Fibromyalgia is characterized by altered frontal and cerebellar structural covariance brain networks

Altered brain morphometry has been widely acknowledged in chronic pain, and recent studies have implicated altered network dynamics, as opposed to properties of individual brain regions, in supporting persistent pain. Structural covariance analysis determines the inter-regional association in morphological metrics, such as gray matter volume, and such structural associations may be altered in chronic pain. In this study, voxel-based morphometry structural covariance networks were compared between fibromyalgia patients (N = 42) and age- and sex-matched pain-free adults (N = 63). We investigated network topology using spectral partitioning, which can delineate local network submodules with consistent structural covariance. We also explored white matter connectivity between regions comprising these submodules and evaluated the association between probabilistic white matter tractography and pain-relevant clinical metrics. Our structural covariance network analysis noted more connections within the cerebellum for fibromyalgia patients, and more connections in the frontal lobe for healthy controls. For fibromyalgia patients, spectral partitioning identified a distinct submodule with cerebellar connections to medial prefrontal and temporal and right inferior parietal lobes, whose gray matter volume was associated with the severity of depression in these patients. Volume for a submodule encompassing lateral orbitofrontal, inferior frontal, postcentral, lateral temporal, and insular cortices was correlated with evoked pain sensitivity. Additionally, the number of white matter fibers between specific submodule regions was also associated with measures of evoked pain sensitivity and clinical pain interference. Hence, altered gray and white matter morphometry in cerebellar and frontal cortical regions may contribute to, or result from, pain-relevant dysfunction in chronic pain patients.

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We conducted structural covariance and tractography analyses in fibromyalgia.

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In fibromyalgia, higher correlations between cerebellar ROI volumes were found.

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In controls, higher correlations between frontal ROI volumes were found.

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Volume of cerebellum, orbitofrontal and inferior parietal areas correlated with BDI.

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WM fiber numbers connecting the areas associated with hyperalgesia and clinical pain

Normalization of aberrant resting state functional connectivity in fibromyalgia patients following a three month physical exercise therapy

Physical exercise is one of the most efficient interventions to mitigate chronic pain symptoms in fibromyalgia (FM). However, little is known about the neurophysiological mechanisms mediating these effects. In this study we investigated resting-state connectivity using functional magnetic resonance imaging (fMRI) before and after a 15 week standardized exercise program supervised by physical therapists. Our aim was to gain an understanding of how physical exercise influences previously shown aberrant patterns of intrinsic brain activity in FM. Fourteen FM patients and eleven healthy controls successfully completed the physical exercise treatment. We investigated post- versus pre-treatment changes of brain connectivity, as well as changes in clinical symptoms in the patient group. FM patients reported improvements in symptom severity. Although several brain regions showed a treatment-related change in connectivity, only the connectivity between the right anterior insula and the left primary sensorimotor area was significantly more affected by the physical exercise among the fibromyalgia patients compared to healthy controls. Our results suggest that previously observed aberrant intrinsic brain connectivity patterns in FM are partly normalized by the physical exercise therapy. However, none of the observed normalizations in intrinsic brain connectivity were significantly correlated with symptom changes. Further studies conducted in larger cohorts are warranted to investigate the precise relationship between improvements in fibromyalgia symptoms and changes in intrinsic brain activity.

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Physical exercise reduced the impact of fibromyalgia (FM) in everyday life.

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Longitudinal changes included restored insular-sensory functional connectivity.

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The links between connectivity and symptom improvements require further studies.

A new aspect of chronic pain as a lifestyle-related disease

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Activation of mesolimbic dopamine system underlies exercise-induced hypoalgesia.

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Interaction between mesolimbic system and hypothalamus determines physical activity.

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Changing the lifestyle inactive to active may attenuate and prevent chronic pain.

