Hilary D. Wilson

Treatment of chronic non-cancer pain

Chronic pain is a pervasive problem that affects the patient, their significant others, and society in many ways. The past decade has seen advances in our understanding of the mechanisms underlying pain and in the availability of technically advanced diagnostic procedures; however, the most notable therapeutic changes have not been the development of novel evidenced-based methods, but rather changing trends in applications and practices within the available clinical armamentarium. We provide a general overview of empirical evidence for the most commonly used interventions in the management of chronic non-cancer pain, including pharmacological, interventional, physical, psychological, rehabilitative, and alternative modalities. Overall, currently available treatments provide modest improvements in pain and minimum improvements in physical and emotional functioning. The quality of evidence is mediocre and has not improved substantially during the past decade. There is a crucial need for assessment of combination treatments, identification of indicators of treatment response, and assessment of the benefit of matching of treatments to patient characteristics.

Fear of Pain as a Prognostic Factor in Chronic Pain: Conceptual Models, Assessment, and Treatment Implications

Chronic pain is a pervasive health care issue affecting over 50 million Americans and costing more than

Toward the identification of symptom patterns in people with fibromyalgia

100 billion dollars annually in lost productivity and health care costs. As a financially and emotionally taxing condition, the families and friends of people with chronic pain, as well as society at large, are affected. Current theory supports the role of biological, psychological, and environmental factors in the etiology, exacerbation, and maintenance of chronic pain. Recently, the specific role of pain-related fear in pain experience has received increasing attention. This article summarizes current understanding of the role of pain-related fear in the onset of acute pain incidents, the transition of acute pain to chronic, and the pain severity and disability of patients with ongoing chronic pain conditions. Treatments demonstrated to reduce pain-related fear are presented, evidence demonstrating their efficacy at reducing disability and pain severity are summarized, and recent criticisms of the fear-avoidance model and future directions are considered.

Hyperbaric oxygen treatment decreases inflammation and mechanical hypersensitivity in an animal model of inflammatory pain.

OBJECTIVE People with fibromyalgia (FM) report a number of physical, cognitive, and psychological symptoms. The purpose of the current study was to determine whether people with FM differed based on the type and severity of symptoms, and if so, whether subgroups differ with respect to health care utilization, functional ability, and work status. METHODS Symptom, health care utilization, work, and physical data were available for 2,182 female responders to an Internet survey. Factor analysis was conducted on the physical and cognitive/psychological symptoms, and resulting factor scores were utilized in a cluster analysis to identify subgroups based on symptoms. Cluster groups were compared on a set of variables (e.g., health care utilization, coping). RESULTS Factor analyses resulted in 3 symptom factor scores: musculoskeletal, non-musculoskeletal, and cognitive/psychological symptoms. The optimal cluster solution to the cluster analysis revealed 4 clusters. Group 1 was high on all 3 symptom domains, group 2 was moderate on the 2 physical symptom domains and high on cognitive/psychological symptoms, group 3 was moderate on the 2 physical symptom domains and low on cognitive/psychological symptoms, and group 4 was low on all symptom domains. The more symptomatic groups reported the greatest amount of health care utilization and difficulty in coping with symptoms. CONCLUSION The FM population is heterogeneous with regard to symptom reporting. Additional research is needed to better understand differential symptom experience among people with FM. Clarification of these differences may increase understanding of the mechanisms involved in FM and provide guidance for treatment decisions.

Heterogeneity Within the Fibromyalgia Population: Theoretical Implications of Variable Tender Point Severity Ratings

Hyperbaric oxygen therapy has been used to treat a variety of ailments from carbon monoxide poisoning to fibromyalgia. The purpose of this experiment was to explore the effect of hyperbaric oxygen treatment on carrageenan-induced inflammation and pain in rats. Hyperbaric oxygen treatment significantly decreased inflammation and pain following carrageenan injection. Clinically hyperbaric oxygen may be used in situations where NSAIDS are contraindicated or in persistent cases of inflammation.

Redesigning Delivery of Opioids to Optimize Pain Management, Improve Outcomes, and Contain Costs

Objective. The American College of Rheumatology (ACR) tender point (TP) criterion is used in diagnosing fibromyalgia syndrome (FM). There has been little research investigating patterns of positive TP. We investigated response patterns of TP in a sample of patients with FM. Methods. Manual TP survey data were available on 1433 patients with FM. Factor analysis was conducted on ACR TP and control (CON) points. Factor scores were cluster analyzed to identify subgroups based on TP scores. Subgroups were compared on demographic and psychosocial variables. Results. Factor analysis resulted in 4 TP groupings: neck/shoulder girdle, gluteal/trochanteric, and upper extremity regions, and a set of CON TP. Cluster analysis revealed 3 clusters. Group 1 was high on all 3 TP regions and the CON set; Group 2 moderate on the 3 TP regions, low on the CON set; and Group 3 was relatively low on all 3 TP regions and the CON set. The group highest on the CON and TP regions reported the greatest pain (7.58 ± 1.23; p < 0.001), sleep disturbance (7.05 ± 1.61; p < 0.001), anxiety (10.14 ± 4.57; p < 0.001), and depression (8.42 ± 4.4; p < 0.001). Conclusion. TP severity ratings varied among cluster groups, suggesting patients with FM are not homogeneous. Variations in TP severity provide information regarding the degree to which FM affects patients’ quality of life. Patients with elevated scores on the CON TP demonstrated a general pattern reflecting lower thresholds for symptom reporting and, perhaps, disease severity. Research is needed to elucidate mechanisms underlying heterogeneity among the FM population.

