Cognitive load and the effectiveness of distraction for acute pain in children.

Background: Distraction tasks that place continuous, high demand on executive resources have been shown to reduce pain intensity and pain unpleasantness ratings in some healthy adult samples. We examined the effects of a high-demand 'working memory' 1-back task compared to a low-demand 'motor control' task on pain intensity and unpleasantness ratings in healthy children. Additionally, dispositional mindfulness was examined to explore the mechanisms of distraction on the affective processing of pain.

Sociodemographic patterns of pain in an urban community sample: an examination of intersectional effects of sex, race, age, and poverty status.

Pain disparities based on race, sex, age, and socioeconomic status have been well documented. This study aimed to examine interactions among these sociodemographic factors on self-reported bodily pain in an urban community sample to assess whether membership in multiple at-risk groups confers greater risk for pain independent of depressive symptomatology. Participants (N = 1173) were enrolled in the epidemiological Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study, and reported experiences of pain in various body sites.

Working memory and visual discrimination distraction tasks improve cold pressor pain tolerance in children.

Objective: Distraction is a well-established pain management technique for children experiencing acute pain, although the mechanisms underlying the effectiveness of distraction are not well understood. It has been postulated that engagement of executive functions, such as working memory, may be a critical factor in attenuating pain via distraction. To test this hypothesis, we compared a 1-back task requiring engagement of working memory with a simple visual discrimination task demanding focused attention, but lower cognitive load (0-back).

An ICA based approach for steady-state and transient analysis of task fMRI data: Application to study of thermal pain response.

Background: Data driven analysis methods such as independent component analysis (ICA) offer the advantage of estimating subject contributions when used in a second-level analysis. With the traditionally used regression-based methods this is achieved with a design matrix that has to be specified a priori.

New Method: We show that the ability of ICA to estimate subject contributions can be effectively used to perform steady-state as well as transient analysis of task functional magnetic resonance imaging (fMRI) data, which can help reveal important group differences.

Higher Dispositional Optimism Predicts Lower Pain Reduction During Conditioned Pain Modulation.

Optimism is associated with lower pain sensitivity, positive adjustment to chronic pain, and greater reduction of pain thresholds in a conditioned pain modulation (CPM) paradigm. We hypothesized that participants with higher levels of optimism would experience greater inhibition of suprathreshold pain during CPM. Seventy-seven healthy adults completed a test of optimism, the Life Orientation Test-Revised, as well as measures of depression, pain catastrophizing, and neuroticism.

Alcohol-triggered signs of migraine: An animal model.

We describe an animal model where characteristics of migraine can be triggered by alcohol administration. In rats chronically implanted with a cannula overlying the transverse sinus, we applied potassium chloride (KCl) (or saline) to the meninges to sensitize trigeminovascular afferents. We assessed effects of repeated KCl application on animal behavior using conditioned place avoidance paradigm.

Intersession reliability of fMRI activation for heat pain and motor tasks.

As the practice of conducting longitudinal fMRI studies to assess mechanisms of pain-reducing interventions becomes more common, there is a great need to assess the test-retest reliability of the pain-related BOLD fMRI signal across repeated sessions. This study quantitatively evaluated the reliability of heat pain-related BOLD fMRI brain responses in healthy volunteers across 3 sessions conducted on separate days using two measures: (1) intraclass correlation coefficients (ICC) calculated based on signal amplitude and (2) spatial overlap. The ICC analysis of pain-related BOLD fMRI responses showed fair-to-moderate intersession reliability in brain areas regarded as part of the cortical pain network.

Conditioned place preference reveals tonic pain in an animal model of central pain.

Unlabelled: A limitation of animal models of central pain is their inability to recapitulate all clinical characteristics of the human condition. Specifically, many animal models rely on reflexive measures of hypersensitivity and ignore, or cannot assess, spontaneous pain, the hallmark characteristic of central pain in humans. Here, we adopt a conditioned place preference paradigm to test if animals with lesions in the anterolateral quadrant of the spinal cord develop signs consistent with spontaneous pain.

Abnormal activity of primary somatosensory cortex in central pain syndrome.

Central pain syndrome (CPS) is a debilitating and chronic pain condition that results from a lesion or dysfunction in the CNS. The pathophysiological mechanisms underlying CPS are poorly understood. We recently demonstrated that CPS is associated with suppressed inputs from the inhibitory nucleus zona incerta to the posterior thalamus (PO).

Zona incerta: a role in central pain.

Central pain syndrome (CPS) is a debilitating condition that affects a large number of patients with a primary lesion or dysfunction in the CNS. Despite its discovery over a century ago, the pathophysiological processes underlying the development and maintenance of CPS are poorly understood. We recently demonstrated that activity in the posterior thalamus (PO) is tightly regulated by inhibitory inputs from zona incerta (ZI).

Sex differences in endogenous pain modulation by distracting and painful conditioning stimulation.

Sex differences in endogenous pain modulation were tested in healthy volunteers (32 men, 30 women). Painful contact heat stimuli were delivered to the right leg alone, and then in combination with various electrical conditioning stimuli delivered to the left forearm. Four conditioning protocols were applied to each subject in separate sessions: mild, non-painful (control); distracting; stressful-yet-non-painful; strongly painful.

Across- and within-session variability of ratings of painful contact heat stimuli.

This study examined within- and across-session consistency of visual analog scale (VAS) pain intensity and unpleasantness ratings of contact heat stimuli in 64 subjects (32 male). Subjects participated in four sessions over 14 days, with three stimulus series per session. Two levels of painful heat (pain-lo: rated 40, and pain-hi: rated 70 on a 0-100 VAS) were delivered in randomized order during each series, with temperatures selected on an individual subject basis to equalize pain perception across subjects.

Age-related changes in nociceptive processing in the human brain.

Functional magnetic resonance imaging (fMRI) was used to compare cortical nociceptive responses to painful contact heat in healthy young (ages 22-30, n = 7) and older (ages 56-75, n = 7) subjects. Compared to young subjects, older subjects had significantly smaller pain-related fMRI responses in anterior insula (aINS) (P < 0.04), primary somatosensory cortex (S1) (P = 0.