Rethinking chronic pain in a primary care setting

Chronic pain substantially impacts patient function and quality of life and is a burden to society at large in terms of increased health care utilization and loss of productivity. As a result, there is an increasing recognition of chronic pain as a public health crisis. However, there remains wide variability in clinical practices related to the prevention, assessment, and treatment of chronic pain. Certain fundamental aspects of chronic pain are often neglected including the contribution of the psychological, social, and contextual factors associated with chronic pain. Also commonly overlooked is the importance of understanding the likely neurobiological mechanism(s) of the presenting pain and how they can guide treatment selection. Finally, physicians may not recognize the value of using electronic medical records to systematically capture data on pain and its impact on mood, function, and sleep. Such data can be used to monitor onset and maintenance of treatments effects at the patient level and evaluate costs at the systems level. In this review we explain how these factors play a critical role in the development of a coordinated, evidence-based treatment approach tailored to meet specific needs of the patient. We also discuss some practical approaches and techniques that can be implemented by clinicians in order to enhance the assessment and management of individuals with chronic pain in primary care settings.     

Altered Resting State Connectivity of the Insular Cortex in Individuals With Fibromyalgia

The insular cortex (IC) and cingulate cortex (CC) are critically involved in pain perception. Previously we demonstrated that fibromyalgia (FM) patients have greater connectivity between the insula and default mode network at rest, and that changes in the degree of this connectivity were associated with changes in the intensity of ongoing clinical pain. In this study we more thoroughly evaluated the degree of resting-state connectivity to multiple regions of the IC in individuals with FM and healthy controls. We also investigated the relationship between connectivity, experimental pain, and current clinical chronic pain. Functional connectivity was assessed using resting-state functional magnetic resonance imaging in 18 FM patients and 18 age- and sex-matched healthy controls using predefined seed regions in the anterior, middle, and posterior IC. FM patients exhibited greater connectivity between 1) right mid IC and right mid/posterior CC and right mid IC, 2) right posterior IC and left CC, and 3) right anterior IC and left superior temporal gyrus. Healthy controls displayed greater connectivity between left anterior IC and bilateral medial frontal gyrus/anterior cingulate cortex; and left posterior IC and right superior frontal gyrus. Within the FM group, greater connectivity between the IC and CC was associated with decreased pressure-pain thresholds.PerspectiveThese data provide further support for altered resting-state connectivity between the IC and other brain regions known to participate in pain perception/modulation, which may play a pathogenic role in conditions such as FM. We speculate that altered IC connectivity is associated with the experience of chronic pain in individuals with FM.     

Improving physical functional status in patients with fibromyalgia: a brief cognitive behavioral intervention

OBJECTIVE: Sustained improvement in physical functional status was the primary goal of a brief, 6 session cognitive behavioral therapy (CBT) protocol for fibromyalgia (FM). METHODS: One hundred forty-five patients with FM were randomly assigned to either (1) standard medical care that included pharmacological management of symptoms and suggestions for aerobic fitness, or (2) the same standard medical treatment plus 6 sessions of CBT aimed at improving physical functioning. Outcome measures included the Medical Outcome Study Short Form-36 Physical Component Score and McGill ratings of pain. Outcomes were treated dichotomously using a preestablished criterion for clinically significant success based upon the reliability of change index from baseline to one year posttreatment. RESULTS: Twenty-five percent of the patients receiving CBT were able to achieve clinically meaningful levels of longterm improvement in physical functioning, whereas only 12% of the patients receiving standard care achieved the same level of improvement. There were no lasting differences on pain ratings between groups. CONCLUSION: Lasting improvements in physical functioning have been among the most difficult outcomes to obtain in studies of FM. These data suggest that the inclusion of CBT to a standard medical regimen for FM can favorably influence physical functioning in a subset of patients.     

Knee pain and radiographic osteoarthritis interact in the prediction of levels of self‐reported disability

Objective

To determine predictors of disability depending on whether joint deformity and pain reporting exist independently or concurrently.

Methods

Subjects were 154 volunteers for an osteoarthritis screening examination. Eligible subjects completed questionnaires for physical function, pain, and depressive symptoms; underwent evoked pain testing for tenderness assessment; and had anteroposterior and lateral radiographs taken of both knees. Two blinded rheumatologists scored the images using Kellgren‐Lawrence criteria to determine presence of deformity.

Results

Subjects were divided into 3 subgroups based on radiographic evidence of deformity and self‐reported pain. Disability was greatest when pain and deformity occurred together (F[2,151] = 18.8, P < 0.0001). Self‐reported disability in the absence of deformity was predicted by body mass index, pain threshold, and anxiety symptoms; disability was predicted by the number of osteophytes and depressive symptoms when pain and deformity occurred together.

