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The greatest increases in long-term opioid use and opioid-related overdose mortality in recent years have been among women in midlife. Common menopausal symptoms broadly affect health and health care utilization in midlife, but their contribution to chronic pain management during this period is unknown.
Learn More >Neck pain is considered a common characteristic of migraine attacks. The relationship between neck pain and migraine can be explained by central sensitization of the trigeminocervical complex, where superior cervical afferents and the trigeminal nerve converge. However, few studies have evaluated motor control of cervical muscles in individuals with migraine. Thus, the purpose of the present study was to determine the extensor/flexor ratio of neck muscle strength and electromyographic activity during a test of maximal voluntary isometric contraction and craniocervical flexion in individuals with migraine and individuals without history of migraine or other headaches.
Learn More >Heightened pain sensitivity, the amount of pain experienced in response to a noxious event, is a known risk factor for development of chronic pain. We have previously reported that pain-free, sensorimotor Peak Alpha Frequency (PAF) is a reliable biomarker of pain sensitivity for thermal, prolonged pains lasting tens of minutes. To test whether PAF can provide information about pain sensitivity occurring over clinically relevant timescales (i.e., weeks), EEG was recorded before and while participants experienced a long-lasting pain model, repeated intramuscular injection of nerve growth factor (NGF), that produces progressively developing muscle pain for up to 21 days. We demonstrate that pain-free, sensorimotor PAF is negatively correlated with NGF pain sensitivity; increasingly slower PAF is associated with increasingly greater pain sensitivity. Furthermore, PAF remained stable following NGF injection indicating that the presence of NGF pain for multiple weeks is not sufficient to induce the PAF slowing reported in chronic pain. In total, our results demonstrate that slower pain-free, sensorimotor PAF is associated with heightened sensitivity to a long-lasting musculoskeletal pain and also suggest that the apparent slowing of PAF in chronic pain may reflect pre-disease pain sensitivity.
Learn More >To assess patterns and impact of small nerve fiber dysfunction and pathology in patients with fibromyalgia syndrome (FMS).
Learn More >Although cognitive behavioral therapy is an effective intervention for chronic pain, it is a lengthy treatment typically applied only in specialty care settings. The aim of this project was to collect preliminary effectiveness data for Brief Cognitive Behavioral Therapy for Chronic Pain (Brief CBT-CP), an abbreviated, modular form of treatment designed for use in primary care.
Learn More >Endometriosis is a common incurable inflammatory disorder that is associated with debilitating pelvic pain in women. Macrophages are central to the pathophysiology of endometriosis: they dictate the growth and vascularization of endometriosis lesions and more recently have been shown to promote lesion innervation. The aim of this study was to determine the mechanistic role of macrophages in producing pain associated with endometriosis. Herein, we show that macrophage depletion in a mouse model of endometriosis can reverse abnormal changes in pain behavior. We identified that disease-modified macrophages exhibit increased expression of IGF-1 in an model of endometriosis-associated macrophages and confirmed expression by lesion-resident macrophages in mice and women. Concentrations of IGF-1 were elevated in peritoneal fluid from women with endometriosis and positively correlate with their pain scores. Mechanistically, we demonstrate that macrophage-derived IGF-1 promotes sprouting neurogenesis and nerve sensitization . Finally, we show that the Igf-1 receptor inhibitor linsitinib reverses the pain behavior observed in mice with endometriosis. Our data support a role for macrophage-derived IGF-1 as a key neurotrophic and sensitizing factor in endometriosis, and we propose that therapies that modify macrophage phenotype may be attractive therapeutic options for the treatment of women with endometriosis-associated pain.-Forster, R., Sarginson, A., Velichkova, A., Hogg, C., Dorning, A., Horne, A. W., Saunders, P. T. K., Greaves, E. Macrophage-derived insulin-like growth factor-1 is a key neurotrophic and nerve-sensitizing factor in pain associated with endometriosis.
Learn More >Although the influence of genetics on chronic low back pain (LBP) has been previously examined, few studies have investigated whether the impact of genetic factors on LBP depends on how the condition is assessed.
Learn More >In this multicenter cross-sectional study, we determined sensory profiles of patients with (NL-1) and without neuropathic pain (NL-0) after nerve lesion and assessed immune related systemic gene expression. Patients and matched healthy controls filled in questionnaires and underwent neurological examination, neurophysiological studies, quantitative sensory testing (QST), and blood withdrawal. Neuropathic pain was present in 67/95 (71%) patients (NL-1). Tactile hyperalgesia was the most prominent clinical sign in NL-1 patients (p<0.05). Questionnaires showed an association between neuropathic pain and the presence of depression, anxiety, and catastrophizing (p<0.05 to p<0.01). Neuropathic pain was frequently accompanied by other chronic pain (p<0.05). QST showed ipsilateral signs of small and large fiber impairment compared to the respective contralateral side, with elevated thermal and mechanical detection thresholds (p<0.001 to p<0.05) and lowered pressure pain threshold (p<0.05). Also, more loss of function was found in patients with NL-1 compared to NL-0. Pain intensity was associated with mechanical hyperalgesia (p<0.05 to p<0.01). However, QST did not detect or predict neuropathic pain. Gene expression of peptidylglycine α-amidating monooxygenase was higher in NL patients compared to healthy controls (NL-1, p<0.01; NL-0, p<0.001). Also, gene expression of tumor necrosis factor-α was higher in NL-1 patients compared to NL-0 (p<0.05), and interleukin-1ß was higher, but IL-10 lower in NL-1 patients compared to healthy controls (p<0.05 each). Our study reveals that nerve lesion presents with small and large nerve fiber dysfunction, which may contribute to the presence and intensity of neuropathic pain and which is associated with a systemic pro-inflammatory pattern.
Learn More >There is an ethical obligation to notify individuals about potential pain associated with diagnoses, treatments, and procedures; however, supplying this information risks inducing nocebo hyperalgesia. Currently there are few empirically-derived strategies for reducing nocebo hyperalgesia. Since nocebo effects are linked to negative affectivity, we tested the hypothesis that a positive affect induction can disrupt nocebo hyperalgesia from verbal suggestion. Healthy volunteers (N =147) were randomly assigned to conditions in a 2 (Affect Induction: Positive vs. Neutral) by 2 (Verbal Suggestion: No Suggestion vs. Suggestion of Pain Increase) between-subjects design. Participants were induced to experience positive or neutral affect by watching movie clips for 15 mins. Next, participants had an inert cream applied to their non-dominant hand and suggestion was manipulated by telling only half the participants the cream could increase the pain of the upcoming cold pressor test. Subsequently, all participants underwent the cold pressor test (8C ±.04C), wherein they submerged the non-dominant hand and rated pain intensity on numerical rating scales every 20 sec up to two mins. In the neutral affect conditions, there was evidence for the nocebo hyperalgesia effect: participants given the suggestion of pain displayed greater pain than participants not receiving this suggestion, ps<.05. Demonstrating a blockage effect, nocebo hyperalgesia did not occur in the positive affect conditions, ps>.5. This is the first study to show that positive affect may disrupt nocebo hyperalgesia thereby pointing to a novel strategy for decreasing nocebo effects without compromising the communication of medical information to patients in clinical settings.
Learn More >Multiple cranial nerve blocks of the greater and lesser occipital, supraorbital, supratrochlear and auriculotemporal nerves are widely used in the treatment of primary headaches. We present efficacy and safety data for these procedures.
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