Neuropathic and Nociplastic Pain Profiles are Common in Adult Chronic Nonbacterial Osteitis (CNO).

Chronic nonbacterial osteitis (CNO) is a rare musculoskeletal disease causing chronic bone pain. It is known that chronic musculoskeletal pain may involve other mechanisms than nociceptive pain only. We investigate the prevalence of neuropathic and nociplastic pain in adult CNO and their association with clinical characteristics and treatment outcomes. Survey study among the Dutch adult CNO cohort (n = 84/195 participated), including PAIN-detect for neuropathic pain, and the Central Sensitization Inventory (CSI), Fibromyalgia Rapid Screening Tool (FiRST), and ACTTION-APS Pain Taxonomy (AAPT) for nociplastic pain. Clinical characteristics and CNO-related bone pain scores were compared between patients with exclusive nociceptive pain and those with nociceptive pain plus neuropathic and/or nociplastic pain (mixed pain). 31% (95% CI 21-41) of patients classified as likely having neuropathic pain according to PAIN-detect. 53% (41-64) of patients displayed central sensitization on CSI, 61% (50-72) screened positive for fibromyalgia on FiRST and 14% (7-23) of patients fulfilled the AAPT criteria, all indicative of nociplastic pain. Mixed pain was associated with longer diagnostic delay (mean difference 2.8 years, 95% CI 0.4-5.2, p = 0.023), lower educational level (72% versus 20%, p < 0.001), and opioid use (37% versus 13%, p = 0.036). Despite comparable disease severity and extent, patients with mixed pain reported significantly higher CNO-related bone pain scores. This study demonstrates the high prevalence of mixed pain in adult CNO, in which neuropathic and nociplastic pain exist alongside nociceptive inflammatory bone pain. Disease burden in CNO may extend beyond inflammatory activity, highlighting the need for a multifaceted management approach.

The effect of somatic pain and comorbid mental distress on oral health-related quality of life in orthodontic patients.

OBJECTIVES: The purpose of the present study was to evaluate the prevalence of somatic pain in orthodontic patients and determine whether somatic pain contributes to worsening oral health-related quality of life (OHRQoL) through the mediating effect of psychological discomfort. MATERIALS AND METHODS: Scale measurements and analyses were conducted on a cohort of 769 orthodontic outpatients, encompassing Patient Health Questionnaire-15-pain (PHQ-15-P), Hua-Xi Emotional-Distress Index (HEI), Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ), and Oral Health Impact Profile-14 (OHIP-14). RESULTS: Among the respondents, 56.3% (N = 433) reported somatic pain and 20.0% (N = 154) had mental discomfort based on PHQ-15-P and HEI scores. Patients with somatic pain symptoms had significantly higher scores of HEI and OHIP-14 (P < 0.001), and higher PHQ-15-P and HEI scores emerged as statistically significant predictors of lower OHIP-14 scores (P < 0.001). HEI scores which assessed anxiety and depression partially mediated the correlation between PHQ-15-P and OHIP-14 scores, of which anxiety accounted for 52.9% of the overall mediation effect, dominating the indirect effect. CONCLUSION: Orthodontic patients reporting somatic pains were at a significantly higher risk of worsening OHRQoL during treatment, and this adverse effect is partially mediated by anxiety and depression. CLINICAL RELEVANCE: Our findings highlight the necessity for the assessment of general health and mental well-being during orthodontic interventions. To prevent delays in treating general disorders and the potential failure of orthodontic treatments, we encourage increased attentiveness towards patients with somatic symptoms and consideration of the adverse effects of comorbid mental distress.

Multiple types of somatic pain increase suicide attempts and depression: A nationwide community sample of Korean adults.

