The journal of pain : official journal of the American Pain Society
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The aim of this present study is to test the hypotheses that the 18 predetermined sites of examination for tender points (TP sites) in fibromyalgia syndrome (FMS) are myofascial trigger points (MTrPs), and that the induced pain from active MTrPs at TP sites may mimic fibromyalgia pain. Each TP site was evaluated with manual palpation followed by intramuscular electromyographic (EMG) registration of spontaneous electrical activity to confirm or refute the existence of an MTrP in 30 FMS patients. Overall spontaneous pain intensity and pain pattern were recorded before manual identification of MTrPs. Local and referred pain pattern from active MTrPs were drawn following manual palpation at TP sites. ⋯ This article underlies the importance of active MTrPs in FMS patients. Most of the TP sites in FMS are MTrPs. Active MTrPs may serve as a peripheral generator of fibromyalgia pain and inactivation of active MTrPs may thus be an alternative for the treatment of FMS.
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Two strategies should greatly improve pain management while minimizing opioid abuse. The first strategy involves the systematic implementation in every clinical practice of "universal precautions," a set of procedures that help physicians implement opioid therapy in a safe and controlled manner. These procedures include: 1) carefully assessing the patient's risk for opioid abuse; 2) selecting the most appropriate opioid therapy; 3) regularly monitoring the patient to evaluate the efficacy and tolerability of the treatment and to detect possible aberrant behaviors; and 4) mapping out solutions if abuse and/or addiction is detected, or in case of treatment failure. The second strategy involves the use of opioid formulations designed to deter or prevent product tampering and abuse. Results of clinical trials of new formulations of existing opioids (including oxycodone, morphine, and hydromorphone) suggest the potential for reduced abuse liability and, if approved, will be evaluated after launch for reduced real-world abuse. Integration of these formulations in clinical practices based on universal precautions should help further minimize the risk of opioid abuse while fostering appropriate prescribing to patients with indications for opioid therapy. ⋯ Undertreated pain and prescription opioid abuse remain important public health problems. In the absence of strong empirical evidence, common sense dictates that a universal-precautions approach-a systematic and easily adopted process that clinicians can quickly put into practice-is advised to promote safe opioid prescribing. Abuse- and tamper-resistant opioid formulations are emerging tools that may enhance safe opioid prescribing; further research and postmarketing analysis will clarify their utility and role in clinical practice.
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Randomized Controlled Trial
Capsaicin-induced central sensitization evokes segmental increases in trigger point sensitivity in humans.
This study investigated whether inducing central sensitization evokes segmental increases in trigger point pressure sensitivity. We evoked central sensitization at the C(5) segment and validated its presence via mechanical cutaneous sensitivity (brush allodynia) testing. Trigger point pressure sensitivity was quantified using the pain pressure threshold (PPT) value. A 50 cm(2) area of the C(5) dermatome at the right lateral elbow was pretreated with 45 degrees heat for 10 minutes. Test subjects (n = 20) then received topical capsaicin cream (0.075%; Medicis, Toronto, Canada) to the C(5) dermatome, whereas control subjects (n = 20) received a topical placebo cream (Biotherm Massage, Montreal, Canada). PPT readings were recorded from the infraspinatus (C(5,6)) and gluteus medius (L(4,5)S(1)) trigger points at zero (pre-intervention), 10, 20, and 30 minutes after intervention; all PPT readings were normalized to pre-intervention (baseline) values. The difference between the PPT readings at the 2 trigger point sites represents the direct influence of segmental mechanisms on the trigger point sensitivity at the infraspinatus site (PPT(seg)). Test subjects demonstrated statistically significant increases in Total Allodynia scores and significant decreases in PPT(seg) at 10, 20, and 30 minutes after application, when compared with control subjects. These results demonstrate that increases in central sensitization evoke increases in trigger point pressure sensitivity in segmentally related muscles. ⋯ Myofascial pain is the most common form of musculoskeletal pain. Myofascial trigger points play an important role in the clinical manifestation of myofascial pain syndrome. Elucidating the role of central sensitization in the pathophysiology of trigger points is fundamental to developing optimal strategies in the management of myofascial pain syndrome.
