Pain
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Affective instability, conceptualized as fluctuations in mood over time, has been related to ill-health and psychopathology. In this study, we examined the role of affective instability on daily pain outcomes in 70 patients with chronic pain (Mage = 49.7 years; 46 females) using an end-of-day diary. During a baseline phase, patients completed self-reported questionnaires of pain severity, pain duration, disability, depression, and anxiety. ⋯ Positive affect instability, however, showed to be unrelated to all outcomes. Current findings extend previous results and reveal the putative role of affective instability on pain-related outcomes and may yield important clinical implications. Indeed, they suggest that targeting NA instability by improving emotion regulation skills may be a strategy to diminish disability and cognitive complaints in patients with chronic pain.
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Limited research suggests that there may be Warm complex regional pain syndrome (CRPS) and Cold CRPS subtypes, with inflammatory mechanisms contributing most strongly to the former. This study for the first time used an unbiased statistical pattern recognition technique to evaluate whether distinct Warm vs Cold CRPS subtypes can be discerned in the clinical population. An international, multisite study was conducted using standardized procedures to evaluate signs and symptoms in 152 patients with clinical CRPS at baseline, with 3-month follow-up evaluations in 112 of these patients. ⋯ A derived total inflammatory score was significantly (P < 0.001) elevated in the Warm CRPS group (compared with Cold CRPS) at baseline but diminished significantly (P < 0.001) over the follow-up period, whereas this score did not diminish in the Cold CRPS group (time × subtype interaction: P < 0.001). Results support the existence of a Warm CRPS subtype common in patients with acute (<6 months) CRPS and a relatively distinct Cold CRPS subtype most common in chronic CRPS. The pattern of clinical features suggests that inflammatory mechanisms contribute most prominently to the Warm CRPS subtype but that these mechanisms diminish substantially during the first year postinjury.
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Childhood maltreatment (CM) has been associated with an increased risk of nonspecific chronic low back pain (nsCLBP). However, the mechanisms underlying this association are unclear. Therefore, this study considered whether distinct types of CM are accompanied by specific alterations in somatosensory function. ⋯ Our findings suggest that CM is nonspecifically associated with a decreased PPT in nsCLBP. Emotional abuse apparently leads to enhanced spinal pain summation, and sexual abuse leads to enhanced touch sensitivity. These results emphasize the importance of emotional abuse in nsCLBP and suggest that CM can induce long-term changes in adult somatosensory function.
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The painDETECT Questionnaire (PDQ) is commonly used as a screening tool to discriminate between neuropathic pain (NP) and nociceptive pain, based on the self-report of symptoms, including pain qualities, numbness, and pain to touch, cold, or heat. However, there are minimal data about whether the PDQ is differentially sensitive to different sensory phenotypes in NP. The aim of the study was to analyze whether the overall PDQ score or its items reflect phenotypes of sensory loss in NP as determined by quantitative sensory testing. ⋯ Patients with loss of thermal sensation (2 and 4) significantly more often reported pain evoked by light touch, and patients with loss of mechanical sensation (3 and 4) significantly more often reported numbness and significantly less often burning sensations and pain evoked by light touch. Although the PDQ was not designed to assess sensory loss, single items reflect thermal and/or mechanical sensory loss at group level, but because of substantial variability, the PDQ does not allow for individual allocation of patients into sensory profiles. It will be useful to develop screening tools according to the current definition of NP.
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Little is known about the economic burden of chronic pain and how chronic pain affects health care utilization. We aimed to estimate the annual per-person incremental medical cost and health care utilization for chronic pain in the Ontario population from the perspective of the public payer. We performed a retrospective cohort study using Ontario health care databases and the electronically linked Canadian Community Health Survey (CCHS) from 2000 to 2011. ⋯ Incremental costs were the highest in those with severe pain ($3960; 95% CI, $3186-$4680) and in those with most activity limitation ($4365; 95% CI, $3631-$5147). The per-person cost to manage chronic pain is substantial and more than 50% higher than a comparable patient without chronic pain. Costs are higher in people with more severe pain and activity limitations.