A review of the evidence for overlap among unexplained clinical conditions

PURPOSE

Unexplained clinical conditions share features, including symptoms (fatigue, pain), disability out of proportion to physical examination findings, inconsistent demonstration of laboratory abnormalities, and an association with "stress" and psychosocial factors. This literature review examines the nature and extent of the overlap among these unexplained clinical conditions and the limitations of previous research.

DATA SOURCES

English-language articles were identified by a search of the MEDLINE database from 1966 to January 2001 by using individual syndromes and their hallmark symptoms as search terms.

STUDY SELECTION

Studies that assessed patients with at least one unexplained clinical condition and that included information on symptoms, overlap with other unexplained clinical conditions, or physiologic markers. Conditions examined were the chronic fatigue syndrome, fibromyalgia, the irritable bowel syndrome, multiple chemical sensitivity, temporomandibular disorder, tension headache, interstitial cystitis, and the postconcussion syndrome.

DATA EXTRACTION

Information on authorship, patient and control groups, eligibility criteria, case definitions, study methods, and major findings.

DATA SYNTHESIS

Many similarities were apparent in case definition and symptoms, and the proportion of patients with one unexplained clinical condition meeting criteria for a second unexplained condition was striking. Tender points on physical examination and decreased pain threshold and tolerance were the most frequent and consistent objective findings. A major shortcoming of all proposed explanatory models is their inability to account for the occurrence of unexplained clinical conditions in many affected patients.

CONCLUSIONS

Overlap between unexplained clinical conditions is substantial. Most studies are limited by methodologic problems, such as case definition and the selection and recruitment of case-patients and controls.

Preventive care of older urban American Indians and Alaska natives in primary care

Little is known about prevention among elderly or urban American Indian/Alaska Native (AI/AN) populations. We reviewed the medical records of 550 older urban AI/AN primary care patients to evaluate how frequently preventive measures were received. Adherence to guidelines was examined by a culturally appropriate (> or =50 years) and standard age threshold (> or =65 years), and by performance of preventive measures at any time ("ever") and in the past year. Lifetime performance was inadequate for the many measures, including mammograms (56%), fecal occult blood testing (37%), audiometry (33%), visual acuity testing (50%), smoking cessation counseling (50%), and pneumococcal (22%) and influenza (49%) vaccinations. Performance of the measures was less frequent in the prior year, but did not differ by age threshold. Predictors of adherence included female gender, having insurance, and having more health problems and medications. Nonadherence infrequently resulted from patients' failure to comply with recommendations. We conclude that use of most preventive services among elderly urban AI/ANs is suboptimal and should be improved.

Decreased nocturnal levels of prolactin and growth hormone in women with fibromyalgia

Fibromyalgia (FM) is a complex syndrome, primarily of women, characterized by chronic pain, fatigue, and sleep disturbance. Altered function of the somatotropic axis has been documented in patients with FM, but little is known about nocturnal levels of PRL. As part of a laboratory study of sleep patterns in FM, we measured the serum concentrations of GH and PRL hourly from 2000--0700 h in a sample of 25 women with FM (mean, 46.9 +/- 7.6 yr) and in 21 control women (mean, 42.6 +/- 8.1 yr). The mean (+/-SEM ) serum concentrations (micrograms per L) of GH and of PRL during the early sleep period were higher in control women than in patients with FM [GH, 1.6 +/- 0.4 vs. 0.6 +/- 0.2 (P < 0.05); PRL, 23.2 +/- 2.2 vs. 16.9 +/- 2.0 (P < 0.025)]. The mean serum concentrations of GH and PRL increased more after sleep onset in control women than in patients with FM [GH, 1.3 +/- 0.4 vs. 0.3 +/- 0.2 (P < 0.05); PRL, 16.2 +/- 2.4 vs. 9.7 +/- 1.5 (P < 0.025)]. Sleep efficiency and amounts of sleep or wake stages on the blood draw night were not different between groups. There was a modest inverse relationship between sleep latency and PRL and a direct relationship between sleep efficiency and PRL in FM. There was an inverse relationship between age and GH most evident in control women. Insulin-like growth factor I levels were not different between the groups. These data demonstrate altered functioning of both the somatotropic and lactotropic axes during sleep in FM and support the hypothesis that dysregulated neuroendocrine systems during sleep may play a role in the pathophysiology of FM.

