The epidemiology of chronic syndromes that are frequently unexplained: do they have common associated factors?

Dentists’ and Specialists’ Knowledge of Chronic Orofacial Pain: Results from a Continuing Professional Development Survey

Aim

To explore the knowledge of chronic orofacial pain within general dental practitioners (GDPs) and dental specialists.

Methods

Following a recent national survey of GDPs and specialists on the diagnosis of facial pain, all those who responded were asked to answer four multiple-choice questions on chronic orofacial pain as part of a continuing professional development exercise. The questions were formulated using a review of the literature and consultation with a facial pain expert and were administered by post.

Results

Of the 380 subjects who completed the original survey, 212 (56%) returned completed multiple-choice questionnaires. Specialists correctly answered significantly more questions than GDPs ( P<0.001). The majority of specialists—49/83 (59%)—obtained a score of three or more, compared to 39/129 (30%) GDPs. This was due to variation in answering one question. Significantly more specialists—50 (60%)—correctly selected trigeminal neuralgia (TN) as a condition that is not associated with COFP, whereas only 41 (32%) GDPs chose this answer. Both specialists and GDPs grossly underestimated the prevalence of COFP in secondary care clinics.

Conclusions

The results suggest that specialists and GDPs may have sufficient knowledge to make an appropriate diagnosis of COFP, but they also highlight the knowledge gaps and perhaps the need for more extensive inclusion of COFP in the dental undergraduate curriculum.

Prevalence of chronic fatigue among Chinese adults in Hong Kong: a population-based study

BACKGROUND

Epidemiologic data is available on chronic fatigue for Western, but not for Chinese populations. The aims of the present study were to determine the prevalence of chronic fatigue in the general population of Hong Kong, compare health and lifestyle characteristics of non-chronic fatigue and chronic fatigue cases, and identify risk factors for chronic fatigue.

METHODS

We performed telephone interviews on 5001 randomly selected Chinese adults aged ≥18 years administering the Chinese version of Chronic Fatigue Scale (ChCFS), the Hospital Anxiety and Depression Scale (HADS), and quality of life (QoL) indexed by Medical Outcomes Study 12-item Short-Form Health Survey (SF12). Lifestyle, and sociodemographic data were also collected. Chronic fatigue was defined according to Fukuda et al.'s (1994) criteria and case criterion was a ChCFS total scores ≥4.

RESULTS

The weighted prevalence of chronic fatigue was 10.7%, which was equivalent to 0.6 million adults in Hong Kong. Higher prevalence rates were found in females, older age groups, and low socioeconomic status. Fully adjusted stepwise regression analyses identified older age, retirees, housewife, existing long-term health problems, higher HADS scores, poor QoL, and low self-perceived health to be significantly associated with increased risk of chronic fatigue, whereas regular exercise was associated with decreased risk of chronic fatigue (all p<0.05).

LIMITATIONS

The cross-sectional design did not allow determination of the time course and causal relationship between chronic fatigue and associated factors.

CONCLUSIONS

Our data evidenced that chronic fatigue is common in the general population of Hong Kong, and the prevalence increased with age and was higher in the women and lower socioeconomic population.

Management of unexplained symptoms in survivors of cancer

Quality health care for survivors of cancer must evaluate and manage symptoms that are reported at the surveillance visit but are not linked to a cancer recurrence or a new cancer. At present, this does not always occur. This article analyzes quality of health care for survivors of cancer, taking empirical evidence and clinical expertise into consideration. Although emotional distress on the part of the survivor of cancer may exacerbate or even explain the presence of experienced symptoms, there are other potential explanations as well. When survivors present with persistent symptoms (even if unexplained) after cancer diagnosis and treatment, the symptoms can impact the survivor's function and well-being. Oncologists and other providers need to assess and directly target these symptoms for appropriate triage to those who can best help these survivors reduce the symptoms and their impact.

Trajectories of pain in adolescents: a prospective cohort study

Identification of different patterns of change in pain over time - trajectories - has the potential to provide new information on the course of pain. Describing trajectories among adolescents would improve understanding of how pain conditions can develop. This prospective cohort study identified distinct trajectories of pain among adolescents (11-14 years) in the general population (n=1336). Latent class growth analysis was carried out on the self-reported frequency of back pain, headache, stomach pain and facial pain, which was collected every 3 months for 3 years. Forty four percent of adolescents had a 'painful' trajectory for at least one pain site, and 12% reported persistent pain at one or more pain site. Headache was the most common; 25% of subjects were in a 'painful' trajectory and 5% reported persistent pain. Back pain and stomach pain were also common, with 22% and 21% of subjects in painful trajectories, respectively. Facial pain was the least common, with only 10% in a painful trajectory, and 1% reporting persistent pain. Trajectory characteristics were similar at baseline across pain sites, with the more painful trajectories having significantly higher levels of depression and somatization, lower life satisfaction and more females. Trajectories did not differ significantly at baseline in physical activity levels or BMI. Agreement of trajectory membership among pain sites was moderate. In summary, reporting a painful trajectory was common among adolescents, but persistent pain was reported by a small minority, and was usually experienced at a single pain site.

