Pain
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Randomized Controlled Trial
Pain sensitivity and opioid analgesia: a pharmacogenomic twin study.
Opioids are the cornerstone medication for the management of moderate to severe pain. Unfortunately, vast inter-individual differences in dose requirements complicate their effective and safe clinical use. Mechanisms underlying such differences are incompletely understood, are likely multifactorial, and include genetic and environmental contributions. ⋯ Significant covariates included age, gender, race, education, and anxiety. Results provide a strong rationale for more detailed molecular genetic studies to elucidate mechanisms underlying inter-individual differences in pain sensitivity and analgesic opioid responses. Such studies will require careful consideration of the studied pain phenotype.
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Randomized Controlled Trial
Growth hormone treatment for sustained pain reduction and improvement in quality of life in severe fibromyalgia.
Functional defects in growth hormone (GH) secretion and its efficacy as a complementary treatment have been suggested for fibromyalgia. This study investigated the efficacy and safety of low-dose GH as an add-on therapy in patients with both severe FM and low insulin-like growth factor 1 levels. A total of 120 patients were enrolled in a multicenter, placebo-controlled study for 18 months. ⋯ Group A patients showed significantly improved FIQ scores (P=.01) compared with group B. Although GH discontinuation worsened all scores in both groups during follow-up, impairment in pain perception was less pronounced in the GH-treated group (P=.05). In this largest and longest placebo-controlled trial performed in FM (NCT00933686), addition of GH to the standard treatment is effective in reducing pain, showing sustained action over time.
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Randomized Controlled Trial
Cognitive Behavioral Therapy increases pain-evoked activation of the prefrontal cortex in patients with fibromyalgia.
Interventions based on Cognitive Behavioral Therapy (CBT) are widely used to treat chronic pain, but the brain mechanisms responsible for these treatment effects are poorly understood. The aim of this study was to validate the relevance of the cortical control theory in response to an exposure-based form of CBT, Acceptance and Commitment Therapy, in patients with chronic pain. Forty-three female patients diagnosed with fibromyalgia syndrome were enrolled in a randomized, 12-week, waiting-list controlled clinical trial (CBT n=25; controls n=18). ⋯ An analysis of fMRI scans revealed that CBT led to increased activations in the ventrolateral prefrontal/lateral orbitofrontal cortex; regions associated with executive cognitive control. We suggest that CBT changes the brain's processing of pain through an altered cerebral loop between pain signals, emotions, and cognitions; leading to increased access to executive regions for reappraisal of pain. Our data thereby support our hypothesis about the activation of a cortical control mechanism in response to CBT treatment in chronic pain.