Recommendations For Core Outcome Domain Set For Whiplash-Associated Disorders (CATWAD) Objective: Inconsistent reporting of outcomes in clinical trials of treatments for Whiplash-associated Disorders (WAD) hinders effective data pooling and conclusions that can be drawn about the effectiveness of tested treatments. The aim of this study was to provide recommendations for core outcome domains that should be included in clinical trials of WAD. Materials and Methods: A 3-step process was used: (1) A list of potential core outcome domains were identified from the published literature. (2) Researchers, health care providers, patients, and insurance personnel participated and rated the importance of each domain via a 3-round Delphi survey. A priori criteria for consensus were established. (3) Experts comprising researchers, health care providers, and a consumer representative participated in a multidisciplinary consensus meeting that made final decisions on the recommended core outcome domains. Results: The literature search identified 63 potential core domains. A total of 223 participants were invited to partake in the Delphi surveys, with 41.7% completing round 1, 45.3% round 2, and 51.4% round 3. Eleven core domains met the criteria for inclusion across the entire sample. After the expert consensus meeting, 6 core domains were recommended: Physical Functioning, Perceived Recovery, Work and Social Functioning, Psychological Functioning, Quality of Life, and Pain. Discussion: A 3-step process was used to recommend core outcome domains for clinical trials in WAD. Six core domains were recommended: Physical Functioning, Perceived Recovery, Work and Social Functioning, Psychological Functioning, Quality of Life, and Pain. The next step is to determine the outcome measurement instruments for each of these domains.

Nocebo Hyperalgesia can be Induced by the Observation of a Model Showing Natural Pain Expressions Objectives: Nocebo hyperalgesia is an increase in pain through the expectation of such an increase as a consequence of a sham treatment. Nocebo hyperalgesia can be induced by observation of a model demonstrating increased pain via verbal pain ratings. The aim of the present study was to investigate whether observing natural pain behavior, such as facial pain expressions, can also induce nocebo responses. Materials and Methods: Eighty female participants (age: 22.4 y±4.8) underwent a pressure-pain procedure (algometer) on both hands and rated their pain on a numerical rating scale. All participants received ointment on one of their hands, but no explanation was given for this. Before their own participation, the participants watched a video in which a woman underwent the same procedure and who either modeled increased pressure pain upon ointment application (nocebo condition) or showed a neutral facial expression throughout (control condition). Results: A 2×2 analysis of variance with condition (nocebo; control) as a between-subjects factor and ointment application (with; without) as a within-subject factor revealed a main effect for ointment and a condition×ointment interaction. In the nocebo condition, pain ratings were higher with ointment than without. Discussion: For the first time, it was shown that watching a model demonstrating pain through facial expressions induced nocebo hyperalgesia. As we mostly express pain through natural pain behavior rather than through pain ratings, this paradigm extends our knowledge of observational learning about pain and may have implications for contexts in which persons watch others undergo painful procedures.

Further Examination of the Pain Stages of Change Questionnaires Among Chronic Low Back Pain Patients: Long-term Predictive Validity of Pretreatment and Posttreatment Change Scores and Stability of Posttreatment Scores Objectives: In order to maximize the therapeutic benefits of cognitive-behavioral therapy (CBT) for chronic pain, individuals need to be motivated to adopt a self-management approach. The Pain Stages of Change Questionnaire (PSOCQ) was developed to measure patients’ readiness to adopt a self-management approach to chronic pain. The present study examined whether pretreatment and posttreatment PSOCQ change scores among chronic low back pain patients could predict 6- and 12-month follow-up outcomes, and the stability of posttreatment PSOCQ scores during follow-up. Methods: Participants were recruited from a VA primary care clinic. Data from 60 participants assigned to either regular CBT or a modified CBT (ie, PRIME CBT) condition were analyzed in the present study. Self-report measures including PSOCQ, pain severity, disability, and depressive symptom severity were administered at pretreatment, 10 weeks posttreatment, 6-month and follow-up assessments. Results: Multiple regression analyses showed that pretreatment and posttreatment changes in the Action/Maintenance scores significantly predicted pain severity at 6 months, and changes in the Precontemplation scores significantly predicted disability at 6 months. None of the PSOCQ change scores significantly predicted depressive symptom severity. Posttreatment Precontemplation and Action/Maintenance scores were quite stable, even at 12-month follow-up. Conclusions: Changes in patients’ attitudes toward adopting a pain self-management approach may serve as one of the therapeutic mechanisms and predict long-term function. This study also revealed that changed attitudes toward chronic pain self-management remain quite stable over time. Adoption of beliefs consistent with chronic pain self-management during treatment may promote sustained benefits.