Central sensitization: implications for the diagnosis and treatment of pain

Nociceptor inputs can trigger a prolonged but reversible increase in the excitability and synaptic efficacy of neurons in central nociceptive pathways, the phenomenon of central sensitization. Central sensitization manifests as pain hypersensitivity, particularly dynamic tactile allodynia, secondary punctate or pressure hyperalgesia, aftersensations, and enhanced temporal summation. It can be readily and rapidly elicited in human volunteers by diverse experimental noxious conditioning stimuli to skin, muscles or viscera, and in addition to producing pain hypersensitivity, results in secondary changes in brain activity that can be detected by electrophysiological or imaging techniques. Studies in clinical cohorts reveal changes in pain sensitivity that have been interpreted as revealing an important contribution of central sensitization to the pain phenotype in patients with fibromyalgia, osteoarthritis, musculoskeletal disorders with generalized pain hypersensitivity, headache, temporomandibular joint disorders, dental pain, neuropathic pain, visceral pain hypersensitivity disorders and post-surgical pain. The comorbidity of those pain hypersensitivity syndromes that present in the absence of inflammation or a neural lesion, their similar pattern of clinical presentation and response to centrally acting analgesics, may reflect a commonality of central sensitization to their pathophysiology. An important question that still needs to be determined is whether there are individuals with a higher inherited propensity for developing central sensitization than others, and if so, whether this conveys an increased risk in both developing conditions with pain hypersensitivity, and their chronification. Diagnostic criteria to establish the presence of central sensitization in patients will greatly assist the phenotyping of patients for choosing treatments that produce analgesia by normalizing hyperexcitable central neural activity. We have certainly come a long way since the first discovery of activity-dependent synaptic plasticity in the spinal cord and the revelation that it occurs and produces pain hypersensitivity in patients. Nevertheless, discovering the genetic and environmental contributors to and objective biomarkers of central sensitization will be highly beneficial, as will additional treatment options to prevent or reduce this prevalent and promiscuous form of pain plasticity.

Risk factors predicting the development of widespread pain from chronic back or neck pain

Emerging evidence suggests that some individuals with regional pain disorders go on to develop chronic widespread pain (CWP). However, the mechanism behind this transition and the nature of risk factors that predispose a person to develop CWP remain to be elucidated. The purpose of this study was to describe the frequency with which participants with chronic back or neck pain develop CWP and to determine the risk factors associated with this development. In a sample of 512 individuals, we found that nearly a quarter (22.6%) of subjects who presented with regional back or neck pain in 2001/2002 had developed CWP by 2007. Logistic regression indicated that 7 factors were associated with the transition to CWP: moderate or severe pain intensity, female gender, history of abuse, family history of CWP, severe interference with general activity, having 1 or more central sensitivity syndromes, and using more pain management strategies. History of abuse was not significant in multivariate analysis. Notably, number of depressive symptoms endorsed, pain duration, age, body mass index, number of medication classes used, and receipt of disability benefits were not significantly associated with this transition.

PERSPECTIVE

This study offers insight into risk factors associated with the development of CWP. This information not only offers clues as to the mechanism behind the expansion of pain sensitivity from a regional pain locus to a widespread pain disorder but also provides insight as to how clinicians might mitigate this transition.

Genetic variation in neuroendocrine genes associates with somatic symptoms in the general population: results from the EPIFUND study

OBJECTIVE

Functional somatic syndromes commonly occur together, share a genetic component and are associated with numerous somatic symptoms. This study aimed to determine if genetic variation in two neuroendocrine systems, the serotoninergic system and the hypothalamic-pituitary-adrenal (HPA) axis, was associated with the number of reported somatic symptoms.

METHODS

This population-based cohort study (Epidemiology of Functional Disorders) recruited participants from three primary care registers in the northwest of England. Somatic symptoms, anxiety, depression, and pain were assessed using the Somatic Symptoms Checklist, Hospital Anxiety and Depression scales, and body manikins, respectively, via a postal questionnaire. Tag Single Nucleotide Polymorphisms (SNPs) (r(2)>0.8) were selected for serotoninergic system genes (TPH2, SLC6A4 and HTR2A) and HPA axis genes (CRH, CRHR1, CRHBP, MC2R, POMC, NR3C1, and SERPINA6) and genotyped using Sequenom technology. Negative binomial regression was used to test for association between SNPs and the number of somatic symptoms. Stepwise-regression was used to identify independent effects and adjustments were made for anxiety, depression, and pain.

RESULTS

A total of 967 subjects were successfully genotyped for 143 (87%) SNPs. Multiple SNP associations with the number of somatic symptoms were observed in HTR2A and SERPINA6 as well as two SNPs in TPH2. Stepwise regression identified two effects in HTR2A and a single effect in TPH2 which were independent of anxiety, depression, and pain. A single effect was also identified in SERPINA6 but was no longer significant when adjusted for pain.

CONCLUSION

This study finds association of SNPs in HTR2A, SERPINA6, and TPH2 with somatic symptoms implicating them as potentially important in the shared genetic component to functional somatic syndromes, although replication is required.

Latent class analysis of functional somatic symptoms in a population-based sample of twins

OBJECTIVE

This study aimed to investigate empirically how and in what way individuals with symptoms of functional somatic syndromes should be classified. We also aimed to look into genetic and environmental influences on the classification.

METHOD

A total of 28,531 twins aged 41-64 underwent screening interviews via a computer-assisted data collection system from 1998 to 2002. Nine functional somatic symptoms (abnormal tiredness, general muscular pain, recurrent abdominal discomfort, back pain, gastroesophageal reflux, recurrent headache, recurrent urinary problem, dizziness, breathlessness at rest) were assessed using structured questions in a blinded manner. Latent class analysis was applied to the data. Structural equation modeling was further performed in order to estimate the relative importance of genetic and environmental influences on class probability.