Physical exercise has been established as a low-cost, safe, and effective way to manage chronic intractable pain. We investigated the underlying mechanisms of exercise-induced hypoalgesia (EIH) using a mouse model of neuropathic pain (NPP). Epigenetic changes in activated microglia and maintained GABA synthesis in the spinal dorsal horn may contribute to EIH. Voluntary exercise (VE), a strong reward for animals, also induced EIH, which may be due in part to the activation of dopamine (DA) neurons in the ventral tegmental area (VTA). VE increases the expression of pCREB in dopaminergic neurons in the VTA, which would enhance dopamine production, and thereby contributes to the activation of the mesolimbic reward system in NPP model mice. We demonstrated that neurons in the laterodorsal tegmental and pedunculopontine tegmental nuclei, a major input source of rewarding stimuli to the VTA, were activated by exercise.

Chronic pain is at least partly attributed to sedentary and inactive lifestyle as indicated by the Fear-avoidance model. Therefore, chronic pain could be recognized as a lifestyle-related disease. Physical activity/inactivity may be determined by genetic/epigenetic and neural factors encoded in our brain. The hypothalamus and reward system is closely related in the axis of food intake, energy metabolism and physical activity. Understanding the interactions between the mesolimbic DA system and the hypothalamus that sense and regulate energy balance is thus of significant importance. For example, proopiomelanocortin neurons and melanocortin 4 receptors may play a role in connecting these two systems. Therefore, in a certain sense, chronic pain and obesity may share common behavioral and neural pathology, i.e. physical inactivity, as a result of inactivation of the mesolimbic DA system. Exercise and increasing physical activity in daily life may be important in treating and preventing chronic pain, a life-style related disease.

Use of Complementary and Integrative Therapies by Fibromyalgia Patients: A 14-Year Follow-up Study

Objective

To reevaluate the frequency and pattern of complementary and integrative medicine (CIM) use in patients with fibromyalgia (FM).

Patients and Methods

Consecutive patients with FM who were referred to the Mayo Clinic fibromyalgia treatment program from January 5 through July 27, 2017, were invited to complete a survey about their use of CIM therapies in the preceding 6 months. The survey asked about 3 primary CIM domains: treatments and techniques, vitamins and minerals, and herbs and other dietary supplements. For direct comparative purposes, we reused the survey instrument from our prior analogous study of CIM use, performed in 2003.

Results

Of the 310 patients who completed the survey, 304 (98.1%) reported using some form of CIM, similar to the percentage reported in our 2003 study (98%). The most frequently used CIM therapies in the current cohort were spiritual healing (54.0% [163 of 302]), massage therapy (50.0% [152 of 304]), chiropractic treatments (39.3% [118 of 300]), aromatherapy (39.0% [117 of 300]), exercise for a specific medical problem (38.6% [117 of 303]), melatonin (37.9% [77 of 203]), magnesium (36.3% [107 of 295]), green tea (36.1% [73 of 202]), and fish oil (34.5% [68 of 197]). We noted numerous substantial differences from the 2003 data in terms of the pattern of CIM use.

Conclusion

The use of CIM therapies among patients with FM continues to be extremely common for adult patients of all ages. Given the continued high prevalence of CIM use, health care professionals must have awareness and knowledge of these various modalities and their potential incorporation into a multifaceted FM treatment regimen.

Tobacco Use in Fibromyalgia Is Associated With Cognitive Dysfunction: A Prospective Questionnaire Study

Objective

To evaluate the association between smoking and cognitive function in patients with fibromyalgia.

Patients and Methods

We surveyed 668 patients with fibromyalgia from May 1, 2012 through November 30, 2013 at a major tertiary referral center. Patients were categorized by smoking status. Primary outcome of interest was cognitive function (MASQ questionnaire), and secondary outcomes included fibromyalgia symptom severity (FIQ-R questionnaire), quality of life (SF-36 questionnaire), fatigue (MFI-20 questionnaire), sleep (MOS-sleep scale), anxiety (GAD-7 questionnaire), and depression (PHQ-9 questionnaire). Independent Students' t-tests and χ² tests were performed for continuous and categorical variables, respectively. Univariate regression analysis identified variables predictive of outcomes, adjusting for age, gender, body mass index, marital status, and educational level.

