Pain
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Although the most widely agreed neurophysiological tool for investigating small fiber damage is laser-evoked potential (LEP) recording, no study has documented its diagnostic accuracy. In this clinical, neurophysiological, and skin biopsy study, we collected age-corrected LEP normative ranges, verified the association of LEPs with pinprick sensory disturbances in the typical diabetic mixed fiber polyneuropathy, and assessed the sensitivity and specificity of LEPs in diabetic small fiber neuropathy. From 288 LEP recordings from the face, hand, and foot in 73 healthy subjects, we collected age-corrected normative ranges for LEPs. ⋯ By applying age-corrected normative ranges for LEPs, we found that LEPs were strongly associated with pinprick sensory disturbances. In relation to the skin biopsy findings, LEPs yielded 78% sensitivity and 81% specificity in the diagnosis of diabetic small fiber neuropathy. Our study, providing age-corrected normative ranges for the main LEP data and their diagnostic accuracy, helps to make LEPs more reliable as a clinical diagnostic tool, and proposes this technique as a less invasive alternative to skin biopsy for diagnosing diabetic small fiber neuropathy.
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Pain evaluation in large community studies is difficult. Analgesics can be a useful tool in estimating pain-related conditions in which analgesic use is highly regulated. In this study, we evaluated analgesics consumption patterns of regular Israel Defense Force soldiers. ⋯ Chronic analgesic use was associated with a significant increase in health care utilization cost per year (911$ per soldier vs 199$ for nonusers), increased sick leave days per year (7.09 vs 0.67 for nonusers), and higher dropout rate from combat units (25% vs 9.2% for nonusers). Chronic use of analgesics is common among young adults, and it is an important predictor for unsuccessful military service and high health care utilization costs. Further studies in other setups are indicated.
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Chronic widespread musculoskeletal pain (CWP), has a considerable heritable component, which remains to be explained. Epigenetic factors may contribute to and account for some of the heritability estimate. We analysed epigenome-wide methylation using MeDIPseq in whole blood DNA from 1708 monozygotic and dizygotic Caucasian twins having CWP prevalence of 19.9%. ⋯ Bioinformatics analyses of the associated methylation bins showed enrichment for neurological pathways in CWP. We estimate that the variance explained by epigenetic factors in CWP is 6%. This, the largest study to date of DNA methylation in CWP, points towards epigenetic modification of neurological pathways in CWP and provides proof of principle of this method in teasing apart the complex risk factors for CWP.
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Effective assessment and management of pain in patients with cancer is strengthened by the patient's report of how much pain interferes with daily functioning. This requires a clear delineation of different levels of pain interference. We derived optimal cutpoints for differentiating between mild, moderate, and severe pain interference assessed by the Brief Pain Inventory (BPI) and describe the prevalence and characteristics of pain-induced functional impairment in patients with cancer. ⋯ The mild (<2), moderate (2-5 or 2-6), and severe (>5 or >6) pain interference groups were significantly concordant with ECOG-PS levels (P < 0.0001). We empirically derived patient-reported pain interference categories in relation to clinician-rated performance status. These cutpoints may facilitate the conduct and interpretation of clinical evaluation, symptom epidemiology, and clinical trials.