OBJECTIVE: Somatic pain is an important risk factor for suicide and suicidal behaviors. However, the association between the number of somatic pain conditions and lifetime suicide attempts (LSA) has not been well established yet. Therefore, the objective of this study was to examine associations between LSA and multiple somatic pain (MSP), singe pain, and no pain in a nationwide survey. METHODS: A total of 12,532 adults were randomly selected from the population using the one-person-per-household method. Each participant completed a face-to-face interview using the Korean Composite International Diagnostic Interview (K-CIDI) with Suicide Module, and the Barratt Impulsiveness Scale 11 (BIS-11). The MSP was defined as pain in two or more parts of one's body, including abdominal pain, back pain, arthralgia, arm or leg pain, chest pain, headache, menstrual pain, dysuria, genital pain, and other pain. RESULTS: Among 12,532 subjects, 858 (6.85%) had MSP. Among the three groups (MSP, single pain, and no pain) of subjects, the MSP group had higher percentages of females, those with lower education, and divorced/widowed/separated individuals. However, there were no significant differences in monthly income or residence among the three groups. The MSP group showed four times higher suicide attempts and six times higher multiple attempts than did the no pain group. The BIS total score of the MSP group was the highest among the three groups. Genital pain showed the highest odds ratio for LSA. The higher the number of somatic pain, the higher the odds ratios were for LSA, major depressive disorder (MDD), and anxiety disorders. Subjects having both MSP and MDD showed a significant association with LSA (AOR = 14.78, 95% CI 10.08-21.67, p < 0.001) compared to those having neither somatic pain nor MDD. CONCLUSIONS: MSP was significantly associated with LSA. It had greater prevalence among individuals reporting a higher number of somatic pain conditions and comorbid MDD.

Chronic Pain in Breast Cancer Survivors: Nociceptive, Neuropathic, or Central Sensitization Pain?

INTRODUCTION: The differentiation between acute and chronic pain can be insufficient for appropriate pain management. The aim of this study was to evaluate the prevalence of the predominant pain type (nociceptive, neuropathic, or central sensitization [CS] pain) in breast cancer survivors (BCS) with chronic pain. The secondary aims were to examine (1) differences in health-related quality of life (HRQoL) between the different pain groups; and (2) the associations between patient-, disease-, and treatment-related factors and the different pain types. METHODS: To determine the prevalence of the predominant type of pain, a recently proposed classification system was used. BCS were asked to complete the VAS for pain, Douleur Neuropathique 4 Questionnaire, Margolis Pain Diagram, Central Sensitization Inventory, and Short Form 36 (SF-36). RESULTS: Ninety-one BCS participated, among whom 25.3% presented neuropathic pain, 18.7% nociceptive pain, and 15.4% CS pain. Mixed pain was found in 40.6%. A significant intergroup difference in HRQoL was found for SF-36 "general health" (P = 0.04). The odds for the presence of CS rather than nociceptive pain are 26 times higher in patients exposed to hormone therapy in comparison to the nonexposed (odds ratio 25.95, 95% confidence interval 1.33 to 504.37, P = 0.03). CONCLUSION: Neuropathic pain is most frequent in BCS. Strong associations were found between CS pain and hormone therapy.

Pegfilgrastim-Induced Bone Pain: A Review on Incidence, Risk Factors, and Evidence-Based Management.

OBJECTIVE: To review the incidence, risk factors, and management of pegfilgrastim-induced bone pain (PIBP). DATA SOURCES: PubMed was searched from 1980 to March 31, 2017, using the terms pegfilgrastim and bone pain. STUDY SELECTION AND DATA EXTRACTION: English-language, human studies and reviews assessing the incidence, risk factors, and management of PIBP were incorporated. DATA SYNTHESIS: A total of 3 randomized, prospective studies and 2 retrospective studies evaluated pharmacological management of PIBP. Naproxen compared with placebo demonstrated a reduction in the degree, incidence, and duration of bone pain secondary to pegfilgrastim. Loratadine was not effective in reducing the incidence of bone pain prophylactically, but a retrospective study evaluating dual antihistamine blockade with loratadine and famotidine demonstrated a decreased incidence in bone pain when administered before pegfilgrastim. CONCLUSION: Naproxen is effective at managing PIBP. Although commonly used, antihistamines have a paucity of data supporting their use. Dose reductions of pegfilgrastim and opioids may also be potential management options; however, data supporting these treatment modalities are scarce.

Hyperacusis in chronic pain: neural interactions between the auditory and nociceptive systems.

OBJECTIVE: Sensory disturbances are common in chronic pain patients. Hyperacusis can be an especially debilitating experience. Here, we review published work on how the auditory and nociceptive systems might interact in chronic pain syndromes to produce pain-hyperacusis. DESIGN: Literature review. STUDY SAMPLE: The PubMed and Scopus databases were searched for relevant articles published between 2000 and 2017 using the primary search terms "hyperacusis"/"hyperacousis" and "pain". Ten papers were found using this strategy. Supplementary sources were identified by browsing textbooks and the reference lists of identified articles. RESULTS: The importance of central mechanisms in pain-hyperacusis was highlighted in the 10 selected papers. Hyperacusis is a significant but under-recognised symptom in conditions such as complex regional pain syndrome and fibromyalgia, and an integral feature of migraine. CONCLUSIONS: Nociceptive circuits become hypersensitive in acute and chronic pain; this sensitivity spreads from the periphery to spinal neurons and higher centres in the brain, leading to hyperalgesia or spontaneous pain even in the absence of peripheral nociceptive input. This "central sensitisation" may alter activity at sensory convergence points in the thalamus and brainstem centres such as the locus coeruleus, and give rise to hyperacusis in certain pain syndromes.