Fibromyalgia and other unexplained clinical conditions

Several unexplained clinical conditions frequently coexist with fibromyalgia; these include chronic fatigue syndrome, irritable bowel syndrome, temporomandibular disorder, tension and migraine headaches, and others. However, only recently have studies directly compared the physiological parameters of these conditions (eg, fibromyalgia vs irritable bowel syndrome) to elucidate underlying pathogenic mechanisms. This review summarizes data from comparative studies and discusses their implications for future research.

Molecular quantification of response to therapy and remission status in TEL-AML1-positive childhood ALL by real-time reverse transcription polymerase chain reaction

Although TEL-AML1 positivity [translocation t(12;21)(p13;q22)], detected in 20-25% of initial childhood acute lymphoblastic leukemia (ALL), has been associated with an excellent prognosis, its positive predictive value is insufficient for appropriate treatment stratification considering reported prevalence in relapsed ALL (3-28%). Molecular quantification of response to therapy by PCR-based methods has been shown to improve risk assessment. Here, we report on the sensitive quantification of leukemia-specific TEL-AML1 fusion transcript levels normalized to beta-actin expression (sensitivity threshholds, 10(-5)) by a novel real-time reverse transcription-PCR (RQ-RT-PCR) based on fluorescent TaqMan technique providing early and rapid evidence on the treatment efficacy of children with initial or relapsed TEL-AML1+ ALL enrolled in frontline or relapse trials of the Berlin-Frankfurt-Münster (BFM)-Study Group. In initial ALL, TEL-AML1/beta-actin decrease was > or =10(5)-fold in 50% of patients after induction therapy (day 33) and stayed TEL-AML1-negative throughout therapy, which suggested high sensitivity of leukemic cells to antineoplastic therapy. The remaining patients were still TEL-AML1+ before reintensification (ratios, 0.7 x 10(-2):10(-4)). In relapsed ALL, TEL-AML1/beta-actin decrease was generally less pronounced at corresponding time points, and conversion to TEL-AML1 negativity was observed in 40% of patients. Most notably, subsequent relapses occurred only among molecular poor responders, whereas all early responders remain in their second complete remission. In conclusion, real-time quantification of TEL-AML1/beta-actin kinetics distinguishes distinct molecular response groups, and provides indications capable of directing therapeutic interventions for patients with TEL-AML1+ ALL. Before considering modification of therapy, results should be interpreted cautiously taking into account the long duration of remission associated with TEL-AML1+ ALL.

Characterization of cytokine, growth factor receptor, costimulatory and adhesion molecule expression patterns of bone marrow blasts in relapsed childhood B cell precursor all

Relapse of childhood acute lymphoblastic leukaemia (ALL) comprises a leading challenge of investigation. Characterization of leukaemic cells regarding their potency to express growth factors and surface molecules can provide insight into their aberrant biology. Thus, we analyzed bone marrow blasts from 10 children with relapsed B cell precursor ALL. The gene and protein expression of essential haematopoietic growth factors (IL-2, IL-4, IL-7, IL-10, IL-15, IFN-gamma, G-CSFR), their corresponding receptors as well as the expression pattern of adhesion molecules (ICAM-1, CD58) and costimulatory proteins (CD40, CD40L, B7.1, B7.2, CD28, MHC-I and II) was analyzed by RT-PCR and flow cytometry. Constitutive gene expression was found for IL-7, IL-10, IL-15 and IFN-gamma and their corresponding receptors. Flow-cytometric analysis showed that IL-10R, IL-7Ralpha, IL-4Ralpha and the gamma(c)chain are constitutively expressed, and that some cells bear the G-CSFR. IL-10 and IL-15 protein-producing leukaemic cells were easily detectable. The neoplastic cells mainly lack B7.1, and ICAM-1 is mostly decreased. Furthermore, high CD40, and, surprisingly, CD40L expression could be found. These studies show that ALL cells are likely to be sensitive to many growth factors and some factors are produced by the neoplastic cell itself. The secretion of IL-10 by leukaemic cells, and the absence or downregulation of conventional adhesion and costimulatory molecules might represent an effective mechanism of escape of immune surveillance in relapsed ALL.

