The journal of pain : official journal of the American Pain Society
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Temporomandibular joint disorders (TMJD) affect women with greater frequency than men, and sex hormones may contribute to this female predominance. Therefore, this study investigated whether estrogen receptor-alpha (XbaI/PvuII) single nucleotide polymorphisms (SNPs) are associated with TMJD in women. DNA was obtained from 200 women with TMJD (100 with chronic pain and 100 with signs of TMJD but no pain) diagnosed according to the Research Diagnostic Criteria for Temporomandibular Disorder (RDC/TMD) and 100 control women without TMJD. Restriction fragment length polymorphisms of polymerase chain reaction products were used to analyze XbaI and PvuII SNPs in DNA fragments. A model directly characterizing specific DNA sequence variants based on the risk haplotypic structure implemented with the EM algorithm was used to analyze the data. The [GC] haplotype of the XbaI locus was significantly more prevalent in both TMJD groups when compared with the control group (P = .0012). Specifically, the [GC] haplotype was more prevalent within the painful TMJD group versus the control group (OR = 3.203, 95% CI = 1.633, 6.284) and in the TMJD no pain versus the control group (OR = 2.51, 95% CI = 1.267, 4.97). In conclusion, the presence of [GC] haplotype in the XbaI locus may increase the susceptibility of women to develop TMJD. ⋯ This study suggests that a polymorphism in the estrogen receptor may increase the risk of women developing temporomandibular joint disorder. This finding may elucidate the interindividual differences in the contribution of estrogen to TMJD, the genetic influences on TMJD predisposition, and may serve as the basis for future treatment tailoring, which could enhance outcomes for these patients.
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Although research has shown that patients' beliefs about their pain are related to pain adjustment and treatment outcomes, little is known about the beliefs of their significant others. The purpose of this study was to develop a measure of pain beliefs in significant others and to examine the correlates of these beliefs. Participants were 104 married couples in which 1 partner reported chronic pain. Spouses completed an amended version of the Survey of Pain Beliefs (SOPA). The scale development procedure described in Jensen et al was used to select appropriate items for the significant other version of the SOPA. This procedure yielded 7 subscales that closely resembled the original SOPA. Spousal pain beliefs about disability, emotion, control, and medication were significantly correlated with partners' pain severity and other indicators of pain adjustment. Emotion, disability, and other beliefs were related to spouse responses to pain, and spouses' depressive symptoms and marital dissatisfaction. Spouses' personal experiences with pain were not related to their beliefs about their partners' pain. Additional research on the pain-related beliefs of significant others may extend cognitive-behavioral theory concerning the social context of pain and provide an additional avenue through which clinicians can address cognition in patients and families. ⋯ This study describes a new measure that can be used to assess significant others' beliefs about their partners' pain problems. Little is known about the beliefs of family members so this measure is expected to provide a way for clinicians and researchers to assess and track changes in those beliefs.
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Nociceptin/orphanin FQ (N/OFQ) is the endogenous peptide for the NOP receptors. Depending on the doses, intrathecal administration of N/OFQ has dual actions (ie, hyperalgesia and antinociception) in rodents. However, the pharmacological profile of intrathecal N/OFQ is not fully known in primates. The aim of this study was to investigate behavioral effects of intrathecal N/OFQ over a wide dose range and to compare its effects with ligands known to produce hyperalgesia or antinociception in monkeys. Intrathecal N/OFQ from 1 fmol to 1 nmol did not produce any hyperalgesic or scratching responses. In contrast, intrathecal substance P 100 nmol produced hyperalgesia, and intrathecal DAMGO 10 nmol produced antinociception. At the dose range between 10 nmol and 1 micromol, intrathecal N/OFQ dose-dependently produced thermal antinociception against a noxious stimulus in 2 intensities. More importantly, N/OFQ in combined with intrathecal morphine dose-dependently potentiated morphine-induced antinociception without inhibiting morphine-induced itch/scratching. Taken together, this study is the first to provide a unique functional profile of intrathecal N/OFQ over a wide dose range in primates. Intrathecal N/OFQ produces thermal antinociception without anti-morphine actions or scratching responses, indicating that N/OFQ or NOP receptor agonists represent a promising target as spinal analgesics. ⋯ Intrathecal administration of N/OFQ only produced thermal antinociception, not hyperalgesia, in monkeys. In addition, intrathecal N/OFQ does not have anti-morphine actions or itch/scratching responses. This study strongly supports the therapeutic potential of N/OFQ or NOP receptor agonists as spinal analgesics for clinical trials.