RESULTS

Latent class analysis resulted in a five-class solution. Individuals in the first class did not show any health problems. Those assigned to the second, third, and fourth classes tended to have abnormal tiredness, gastrointestinal problems, and pain-related symptoms, respectively. Individuals in the fifth class had multiple symptoms to a greater extent than the other classes. All the five classes showed modest genetic influences (7-29% of the total variation) with gender differences except Class 3; however, the majority of influences on the class membership derived from unique environmental effects.

CONCLUSION

The findings suggested the necessity of redefining the existing classification criteria for functional somatic syndromes in terms of single (uncomplicated) or multiple (complicated) syndromes. Environmental influences are important for the etiology of functional somatic syndromes.

Towards positive diagnostic criteria: a systematic review of somatoform disorder diagnoses and suggestions for future classification

OBJECTIVES

The classification of somatoform disorders is currently being revised in order to improve its validity for the DSM-V and ICD-11. In this article, we compare the validity and clinical utility of current and several new diagnostic proposals of those somatoform disorders that focus on medically unexplained somatic symptoms.

METHODS

We searched the Medline, PsycInfo, and Cochrane databases, as well as relevant reference lists. We included review papers and original articles on the subject of somatoform classification in general, subtypes of validity of the diagnoses, or single diagnostic criteria.

RESULTS

Of all diagnostic proposals, only complex somatic symptom disorder and the Conceptual Issues in Somatoform and Similar Disorders (CISSD) example criteria reflect all dimensions of current biopsychosocial models of somatization (construct validity) and go beyond somatic symptom counts by including psychological and behavioral symptoms that are specific to somatization (descriptive validity). Predictive validity of most of the diagnostic proposals has not yet been investigated. However, the number of somatic symptoms has been found to be a strong predictor of disability. Some evidence indicates that psychological symptoms can predict disease course and treatment outcome (e.g., therapeutic modification of catastrophizing is associated with positive outcome). Lengthy symptom lists, the requirement of lifetime symptom report (as in abridged somatization), complicated symptom patterns (as in current somatization disorder), and imprecise definitions of diagnostic procedures (e.g., missing symptom threshold in complex somatic symptom disorder) reduce clinical utility.

CONCLUSION

Results from the reviewed studies suggest that, of all current and new diagnostic suggestions, complex somatic symptom disorder and the CISSD definition appear to have advantages regarding validity and clinical utility. The integration of psychological and behavioral criteria could enhance construct and descriptive validity, and confers prospectively relevant treatment implications. The incorporation of a dimensional approach that reflects both somatic and psychological symptom severity also has the potential to improve predictive validity and clinical utility.

Chronic fatigue syndrome: Is it one discrete syndrome or many? Implications for the "one vs. many" functional somatic syndromes debate

There is a current debate as to whether "functional somatic syndromes" (FSSs) are more similar to or different from each other. While at the same time, there is evidence of heterogeneity within single syndromes. So, it could be that these syndromes are all part of one big process/illness, are discrete in their own right, or that they are heterogeneous collections of different illnesses lumped together by common symptoms but separated by uncommon pathophysiologies. The example of chronic fatigue syndrome (CFS) is instructive. There is evidence to support all three models of understanding. Three recent large studies have suggested that FSSs are both similar and dissimilar at the same time. The solution to the debate is that we need to both "lump" and "split." We need to study both the similarities between syndromes and their dissimilarities to better understand what we currently call the FSSs.

Unexplained toothache: an evidence-based approach to diagnosis and management

This 'in my opinion' paper uses two case studies to highlight the importance of making an early diagnosis of unexplained orofacial pain. Patients with this condition can present with symptoms that can easily be confused with more common dental pain that is related to an organic pathology. An incorrect diagnosis can lead to invasive and irreversible treatment using advanced surgical or restorative techniques that are not evidence-based. Current evidence supports the use of non-invasive techniques such as behavioural interventions; for example, cognitive behaviour therapy. It is therefore imperative that patients with this condition are recognised early in primary care so that management is appropriate from the outset. This will prevent unnecessary invasive intervention, protecting the patient from harm and the practitioner from litigation.

Risk factors for onset of chronic oro-facial pain--results of the North Cheshire oro-facial pain prospective population study

Due to the cross-sectional nature of previous studies, whether mechanical factors predict the onset of Chronic oro-facial pain remains unclear. Aims of the current study were to test the hypotheses that self-reported mechanical factors would predict onset of Chronic oro-facial pain and that any observed relationship would be independent of the confounding effects of psychosocial factors and reporting of other unexplained symptoms. About 1735 subjects who had completed a baseline questionnaire were assessed at 2year follow-up for the presence of Chronic oro-facial pain, psychosocial factors (anxiety and depression, illness behaviour, life stressors and reporting of somatic symptoms), mechanical dysfunction (facial trauma, grinding, phantom bite and missing teeth) and reporting of other unexplained symptoms (chronic widespread pain, irritable bowel syndrome and chronic fatigue). About 1329 subjects returned completed questionnaires (adjusted response rate 87%). About 56 (5%) reported new episodes of Chronic oro-facial pain at follow-up. Univariate analyses showed that age, gender, reporting of other unexplained symptoms, psychosocial factors and two self-report mechanical factors predicted the onset of Chronic oro-facial pain. However multivariate analysis showed that mechanical factors did not independently predict onset. The strongest predictors were health anxiety (Relative Risk (RR) 2.8, 95% CI 1.3-6.2), chronic widespread pain (RR 4.0 95% C.I. 2.2-7.4) and age (RR 0.2, 95% CI 0.1-0.7). The findings from this prospective study support the hypothesis that psychosocial factors are markers for onset of Chronic oro-facial pain. The efficacy of early psychological management of Chronic oro-facial pain to address these factors should be a priority for future investigations.

