forms of DE and other comorbid CPS.

PERSPECTIVE

DE patients reported more frequent CPS (high CPS group) and reported worse DE symptoms and ocular and nonocular pain scores. The high CPS group reported symptoms of NOP that share causal genetic factors with comorbid CPS. These results imply that an NOP evaluation and treatment should be considered for DE patients.

Suppression of Peripheral Pain by Blockade of Voltage-Gated Calcium 2.2 Channels in Nociceptors Induces RANKL and Impairs Recovery From Inflammatory Arthritis in a Mouse Model

OBJECTIVE

A hallmark of rheumatoid arthritis (RA) is the chronic pain that accompanies inflammation and joint deformation. Patients with RA rate pain relief as the highest priority; however, few studies have addressed the efficacy and safety of therapies directed specifically toward pain pathways. The ω-conotoxin MVIIA (ziconotide) is used in humans to alleviate persistent pain syndromes, because it specifically blocks the voltage-gated calcium 2.2 (CaV 2.2) channel, which mediates the release of neurotransmitters and proinflammatory mediators from peripheral nociceptor nerve terminals. The aims of this study were to investigate whether blockade of CaV 2.2 can suppress arthritis pain, and to examine the progression of induced arthritis during persistent CaV 2.2 blockade.

METHODS

Transgenic mice expressing a membrane-tethered form of MVIIA under the control of a nociceptor-specific gene (MVIIA-transgenic mice) were used in the experiments. The mice were subjected to unilateral induction of joint inflammation using a combination of antigen and collagen.

RESULTS

CaV 2.2 blockade mediated by tethered MVIIA effectively suppressed arthritis-induced pain; however, in contrast to their wild-type littermates, which ultimately regained use of their injured joint as inflammation subsided, MVIIA-transgenic mice showed continued inflammation, with up-regulation of the osteoclast activator RANKL and concomitant joint and bone destruction.

CONCLUSION

Taken together, our results indicate that alleviation of peripheral pain by blockade of CaV 2.2- mediated calcium influx and signaling in nociceptor sensory neurons impairs recovery from induced arthritis and point to the potentially devastating effects of using CaV 2.2 channel blockers as analgesics during inflammation.

Irritable bowel syndrome: an integrated explanatory model for clinical practice

BACKGROUND

Although irritable bowel syndrome (IBS) is a symptom-based diagnosis, clinicians' management of and communication about the disorder is often hampered by an unclear conceptual understanding of the nature of the problem. We aimed to elucidate an integrated explanatory model (EM) for IBS from the existing literature for pragmatic use in the clinical setting.

METHODS

Systematic and exploratory literature searches were performed in PubMed to identify publications on IBS and EMs.

KEY RESULTS

The searches did not identify a single, integrated EM for IBS. However, three main hypotheses were elucidated that could provide components with which to develop an IBS EM: (i) altered peripheral regulation of gut function (including sensory and secretory mechanisms); (ii) altered brain-gut signaling (including visceral hypersensitivity); and (iii) psychological distress. Genetic polymorphisms and epigenetic changes may, to some degree, underlie the etiology and pathophysiology of IBS and could increase the susceptibility to developing the disorder. The three model components also fit into one integrated explanation for abdominal symptoms and changes in stool habit. Additionally, IBS may share a common pathophysiological mechanism with other associated functional syndromes.

CONCLUSIONS & INFERENCES

It was possible to elucidate an integrated, three-component EM as a basis for clinicians to conceptualize the nature of IBS, with the potential to contribute to better diagnosis and management, and dialog with sufferers.

Juvenile Fibromyalgia: A Multidisciplinary Approach to Treatment

A 14-year-old boy presented with months of severe widespread musculoskeletal pain. He was profoundly fatigued and unable to attend school. Laboratory evaluation, including complete blood count, comprehensive metabolic panel, inflammatory markers, and thyroid function, was unrevealing. Physical examination was also normal except for multiple tender points. The patient was diagnosed with juvenile primary fibromyalgia syndrome and referred for multidisciplinary treatment including physical therapy, exercise, and counseling, and his daily functioning gradually improves. Juvenile fibromyalgia is a complex syndrome that often severely limits patients' activities and can impede normal adolescent development. Effective treatment requires an understanding of the biologic, psychologic, and social factors contributing to the perpetuation of chronic pain. The author reviews the diagnostic criteria, pathophysiology, and treatment of juvenile fibromyalgia. Medications, particularly antidepressants and anticonvulsants, can be useful adjuncts to therapy. However, multimodal pain management including intensive physical therapy, exercise, counseling, and sleep hygiene is most effective in treating fibromyalgia.