Individualization of Migraine Prevention: A Randomized Controlled Trial of Psychophysical-based Prediction of Duloxetine Efficacy Objective: Finding an effective preventive agent for the individual migraineur is often long and frustrating. An individual-specific, efficacy-predicting tool would be invaluable in directing, shortening, and improving this process. As the serotonin-norepinephrine reuptake inhibitor duloxetine is a pain modulator, we hypothesized that pronociceptivity will directly predict drug efficacy, so that the more pronociceptive the patient is, the more efficacious the drug. Therefore, we used psychophysical pain measures to predict duloxetine efficacy in migraine prevention. Methods: Fifty-five migraineurs participated: 27 received duloxetine and 28 nonactive placebo. Responses to painful stimuli, conditioned pain modulation, and temporal summation of pain were measured before treatment. Treatment outcome measures included changes in attack frequency, migraine days, pain levels, and a reported self-estimate of migraine improvement at weeks 4 and 5. To examine treatment effects, the outcome measures were compared with pretreatment levels. Treatment by the psychophysical-predictor effect on treatment outcome was examined in separate regression models. Results: Duloxetine was more efficacious than placebo in migraine prevention, as indicated by the patient’s estimation of migraine improvement (duloxetine: 52.3±30.4%; placebo: 26.0±27.3%; P=0.001). Further, this measure, in the duloxetine group, was predicted by higher pretreatment pain ratings for tonic heat pain (P=0.012); greater pain sensitivity at baseline predicted greater percent of migraine improvement in duloxetine (r=0.47; P=0.013), but not in placebo (r=−0.36; P=0.060). Discussion: Our results suggest how personalized medicine can be applied to designing appropriate migraine prevention treatment. Psychophysical testing can reveal and characterize pronociceptive migraineurs, who seem to be more likely than non–pronociceptive ones to benefit from migraine prevention with serotonin-norepinephrine reuptake inhibitors.

Comparing Postoperative Analgesic Effect of Dexmedetomidine or Dexamethasone Added to Lidocaine Through Infraclavicular Block in Forearm Surgery Objective: The objective of this study was to compare the analgesic efficacy of dexamethasone versus dexmedetomidine added to lidocaine using infraclavicular block in patients undergoing forearm fracture surgery. Method: Seventy-five patients aged 20 to 60 years were recruited for a prospective, double-blinded, randomized clinical trial. Ultrasound-guided infraclavicular brachial plexus block was performed in 3 groups by injecting 28 mL lidocaine plus 2 mL distilled water (Lido), 28 mL lidocaine plus 2 mL (8 mg) dexamethasone (Dexa), and 28 mL lidocaine plus 2 mL (1 µg/kg) dexmedetomidine (Dexm). Sensory and motor block onset time and the duration, hemodynamic variables, the time for the first analgesic request, and the total analgesic agents consumed within 6 hours after infraclavicular block were assessed. Results: Sensory block duration in the Dexm group was significantly greater than in the Lido (P=0.019) and Dexa (P=0.046) groups. The mean motor block duration in the Dexm group showed to be significantly longer than that in the Lido group (P=0.009). Pain intensity within 4 hours after block significantly increased in the Lido group compared with that in the Dexa and Dexm groups (P=0.001). Analgesic consumption during 6 hours after the procedure was higher in the Lido group when compared with the other 2 groups (P=0.001). The Dexm group showed the highest reduction in the mean arterial pressure (P=0.006) and heart rate (P=0.001) among the 3 groups. Conclusions: There was no significant difference in postoperative pain intensity between the Dexa and Dexm groups, although DEXm demonstrated a longer sensory block duration in comparison with dexamethasone as a lidocaine adjuvant in infraclavicular block.

Improving Distress and Behaviors for Parents of Adolescents With Chronic Pain Enrolled in an Intensive Interdisciplinary Pain Program Objectives: Intensive interdisciplinary treatment is emerging as an effective treatment of chronic pain in youth. These programs often include a parental component with the belief that targeting parental distress and responses to a child’s pain will improve outcomes. However, few studies have evaluated the impact of a parental intervention in the interdisciplinary treatment of pediatric chronic pain. The present study consists of a nonrandomized pre-post design to evaluate change in psychological and behavioral functioning of parents who participated in intensive parent programming that utilized cognitive-behavioral therapy and acceptance and commitment therapy, delivered within the context of an interdisciplinary intensive 3-week pain treatment program for youth with chronic pain. Materials and Methods: Two hundred twelve parents and their children participated in the study, with 116 participants completing 3-month follow-up measures. Parents completed measures of depressive symptoms, pain catastrophizing, protective responses, and psychological flexibility at admission, discharge, and 3 months after the program. Child functional disability was assessed at the same time points. We examined change in parent factors over time, while controlling for change in child distress. Results: Parents reported significant improvements in all areas of functioning from admission to discharge and improvements were maintained at 3-month follow-up. Discussion: This study provides evidence suggesting parent interventions can be effective in reducing parent distress and behaviors known to be associated with child outcomes.