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Randomized Controlled Trial Comparative Study
Adrenergic dysregulation and pain with and without acute beta-blockade in women with fibromyalgia and temporomandibular disorder.
In patients with fibromyalgia syndrome (FMS) and temporomandibular disorder (TMD), stress and pain may chronically enhance sympathetic activity, altering cardiovascular responses and worsening pain. This study examined cardiovascular, epinephrine (EPI), norepinephrine (NE), cortisol and clinical pain responses in 54 female patients with these disorders and 34 controls. In a subsample of 10 FMS, 10 TMD patients and 16 controls, using a counterbalanced, double-blind, crossover design, the same responses were assessed after intravenous administration of low dose propranolol vs placebo. Testing included baseline, postural, speech and ischemic pain stressors. FMS patients showed lesser heart rate (HR) increases to posture challenge but greater blood pressure (BP) increases to postural and speech tasks than controls, as well as higher overall BP and greater total vascular resistance (TVR) than TMDs or controls. TMDs showed higher overall cardiac output and lower TVR than controls. Both FMS and TMD groups showed lower baseline NE than controls, and TMDs showed lower overall EPI and NE levels. Group differences in HR, EPI and NE were abolished after propranolol although BP, CO and TVR differences persisted. In both FMS and TMD, the number of painful body sites and ratings of total clinical pain obtained 4 times during each session were significantly lower after beta-blockade vs placebo. ⋯ These findings support the hypothesis that both FMS and TMD may frequently involve dysregulation of beta-adrenergic activity that contributes to altered cardiovascular and catecholamine responses and to severity of clinical pain. Acute treatment with low-dose propranolol led to short-term improvement in all these domains.
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Randomized Controlled Trial Comparative Study
Qigong and exercise therapy for elderly patients with chronic neck pain (QIBANE): a randomized controlled study.
The aim of this study was to evaluate the effectiveness of qigong compared with exercise therapy and no treatment. Elderly patients with chronic neck pain (>6 months) were randomly assigned to qigong or exercise therapy (each 24 sessions over a period of 3 months) or to a waiting list control. Patients completed standardized questionnaires at baseline and after 3 and 6 months. The main outcome measure was average neck pain on the visual analogue scale after 3 months. Secondary outcomes were neck pain and disability (NPAD) and quality of life (SF-36). One hundred seventeen patients (age, 76 +/- 8 years, 95% women) were included in the intention-to-treat analysis. The average duration of neck pain was 19.0 +/- 14.9 years. After 3 months, no significant differences were observed between the qigong group and the waiting list control group (visual analogue scale mean difference, -11 mm [CI, -24.0; 2.1], P = .099) or between the qigong group and the exercise therapy group (-2.5 mm [ - 15.4; 10.3], P = .699). Results for the NPAD were similar (qigong vs waiting list -6.7 (-15.4; 2.1), P = .135; qigong vs exercise therapy 2.3 (-6.2; 10.8); P = .600). We found no significant effect after 3 months of qigong or exercise therapy compared with no treatment. Further studies should include outcomes more suitable to elderly patients, longer treatment, and patients with less chronic pain. ⋯ In a randomized controlled study, we evaluated whether a treatment of 24 qigong sessions over a period of 3 months is (1) superior to no treatment and (2) superior to the same amount of exercise therapy in elderly patients (age, 76 +/- 8 years, 95% women) with long-term chronic neck pain (19.0 +/- 14.9 years). After 3 and 6 months, we found no significant differences for pain, neck pain, disability, and quality of life among the 3 groups.