Ischemia-hyperpnea test is useful to detect patients with fibromyalgia syndrome

OBJECTIVE

To demonstrate the prevalence of neuromuscular hyperexcitability in Fibromyalgia Syndrome (FMS) by electromyography ischaemia-hyperpnea test (IHT) and its correlation with clinical and clinimetric parameters.

MATERIAL AND METHODS

One hundred and forty-five FMS patients underwent IHT to evaluate neuromuscular hyperexcitability and were evaluated for pain (numeric Rating Scale and Regional Pain Scale), tenderness (tender points), disability [Fibromyalgia Impact Questionnaire (FIQ), Health Assessment Questionnaire (HAQ)], quality of life (QOL) [Short Form 36 (SF36)], mood [Hospital Anxiety and Depression Scale (HADS)], sleep [numeric rating scale (NRS)], and fatigue [Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT)].

RESULTS

Of the 145 patients, 95 were tested positive by IHT, and 33 and 17 patients were negative and borderline, respectively. By comparing the three groups, IHT positive patients had lower age and lower SF36 vitality (V), social activities (SA), and mental summary index (MSI) than negative patients (p<0.05). By comparing positive versus negative patients and by comparing positive and borderline patients versus negative patients, it was found that FACIT was higher, whereas age, SF36 V, SA, mental health (MH), and MSI were lower (p<0.05).

CONCLUSION

FMS patients present a high prevalence of neuromuscular hyperexcitability, as assessed by IHT. IHT positive patients have poor QOL and higher fatigue than IHT negative patients. Thus, IHT positivity could identify FMS patients with a more severe disease.

Fibrofog and fibromyalgia: a narrative review and implications for clinical practice

Patients with fibromyalgia often report forgetfulness as well as declines in cognitive function, memory, and mental alertness-symptoms that have been termed "fibrofog" in popular and electronic media as well as in professional literature. "Fibrofog" is the subjectively experienced cognitive dysfunction associated with fibromyalgia and is a clinically important yet comparatively less well-studied aspect of the disorder; it includes loss of mental clarity (mental fogginess) as well as attention and memory impairment. Although until recently cognitive symptoms have been largely ignored, these symptoms can be more disturbing than the widespread pain and can change these patients' lives, sometimes dramatically so. Whereas widespread musculoskeletal pain, tenderness, and fatigue may be the hallmark symptoms of fibromyalgia, patients rank cognitive dysfunction highly in terms of disease impact. This review addresses (1) the prevalence of self-reported cognitive disturbances in fibromyalgia, (2) the clinical presentation of fibrofog, (3) neuropsychological test performance, with particular attention to discrepancies between self-report and test results, (3) clinical correlates of impaired cognitive function in fibromyalgia, (4) neurobiology relevant to cognitive disturbances in fibromyalgia, and (5) clinical management of fibrofog. Although the pathophysiology of fibromyalgia remains an enigma, evidence suggests that it may be a brain disorder, with cognitive deficits ("fibrofog") reflecting disturbed centrally mediated processes.

MMPI-2-RF characteristics of individuals with interstitial cystitis

OBJECTIVES

This study aimed to describe the psychological functioning of interstitial cystitis/bladder pain syndrome patients utilizing MMPI-2-RF scoring.

METHODS

The MMPI-2 was administered to 60 individuals who reported a diagnosis of IC. Responses were scored in the MMPI-2-RF format. Fifty-one protocols were deemed valid.

RESULTS

Elevations were discovered on scales FBS-r (symptom validity), RC1 (somatic complaints), and MLS (malaise). Participants were split into two groups based on extreme elevations on RC1; the high RC1 group produced higher scores on 39 scales including clinically significant elevations on 17 scales.

CONCLUSION

Over 25% of this sample had an emotional component to their physical concerns. This knowledge about the psychological characteristics of IC patients may have clinical utility for physicians and other treatment providers. The results argue strongly for psychological evaluation as a component of IC diagnosis and treatment. Those with significant emotional overlay to their somatic complaints may be best managed through psychological interventions and minimally invasive treatments.

Prevalence of low back pain as the primary pain site and factors associated with low health-related quality of life in a large Japanese population: a pain-associated cross-sectional epidemiological survey

OBJECTIVES

This study aimed to estimate the prevalence, magnitude, and direction of the associations among disability, pain intensity, number of pain sites, and health-related quality of life (HRQoL) in patients reporting low back pain (LBP) as their primary pain.

METHODS

In January 2009, an Internet survey was performed for randomly selected adults aged 20-79 years who were registered as Internet research volunteers. Of 20 044 respondents, individuals with LBP as the primary pain were analyzed for associations among disability, number of pain sites, and HRQoL. Factors associated with low HRQoL were examined using multiple logistic regression modeling.