Development of temporomandibular disorders is associated with greater bodily pain experience

OBJECTIVES

The aim of this study is to examine the difference in the report of bodily pain experienced by patients who develop temporomandibular disorders (TMD) and by those who do not develop TMD over a 3-year observation period.

METHODS

This is a 3-year prospective study of 266 females aged 18 to 34 years initially free of TMD pain. All patients completed the Symptom Report Questionnaire (SRQ) at baseline and yearly intervals, and at the time they developed TMD (if applicable). The SRQ is a self-report instrument evaluating the extent and location of pain experienced in the earlier 6 months. Statistical analysis was carried out using repeated measures ANOVA.

RESULTS

Over the 3-year period, 16 patients developed TMD based on the Research Diagnostic Criteria for TMD. Participants who developed TMD reported more headaches (P=0.0089), muscle soreness or pain (P=0.005), joint soreness or pain (P=0.0012), back pain (P=0.0001), chest pain (P=0.0004), abdominal pain (P=0.0021), and menstrual pain (P=0.0036) than Participants who did not develop TMD at both the baseline and final visits. Participants who developed TMD also reported significantly more headache (P=0.0006), muscle soreness or pain (P=0.0059), and other pains (P=0.0188) when they were diagnosed with TMD compared with the baseline visit.

DISCUSSION

The development of TMD was accompanied by increases in headaches, muscle soreness or pain, and other pains that were not observed in the Participants who did not develop TMD. Participants who developed TMD also report higher experience of joint, back, chest, and menstrual pain at baseline.

Milnacipran: beyond a role of antidepressant

Milnacipran is a serotonin and norepinephrine reuptake inhibitor (SNRI) with negligible effects on any presynaptic or postsynaptic receptors. Milnacipran has unique pharmacokinetic and pharmacodynamic characteristics that distinguish it from the other marketed serotonin and norepinephrine reuptake inhibitors, venlafaxine, desvenlafaxine, and duloxetine such as equipotent serotonin and norepinephrine reuptake inhibition and a linear dose-concentration trend at therapeutic doses. The half-life of milnacipran is approximately 8 hours. In addition, milnacipran does not inhibit the cytochrome P 450 system, indicating minimal propensity for drug-drug interactions. The antidepressant efficacy of milnacipran has been clearly established in a number of randomized, double-blind, placebo-controlled clinical trials, and it has been widely used for treating major depressive disorder. Moreover, evidence suggests that milnacipran is effective and tolerable in the treatment of fibromyalgia and may have usefulness for fatigue and anxiety symptoms. The current paper reviews researches conducted to date that is relevant to the efficacy, tolerability, and mechanism of action of milnacipran in the treatment of depression, fibromyalgia, and other psychiatric syndromes. Future directions of research are also identified.

Extending conceptual frameworks: life course epidemiology for the study of back pain

BACKGROUND

Epidemiological studies have identified important causal and prognostic factors for back pain, but these frequently only identify a proportion of the variance, and new factors add little to these models. Recently, interest has increased in studying diseases over the life course, stimulated by the 1997 book by Kuh and Ben-Shlomo, a move accompanied by important conceptual and methodological developments. This has resulted in improvements in the understanding of other conditions like cardiovascular and respiratory disease. This paper aims to examine how conceptual frameworks from life course epidemiology could enhance back pain research.

DISCUSSION

Life course concepts can be divided into three categories. Concept 1: patterns over time, risk chains and accumulation. Simple 'chains of risk' have been studied - e.g. depression leading to back pain - but studies involving more risk factors in the chain are infrequent. Also, we have not examined how risk accumulation influences outcome, e.g. whether multiple episodes or duration of depression, throughout the life course, better predicts back pain. One-year back pain trajectories have been described, and show advantages for studying back pain, but there are few descriptions of longer-term patterns with associated transitions and turning points. Concept 2: influences and determinants of pathways. Analyses in back pain studies commonly adjust associations for potential confounders, but specific analysis of factors modifying risk, or related to the resilience or susceptibility to back pain, are rarely studied. Concept 3: timing of risk. Studies of critical or sensitive periods - crucial times of life which influence health later in life - are scarce in back pain research. Such analyses could help identify factors that influence the experience of pain throughout the life course.

SUMMARY

Back pain researchers could usefully develop hypotheses and models of how risks from different stages of life might interact and influence the onset, persistence and prognosis of back pain throughout the life course. Adoption of concepts and methods from life course epidemiology could facilitate this.

Responsiveness of motor and nonmotor symptoms of Parkinson disease to dopaminergic therapy

BACKGROUND

The duration of clinical control of motor symptoms of Parkinson disease (PD) treated with levodopa/carbidopa preparations eventually starts to shorten, a phenomenon known as end-of-dose "wearing off." The involvement of core nonmotor symptoms of "wearing off" (depressed mood, pain/aching, anxiety, and cloudy/slowed thinking) is not well understood.

METHODS

A post hoc analysis from a study to validate the self-rated 9-item, Wearing-Off Questionnaire (WOQ-9), which was designed to identify motor and nonmotor symptoms of "wearing off" in PD patients, was performed to compare the frequency and sensitivity of motor and nonmotor symptoms of "wearing off" from dopaminergic therapy.

RESULTS

Analysis of responses to the WOQ-9 from 216 PD patients found that individual nonmotor symptoms were reported by 25% to 50% and motor symptoms by 55% to 80% of patients. Individual nonmotor symptoms improved following the next dose of dopaminergic therapy in 43% to 53% of the patients who presented with such symptoms, whereas motor symptoms improved in 48% to 66% of the cases, suggesting both types of symptoms respond to dopaminergic therapies.

