Pain
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This article investigates the effects of postherpetic neuralgia (PHN) on resting-state brain activity utilizing arterial spin labeling (ASL) techniques. Features of static and dynamic cerebral blood flow (CBF) were analyzed to reflect the specific brain response to PHN pain. Eleven consecutive patients suffering from PHN and 11 age- and gender-matched control subjects underwent perfusion functional magnetic resonance imaging brain scanning during the resting state. ⋯ Regional CBF in the left caudate, left insula, left S1, and right thalamus was highly correlated with the pain intensity, and further comparison showed that the regional CBF in these regions is significantly higher in PHN groups. Functional connectivity results demonstrated that the reward circuitry involved in striatum, prefrontal cortex, amygdala, and parahippocampal gyrus and the circuitry among striatum, thalamus, and insula were highly correlated with each element in PHN patients. In addition, noninvasive brain perfusion imaging at rest may provide novel insights into the central mechanisms underlying PHN pain.
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The objectives of this study were to examine whether (1) daily pain-related changes in physical functioning differed between happily partnered, unhappily partnered, and unpartnered female chronic pain patients, and (2) affect and pain cognitions mediated the partner status effect on pain-related changes in physical functioning. Two hundred fifty-one women with chronic pain due to osteoarthritis and/or fibromyalgia completed 30 daily electronic diaries assessing pain, affect, pain-related cognitions, and physical functioning. Patients living with a romantic partner also completed a modified version of the Locke-Wallace Marital Adjustment Scale to assess relationship satisfaction. ⋯ The impact of relationship status on pain-related changes in physical functioning was partly mediated by the pain cognitions catastrophizing and coping difficulty. These results indicate that happily partnered pain patients show less pain-related physical disability and more adaptive affective and cognitive responses to daily pain changes than do unhappily partnered and unpartnered patients. Living in a happy union may bolster the capacity of patients to sustain a sense of pain coping efficacy during pain episodes, which in turn, minimizes pain-related physical activity limitations.
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Despite well-documented racial disparities in prescribing opioid medications for pain, little is known about whether there are disparities in the monitoring and follow-up treatment of patients who are prescribed opioid medications. We conducted a retrospective cohort study to examine whether there are racial differences in the use of recommended opioid monitoring and follow-up treatment practices. Our sample included 1646 white and 253 black patients who filled opioid prescriptions for noncancer pain for ≥ 90 consecutive days at the Veterans Affairs Pittsburgh Healthcare System pharmacy in fiscal years 2007 and 2008. ⋯ Among those who had at least 1 urine drug test, black patients were subjected to more tests, especially if they were on higher doses of opioids. Compared with white patients, black patients were less likely to be referred to a pain specialist and more likely to be referred for substance abuse assessment. Addressing disparities in opioid monitoring and follow-up treatment practices may be a previously neglected route to reducing racial disparities in pain management.
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Randomized Controlled Trial
Amygdala activity contributes to the dissociative effect of cannabis on pain perception.
Cannabis is reported to be remarkably effective for the relief of otherwise intractable pain. However, the bases for pain relief afforded by this psychotropic agent are debatable. Nonetheless, the frontal-limbic distribution of cannabinoid receptors in the brain suggests that cannabis may target preferentially the affective qualities of pain. ⋯ Critically, the reduction in sensory-limbic functional connectivity was positively correlated with the difference in drug effects on the unpleasantness and the intensity of ongoing pain. Peripheral mechanisms alone cannot account for the dissociative effects of THC on the pain that was observed. Instead, the data reveal that amygdala activity contributes to interindividual response to cannabinoid analgesia, and suggest that dissociative effects of THC in the brain are relevant to pain relief in humans.