RESULTS

Of the 20 044 respondents, 25.2 % (n = 5060) reported LBP and 13.5 % (n = 2696) reported LBP as their primary pain. Among those with LBP as the primary pain, HRQoL decreased with increase in disability and number of pain sites. In multivariate analyses, disability [adjusted odds ratio (aOR), 2.93-4.58], number of pain sites (aOR, 1.42-6.12), pain intensity ≥7 (aOR, 1.88), and age ≥60 years (aOR, 1.55) were associated with low HRQoL.

CONCLUSIONS

Approximately 13.5 % of patients reported LBP as their primary pain. Disability with absence from social activity and ≥7 pain sites were strongly associated with low HRQoL.

Experimental pain responses support peripheral and central sensitization in patients with unilateral shoulder pain

OBJECTIVE

The aims of this study were to (1) examine the pattern of experimental pain responses in the affected and nonaffected extremities in patients with shoulder pain and (2) explore the intraindividual association between sensitization states derived from experimental pain testing.

METHODS

Experimental pain responses from 58 patients with shoulder pain (17 women, aged 18 to 52 y) were compared with those from 56 age-matched and sex-matched pain-free volunteers (16 women, aged 21 to 58 y). Experimental pain responses included pressure pain threshold (PPT), thermal pain threshold and tolerance, and suprathreshold heat pain response. Comparisons were made between the affected and nonaffected extremities of clinical participants and the average response of extremities in control participants. Peripheral and central sensitization indexes were computed for clinical participants using standardized scores and percentile cutoffs on the basis of the data from the control sample. Experimental pain responses in clinical participants observed beyond the 25th and 75th percentile of control sample responses were used for investigation of intraindividual association of sensitization states.

RESULTS

PPT at the acromion and masseter on the affected side of clinical participants were diminished compared with that on their nonaffected side (P<0.015). Bilateral sensitivity in clinical participants was noted for PPT at the acromion and suprathreshold heat pain response (P<0.015). Peripheral and central sensitization indexes demonstrated that individuals with shoulder pain present with variable patterns of peripheral and central sensitization.

CONCLUSIONS

Collectively, experimental pain responses supported peripheral and central sensitization in response to pressure and thermal stimuli. No clear association was made between individuals exhibiting peripheral or central sensitization, thus suggesting heterogeneity in pain processing in this clinical population.

A collaborative approach between chiropractic and dentistry to address temporomandibular dysfunction: a case report

OBJECTIVE

The purpose of this case report is to describe the chiropractic and dental comanagement of a patient with temporomandibular dysfunction, headaches, and myalgia.

CLINICAL FEATURES

A 38-year-old black female patient presented for chiropractic care with a chief concern of jaw pain, tinnitus, headaches, and neck and shoulder soreness of 8 months' duration. The patient rated the pain a 6/10. The patient had a maximum mouth opening of 42 mm, graphed evidence of disk displacement, loss of translation on opening of the right temporomandibular joint viewed on the lateral radiograph, and numerous areas of point tenderness on the Kinnie-Funt Chief Complaint Visual Index. She had decreased lateral cervical flexion.

INTERVENTION AND OUTCOME

Dental treatment consisted of an anterior repositioning splint. Chiropractic care consisted of Activator treatment to the pelvis and the thoracic and cervical spine. Manual manipulation of the temporomandibular joint was performed along with a soft tissue technique intraorally on the lateral pterygoid. Postisometric relaxation in the head and neck region was also done. The patient was treated 6 times over 3 weeks. At the end of treatment, the patient had a pain rating of 0/10, maximum mouth opening of 49 mm, no tender points on the follow-up Kinnie-Funt, and increased cervical range of motion.

CONCLUSION

The patient demonstrated increased mouth opening, decreased pain rating, improved Kinnie-Funt visual index, and an increased cervical lateral flexion range of motion after 3 weeks of a combination of chiropractic and dental care.