Results

Ninety-four (14.07%) patients self-identified as smokers. There was an association of lower education level, unmarried status, and younger age in smokers compared with nonsmokers. In the adjusted univariate regression analysis, fibromyalgia smokers reported greater perceived total cognitive dysfunction (P=.009) and greater subscale scores of perceived difficulty in language (P=.03), verbal memory (P=.003), visual-spatial memory (P=.02), and attention (P=.04) compared with nonsmokers with fibromyalgia. For secondary outcomes, smokers with fibromyalgia reported greater severity of fibromyalgia-related symptoms (P=.006), worse quality-of-life index in the mental component scale (P=.02), greater sleep problems (P=.01), and increased anxiety (P=.001) compared with nonsmokers who had fibromyalgia.

Conclusion

In patients with fibromyalgia, smoking is a risk factor for cognitive dysfunction. Moreover, smokers with fibromyalgia were more likely to report increased severity of fibromyalgia symptoms, worse quality of life, more sleep problems, and increased anxiety compared with nonsmokers with fibromyalgia.

Brain responses to vestibular pain and its anticipation in women with Genito-Pelvic Pain/Penetration Disorder

Objective

In DSM-5, pain-related fear during anticipation of vaginal penetration is a diagnostic criterion of Genito-Pelvic Pain/Penetration Disorder (GPPPD). We aimed to investigate subjective and brain responses during anticipatory fear and subsequent induction of vestibular pain in women with GPPPD.

Methods

Women with GPPPD (n = 18) and age-matched healthy controls (HC) (n = 15) underwent fMRI scanning during vestibular pain induction at individually titrated pain threshold after a cued anticipation period. (Pain-related) fear and anxiety traits were measured with questionnaires prior to scanning, and anticipatory fear and pain intensity were rated during scanning using visual analog scales.

Results

Women with GPPPD reported significantly higher levels of anticipatory fear and pain intensity. During anticipation and pain induction they had stronger and more extensive brain responses in regions involved in cognitive and affective aspects of pain perception, but the group difference did not reach significance for the anticipation condition. Pain-related fear and anxiety traits as well as anticipatory fear ratings were positively associated with pain ratings in GPPPD, but not in HC. Further, in HC, a negative association was found between anticipatory fear ratings and brain responses in regions involved in cognitive and affective aspects of pain perception, but not in women with GPPPD.

Conclusions

Women with GPPPD are characterized by increased subjective and brain responses to vestibular pain and, to a lesser extent, its anticipation, with fear and anxiety associated with responses to pain, supporting the introduction of anticipatory fear as a criterion of GPPPD in DSM-5.

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Both subjective and brain responses during anticipation and induction of vestibular pain are increased in women with GPPPD.

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Between-group differences were found in brain regions involved in cognitive and affective aspects of the pain experience.

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These results support the addition of pain-related fear and anxiety in the diagnostic criteria of GPPPD in DSM-5.

Sex-Related Differences in Symptoms and Psychosocial Outcomes in Patients With Fibromyalgia: A Prospective Questionnaire Study

Objective

To investigate sex-related differences in patients with fibromyalgia (FM) in terms of demographic characteristics and clinical features, including tender point count (TPC), mood disorders, sleep problems, FM symptom severity, fatigue, cognitive dysfunction, and quality of life (QOL).

Patients and Methods

We studied 668 consecutive patients with FM (606 women) from May 1, 2012, to November 30, 2013. Validated questionnaires assessed outcomes of depression (Patient Health Questionnaire-9), anxiety (Generalized Anxiety Disorder-7), sleep problems (Medical Outcomes Study Sleep Scale), FM symptom severity (Revised Fibromyalgia Impact Questionnaire), fatigue (Multidimensional Fatigue Inventory), cognitive dysfunction (Multiple Ability Self-report Questionnaire), and QOL (36-Item Short Form Health Survey). Nonparametric Mann-Whitney U and Pearson χ² tests were used to compare continuous and categorical outcome measures, respectively, between men and women. Linear regression models were performed for all continuous dependent variables, adjusting for age, body mass index, ethnicity, marital status, and highest education level completed. P<.05 was considered statistically significant. The Benjamini-Hochberg procedure was used to adjust for multiple comparisons.