Comorbid clinical conditions in chronic fatigue: a co-twin control study

OBJECTIVES

Chronically fatiguing illness, defined as fatigue for at least 6 months, has been associated with various physical health conditions. Our objective was to determine whether there is a significant relationship between chronically fatiguing illness and 10 clinical conditions that frequently appear to be associated with fatigue, adjusting for the potentially confounding effects of psychiatric illness.

DESIGN

A co-twin control study controlling for genetic and many environmental factors by comparing chronically fatigued twins with their nonfatigued co-twins.

SETTING

A nationally distributed volunteer twin registry.

PARTICIPANTS

The study included 127 twin pairs in which one member of the pair experienced fatigue of at least 6 months' duration and the co-twin was healthy and denied chronic fatigue. Fatigued twins were classified into 3 levels using increasingly stringent diagnostic criteria.

MEASUREMENTS AND MAIN RESULTS

Twins reported on a history of fibromyalgia, irritable bowel syndrome, multiple chemical sensitivities, temporomandibular disorder, interstitial cystitis, postconcussion syndrome, tension headache, chronic low back pain, chronic pelvic pain (women), and chronic nonbacterial prostatitis (men). The prevalence of these comorbid clinical conditions was significantly higher in the fatigued twins compared to their nonfatigued co-twins. Most notably, compared to their nonfatigued co-twins, the chronically fatigued twins had higher rates of fibromyalgia (> 70% vs < 10%) and irritable bowel syndrome (> 50% vs < 5%). The strongest associations were observed between chronic fatigue and fibromyalgia (odds ratios > 20), irritable bowel syndrome, chronic pelvic pain, multiple chemical sensitivities, and temporomandibular disorder (all with odds ratios > or = 4). Regression analysis suggested that the number of comorbid clinical conditions associated with chronic fatigue could not be attributed solely to psychiatric illness.

CONCLUSIONS

Chronically fatiguing illnesses were associated with high rates of many other clinical conditions. Thus, patients with chronic fatigue may present a complex clinical picture that poses diagnostic and management challenges. Nonetheless, clinicians should assess such patients for the presence of comorbid clinical conditions. Future research should provide a better understanding of the temporal relationship of the onset of fatigue and these conditions, and develop strategies for early intervention.

Comorbid clinical conditions in chronic fatigue: a co-twin control study

OBJECTIVES

Chronically fatiguing illness, defined as fatigue for at least 6 months, has been associated with various physical health conditions. Our objective was to determine whether there is a significant relationship between chronically fatiguing illness and 10 clinical conditions that frequently appear to be associated with fatigue, adjusting for the potentially confounding effects of psychiatric illness.

DESIGN

A co-twin control study controlling for genetic and many environmental factors by comparing chronically fatigued twins with their nonfatigued co-twins.

SETTING

A nationally distributed volunteer twin registry.

PARTICIPANTS

The study included 127 twin pairs in which one member of the pair experienced fatigue of at least 6 months' duration and the co-twin was healthy and denied chronic fatigue. Fatigued twins were classified into 3 levels using increasingly stringent diagnostic criteria.