CONCLUSION

Nonmotor symptoms of PD appear sensitive to dopaminergic treatment. These symptoms resemble those seen with depressive, anxiety, and somatoform disorders suggesting potential shared mechanisms as well as possible treatment implications.

Reliability of intraoral quantitative sensory testing (QST)

The German Research Network on Neuropathic Pain (DFNS) has recommended a protocol with 13 quantitative sensory testing (QST) measures for detecting somatosensory abnormalities. Reliability is an important scientific property and has been adequately tested for cutaneous QST. This study evaluates intraoral sites for which no reliability trials have yet been published. Inter- and intra-examiner reliability of 13 QST measures at intra- and extraoral trigeminal sites were investigated. Twenty-one healthy volunteers from Malmö University, Malmö, Sweden (13 women and 8 men, mean age 40.4 years, range 24-71) participated. Two independent examiners previously trained in the DFNS QST protocol examined the participants using the entire protocol. Each participant was examined twice on the same day, once by each examiner (inter-examiner reliability). After 1-3 weeks, one examiner re-examined all participants (intra-examiner reliability). The measurements were made on the skin of the right cheek, the tip of the tongue, and bilaterally on the gingival mucosa of the upper premolar region. The intraclass correlation coefficient (ICC) or kappa was used to calculate variations. Most tests had acceptable to excellent inter-examiner (ICC 0.41-0.89) and intra-examiner (ICC 0.43-0.87) reliability. For each test, inter- and intra-examiner reliabilities at intra- and extraoral sites were similar. No significant differences between right and left sides were found intraorally. We conclude that inter- and intra-examiner reliabilities of most QST measures are acceptable for assessing somatosensory function in the orofacial region.

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

The aim of this study was to review emerging data from the fields of nursing, rheumatology, dentistry, gastroenterology, gynecology, neurology, and orthopedics that support or dispute pathophysiologic similarities in pain syndromes studied by each specialty. A literature search was performed through PubMed and Ovid using the terms fibromyalgia, temporomandibular joint disorder, irritable bowel syndrome, irritable bladder/interstitial cystitis, headache, chronic low back pain, chronic neck pain, functional syndromes, and somatization. Each term was linked with pathophysiology and/or central sensitization. This paper presents a review of relevant articles with a specific goal of identifying pathophysiologic findings related to nociceptive processing. The extant literature presents considerable overlap in the pathophysiology of these diagnoses. Given the psychosomatic lens through which many of these disorders are viewed, demonstration of evidence-based links supporting shared pathophysiology between these disorders could provide direction to clinicians and researchers working to treat these diagnoses. "Central sensitivity syndromes" denotes an emerging nomenclature that could be embraced by researchers investigating each of these disorders. Moreover, a shared paradigm would be useful in promoting cross-fertilization between researchers. Scientists and clinicians could most effectively forward the understanding and treatment of fibromyalgia and other common chronic pain disorders through an appreciation of their shared pathophysiology.

Risk markers for both chronic fatigue and irritable bowel syndromes: a prospective case-control study in primary care

BACKGROUND

Fatigue syndromes and irritable bowel syndrome (IBS) often occur together. Explanations include being different manifestations of the same condition and simply sharing some symptoms.

METHOD

A matched case-control study in UK primary care, using data collected prospectively in the General Practice Research Database (GPRD). The main outcome measures were: health-care utilization, specific symptoms and diagnoses. Risk markers were divided into distant (from 3 years to 1 year before diagnosis) and recent (1 year before diagnosis).

RESULTS

A total of 4388 patients with any fatigue syndrome were matched to two groups of patients: those attending for IBS and those attending for another reason. Infections were specific risk markers for both syndromes, with viral infections being a risk marker for a fatigue syndrome [odds ratios (ORs) 2.3-6.3], with a higher risk closer to onset, and gastroenteritis a risk for IBS (OR 1.47, compared to a fatigue syndrome). Chronic fatigue syndrome (CFS) shared more distant risk markers with IBS than other fatigue syndromes, particularly other symptom-based disorders (OR 3.8) and depressive disorders (OR 2.3), but depressive disorders were a greater risk for CFS than IBS (OR 2.4). Viral infections were more of a recent risk marker for CFS compared to IBS (OR 2.8), with gastroenteritis a greater risk for IBS (OR 2.4).

CONCLUSIONS

Both fatigue and irritable bowel syndromes share predisposing risk markers, but triggering risk markers differ. Fatigue syndromes are heterogeneous, with CFS sharing predisposing risks with IBS, suggesting a common predisposing pathophysiology.

Primary care assessment instruments for patients at risk of, or with, persistent pain: opportunistic findings from a systematic literature review

BACKGROUND

Early identification in primary care settings of individuals with, or at-risk of, developing persistent pain, is important to limit development of disability. There is little information to assist primary care providers to choose or deliver relevant, efficient, and soundly constructed assessment instruments for this purpose.

OBJECTIVE

We recently published the findings of a literature review, which produced a compendium of assessment instruments to identify adults with, or at-risk of developing, persistent pain of noncancer origin. This paper reports on instruments opportunistically identified during this review which may be appropriate to primary health care settings for early identification of such patients.

RESULTS

One hundred sixteen potentially useful instruments were initially identified in the review, measuring pain severity, psychological distress, functional capacity, quality of life or multidimensional constructs of persistent pain. Following a series of steps, 45 instruments were shortlisted, with sound clinical utility and strong psychometric properties. Of these, 16 instruments were appropriate to primary health care settings because of simple wording, brief items, short administration time, and ease of scoring.