Current Status of Malignant Neuropathic Pain in Chinese Patients with Cancer: Report of a Hospital-based Investigation of Prevalence, Etiology, Assessment, and Treatment.

OBJECTIVES: This study investigated the prevalence, etiology, assessment, treatment of pain in patients with cancer as well as their quality of life (QOL). METHODS: Patients at the West China Hospital Cancer Center were invited to complete a questionnaire under the guidance of pain specialists. The questionnaire included general information, cancer pain status, its assessment, use of analgesics, and the effects of pain on QOL. RESULTS: In total, 1,050 patients were enrolled in the study. Of these, valid data were collected from 919 patients, among whom 454 (49.4%) suffered from pain, including 333 (36.2%) patients who had neuropathic pain symptoms. On average, the visual analog scale (VAS) score of patients with cancer pain was 3.30 ± 1.68. Significant differences in the VAS score and pain frequency between patients with nociceptive and neuropathic pain were observed (both P < 0.05). Dull pain ranked first (64, 52.9%) among the patients with nociceptive pain, whereas pins and needles pain (97, 64.7%) was the most common type of pain in patients with neuropathic pain. There was a significant difference in QOL between the nociceptive and neuropathic pain groups (P < 0.05). Only 183 of 454 patients with cancer pain used analgesics. Compared with the patients with pain not using any analgesics, those receiving analgesics had a significantly lower average pain relief rate (P = 0.027). Adjuvant analgesics were inadequately used (9.3%) in patients with neuropathic cancer pain. CONCLUSION: This study revealed the prevalence of neuropathic cancer pain in Chinese patients with cancer. Malignant neuropathic pain significantly impaired the patients' QOL. Insufficient assessment and inadequate analgesia still exist. These require more awareness and attention from both doctors and patients.

Neuropathic pain in patients with rotator cuff tears.

BACKGROUND: Recent studies have confirmed the existence of neuropathic pain (NeP) components in patients with musculoskeletal disorders. However, the presence of NeP in patients with rotator cuff tears has not been investigated thus far. Therefore, we studied the prevalence of NeP and the prognostic factors for NeP in patients with rotator cuff tears. METHODS: Data were collected from 110 patients with rotator cuff tears, diagnosed by physical examination and magnetic resonance imaging, who attended an outpatient clinic between August 2013 and August 2014. The measured parameters included visual analog scale (VAS) pain scores, painDETECT questionnaire (PDQ) responses, a physical examination, and magnetic resonance imaging. To evaluate the factors associated with NeP, we performed a two-stage analysis. For univariate analysis, we used the Mann-Whitney U test. For multivariate analysis, forward stepwise regression was performed using factors that demonstrated statistical significance in the univariate analysis. RESULTS: Patients were classified into three groups according to their PDQ score: an NeP group (n = 12; 10.9 %), possible NeP group (n = 33; 30.0 %), and a nociceptive pain (NoP) group (n = 65; 59.1 %). In the univariate analysis between the NeP group and NoP group, NeP was affected by sex (p = 0.034), VAS score (average pain during the past 4 weeks; p = 0.013), and positive Neer and Hawkins impingement signs (p = 0.039). In the multivariate analysis, VAS score (p = 0.031) was an independent prognostic factor for NeP. CONCLUSIONS: Using the PDQ, we found that 10.9 % of patients with rotator cuff tears may have NeP. The VAS score (average pain during the past 4 weeks) was a prognostic factor for NeP. Clinicians should remain vigilant for heterogeneous etiologies of pain in patients with rotator cuff tears.

Efficacy of venlafaxine XR for the treatment of pain in patients with spinal cord injury and major depression: a randomized, controlled trial.