The relationship between basal level of anxiety and the affective response to inflammation

INTRODUCTION Chronic pain is a public health concern, and in the last decade, there has been a dramatic increase in the use and abuse of prescription opioids for chronic non-cancer pain. METHODS We present an overview of a five-component model of pain management implemented at the University of Washington Division of Pain Medicine designed to facilitate recent state guidelines to reduce the risks associated with long-term use of prescription opioids. RESULTS Central to the model described are guidelines for best clinical practice, a collaborative care approach, telehealth solutions, comprehensive prescription-monitoring, and measurement-based care. DISCUSSION The model presented is a patient-centered, efficient, and cost-effective approach to the management of chronic pain.

The Role of Fear of Movement in Subacute Whiplash-Associated Disorders Grades I and II

Pain is a multidimensional experience and is modulated by a number of factors. One such factor that plays a critical role in pain modulation is anxiety. However, the influence of individual differences in anxiety on higher order pain processing in rodents remains unclear. Therefore, the purpose of this study was to identify animals that have baseline levels of high and low anxiety using the elevated plus maze and then measure pain threshold and place escape/avoidance responding (a measure of pain affect) in the animals. As expected, there was a range of baseline behavior in the elevated plus maze that was used to separate animals into high and low anxiety groups. Following carrageenan injection, both groups of animals developed a similar degree of mechanical hypersensitivity and both groups showed similar place escape/avoidance behavior. These findings suggest that individual differences in baseline anxiety levels do not significantly contribute to the development of mechanical sensitivity and do not modulate higher order pain processing related to pain affect and motivation.

Electrical stimulation of the primary somatosensory cortex inhibits spinal dorsal horn neuron activity

Summary Fear of movement plays and important role in individuals with subacute whiplash‐associated disorders and it should be directly targeted in treatment. ABSTRACT Fear and avoidance of activity may play a role in fostering disability in whiplash‐associated disorders (WAD). This study examined the role of fear after WAD and assessed the effectiveness of 3 treatments targeting fear. People still symptomatic from WAD grade I‐II injuries approximately 3 months previously (n = 191) completed questionnaires (eg, Neck Disability Index [NDI]) and were randomized to 1 of the treatments: (1) informational booklet (IB) describing WAD and the importance of resuming activities, (2) IB + didactic discussions (DD) with clinicians reinforcing the booklet, and (3) IB + imaginal and direct exposure desensitization (ET) to feared activities. DD and ET participants received three 2‐hour treatment sessions. Absolute improvements in NDI were in predicted direction (ET = 14.7, DD = 11.9, IB = 9.9). ETs reported significantly less posttreatment pain severity compared with the IB (Mean = 1.5 vs 2.3, P < .001, d = 0.6) and DD (M = 1.5 vs 2.0, P = .039, d = 0.6) groups. Reduction in fear was the most important predictor of improvement in NDI (β = 0.30, P < .001), followed by reductions in pain (β = 0.20, P = .003) and depression (β = 0.18, P = .004). The mediational analysis confirmed that fear reduction significantly mediated the effect of treatment group on outcome. Results highlight the importance of fear in individuals with subacute WAD and suggest the importance of addressing fear via exposure therapy and/or educational interventions to improve function.

Temporal stability of conditioned pain modulation in healthy women over four menstrual cycles at the follicular and luteal phases

Cortical stimulation has been demonstrated to alleviate certain pain conditions. The aim of this study was to determine the responses of the spinal cord dorsal horn neurons to stimulation of the primary somatosensory cortex (SSC). We hypothesized that direct stimulation of the SSC will inhibit the activity of spinal dorsal horn neurons by activating the descending inhibitory system. Thirty-four wide dynamic range spinal dorsal horn neurons were recorded in response to graded mechanical stimulation (brush, pressure, and pinch) at their respective receptive fields while a stepwise electrical stimulation (300 Hz, 0.1 ms, at 10, 20, and 30 V) was applied in the SSC through a bipolar tungsten electrode. The responses to brush at control, 10 V, 20 V, 30 V, and recovery were 16.0 +/- 2.3, 15.8 +/- 2.2, 14.6 +/- 1.8, 14.8 +/- 2.0, and 17.0 +/- 2.2 spikes/s, respectively. The responses to pressure at control, 10 V, 20 V, 30 V, and recovery were 44.7 +/- 5.5, 37.0 +/- 5.6, 29.5 +/- 4.8, 31.6 +/- 5.2, and 43.2 +/- 5.7 spikes/s, respectively. The responses to pinch at control, 10 V, 20 V, 30 V, and recovery were 58.1 +/- 7.0, 42.9 +/- 5.5, 34.8 +/- 3.9, 34.6 +/- 4.4, and 52.6 +/- 6.0 spikes/s, respectively. Significant decreases of the dorsal horn neuronal responses to pressure and pinch were observed during SSC stimulation. It is concluded that electrical stimulation of the SSC produces transient inhibition of the responses of spinal cord dorsal horn neurons to higher intensity mechanical stimuli without affecting innocuous stimuli.