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The Chronic Pain Coping Inventory (CPCI) is a frequently used measure that assesses 8 categories of coping strategies that patients might use to cope with chronic pain. Despite its good psychometric properties and widespread use, the instrument has not been tested for its applicability and validity in non-Western populations, such as among Chinese. This study evaluated the reliability and validity of a Chinese translation of the 42-item CPCI (ChCPCI-42) in a sample of Chinese patients with chronic pain (n = 208). In addition to the ChCPCI-42, the patients were administered the Chronic Pain Grade (CPG) questionnaire, the Pain Catastrophizing Scale (PCS), the Centre for Epidemiological Studies-Depression Scale (CES-D), and questions assessing sociodemographic characteristics. Results of confirmatory factor analyses revealed that of the ChCPCI-42 8 scales, 6 demonstrated acceptable-to-good data-model fit (CFI >or= 0.90) and 2 demonstrated medium fit (CFI >or= 0.85). The 8 scales demonstrated adequate to good internal consistency (Cronbach alpha, 0.69 to 0.79) and correlated with CES-D, PCS, pain intensity, and disability in expected directions. Results of hierarchical multiple regression analyses showed that the ChCPCI-42 scales predicted concurrent depression (F (8,177) = 3.07, P < .01) and pain disability (F (1, 179) = 4.35, P < .001) scores, the Task Persistence scale being the strongest unique predictor among the 8 scales. The findings support the factorial validity and reliability of a 42-item CPCI that can be used among Chinese patients with chronic pain. ⋯ The report outlines the first validation of the CPCI for use in Hong Kong Chinese. This makes available a suitable instrument for chronic pain research in the Southern Chinese population and will help to elucidate similarities and differences in pain coping between Chinese and other ethnic groups.
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The aim of the current study was to estimate the prevalence and time trend of invalidating musculoskeletal pain in the Spanish population and its association with socio-demographic factors, lifestyle habits, self-reported health status, and comorbidity with other diseases analyzing data from 1993-2006 Spanish National Health Surveys (SNHS). We analyzed individualized data taken from the SNHS conducted in 1993 (n = 20,707), 2001 (n = 21,058), 2003 (n = 21,650) and 2006 (n = 29,478). Invalidating musculoskeletal pain was defined as pain suffered from the preceding 2 weeks that decreased main working activity or free-time activity by at least half a day. We analyzed socio-demographic characteristics, self-perceived health status, lifestyle habits, and comorbid conditions using multivariate logistic regression models. Overall, the prevalence of invalidating musculoskeletal pain in Spanish adults was 6.1% (95% CI, 5.7-6.4) in 1993, 7.3% (95% CI, 6.9-7.7) in 2001, 5.5% (95% CI, 5.1-5.9) in 2003 and 6.4% (95% CI 6-6.8) in 2006. The prevalence of invalidating musculoskeletal pain among women was almost twice that of men in every year (P < .05). The multivariate analysis showed that occupational status (unemployed), sleep <8 hours/day and having any accident in the preceding year were significantly associated in both gender with a higher likelihood of suffering from invalidating musculoskeletal pain among Spanish adults. Within men, other predictors of invalidating musculoskeletal pain were to be married and lower educational level, whereas in women were age of 45-64 years old (OR 1.89, 95% CI 1.32-2.7), obesity (OR 1.23, 95% CI 1.06-1.42), a sedentary lifestyle (OR 1.23, 95% CI 1.06-1.42), and presence of comorbid chronic diseases (OR 1.32, 95% CI 1.14-1.53). Further, worse self-reported health status was also related to a greater prevalence of invalidating musculoskeletal pain (OR 6.88, 95% 5.62-8.40 men, OR 7.24, 95% 6.11-8.57 women). Finally, we found that the prevalence of invalidating musculoskeletal pain increased from 1993 to 2001 for both men (OR 1.31, 95% 1.08-1.58) and women (OR 1.19, 95% 1.03-1.39) with no significant increase from the remaining surveys. Our results suggest that invalidating musculoskeletal pain deserves an increased awareness among health professionals. More educational programs which address postural hygiene, physical exercise, and how to prevent obesity and sedentary lifestyle habits should be provided by Public Health Services. ⋯ This population-based study indicates that invalidating musculoskeletal pain that reduces main working activity is a public health problem in Spain. The prevalence of invalidating musculoskeletal pain was higher in women than in men and associated to lower income, poor sleeping, worse self-reported health status, and other comorbid conditions. Further, the prevalence of invalidating musculoskeletal pain increased from 1993 to 2001, but remained stable from the last years (2001 to 2006).