OBJECTIVES: To (1) determine the efficacy of venlafaxine XR for the treatment of pain (secondary aim) in individuals with spinal cord injury (SCI) enrolled in a randomized controlled trial (RCT) on the efficacy of venlafaxine XR for major depressive disorder (MDD) (primary aim); and (2) test the hypothesis that venlafaxine XR would be effective for both neuropathic and nociceptive pain. DESIGN: Multisite, double-blind, randomized (1:1) controlled trial with subjects block randomized and stratified by site, lifetime history of substance abuse, and prior history of MDD. SETTING: Six Departments of Physical Medicine and Rehabilitation in university-based medical schools. PARTICIPANTS: Individuals (N=123) with SCI and major depression between 18 and 64 years of age, at least 1 month post-SCI who also reported pain. INTERVENTION: Twelve-week trial of venlafaxine XR versus placebo using a flexible titration schedule. OUTCOME MEASURES: A 0-to-10 numeric rating scale for pain, pain interference items of the Brief Pain Inventory; 30% and 50% responders. RESULTS: The effect of venlafaxine XR on neuropathic pain was similar to that of placebo. However venlafaxine XR resulted in statistically significant and clinically meaningful reductions in nociceptive pain site intensity and interference even after controlling for anxiety, depression, and multiple pain sites within the same individual. For those who achieved a minimally effective dose of venlafaxine XR, some additional evidence of effectiveness was noted for those with mixed (both neuropathic and nociceptive) pain sites. CONCLUSIONS: Venlafaxine XR could complement current medications and procedures for treating pain after SCI and MDD that has nociceptive features. Its usefulness for treating central neuropathic pain is likely to be limited. Research is needed to replicate these findings and determine whether the antinociceptive effect of venlafaxine XR generalizes to persons with SCI pain without MDD.

Depression and chronic pain.

Chronic pain and major depression commonly occur together. Major depression in patients with chronic pain is associated with decreased function, poorer treatment response and increased health care costs. The experience and expression of chronic pain vary between individuals, reflecting complex and changing interactions between physical, psychological and social processes. The diagnosis of major depression in patients with chronic pain requires differentiation between the symptoms of pain and symptoms of physical illness. Antidepressants and psychological therapies can be effective and should be delivered as part of a coordinated, cohesive, multidisciplinary pain management plan.

Prospective associations between benzodiazepine use and later life satisfaction, somatic pain and psychological health among the elderly.

OBJECTIVE: This study aimed to investigate prospective associations between benzodiazepine use and later life satisfaction, sleep difficulties, perceived general health, anxiety symptoms and somatic pain among the elderly. METHODS: A 13-year prospective cohort study was conducted in a Norwegian population-based sample of 15 830 elderly individuals. Baseline control measures of the investigated psychological constructs and a wide range of demographic and health-relevant covariates were obtained from the Nord-Trøndelag Health Study (HUNT 2, 1995-1997). Follow-up data were obtained from the third wave (HUNT 3, 2006-2008) of the same epidemiological study. The Norwegian Prescription Database (2004-2008) was used to link pharmacy prescription records of benzodiazepines for each case to the HUNT 2 and HUNT 3 materials. RESULTS: Use of benzodiazepines was associated with less life satisfaction and more sleep difficulties at follow-up. These tendencies increased by more frequent patterns of use. Benzodiazepine use had relatively weak relations to perceived general health, but intermittent and chronic use was related to higher anxiety symptoms at follow-up. Such patterns were also modestly related to somatic pain at follow-up. DISCUSSION AND CONCLUSION: Benzodiazepines should be dispensed at a high-threshold policy among the elderly. By developing clear-cut discontinuation plans, clinicians could avoid chronic use and focus on psychosocial treatment for psychological disorders.

Pain in postsurgical orthopedic rehabilitation: a multicenter study.

OBJECTIVE: The aim of this study was to quantify and characterize pain in patients undergoing lower limb postsurgical orthopedic rehabilitation and to investigate the impact of pain in slowing or interrupting their rehabilitation. DESIGN: The study was designed as a multicenter cross-sectional study. SETTING: The study was set in rehabilitation departments of the Don Gnocchi Foundation. SUBJECTS: The study subjects were the inpatients attending rehabilitation. INTERVENTIONS: There were no interventions used in the study. OUTCOME MEASURES: Pain intensity was measured with a numeric rating scale (NRS); pain characteristics were assessed with the McGill Pain Questionnaire and the ID Pain (able to discriminate nociceptive from neuropathic pain). Quality of life (QoL) was measured with the Short Form 36 Health Status Survey. A semi-structured questionnaire on pain occurrence, impact, and management was administered by the physiotherapist in charge of the patients and by the physician. RESULTS: We studied 139 patients, 82% of whom complained of at least moderate pain (NRS ≥ 3). According to ID pain, 45.6% patients complained of probable (33.8%) or highly probable (11.8%) neuropathic pain. A higher pain intensity was significantly related to the probability of having neuropathic pain (P < 0.001). Patients with more severe pain reported lower physical and mental QoL scores. In 38.6% of cases, pain interfered with the rehabilitation process, and in 18.5% it was the cause of physical therapy discontinuation. CONCLUSIONS: In light of the high occurrence and intensity of pain in the sample, and of the significant impact on the rehabilitation program, clinicians should pay more attention to pain, especially neuropathic pain, in postsurgical patients. Tailored pain pharmacological therapy could possibly improve patient compliance during the rehabilitation process and enhance long-term outcomes.