Results

Multiple linear regression analysis revealed a significant association of female sex and greater TPC (P<.001), lower overall FM symptom severity (lower overall Revised Fibromyalgia Impact Questionnaire score; P=.03), and higher QOL subscale score for vitality (36-Item Short Form Health Survey vitality subscale score; P=.02). After adjustment for multiple comparisons, only the association between female sex and greater TPC remained significant. There were no sex-related differences in demographic characteristics, depression, anxiety, sleep problems, FM symptom severity, cognitive dysfunction, and QOL.

Conclusion

A higher TPC may be associated with female sex in patients with FM. The assumption of other sex-based differences in the clinical presentation of FM was not supported in our study.

Outcomes of a Comprehensive Pain Rehabilitation Program for Patients With Fibromyalgia

OBJECTIVE

To analyze opioid intake interference with psychological, well-being, and functional outcomes and medication tapering in patients with fibromyalgia admitted to the Mayo Clinic Pain Rehabilitation Program (MCPRP) in Florida.

PATIENTS AND METHODS

A retrospective study on MCPRP outcomes was conducted. We reviewed the health records of 150 patients with fibromyalgia who participated in the program from May 1, 2014, to May 1, 2015. All patients were asked to fill out a survey at admission to and dismissal from the program. Surveys contained questions from the numeric pain score, Multidimensional Pain Inventory (perceived life control and interference of pain subscales), Center for Epidemiological Studies-Depression Scale, Pain Catastrophizing Scale, 36-Item Short-Form Health Status Survey (general health perceptions subscale), and Pain Self-Efficacy Questionnaire. A medical record review identified categories and number of medications at program admission and dismissal. Patients were divided in 2 groups: those whose concomitant medication did not include opioids at admission (no opioids group) and those whose concomitant medication included opioids at admission (opioids group).

RESULTS

By dismissal from the MCPRP, patients with fibromyalgia in the no opioids group had a significant (P<.05) improvement in all the self-reported scores. Medication, including opioids, were effectively tapered at a substantially higher percentage in the opioids group.

CONCLUSION

Benefit of the comprehensive pain rehabilitation program in patients with fibromyalgia was indicated by clinical improvements in pain severity, physical and emotional health, and functional capacity while successfully tapering medication. Opioid intake at admission may modify the program outcomes.

The effects of a 15-week physical exercise intervention on pain modulation in fibromyalgia: Increased pain-related processing within the cortico-striatal- occipital networks, but no improvement of exercise-induced hypoalgesia

Dysfunctional top-down pain modulation is a hallmark of fibromyalgia (FM) and physical exercise is a cornerstone in FM treatment. The aim of this study was to explore the effects of a 15-week intervention of strengthening exercises, twice per week, supervised by a physiotherapist, on exercise-induced hypoalgesia (EIH) and cerebral pain processing in FM patients and healthy controls (HC). FM patients (n = 59) and HC (n = 39) who completed the exercise intervention as part of a multicenter study were examined at baseline and following the intervention. Following the exercise intervention, FM patients reported a reduction of pain intensity, fibromyalgia severity and depression. Reduced EIH was seen in FM patients compared to HC at baseline and no improvement of EIH was seen following the 15-week resistance exercise intervention in either group. Furthermore, a subsample (Stockholm site: FM n = 18; HC n = 19) was also examined with functional magnetic resonance imaging (fMRI) during subjectively calibrated thumbnail pressure pain stimulations at baseline and following intervention. A significant main effect of exercise (post > pre) was observed both in FM patients and HC, in pain-related brain activation within left dorsolateral prefrontal cortex and caudate, as well as increased functional connectivity between caudate and occipital lobe bordering cerebellum (driven by the FM patients). In conclusion, the results indicate that 15-week resistance exercise affect pain-related processing within the cortico-striatal-occipital networks (involved in motor control and cognition), rather than directly influencing top-down descending pain inhibition. In alignment with this, exercise-induced hypoalgesia remained unaltered.