CONCLUSION

No one assessment instrument captured all constructs of persistent pain. The 16 instruments provide a broad choice for primary care clinicians to assist with early identification of adults at risk of, or with persistent pain.

Implications of gender in chronic Lyme disease

BACKGROUND

"Post-Lyme disease syndrome" refers to prolonged subjective symptoms after antibiotic treatment and resolution of an objective manifestation of Borrelia burgdorferi infection (Lyme disease). "Chronic Lyme disease" is a vaguely defined term that has been applied to patients with unexplained prolonged subjective symptoms, whether or not there was or is evidence of B. burgdorferi infection.

OBJECTIVE

To determine if the population of patients with chronic Lyme disease differs from the populations of patients with either Lyme disease or post-Lyme disease syndrome by examining the gender of patients with these diagnoses.

METHODS

Data on gender were compiled in this cross-sectional study based on a systematic review of published studies of antibiotic treatment in United States patients with post-Lyme disease syndrome (n = 184) or chronic Lyme disease (n = 490), and on cases of adults with Lyme disease reported to the Centers for Disease Control and Prevention from 2003 to 2005 (n = 43,282).

RESULTS

Patients with chronic Lyme disease were significantly more likely to be female than were patients diagnosed with either Lyme disease (odds ratio [OR] 2.42, 95% confidence interval [CI] 1.98-2.94, p < 0.0001) or with post-Lyme disease syndrome (OR 2.32, 95% CI 1.62-3.34, p < 0.0001).

CONCLUSIONS

Patients with chronic Lyme disease differ with regard to gender from those with either B. burgdorferi infection or post-Lyme disease syndrome. This finding suggests that illnesses with a female preponderance, such as fibromyalgia, chronic fatigue syndrome, or depression, may be misdiagnosed as chronic Lyme disease.

Children's Somatization Inventory: psychometric properties of the revised form (CSI-24)

OBJECTIVE

To conduct a multimethod psychometric evaluation to refine the Children's Somatization Inventory (CSI) and to investigate its dimensionality.

METHOD

The CSI was administered to 876 pediatric patients with chronic abdominal pain at their initial visit to a pediatric gastroenterology clinic. Tools from three psychometric models identified items that most effectively measured the construct of somatization and examined its dimensionality.

RESULTS

Eleven statistically weak items were identified and removed, creating a 24-item CSI (CSI-24). The CSI-24 showed good psychometrics according to the three measurement models and correlated .99 with the original CSI. The CSI-24 has one dominant general factor but is not strictly unidimensional.

CONCLUSIONS

The CSI-24 is a reliable and psychometrically sound refinement of the original CSI. Findings are consistent with the view that somatization has a strong general factor that represents a continuum of symptom reporting, as well as minor components that represent specific symptom clusters in youth with chronic abdominal pain.

Psychiatric disorder, irritable bowel syndrome, and extra-intestinal symptoms in a population-based sample of twins

OBJECTIVES

To determine, in a population-based sample of twin pairs, if extra-intestinal symptoms (EIS) are closely associated with both irritable bowel syndrome (IBS) and psychiatric disorders and whether such associations are explained on a genetic basis.

METHODS

A random sample of twins between the ages of 44 and 64 years enrolled in the Minnesota Twins Registry completed the Modified Mayo Clinic Bowel Disease Questionnaire, a questionnaire on extra-intestinal symptoms, and the Psychiatric Diagnostic Screening Questionnaire.

RESULTS

Of the 3,048 participants (51% response rate), 371 (12.2%) fulfilled Rome II criteria for IBS; 61 (16.4%) had a psychiatric disorder compared with 7.6% (n=204) of those without IBS (P<0.001). In regression analysis both IBS and psychiatric disorders were independently associated with the number of extra-intestinal symptoms (P<0.0005). Concordance rates for high EIS score were 30.0% for monozygote (MZ) twins and 16.7% in dizygote (DZ) twins (P=0.020) and the OR for concordance remained substantially higher for MZ than DZ twins after adjustment for psychiatric disorder and presence of IBS (6.82 (95% CI 4.45-10.45) and 2.71 (95% CI 1.69-4.37)). In MZ twins discordant for IBS, EIS and IBS were significantly associated (P=0.004) and psychiatric disorder and EIS were significantly associated (P=0.001).

CONCLUSIONS

Extra-intestinal symptoms are independently associated with both IBS and psychiatric disorders. There is evidence that there is a genetic basis to EIS, but the association with IBS and psychiatric disorders is not primarily explained by genetic influences.

Psychosocial profile in men and women with unexplained chest pain

OBJECTIVE

The aim of this study was to compare men and women with unexplained chest pain (UCP) to a randomly selected population sample free of clinical heart disease with regard to sleep problems, mental strain at work, stress at home, negative life events and health-related quality of life (HRQOL).

DESIGN AND SUBJECTS

The study was conducted at a university hospital in Sweden including 231 patients aged 25-69 without any organic cause for chest pain. As a reference group, 1069 participants, were recruited from the INTERGENE population-based study.

RESULTS

Patients with UCP had more sleep problems (OR = 1.8, P < 0.0001), were almost three times more worried about stress at work (OR = 2.9, P < 0.0001), or had more stress at home (OR = 2.8, P < 0.0001), and were twice as likely to have negative life events (OR = 2.1, P < 0.0001). Women, but not men, with UCP, had a higher prevalence of cardiovascular risk factors (obesity, smoking, diabetes and hypertension) compared with references. With regard to HRQOL, UCP patients scored significantly lower than references in all dimensions of the SF-36.