Insomnia Increases Symptom Severity and Health Care Utilization in Patients With Fibromyalgia: A Population-based Study Objective: This study aimed to determine whether comorbid insomnia is associated with increased use of fibromyalgia-related medications and health resources in fibromyalgia (FM) patients. Materials and Methods: We analyzed data retrieved from the Longitudinal Health Insurance Database 2010, which contains claims data of 1 million beneficiaries randomly selected from Taiwan’s National Health Insurance program. Patients treated for FM (n=17,920) on 2 separate visits between 2000 and 2001 were selected and subsequently divided into 2 groups: patients with and without comorbid insomnia (n=5466 and 12,454, respectively). Insomnia was identified through diagnosis on 2 separate visits after the index FM date. FM-related pharmacotherapies and ambulatory care visits were tracked from the index date to the end of 2013. Results: Insomnia was associated with increased likelihood of future use of antidepressants (adjusted odds ratio [OR]=3.84, P<0.001), gabapentin (adjusted OR=1.67, P<0.001), pregabalin (adjusted OR=1.79, P=0.046), muscle relaxants (adjusted OR=3.05, P<0.001), and opioids and tramadol (adjusted OR=1.59, P<0.001) among FM patients compared with FM patients without insomnia. In addition, a diagnosis of insomnia was associated with an increased frequency of visits to ambulatory care services for both FM (β=1.79; 95% confidence interval, 1.57-2.02; P<0.001) and other conditions (β=108.51; 95% confidence interval, 103.14-113.89; P<0.001). Discussion: This study demonstrates the substantial burden of comorbid insomnia in patients with FM.

Patient and Disease Characteristics Associate With Sensory Testing Results in Chronic Pancreatitis Background: Abdominal pain is the most common symptom in chronic pancreatitis (CP) and has an extensive impact on patients’ lives. Quantitative sensory testing (QST) provides information on sensitivity to pain and mechanisms that can help quantify pain and guide treatment. The aims of this study were (1) to explore sensitivity to pain in patients with CP using QST and (2) to associate patient and disease characteristics with QST results. Methods: Ninety-one patients with painful CP and 28 healthy control participants completed a QST paradigm using static tests (muscle pressure stimulation and electrical skin stimulations) to unravel segmental and widespread hyperalgesia as a consequence of visceral pain. A dynamic conditioned pain modulation (CPM) paradigm was used as a proxy of pain modulation from the brainstem to inhibit incoming nociceptive barrage, and questionnaires were used to gather information on pain experience and quality of life. Results: Patients had impaired CPM compared with controls (18.0±29.3% vs. 30.9±29.3%, P=0.04) and were hypersensitive to pressure stimulation, specifically in the pancreatic (Th10) dermatome (P<0.001). The capacity of CPM was associated with clinical pain intensity (P=0.01) and (in the univariate analysis only) the use of opioids was associated with hyperalgesia to pressure stimulation (P<0.05). Conclusions: Sensitivity to pain in CP patients can be characterized by a simple bedside QST. Severe clinical pain in CP was associated with reduced CPM function and should be targeted in management.

Effects of Conditioned Pain Modulation on the Nociceptive Flexion Reflex in Healthy People: A Systematic Review Objectives: The nociceptive flexion reflex (NFR) is a spinal reflex induced by painful stimuli resulting in a withdrawal response. Research has shown that the NFR is inhibited through endogenous pain inhibitory mechanisms, which can be assessed by conditioned pain modulation (CPM) paradigms. Although accumulating research suggests that the NFR can be affected by CPM, no clear overview of the current evidence exists. Therefore, the present review aimed at providing such a synthesis of the literature. In addition, the influence of personal factors on the CPM of the NFR was investigated. Materials and Methods: A systematic review was performed and reported following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Five electronic databases were searched to identify relevant articles. Retrieved articles were screened on eligibility using predefined inclusion criteria. Risk of bias was investigated according to the modified Newcastle-Ottawa Scale. Levels of evidence and strength of conclusion were assigned following the guidelines of the Dutch Institute for Healthcare Improvement. Results: Forty articles were included. There is some evidence that CPM produced by thermal or mechanical stimuli induces inhibitory effects on the NFR. However, inconclusive evidence exists with regard to the effect of electrical conditioning stimuli. While several personal factors do not affect CPM of the NFR, increased cognitive interference is associated with reduced NFR inhibition. Discussion: The present review demonstrates that certain types of nociceptive conditioning stimuli have the potential to depress, at the spinal level, nociceptive stimuli elicited from distant body regions. Although CPM of the NFR seems to be robust to the influence of several personal factors, it can be affected by cognitive influences.