Creation of a Multispecialty Clinic for Patients with Central Sensitization-Based Chronic Pain Conditions

Objective

To design and evaluate, through a human-centered design approach, a multispeciality clinic for patients with central sensitization syndromes that combined virtual previsit consultations, traditional face-to-face appointments, and technology-enabled educational programming.

Patients and Methods

Patients with suspected fibromyalgia and chronic abdominal pain were seen in a multispecialty practice, and the performance of the clinic was evaluated against a contemporary cohort. Quantitative and qualitative evaluation measures included team estimates of time spent on care-related tasks, physician rank of alignment of patient need with clinic design, major appointment changes, and nonvisit care tasks. Members of the care team also evaluated strengths, weaknesses, opportunities, and threats to the success of the clinic.

Results

The pilot clinic was operated from April 1, 2020, to April 30, 2021, and included 34 patients with suspected fibromyalgia/chronic abdominal pain. During the pilot period, physicians ranked the value of the virtual previsit consultations in providing care as 7.5 on a scale of 0 to 10 and reported an average of 50 minutes in preparation for the appointment, execution of the appointment, and postvisit documentation. We did not observe substantial differences in the number of added appointments or messages received within the patient portal when compared with a comparison cohort. Patients who participated in the combination nurse educator–led and digital education program provided positive feedback about their experience.

Conclusion

Our clinic model provides a framework for the treatment of patients with debilitating centrally sensitized conditions and future expansion of virtual care delivery models to better meet patient care and educational needs.

Statin Therapy and Symptom Burden in Patients With Fibromyalgia: A Prospective Questionnaire Study

Objective

To evaluate the association between statin use and symptom severity, tender point count, fatigue, cognition, mood, and sleep issues in patients with fibromyalgia (FM).

Methods

Between May 2012 and November 2013, 668 patients with FM were surveyed. Patients were stratified into statin users and statin nonusers. Primary outcome was FM symptom severity (FIQ-R questionnaire) and tender point count. Secondary outcomes included fatigue (MFI-20), cognitive dysfunction (MASQ), anxiety (GAD-7), depression (PHQ-9), and sleep issues (SPI-II). Regression analysis assessed for differences in these clinical outcomes between statin users and statin nonusers and adjusted for age, sex, body mass index, ethnicity, tobacco use, opioid use, and neuropathic medication use.

Results

Of the FM patients, 79 (11.8%) were statin users, whereas 589 (88.2%) reported no current statin use. Compared with the control cohort, statin users were older (55.0±11.3 years vs 46.2±12.9 years; P<.001) and had a higher body mass index (33.0±7.0 kg/m² vs 29.8±7.7 kg/m²; P=.001). Adjusted linear regression revealed no association between statin use and symptom severity (total FIQ-R scores, 57.7±18.3 vs 59.0±18.1; adjusted β coefficient, −0.4; 95% CI, −4.8 to 4.1; P=.871). There was also no association between statin use and tender point count (14.8±4.1 vs 14.5±4.2; adjusted β coefficient, 0.2; 95% CI, −0.8 to 1.2; P=.732). Secondary outcome analysis revealed no difference between statin users and statin nonusers in metrics measuring fatigue, cognition, anxiety, depression, and sleep problems.

Conclusion

Administration of statin therapy for at least 1 month is not a risk factor for worse symptom burden in patients with FM. Statin therapy should be offered to dyslipidemic FM patients with an appropriate medical indication to optimize their cardiovascular health.