Pain Symptoms in Fibromyalgia Patients with and without Provoked Vulvodynia

Objective. The aim of the study was to compare the pain symptoms of fibromyalgia patients exhibiting (FMS+PVD) and not exhibiting (FMS) comorbidity with provoked vulvodynia. Study Design. The case control study was performed in 39 patients who had been diagnosed with FMS and accepted to undergo gynaecological examination and in 36 healthy women (C). All patients completed standardized questionnaires for pain intensity, pain area, and psychological functioning. The gynaecological examination included vulvar pain pressure reactivity (Q-tip), pelvic tone assessment (Kegel manoeuver), and a semistructured interview collecting detailed information about pelvic symptoms and sexual function. Results. FMS+PVD patients displayed a higher number of associated symptoms than FMS patients. The vulvar excitability was significantly higher in FMS+PVD than in FMS and in both groups than in Controls. Half of FMS+PVD patients were positive to Kegel manoeuver and displayed higher scores in widespread pain intensity, STAI-Y2, and CESD levels than Kegel negative patients. Conclusions. The study reveals that increased vulvar pain excitability may occur in FMS patients independently of the presence of coital pain. Results suggest that coital pain develops in patients with higher FMS symptoms severity due to the cooperative effects of peripheral and central sensitization mechanisms.

Spinal manipulative therapy-specific changes in pain sensitivity in individuals with low back pain (NCT01168999)

Spinal manipulative therapy (SMT) is effective for some individuals experiencing low back pain; however, the mechanisms are not established regarding the role of placebo. SMT is associated with changes in pain sensitivity, suggesting related altered central nervous system response or processing of afferent nociceptive input. Placebo is also associated with changes in pain sensitivity, and the efficacy of SMT for changes in pain sensitivity beyond placebo has not been adequately considered. We randomly assigned 110 participants with low back pain to receive SMT, placebo SMT, placebo SMT with the instructional set "The manual therapy technique you will receive has been shown to significantly reduce low back pain in some people," or no intervention. Participants receiving the SMT and placebo SMT received their assigned intervention 6 times over 2 weeks. Pain sensitivity was assessed prior to and immediately following the assigned intervention during the first session. Clinical outcomes were assessed at baseline and following 2 weeks of participation in the study. Immediate attenuation of suprathreshold heat response was greatest following SMT (P = .05, partial η(2) = .07). Group-dependent differences were not observed for changes in pain intensity and disability at 2 weeks. Participant satisfaction was greatest following the enhanced placebo SMT. This study was registered at www.clinicaltrials.gov under the identifier NCT01168999.

PERSPECTIVE

The results of this study indicate attenuation of pain sensitivity is greater in response to SMT than the expectation of receiving an SMT. These findings suggest a potential mechanism of SMT related to lessening of central sensitization and may indicate a preclinical effect beyond the expectations of receiving SMT.

A pilot study of myofascial release therapy compared to Swedish massage in fibromyalgia

Fibromyalgia (FM) is characterized by widespread muscle pain and soft tissue tenderness. However, a lack of definitive muscle pathology has made FM both a diagnostic and a treatment puzzle. Much of the evidence for pathology in FM lies in the central nervous system - in particular abnormal amplification of pain signals in the spinal cord - a manifestation of central sensitization. An emerging body of evidence posits that peripheral pain generated from the muscles and fascia may trigger and maintain central sensitization in FM. Since FM patients so frequently seek manual therapy to relieve muscle symptoms, the present study compared two different manual therapy techniques in a parallel study of women with FM. Eight subjects received myofascial release (MFR) while four subjects received Swedish massage, 90 min weekly for four weeks. Overall symptom burden and physical function were assessed by the Fibromyalgia Impact Questionnaire Revised (FIQ-R). A unique challenge for the manual therapist in treating conditions involving central sensitization is to determine if localized pain reduction can be achieved with targeted therapy in the context of ongoing widespread pain. Localized pain improvement was measured by a novel questionnaire developed for this study, the modified Nordic Musculoskeletal Questionnaire (NMQ). Between-group differences in FIQ-R did not reach statistical significance, but the total change scores on FIQ-R for the MFR group (mean = 10.14, SD = 16.2) trended in the hypothesized and positive direction compared to the Swedish massage group (mean = 0.33, SD = 4.93) yielding a positive Aikin separation test. Although overall modified NMQ scores improved in both groups there were no consistent focal areas of improvement for the Swedish massage group. In contrast, the MFR group reported consistent pain reductions in the neck and upper back regions on the NMQ. These data support the need for larger randomized controlled trials of MFR versus other massage techniques and support the assessment of localized pain reduction in future manual therapy studies in FM.