CONCLUSIONS

In comparison with a healthy reference group, patients with UCP reported more sleep problems, mental strain at work, stress at home and negative life events and had lower health-related quality of life. Aside from immigration the strongest independent psychosocial factors were mental strain at work and negative life events last year in men and stress at home in women.

The relationship between fibromyalgia and major depressive disorder: a comprehensive review

OBJECTIVE

A large body of evidence suggests that the relationship between major depressive disorder (MDD) and fibromyalgia (FM) is complex. Improved understanding of this relationship promises to provide clinicians with better assessment and treatment options for both disorders.

METHOD

This paper reviews research on the prevalence, etiology and pathogenesis, clinical characterization, and treatment of FM and MDD, as well as studies that examined the relationship between these disorders. Studies were identified via PubMed literature search.

RESULTS

Our findings point to substantial similarities in neuroendocrine abnormalities, psychological characteristics, physical symptoms and treatments between FM and MDD. However, currently available findings do not support the assumption that MDD and FM refer to the same underlying construct or can be seen as subsidiaries of one disease concept.

CONCLUSION

New methodological and theoretical approaches may lead to a better understanding of the link between FM and MDD, and to more effective psychological and psychopharmacological therapies for FM patients. In the meantime, clinicians should carefully screen for a history of MDD in patients with FM.

Chronic Lyme disease: a review

Studies have shown that most patients diagnosed with chronic Lyme disease either have no objective evidence of previous or current infection with Borrelia burgdorferi or are patients who should be classified as having post-Lyme disease syndrome, which is defined as continuing or relapsing nonspecific symptoms (such as fatigue, musculoskeletal pain, and cognitive complaints) in a patient previously treated for Lyme disease. Despite extensive study, there is currently no clear evidence that post-Lyme disease syndrome is caused by persistent infection with B burgdorferi. Four randomized placebo-controlled studies have shown that antibiotic therapy offers no sustained benefit to patients who have post-Lyme disease syndrome. These studies also showed a substantial placebo effect and a significant risk of treatment-related adverse events. Further research to elucidate the mechanisms underlying persistent symptoms after Lyme disease and controlled trials of new approaches to the treatment and management of these patients are needed.

Attentional bias towards health-threat information in chronic fatigue syndrome

OBJECTIVE

To investigate whether individuals with chronic fatigue syndrome (CFS) show an attentional bias towards health-threat information.

METHODS

Attentional bias (AB) was assessed in individuals with CFS and healthy controls using a visual probe task which presented health-threat and neutral words and pictures for 500 ms. Self-report questionnaires were used to assess CFS symptoms, depression, anxiety, and social desirability.

RESULTS

Compared to a healthy control group, the CFS group showed an enhanced AB towards heath-threat stimuli relative to neutral stimuli. The AB was not influenced by the type of stimulus (pictures vs. words).

CONCLUSION

The finding of an AB towards health-threat information in individuals with CFS is supportive of models of CFS which underlie cognitive behavior therapy.

Rejection sensitivity relates to hypocortisolism and depressed mood state in young women

Rejection sensitivity and the associated fear of negative social evaluation (FNSE) trait are characteristics of hypocortisolemic syndromes such as atypical depression. However, a meta-analysis showed that acute FNSE evokes strong cortisol responses in humans. This is consistent with suggestions that hypocortisolism reflects a protective adaptation to a history of high cortisol responses. This leads us to hypothesize that measures of trait FNSE relate to hypocortisolism. Moreover, because FNSE relates positively to depressed mood state, but negatively to cortisol, we expect that the positive relationship between depressed mood state and cortisol will show up most clearly when controlling for the confounding effect of FNSE on this relationship. In the present study we measured salivary cortisol awakening response and psychological variables in 194 community women aged 18-30 years. The results confirmed our hypotheses. We propose that dispositional FNSE is associated with a history of frequent high cortisol responses, leading to long-term protective inhibition of further cortisol and energy mobilization. The present results have special relevance for mental health problems that have high prevalence among young women.

Irritable bowel syndrome and somatoform disorders

OBJECTIVE

This article aims to review the conceptual and empirical relation of irritable bowel syndrome (IBS) and somatoform disorders (SFDs).

METHOD

The method used is a narrative review that is partially based on discussions held at a symposium with the same topic in March 2007.

RESULTS

The conceptual distance between IBS and SFDs has diminished due to developments of both concepts. There is widespread agreement about the existence of syndrome patterns restricted to core IBS and also characterized by multiple unexplained symptoms and additional psychobehavioral features. Current concepts for etiology, pathophysiology, and management reflect the usefulness, the common ground, and the need for differentiation between these two prototypes. An umbrella category such as "interface disorders" between general medicine and psychiatry and wider descriptive frameworks like somatization and medically unexplained symptoms might be useful.

CONCLUSION

Further elaboration with an aim of abolishing counterproductive double perspectives on the same group of patients seems warranted.