MEASUREMENTS AND MAIN RESULTS

Twins reported on a history of fibromyalgia, irritable bowel syndrome, multiple chemical sensitivities, temporomandibular disorder, interstitial cystitis, postconcussion syndrome, tension headache, chronic low back pain, chronic pelvic pain (women), and chronic nonbacterial prostatitis (men). The prevalence of these comorbid clinical conditions was significantly higher in the fatigued twins compared to their nonfatigued co-twins. Most notably, compared to their nonfatigued co-twins, the chronically fatigued twins had higher rates of fibromyalgia (> 70% vs < 10%) and irritable bowel syndrome (> 50% vs < 5%). The strongest associations were observed between chronic fatigue and fibromyalgia (odds ratios > 20), irritable bowel syndrome, chronic pelvic pain, multiple chemical sensitivities, and temporomandibular disorder (all with odds ratios > or = 4). Regression analysis suggested that the number of comorbid clinical conditions associated with chronic fatigue could not be attributed solely to psychiatric illness.

CONCLUSIONS

Chronically fatiguing illnesses were associated with high rates of many other clinical conditions. Thus, patients with chronic fatigue may present a complex clinical picture that poses diagnostic and management challenges. Nonetheless, clinicians should assess such patients for the presence of comorbid clinical conditions. Future research should provide a better understanding of the temporal relationship of the onset of fatigue and these conditions, and develop strategies for early intervention.

Results of isoproterenol tilt table testing in monozygotic twins discordant for chronic fatigue syndrome

BACKGROUND

The pathogenesis of chronic fatigue syndrome (CFS) is unknown. Neurally mediated hypotension (NMH) has been suggested as a common comorbid condition or a potential underlying cause.

METHODS

We conducted a cotwin control study of 21 monozygotic twins who were discordant for CFS. One twin met the 1994 Centers for Disease Control and Prevention criteria for CFS, and the other twin was healthy and denied chronic fatigue. The twins were selected from a volunteer twin registry in which at least 1 member reported persistent fatigue. As part of a 7-day clinical evaluation, all 21 twin pairs were evaluated with a 3-stage tilt table test with isoproterenol hydrochloride for the assessment of NMH. The presence of NMH was defined as syncope or presyncope associated with a decrease of 25 mm Hg in blood pressure and no associated increase in heart rate.

RESULTS

A positive tilt table test result was observed in 4 twins with CFS (19%) and in 4 healthy twins (19%). This difference was not statistically significant (matched pair odds ratio, 1.0; 95% confidence interval, 0.2-5.4; P>.90). Compared with the healthy twins, the twins with CFS reported more severe symptoms of CFS and NMH both in the week before and during the tilt table test.

CONCLUSIONS

These results do not support a major role for NMH in CFS. They highlight the importance of selecting well-matched control subjects, as well as the unique value of the monozygotic cotwin control design in the study of this illness. Arch Intern Med. 2000;160:3461-3468.

Use of traditional health practices among Native Americans in a primary care setting

BACKGROUND

This study was undertaken to ascertain the extent that traditional health practices are used by urban American Indian/Alaska Native (AI/AN) primary care patients, to identify related patient characteristics, to determine associations with health status and functioning, and to describe attitudes about care received.

METHODS

This study used a brief self-report survey of 869 adult AI/AN patients randomly sampled over a 14-month period from a comprehensive urban primary care program. Current medications were determined by follow-up medical record review.

RESULTS

Seventy percent of urban AI/AN patients in primary care often used traditional health practices; use was strongly associated with cultural affiliation. In bivariate analyses, use was significantly associated with male gender, cultural affiliation, poor functional status, alcohol abuse, and trauma and, except for musculoskeletal pain, not with specific medical problems. The multiple logistic regression model for any use versus no use was significant (P < or =0.001). Being of male gender (P < or =0.001), having more than a high school education (P < or =0.05), visiting friends/relatives on a reservation (P < or =0.01), living the Native way of life (P < or =0.001) and not the white way (P < or =0.05), experiencing back pain (P < or =0.01), and having a physical injury inflicted by a family member (P < or =0.001) were predictive of use.

