Pain
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Multicenter Study
The Pain in Neuropathy Study (PiNS): a cross-sectional observational study determining the somatosensory phenotype of painful and painless diabetic neuropathy.
Disabling neuropathic pain (NeuP) is a common sequel of diabetic peripheral neuropathy (DPN). We aimed to characterise the sensory phenotype of patients with and without NeuP, assess screening tools for NeuP, and relate DPN severity to NeuP. The Pain in Neuropathy Study (PiNS) is an observational cross-sectional multicentre study. ⋯ Brush-evoked allodynia was present in only those with NeuP (15%); the paradoxical heat sensation did not discriminate between those with (40%) and without (41.3%) NeuP. The "irritable nociceptor" subgroup could only be applied to a minority of patients (6.3%) with NeuP. This study provides a firm basis to rationalise further phenotyping of painful DPN, for instance, stratification of patients with DPN for analgesic drug trials.
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Sex differences in pain perception are known to exist; however, the exact pathomechanism remains unclear. This work aims to elucidate sex differences in subjective and objective measures of pain, functional impairment, and health-related quality of life (HRQoL) in patients with lumbar degenerative disc disease. In a prospective 2-center study, back and leg pain (visual analogue scale [VAS]), functional disability (Oswestry Disability Index and Roland-Morris Disability Index), and HRQoL (EuroQol-5D and Short Form [SF12]) were collected for consecutive patients undergoing lumbar spine surgery. ⋯ Female patients reported higher VAS back and leg pain, functional impairment, and reduced HRQoL than male patients. However, there were no sex differences with respect to the presence and degree of OFI measured by the TUG test using age-adjusted and sex-adjusted cutoff values. As such, the TUG may be a good test to overcome sex bias for the clinical assessment of patients with degenerative disc disease.
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Multicenter Study
Normative data for Aδ contact heat evoked potentials (CHEPs) in adult population: A multicenter study.
There has been a significant increase over recent years in the use of contact heat evoked potentials (CHEPs) for the evaluation of small nerve fiber function. Measuring CHEP amplitude and latency has clinical utility for the diagnosis and assessment of conditions with neuropathic pain. This international multicenter study aimed to provide reference values for CHEPs to stimuli at 5 commonly examined body sites. ⋯ In general, larger CHEP amplitudes were associated with higher evoked pain scores. Females had CHEPs of larger amplitude and shorter latency than males. This substantive data set of normative values will facilitate the clinical use of CHEPs as a rapid, noninvasive, and objective technique for the assessment of patients presenting with neuropathic pain.
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Multicenter Study
COMPLEXITY, COMORBIDITY AND HEALTHCARE COSTS ASSOCIATED WITH CHRONIC WIDESPREAD PAIN IN PRIMARY CARE.
The objective was to estimate the prevalence of chronic widespread pain (CWP) and compare the quality-of-life (QoL), cardiovascular risk factors, comorbidity, complexity, and health costs with the reference population. A multicenter case-control study was conducted at 3 primary care centers in Barcelona between January and December 2012: 3048 randomized patients were evaluated for CWP according to the American College of Rheumatology definition. Questionnaires on pain, QoL, disability, fatigue, anxiety, depression, and sleep quality were administered. ⋯ In conclusion, the average patient with CWP has a worse QoL and a greater burden of mental health disorders and cardiovascular risk. The average annual cost associated with CWP is nearly 3 times higher than that of patients without CWP, controlling for other clinical factors. These findings have implications for disease management and budgetary considerations.
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Quantitative sensory testing (QST) in accordance with the DFNS (German Research Network on Neuropathic Pain) protocol assesses the function of afferent nerve fibers on the basis of 13 parameters. Within the consortia IMI (Innovative Medicines Initiative) Europain and Neuropain, QST results from pain research units experienced in QST across Europe can be compared for the first time. Aim of this analysis was to identify possible biases in the QST assessment between 10 centers from 8 different European countries. ⋯ There was no systematic heterogeneity for patients with painful peripheral nerve injury and painful polyneuropathy. For healthy subjects, only blunt pressure pain threshold showed a considerable heterogeneity of 42% (95% confidence interval: 0%-66%). In conclusion, QST of both healthy subjects and patients with peripheral neuropathic pain is largely homogenous within the European centers, an essential prerequisite for performing multicenter QST-based studies.