Multidimensionality of symptom complexes in irritable bowel syndrome and other functional gastrointestinal disorders

The definition of irritable bowel syndrome (IBS) by Rome criteria was a major advancement in the nosology of the disease, but this goal was achieved by employing symptoms related to the gastrointestinal tract and by eliminating all symptoms that were nonspecific. The description of the course of the illness and response to treatment has been hampered by restrictions to the defining characteristics, abdominal pain and altered bowel habit. Other abdominal symptoms (e.g., bloating, nausea, and epigastric discomfort) and general somatic symptoms (e.g., fatigue, headache, and sleep disturbance) are not included in the Rome definition, yet are commonly reported by patients with IBS. This article addresses the following questions: Are comorbid conditions part of or distinct from the syndrome of IBS and other functional gastrointestinal disorders (FGIDs)? Are there overlapping abdominal or extra-abdominal symptoms confounding the definition of IBS? Are extra-abdominal somatic symptoms and/or syndromes part of the clinical presentation of IBS? Are "nondiagnostic" abdominal symptoms important in defining symptom burden in IBS? Is the concept of somatization related to IBS, and, if so, how? How can we better define the symptom burden in IBS and other FGIDs? In short, have we hampered the evaluation of IBS (and other FGIDs) by making the definitions too reductionist? While definite answers to the above questions are not possible at this time, this article proposes that the definitions of IBS or other FGIDs not be altered, but that in the process of evaluation of the clinical end points and/or severity of the diseases, consideration be given to the possibility of including other components of the symptom burden of these disorders.

Attitudes towards fibromyalgia: a survey of Canadian chiropractic, naturopathic, physical therapy and occupational therapy students

Background

The frequent use of chiropractic, naturopathic, and physical and occupational therapy by patients with fibromyalgia has been emphasized repeatedly, but little is known about the attitudes of these therapists towards this challenging condition.

Methods

We administered a cross-sectional survey to 385 senior Canadian chiropractic, naturopathic, physical and occupational therapy students in their final year of studies, that inquired about attitudes towards the diagnosis and management of fibromyalgia.

Results

336 students completed the survey (response rate 87%). While they disagreed about the etiology (primarily psychological 28%, physiological 23%, psychological and physiological 15%, unsure 34%), the majority (58%) reported that fibromyalgia was difficult to manage. Respondants were also conflicted in whether treatment should prioritize symptom relief (65%) or functional gains (85%), with the majority (58%) wanting to do both. The majority of respondents (57%) agreed that there was effective treatment for fibromyalgia and that they possessed the required clinical skills to manage patients (55%).

Chiropractic students were most skeptical in regards to fibromyalgia as a useful diagnostic entity, and most likely to endorse a psychological etiology. In our regression model, only training in naturopathic medicine (unstandardized regression coefficient = 0.33; 95% confidence interval = 0.11 to 0.56) and the belief that effective therapies existed (unstandardized regression coefficient = 0.42; 95% confidence interval = 0.30 to 0.54) were associated with greater confidence in managing patients with fibromyalgia.

Conclusion

The majority of senior Canadian chiropractic, naturopathic, physical and occupational therapy students, and in particular those with naturopathic training, believe that effective treatment for fibromyalgia exists and that they possess the clinical skillset to effectively manage this disorder. The majority place high priority on both symptom relief and functional gains when treating fibromyalgia.

Risk factors for physical symptoms after a disaster: a longitudinal study

BACKGROUND

Although symptoms such as fatigue, headache and pain in bones and muscles are common after disasters, risk factors for these symptoms among disaster survivors have rarely been studied. We examined predisposing, precipitating and perpetuating factors for these physical symptoms among survivors of a man-made disaster. In addition, we examined whether risk factors for physical symptoms differ between survivors and controls.

METHOD

Survivors completed a questionnaire 3 weeks (n=1567), 18 months and 4 years after the disaster. Symptoms and risk factors were measured using validated questionnaires. A comparison group was included at waves 2 and 3 (n=821). Random coefficient analysis (RCA) was used to study risk factors for symptoms.

RESULTS

Female gender [beta (beta)=1.0, 95% confidence interval (CI) 0.6-1.4], immigrant status (beta=1.0, 95% CI 0.6-1.4) and pre-disaster psychological problems (beta=0.8, 95% CI 0.1-1.4) were predisposing factors for symptoms. Although disaster-related factors were predictors, the relationship between symptoms and disaster-related factors was not very strong and the magnitude of this association was reduced when perpetuating factors were added. Intrusions and avoidance, depression, anxiety and sleeping problems were important perpetuating factors for physical symptoms among survivors and mediated the association between traumatic stress and physical symptoms. Risk factors for symptoms were comparable between survivors and controls.

CONCLUSIONS

The results indicate that health-care workers should be alert for physical symptoms among female survivors, immigrant survivors and individuals with a high level of psychological problems both before and after a disaster.

Differences in four reported symptoms related to temporomandibular disorders in a cohort of 50-year-old subjects followed up after 10 years

OBJECTIVE

To assess possible changes in the prevalence of four temporomandibular disorder (TMD) symptoms reported by subjects at age 50 and again 10 years later.

MATERIAL AND METHODS

Identical questionnaires were sent out in 1992 and in 2002 to all subjects born in 1942 and living in two Swedish counties. Of those who answered the four questions on TMD symptoms in 1992, 74% responded in 2002 (n=4639). The response alternatives were dichotomized into two groups: 1) No problems and 2) some, rather severe and severe problems.

RESULTS

The mean prevalence of TMD-related symptoms reflected small and mainly non-significant changes, whereas the prevalence of reported bruxism was significantly greater at age 60 than at age 50. Among those with no TMD symptoms at age 50, 5-7% of the men and 8-9% of the women reported symptoms at age 60. Of those reporting one or more TMD symptoms at age 50, 47-65% of the men and 40-48% of the women had no symptoms 10 years later. There was a significant and markedly increased risk of reporting TMD symptoms and bruxism (OR>10) at age 60 among those who had symptoms at age 50.

CONCLUSIONS

The mean prevalence of reported TMD symptoms was relatively consistent from age 50 to age 60. The group reporting symptoms at the first examination were highly likely still to have the symptoms 10 years later. However, approximately half of the subjects with TMD symptoms at age 50 reported no symptoms at age 60.