CONCLUSIONS

The results in this clinical setting suggest that health care providers should anticipate use of traditional health practices among urban AI/AN patients. Use was predicted by important demographic, clinical, and cultural characteristics.

Physical abuse of urban Native Americans

To ascertain the extent of, and risk factors for, physical abuse among older urban American Indian/Alaska Natives (AI/ANs), we conducted a chart review of 550 urban AI/AN primary care patients >/=50 years old seen during 1 year. Mistreatment was documented in 10%. A logistic regression found younger age (P <.001), female gender (P <.001), current depression (P <.001), and dependence on others for food (P <.05) to be significant correlates of physical abuse. In only 31% of instances of definite abuse were the authorities notified. We conclude that providers should be alert to the possibility of physical mistreatment among older urban AI/ANs. Improvements in detection and management are sorely needed.

Use of and attitudes about alternative and complementary therapies among outpatients and physicians at a municipal hospital

OBJECTIVES

To survey outpatients and physicians about their use of, knowledge of, and interest in alternative therapies.

DESIGN

Anonymous self-administered survey.

SETTINGS/LOCATION

Outpatient clinics at a major municipal medical center.

SUBJECTS

Outpatients visiting clinics and staff physicians.

INTERVENTIONS

Patient survey about overall use of 7 categories and 19 types of alternative therapies, and their desire to have specific therapies offered at the institution. Survey to physicians about whether their patients used the same categories and types of alternative therapies, whether they provided or recommended their use, and their interest in having them available at the institution.

OUTCOME MEASURES

Frequency of use of different alternative therapies by gender and race. Frequency of patient use of alternative therapies according to their physicians and frequency of physicians who provide or recommend alternative therapies.

RESULTS

A total of 567 outpatients completed questionnaires during the survey week. When given a list of alternative therapies, 85% of patients acknowledged use of one or more alternative therapies. When Diet/Nutrition was excluded, 42% reported use of alternative therapies. No differences in overall use were seen by age, sex, or race; but when Diet/Nutrition was excluded, women were more likely to use alternative therapies, and use of Manual Healing and Herbal Medicine differed by race. Of the 85 responding physicians, 86% reported that their ambulatory patients used alternative therapies. Similar proportions (35%-38%) of patients and physicians wanted Manual Healing and Mind/Body Control therapies to be available.

CONCLUSIONS

Frequency of use of alternative therapies was high, and similar according to patients and physicians. Overall use did not differ by gender and race, except when Diet/Nutrition was excluded. Patients and physicians had similar interests in having alternative therapies provided, and both were hampered by lack of information about many therapies.

Influenza and pneumococcal vaccination among Native American elders in a primary care practice

BACKGROUND

More than 2 million Native Americans (ie, Native Americans and Native Alaskans) live in the United States; 60% reside in cities. This population, especially its elders, is especially susceptible to respiratory diseases; yet, adherence to guidelines for influenza and pneumococcal immunizations is unknown.

OBJECTIVES

To evaluate how frequently older and high-risk adults received vaccinations for influenza and pneumococcal infection and to identify patient characteristics associated with adherence to published recommendations.

METHODS

Retrospective medical record review of 550 Native American elders seen in an urban primary care practice defined using a culturally appropriate age threshold (> or =50 years) and standard criteria (> or =65 years). Univariate analyses examined demographic and clinical information by vaccination status. Logistic regressions identified factors associated with adherence to immunization guidelines.

RESULTS

Among patients aged 50 years and older with any indication according to published recommendations, rates were low for influenza (31%) and pneumococcal (21%) immunizations. Likewise, few subjects at least 65 years of age had been immunized appropriately against influenza (38%) or pneumococcus (32%). Younger age and alcohol use were significantly associated with less frequent immunization; Medicare insurance, depression, and more health problems and taking more medications predicted significantly higher immunization rates. Aged 65 years or older and having cardiovascular disease or diabetes mellitus were specific indications significantly correlated with receipt of influenza and pneumococcal vaccine.