Prevalence of low back pain as the primary pain site and factors associated with low health-related quality of life in a large Japanese population: a pain-associated cross-sectional epidemiological survey

OBJECTIVES: This study aimed to estimate the prevalence, magnitude, and direction of the associations among disability, pain intensity, number of pain sites, and health-related quality of life (HRQoL) in patients reporting low back pain (LBP) as their primary pain. METHODS: In January 2009, an Internet survey was performed for randomly selected adults aged 20-79 years who were registered as Internet research volunteers. Of 20 044 respondents, individuals with LBP as the primary pain were analyzed for associations among disability, number of pain sites, and HRQoL. Factors associated with low HRQoL were examined using multiple logistic regression modeling. RESULTS: Of the 20 044 respondents, 25.2 % (n = 5060) reported LBP and 13.5 % (n = 2696) reported LBP as their primary pain. Among those with LBP as the primary pain, HRQoL decreased with increase in disability and number of pain sites. In multivariate analyses, disability [adjusted odds ratio (aOR), 2.93-4.58], number of pain sites (aOR, 1.42-6.12), pain intensity ≥7 (aOR, 1.88), and age ≥60 years (aOR, 1.55) were associated with low HRQoL. CONCLUSIONS: Approximately 13.5 % of patients reported LBP as their primary pain. Disability with absence from social activity and ≥7 pain sites were strongly associated with low HRQoL.

Orofacial pain and temporomandibular disorders: the impact on oral health and quality of life

Many conditions may cause painful symptoms in orofacial structures. Among the chronic conditions that affect this area, temporomandibular disorders are the most common. Temporomandibular Disorder is a collective term that includes a number of clinical complaints involving the masticatory muscles, the Temporomandibular Joint and associated structures. In some cases, these complaints can be associated with depression, catastrophizing behavior and impact on quality of life. The present study aims to explain the relationship between Temporomandibular Disorders and pain chronification and their relation to a variety of psychosocial and behavioral comorbid conditions. The mechanisms of pain conduction and suggestions for management are also addressed.

The Central Sensitization Inventory (CSI): establishing clinically significant values for identifying central sensitivity syndromes in an outpatient chronic pain sample

Central sensitization (CS) is a proposed physiological phenomenon in which central nervous system neurons become hyperexcitable, resulting in hypersensitivity to both noxious and non-noxious stimuli. The term central sensitivity syndrome (CSS) describes a group of medically indistinct (or nonspecific) disorders, such as fibromyalgia, chronic fatigue syndrome, and irritable bowel syndrome, for which CS may be a common etiology. In a previous study, the Central Sensitization Inventory (CSI) was introduced as a screening instrument for clinicians to help identify patients with a CSS. It was found to have high reliability and validity (test-retest reliability = .82; Cronbach's alpha = .88). The present study investigated a cohort of 121 patients who were referred to a multidisciplinary pain center, which specializes in the assessment and treatment of complex pain and psychophysiological disorders, including CSSs. A large percentage of patients (n = 89, 74%) met clinical criteria for one or more CSSs, and CSI scores were positively correlated with the number of diagnosed CSSs. A receiver operating characteristic analysis determined that a CSI score of 40 out of 100 best distinguished between the CSS patient group and a nonpatient comparison sample (N = 129) (area under the curve = .86, sensitivity = 81%, specificity = 75%).

PERSPECTIVE

The CSI is a new self-report screening instrument to help identify patients with CSSs, including fibromyalgia. The present study investigated CSI scores in a heterogeneous pain population with a large percentage of CSSs, and a normative nonclinical sample to determine a clinically relevant cutoff value.

The prevalence of fibromyalgia and its relation with headache characteristics in episodic migraine

The objective of this study was to assess the prevalence of fibromyalgia (FM) in patients with episodic migraine and to evaluate the relationship between migraine characteristics and FM. One hundred and eighteen consecutive patients (mean age = 38 years, 75% women) fulfilling the International Classification of Headache Disorders-II criteria for migraine with (n = 22) and without (n = 96) aura from an outpatient headache clinic of a university hospital were evaluated. The diagnosis of FM was made based on the 1990 American College of Rheumatology classification criteria. Participants completed some self-administered questionnaires ascertaining sociodemographics, headache severity, frequency and duration, headache-related disability (Headache Impact Test [HIT-6]) and Migraine Disability Assessment Scale, widespread musculoskeletal pain (visual analog scale), depression (Beck depression inventory), anxiety (Beck anxiety inventory), sleep quality (Pittsburgh Sleep Quality Index), fatigue (Multidimensional Assessment of Fatigue), and quality of life (Short Form-36 Health Survey [SF-36]). In patients with FM, the tender point count and the Fibromyalgia Impact Questionnaire were employed. FM was diagnosed in 37 (31.4%) of the patients. FM comorbidity was equally distributed across patients with and without aura. Severity of migraine headache, HIT-6, and anxiety were especially associated with FM comorbidity. Patients suffering from migraine plus FM reported lower scores on all items of the SF-36. This study indicates that the assessment and management of coexisting FM should be taken into account in the assessment and management of migraine, particularly when headache is severe or patients suffer from widespread musculoskeletal pain.