Pain
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Chronic pain symptoms often change over time, even in individuals who have had symptoms for years. Studying biological factors that predict trends in symptom change in chronic pain may uncover novel pathophysiological mechanisms and potential therapeutic targets. In this study, we investigated whether brain functional connectivity measures obtained from resting-state functional magnetic resonance imaging at baseline can predict longitudinal symptom change (3, 6, and 12 months after scan) in urologic chronic pelvic pain syndrome. ⋯ In addition, we found that the brain regions with greatest contribution to the classification were preferentially aligned with the left frontoparietal network. Resting-state functional magnetic resonance imaging measures seemed to be less informative about 6- or 12-month symptom change. Our study provides the first evidence that future trends in symptom change in patients in a state of chronic pain may be linked to functional connectivity within specific brain networks.
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Cutaneous allodynia is an established marker for central sensitization in migraine. There is debate whether cutaneous allodynia may also occur in cluster headache, another episodic headache disorder. Here, we examined the presence and severity of allodynia in a large well-defined nationwide population of people with cluster headache. ⋯ Female gender (odds ratio [OR] 2.05, 95% confidence interval [95% CI] 1.28-3.29), low age at onset (OR 0.98, 95% CI 0.96-0.99), lifetime depression (OR 1.63, 95% CI 1.06-2.50), comorbid migraine (OR 1.96, 95% CI 1.02-3.79), and having recent attacks (OR 1.80, 95% CI 1.13-2.86), but not duration of attacks and chronic cluster headache, were independent risk factors for allodynia. The high prevalence of cutaneous allodynia with similar risk factors for allodynia as found for migraine suggests that central sensitization, like in migraine, also occurs in cluster headache. In clinical practice, awareness that people with cluster headache may suffer from allodynia can in the future be an important feature in treatment options.
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Complex regional pain syndrome (CRPS) is a persistent pain condition that remains incompletely understood and challenging to treat. Historically, a wide range of different outcome measures have been used to capture the multidimensional nature of CRPS. This has been a significant limiting factor in the advancement of our understanding of the mechanisms and management of CRPS. ⋯ The domains encompassing the key concepts necessary to answer the research question were agreed as follows: pain, disease severity, participation and physical function, emotional and psychological function, self-efficacy, catastrophizing, and patient's global impression of change. The final core measurement set included the optimum generic or condition-specific patient-reported questionnaire outcome measures, which captured the essence of each domain, and 1 clinician-reported outcome measure to capture the degree of severity of CRPS. The next step is to test the feasibility and acceptability of collecting outcome measure data using the core measurement set in the CRPS population internationally.
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Provoked vestibulodynia (PVD) and painful bladder syndrome (PBS), subgroups of chronic pelvic pain syndromes (CPPS), are considered to share common biophysiological peripheral mechanisms. In addition, indications of a pronociceptive pain profile coexisting with psychological vulnerability suggest common dysfunctional pain processing and pain modulation in these 2 subgroups of CPPS. We therefore aimed at comparing the pain profile and psychological traits of patients with PVD and PBS to see whether the pain profile contributes to intersubject variability of clinical pain symptoms. ⋯ The latter was also correlated with pain catastrophizing (r = 0.504, P = 0.001) and depression symptoms (r = 0.361, P = 0.024). The findings suggest common mechanisms underlying a dysfunctional nociceptive system in both PVD and PBS. The intersubject variability in the level of dysfunction and its association with disease severity recommends a personalized pain treatment that may alleviate daily pain and dysfunction in patients with CPPS.
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The prediction of acute postoperative pain would be of great clinical advantage, but results of studies investigating possible predictors are inconsistent. Here, we studied the role of a wide variety of previously suggested predictors in 74 patients undergoing breast surgery. Preoperatively, patients filled out the Pain Sensitivity Questionnaire (PSQ) and a set of psychological questionnaires (the Beck Depression Inventory [BDI], State-Trait Anxiety Inventory [STAI], and Pain Catastrophizing Scale [PCS]) and participated in an experimental pain testing session, including assessment of conditioned pain modulation (CPM), temporal summation, and responses to heat, pinprick, and pressure pain. ⋯ In conclusion, prediction of acute postoperative pain in the whole group was limited. This might be due to differing predictors in specific subgroups of patients. Although CPM predicted pain in patients without pre-existing chronic pain, PSQ and PCS predicted pain in patients with pre-existing chronic pain.