CONCLUSIONS

Regardless of age or risk, inadequate vaccination rates were observed in elderly Native Americans. Our findings suggest the need to identify obstacles to immunization and to conduct prospective and elderly intervention studies in Native American populations.

Use of alternative treatments by chronic fatigue syndrome discordant twins

Background: Patients with chronic fatigue syndrome (CFS) have been faced with difficulties in diagnosis and lack of effective treatments. Anecdotal evidence suggests that use of alternative treatments may be common in these patients. Our primary objective was to compare the prevalence and patterns of alternative medicine use among twins who met the Centers for Disease Control and Prevention (CDC) CFS criteria to that of their non-CFS co-twins. Secondary goals were to assess how often alternative medicine use was discussed with physicians and the perceived benefit of these therapies. Methods: Sixty-three twin pairs discordant for CFS completed a survey about their use of 22 alternative therapies. Matched pair odds ratios and 95% confidence intervals were used to examine differences in the use between CFS twins and their non-CFS co-twins. Results: 91% of twins with CFS and 71% of non-CFS twins had used at least 1 alternative treatment in their lifetime. Twins with CFS were more likely to use homeopathy, mega-vitamins, herbal therapies, biofeedback, relaxation/meditation, guided imagery, massage therapy, energy healing, religious healing by others, and self-help groups than their non-CFS counterparts. A large proportion of all twins found alternative therapies helpful; however, only 42% of those with CFS and 23% of those without CFS discussed their use of alternative medicine with a physician. Conclusions: Individuals with CFS frequently used alternative medical treatments yet rarely communicated this use to their medical doctor. Future research should ascertain the usefulness of alternative practices in the management of CFS.

Diabetes education materials: recommendations of tribal leaders, Indian health professionals, and American Indian community members

PURPOSE

The Association of American Indian Physicians, the only national organization of its kind, conducted a series of focus groups to gather input from tribal leaders, Indian health professionals, and American Indian community members to guide the development of culturally appropriate diabetes education materials for the National Diabetes Education Program.

METHODS

During the focus groups, participants shared their experiences with and recommendations for a variety of diabetes education materials.

RESULTS

Overall, 95% of participants expressed a strong preference for diabetes education materials relevant to their specific tribe or culture.

CONCLUSIONS

Recommendations from these focus groups were used to develop a national diabetes education campaign for American Indian communities.

Overlapping conditions among patients with chronic fatigue syndrome, fibromyalgia, and temporomandibular disorder

BACKGROUND

Patients with chronic fatigue syndrome (CFS), fibromyalgia (FM), and temporomandibular disorder (TMD) share many clinical illness features such as myalgia, fatigue, sleep disturbances, and impairment in ability to perform activities of daily living as a consequence of these symptoms. A growing literature suggests that a variety of comorbid illnesses also may commonly coexist in these patients, including irritable bowel syndrome, chronic tension-type headache, and interstitial cystitis.

OBJECTIVE

To describe the frequency of 10 clinical conditions among patients with CFS, FM, and TMD compared with healthy controls with respect to past diagnoses, degree to which they manifested symptoms for each condition as determined by expert-based criteria, and published diagnostic criteria.

METHODS

Patients diagnosed as having CFS, FM, and TMD by their physicians were recruited from hospital-based clinics. Healthy control subjects from a dermatology clinic were enrolled as a comparison group. All subjects completed a 138-item symptom checklist and underwent a brief physical examination performed by the project physicians.

RESULTS

With little exception, patients reported few past diagnoses of the 10 clinical conditions beyond their referring diagnosis of CFS, FM, or TMD. In contrast, patients were more likely than controls to meet lifetime symptom and diagnostic criteria for many of the conditions, including CFS, FM, irritable bowel syndrome, multiple chemical sensitivities, and headache. Lifetime rates of irritable bowel syndrome were particularly striking in the patient groups (CFS, 92%; FM, 77%; TMD, 64%) compared with controls (18%) (P<.001). Individual symptom analysis revealed that patients with CFS, FM, and TMD share common symptoms, including generalized pain sensitivity, sleep and concentration difficulties, bowel complaints, and headache. However, several symptoms also distinguished the patient groups.