Conclusion

Self‐reported disability in osteoarthritis of the knee is greatest with concurrent pain and joint deformity. When pain and deformity do not cooccur, disability appears to be related to separate factors, including anxiety and pain threshold (e.g., tenderness).

     

The Role of the Central Nervous System in Osteoarthritis Pain and Implications for Rehabilitation

It has been known for some time that central nervous system (CNS) pain amplification is present in some individuals with osteoarthritis; the implications of this involvement, however, are just starting to be realized. In the past year, several research reviews have focused on evidence supporting shared mechanisms across chronic pain conditions for how pain is generated and maintained in the CNS, irrespective of the underlying structural pathology. This review article focuses on current literature describing CNS amplification in osteoarthritis by discussing peripheral sensitization, central sensitization, and central augmentation, and the clinical manifestation of central augmentation referred to as centralized pain, and offers considerations for rehabilitation treatment and future directions for research.     

A Pooled Analysis of Two Randomized,Double‐Blind,Placebo‐Controlled Trials of Milnacipran Monotherapy in the Treatment of Fibromyalgia

Milnacipran has been shown to significantly improve the pain, global well‐being, and physical function of fibromyalgia (FM), and is approved by the U.S. Food and Drug Administration for the management of this disorder. Post hoc analyses of data from two pivotal trials were conducted to further assess the clinical benefits of milnacipran, to determine the impact of baseline pain severity on treatment outcomes, and to confirm the safety and tolerability of this medication in patients with FM. Patients in these trials were randomized to placebo (n = 624), milnacipran 100 mg/day (n = 623), or milnacipran 200 mg/day (n = 837). Two different composite responder analyses were used to evaluate efficacy: a 2‐measure analysis, requiring ≥ 30% improvement from baseline visual analog scale 24‐hour recall pain scores and a Patient Global Impression of Change (PGIC) score of “very much improved” or “much improved”; and a 3‐measure analysis, requiring a ≥ 6‐point improvement from baseline in SF‐36 Physical Component Summary scores in addition to the pain and PGIC criteria. Additionally, a pooled analysis of mean changes from baseline pain scores was conducted in order to evaluate the efficacy of milnacipran over the entire course of treatment. At 3 months, composite responder rates were significantly higher in the milnacipran treatment groups than in the placebo group (2‐ and 3‐measure composite responder analyses: P ≤ 0.001, both doses vs. placebo). These improvements were not dependent on baseline pain severity. Similar composite responder results were observed in patients who continued treatment for up to 6 months. Significant improvements in mean pain scores were seen with both doses of milnacipran vs. placebo as early as 1 week after treatment initiation and were sustained for up to 6 months of milnacipran treatment. The most common adverse events associated with milnacipran were nausea, headache, and constipation.     

Before the onset of interstitial cystitis/bladder pain syndrome,the presence of multiple non-bladder syndromes is strongly associated with a history of multiple surgeries

Objective

Certain functional somatic syndromes (FSSs) such as fibromyalgia and irritable bowel syndrome are accompanied by diffuse pain amplification. Women with interstitial cystitis/bladder pain syndrome (IC/BPS) have numerous FSSs, as well as other non-bladder syndromes (NBSs) that are linked to the FSSs. They also report multiple surgeries. Since pain is a common indication for surgery, we tested the hypothesis that NBSs were associated with surgeries.

Methods

We interviewed 312 incident IC/BPS cases and controls on NBSs and number of surgeries before the index date (for cases, IC/BPS onset date). Poisson and logistic regression analyses adjusted for age, race, educational level, and menopause.

Results

Number of surgeries increased with number of NBSs in both cases and controls whether chronic pelvic pain (CPP), the only NBS generally accepted as an indication for surgery, was present or not. Logistic regression analysis showed that among cases CPP was the only individual NBS associated with a history of multiple surgeries, and then only modestly [odds ratio (OR) 1.9, confidence intervals (CI) 1.06, 3.2]. By far the strongest association was the number of NBSs. The OR for multiple surgeries increased with number of NBSs: for cases with 4–5 NBSs the OR was 14.1 (1.8, 113) and with 6–9 NBSs, 33.1 (3.9, 279). Controls had fewer syndromes and fewer surgeries and this linkage was less prominent.

Conclusion

Among IC/BPS cases, the number of NBSs was strongly correlated with the number of surgeries. Understanding temporal relationships will be necessary to explore causal linkages and may modify surgical practice.