The journal of pain : official journal of the American Pain Society
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At-level and above-level hypersensitivity was assessed in patients with chronic complete thoracic spinal cord injury (SCI). Patients were classified using somatosensory mapping (brush, cold, pinprick) and assigned into 2 groups (ie, patients with at-level hypersensitivity [SCIHs, n = 8] and without at-level hypersensitivity [SCINHs, n = 7]). Gender and age-matched healthy subjects served as controls. ⋯ However, electrically evoked pain was not significantly different between SCI patients. Thus, SCI-induced enhanced excitability of nociceptive processing does not necessarily lead to neuropathic pain. QST and LEP revealed no crucial role of deafferentation for hypersensitivity development after SCI.
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Fear learning deficiencies might contribute to the development and maintenance of chronic pain disability. Fear is often not restricted to movements (conditioned stimulus [CS+]) originally associated with pain (unconditioned stimulus), but expands to similar movements (generalization stimuli [GSs]). This spreading of fear becomes dysfunctional when overgeneralization to safe stimuli occurs. ⋯ Results revealed flatter pain expectancy generalization gradients in FM than in HC due to elevated responses to GSs more similar to the CS-; the fear generalization gradients did not differ. Although pain-related fear and expectancy to the GSs decreased during extinction, responses to the GSs remained higher for FM than HC, suggesting that extinction of generalization is impaired in chronic pain patients. Persistence of excessive protective responses may contribute to maintaining long-term chronic pain disability.
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Migraine is a common neurological disorder with significant economic burden in the United States. However, changes in the economic burden of migraine in the past decade have not been examined considering therapeutic advances at the national level. Therefore, we estimated cross-sectional trends in the incremental total and types of direct health care expenditures among individuals with migraine using nationally representative data, the Medical Expenditures Panel Survey. ⋯ Individuals with migraine had $866 (SE = $298) and $1,519 (SE = $400) greater adjusted annual total direct health care expenditures in 2004/2005 and 2012/2013 compared with those without migraine. However, those with migraine in 2012/2013 did not have significant changes in the total direct health care expenditures compared with those having migraine in 2004/2005 (changes: -$330, SE = $480). The estimated adjusted incremental total direct health care expenditures for individuals with migraine was approximately $9.20 billion per year compared with those without migraine.
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Trauma survivors, and particularly torture survivors, suffer from high rates of chronic pain and posttraumatic stress disorder (PTSD) for years afterward, along with alterations in the function of the pain system. On the basis of longitudinal data on PTSD symptomatology, we tested whether exposure to torture, PTSD or PTSD trajectories accounted for chronic pain and altered pain perception. Participants were 59 torture survivors and 44 age-matched healthy control subjects. ⋯ It appears that the duration and severity of posttraumatic distress, rather than the exposure to trauma, are crucial factors that mediate the association between trauma and chronic pain. Because PTSD and its resultant distress are measurable, their evaluation seems particularly important in the management of pain among trauma survivors. The results may be generalized to other instances in which chronic pain persists after traumatic events.