CONCLUSIONS

This study provides preliminary evidence that patients with CFS, FM, and TMD share key symptoms. It also is apparent that other localized and systemic conditions may frequently co-occur with CFS, FM, and TMD. Future research that seeks to identify the temporal relationships and other pathophysiologic mechanism(s) linking CFS, FM, and TMD will likely advance our understanding and treatment of these chronic, recurrent conditions.

The Chronic Fatigue Twin Registry: method of construction, composition, and zygosity assignment

Chronic fatigue syndrome (CFS) and the symptom of chronic fatigue are conditions of unknown etiology. The Centers for Disease Control and Prevention (CDC) define CFS as an illness characterized by > or = 6 months of disabling fatigue associated with muscle pain, pharyngitis, and alterations in mood, sleep and neurocognition. We constructed a registry of twins with chronic fatigue to facilitate research on the impact of illness, the associated medical and psychosocial factors, and the heterogeneous proposed mechanisms for these conditions. We have recruited 204 twin pairs in which one or both members reported persistent fatigue through patient support group newsletters (60%), clinicians/researchers familiar with CFS (12%), notices placed on electronic bulletin boards for CFS (11%), twin organizations and researchers (6%), relatives and friends (3%) and other sources (8%). Complete data are available for 177 pairs (87%). Twins completed an extensive questionnaire booklet that included measures of physical and mental health, functional status, and psychosocial factors; a structured psychiatric interview was also conducted by telephone. Twins were classified using three increasingly more stringent diagnostic criteria for chronic fatigue: 1) > or = 6 months of fatigue (115 discordant and 61 concordant pairs); 2) chronic fatigue with additional symptoms and application of the medial exclusions of the CDC CFS case definition as obtained by self-report (92 discordant and 41 concordant pairs) and; 3) chronic fatigue with additional symptoms unexplained by self-reported medical conditions and psychiatric diagnoses as determined by the structured interview (69 discordant pairs and 25 concordant pairs). Despite the limitations of a volunteer registry, the Chronic Fatigue Twin Registry promises to be an important resource for research on CFS and chronic fatigue.

A prospective study of tender points and fibromyalgia during and after an acute viral infection

BACKGROUND

Tender points (TPs) and fibromyalgia (FM) may be precipitated by infections, but the frequency, associated characteristics, and predictors of these outcomes are unknown.

OBJECTIVES

To determine if acute infectious mononucleosis (AIM) is associated with the development of TPs or FM acutely or during the subsequent 6 months; if demographic, clinical, or psychosocial features predict TPs or FM; and if TPs or FM correlate with nonrecovery.

METHODS

A total of 150 subjects diagnosed as having AIM were assessed with physical examinations (including palpation of 18 TPs), laboratory tests, and measures of psychosocial and somatic functioning at enrollment and at 2 and 6 months. Subjects also completed a structured psychiatric interview at the initial evaluation.

RESULTS

At presentation and at 2 and 6 months, the mean TP counts were 7.5, 4.6, and 3.0, respectively; at these time points, 19%, 3%, and 1% of subjects also met modified criteria for FM. Tender points and degree of pain diminished over time following AIM. Acutely, TPs were associated only with higher temperature (P<.001). Baseline features that predicted more TPs at 2 and 6 months were female sex, older age, less family social support, and more TPs at presentation. Neither initial laboratory tests nor psychiatric disease or distress predicted TPs. Differences between those who had and had not recovered at 6 months were found for the mean number of TPs (P<.008), the proportion of subjects with 11 or more TPs (P<.002), and the degree of pain.

CONCLUSIONS

Tender points are a common, transient finding associated with AIM, but FM is an unusual long-term outcome. Demographic, social, and physical examination features predicted TPs.