The journal of pain : official journal of the American Pain Society
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Randomized Controlled Trial
Altered cortical activation in adolescents with acute migraine: a magnetoencephalography study.
To quantitatively assess cortical dysfunction in pediatric migraine, 31 adolescents with acute migraine and age- and gender-matched controls were studied using a magnetoencephalography (MEG) system at a sampling rate of 6,000 Hz. Neuromagnetic brain activation was elicited by a finger-tapping task. The spectral and spatial signatures of magnetoencephalography data in 5 to 2,884 Hz were analyzed using Morlet wavelet and beamformers. Compared with controls, 31 migraine subjects during their headache attack phases (ictal) showed significantly prolonged latencies of neuromagnetic activation in 5 to 30 Hz, increased spectral power in 100 to 200 Hz, and a higher likelihood of neuromagnetic activation in the supplementary motor area, the occipital and ipsilateral sensorimotor cortices, in 2,200 to 2,800 Hz. Of the 31 migraine subjects, 16 migraine subjects during their headache-free phases (interictal) showed that there were no significant differences between interictal and control MEG data except that interictal spectral power in 100 to 200 Hz was significantly decreased. The results demonstrated that migraine subjects had significantly aberrant ictal brain activation, which can normalize interictally. The spread of abnormal ictal brain activation in both low- and high-frequency ranges triggered by movements may play a key role in the cascade of migraine attacks. ⋯ This is the first study focusing on the spectral and spatial signatures of cortical dysfunction in adolescents with migraine using MEG signals in a frequency range of 5 to 2,884 Hz. This methodology analyzing aberrant brain activation may be important for developing new therapeutic interventions for migraine in the future.
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Observational Study
General health status and incidence of first-onset temporomandibular disorder: the OPPERA prospective cohort study.
Temporomandibular disorder (TMD) overlaps with other health conditions, but no study has examined which of these conditions increase the risk of developing first-onset TMD. The authors prospectively evaluated the relationship between health status at enrollment and subsequent incidence of TMD in 2,722 men and women. Participants aged 18 to 44 years had no history of TMD and were clinically free of TMD when enrolled in 2006 to 2008 at 4 U.S. study sites in the Orofacial Pain: Prospective Evaluation and Risk Assessment (OPPERA) prospective cohort study. First-onset examiner-classified TMD developed in 260 people over a median 2.8 years of follow-up. Cox regression estimated the association between health conditions and TMD incidence while accounting for potential confounders. Incidence of first-onset TMD was 50% higher for people with low back pain (adjusted hazard ratio [AHR] = 1.50, 95% confidence limits [CLs]: 1.08, 2.10) and 75% higher for people with genital pain symptoms (AHR = 1.75, 95% CLs = 1.04, 2.93) than people without a history of these pain disorders. Digit ratio, a marker of intrauterine exposure to sex hormones, was significantly associated with TMD incidence. Other independent predictors of first-onset TMD were sleep disturbance and cigarette smoking. These findings reveal multiple influences of health status on incidence of first-onset TMD. ⋯ This article examines health conditions that commonly overlap with TMD to determine which ones predict first-onset TMD. A history of low back pain and genital pain conditions at baseline were important predictors. Novel findings were that disrupted sleep and conditions in utero may increase incidence of first-onset TMD.
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Alterations in the rs4680 Val158Met polymorphism are associated with the presence of pain. No study has investigated the role of Val158Met polymorphism in the susceptibility to exhibit pain in multiple sclerosis (MS). Our aim was to investigate the relationship between Val158Met polymorphism (rs4680) and the presence of pain in MS. One hundred eight (n = 108) patients (mean age: 44 ± 8 years) with a definitive diagnosis of MS and 108 matched controls participated. Fifty-eight patients (54%) had pain and 50 (46%) did not report pain. After amplifying Val158Met polymorphisms by polymerase chain reactions, rs4680 genotype frequencies and allele distributions were calculated. We classified individuals according to their Val158Met polymorphism: Val/Val, Val/Met, and Met/Met. The results showed that distribution of rs4680 Val158Met genotypes was not significantly different between individuals with MS in general and healthy people (χ2 = 2.212, P = .331). When we differentiate MS patients with pain and those without pain, the prevalence of Val158Met genotypes was significantly different (χ2 = 9,610, P = .046): Patients experiencing pain exhibited higher prevalence of Met/Met genotype than those without pain and healthy controls. Current results suggest that the Met allele of Val158Met polymorphism could be a potential risk factor for the development of pain in MS but not for the predisposition of MS itself. ⋯ This study suggests that the Val158Met polymorphism is associated with the presence of pain in MS, but it is not a risk factor for MS itself because the presence of the Met/Met genotype was more prevalent in those patients with pain. This study provides further evidence of potential genetic factors that predispose patients with MS to develop pain.
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Observational Study
Changes in opioid prescribing for Washington workers' compensation claimants after implementation of an opioid dosing guideline for chronic noncancer pain: 2004 to 2010.
An opioid overdose epidemic emerged in the United States following increased opioid prescribing for chronic noncancer pain. In 2007, Washington State agencies implemented an opioid dosing guideline on safe prescribing for chronic noncancer pain. The objective of this population-based observational study was to evaluate opioid use and dosing before and after guideline implementation. We identified 161,283 workers aged 18 to 64 years with ≥1 opioid prescriptions in Washington Workers' Compensation, April 1, 2004, to December 31, 2010. Prevalence and incidence rates of opioid use were assessed. We compared pre- and postguideline chronic and high-dose use (≥120 mg/d) among incident users. The mean monthly prevalence of opioid use declined by 25.6% between 2004 (14.4%) and 2010 (10.7%). Fewer incident users went on to chronic opioid therapy in the postguideline period (4.7%; 95% confidence interval [CI], 4.5-5.0%) than in the preguideline period (6.3%; 95% CI, 6.1-6.6%). Compared with preguideline incident users, postguideline incident users were 35% less likely to receive high doses (adjusted odds ratio = .65; 95% CI, .59-.71). Although the extent to which decreases were due to the guidelines is uncertain, to our knowledge, this is the first report of significant decreases in chronic and high-dose prescription opioid use among incident users. ⋯ Evidence-based strategies for opioid risk management are needed to help abate the epidemic of opioid-related morbidity and mortality. The study findings suggest that opioid dosing guidelines that specify a "yellow flag" dosing threshold may be a useful tool in preventing escalation of doses into ranges associated with increased mortality risk.
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To improve U.S. pain education and promote interinstitutional and interprofessional collaborations, the National Institutes of Health Pain Consortium has funded 12 sites to develop Centers of Excellence in Pain Education (CoEPEs). Each site was given the tasks of development, evaluation, integration, and promotion of pain management curriculum resources, including case studies that will be shared nationally. Collaborations among schools of medicine, dentistry, nursing, pharmacy, and others were encouraged. The John D. Loeser CoEPE is unique in that it represents extensive regionalization of health science education, in this case in the region covering the states of Washington, Wyoming, Alaska, Montana, and Idaho. This paper describes a blueprint of pain content and teaching methods across the University of Washington's 6 health sciences schools and provides recommendations for improvement in pain education at the prelicensure level. The Schools of Dentistry and Physician Assistant provide the highest percentage of total required curriculum hours devoted to pain compared with the Schools of Medicine, Nursing, Pharmacy, and Social Work. The findings confirm the paucity of pain content in health sciences curricula, missing International Association for the Study of Pain curriculum topics, and limited use of innovative teaching methods such as problem-based and team-based learning. ⋯ Findings confirm the paucity of pain education across the health sciences curriculum in a CoEPE that serves a large region in the United States. The data provide a pain curriculum blueprint that can be used to recommend added pain content in health sciences programs across the country.