PROMIS Neuropathic and Nociceptive Pain Quality in Musculoskeletal Pain Presentations.

OBJECTIVE: Musculoskeletal pain is a significant contributor to the global disease burden. Management of musculoskeletal pain where a neuropathic component is present can be challenging. This study evaluated the internal structure of the Patient-Reported Outcome Measures Information System (PROMIS) pain quality scales, explored the prevalence of neuropathic and nociceptive pain, and identified health demographics and behaviors related to musculoskeletal pain presentations. METHODS: Patients presenting to the Victoria University Osteopathy Clinic (Melbourne, Vic., Australia) were invited to complete a health demographics and behaviors questionnaire, and the PROMIS Neuropathic (NeuroPQ) and Nociceptive (NociPQ) pain quality scales, before their initial consultation. Descriptive, inferential, and correlation statistics were used to evaluate the PROMIS scales, health demographics, and behaviors. Mokken scale analysis was used to evaluate the internal structure and dimensionality of the NeuroPQ and NociPQ scales. RESULTS: Three hundred eighty-three (N=383) patients completed the measures. Mokken scaling suggested the PROMIS scales demonstrated acceptable internal structure and were unidimensional. Over 22% of patients demonstrated cutoff scores above 50, suggesting a substantive neuropathic pain component to their musculoskeletal presentation. Patients who reported cigarette smoking, not being born in Australia or not speaking English at home, demonstrated higher NeuroPQ scores. Females demonstrated significantly higher NociPQ scores than males. Pain intensity demonstrated small to medium correlations with NeuroPQ and NociPQ scores. DISCUSSION: This study provides support for the use of the NeuroPQ and NociPQ scales in musculoskeletal pain patients. Associations with health demographics and behaviors were identified, and patients typically experienced a combination of neuropathic and nociceptive pain.

Pain response to vaccination in newborn infants of diabetic mothers.

BACKGROUND: Response to pain is altered in infants who were exposed to pain- and stressful events in the neonatal period. Infants of diabetic mothers receive several heel sticks after birth for measuring blood glucose and thus may show changes in their behavioral and physiologic response to pain. Moreover, maternal hyperglycemia may alter activity of the hypothalamic pituitary adrenal (HPA) axis reactivity. STUDY DESIGN: In total, 43 infants of diabetic mothers and 30 control infants were included into the study. Response to pain was assessed at 3 months of age following two intramuscular injections for vaccination. We assessed behavioral (Bernese pain scale), physiologic (heart rate) and hormonal (salivary cortisol) pain response to vaccination as well as spinal sensitization (flexion withdrawal reflex). RESULTS: Infants of diabetic mothers received a median number of 5 [4-19] painful events compared to 1 [1-3] in the control group. Heart rate reactivity differed significantly between groups. Infants of diabetic mothers had higher peaks (p = 0.002) and needed more time to recover to baseline (p < 0.001). Moreover, infants of diabetic mothers showed higher peak cortisol (p = 0.001) and a higher relative cortisol increase (p = 0.015). Flexor withdrawal reflex thresholds were significantly lower in infants of diabetic mothers (p = 0.003). CONCLUSION: The increase of physiologic and hormonal responses to pain in infants of diabetic mothers is probably caused by repeated painful events and an altered metabolic profile.

Heightened affective response to perturbation of respiratory but not pain signals in eating, mood, and anxiety disorders.

Several studies have recently suggested that an abnormal processing of respiratory interoceptive and nociceptive (painful) stimuli may contribute to eating disorder (ED) pathophysiology. Mood and anxiety disorders (MA) are also characterized by abnormal respiratory symptoms, and show substantial comorbidity with ED. However, no studies have examined both respiratory and pain processing simultaneously within ED and MA. The present study systematically evaluated responses to perturbations of respiratory and nociceptive signals across the levels of physiology, behavior, and symptom report in a transdiagnostic ED sample (n = 51) that was individually matched to MA individuals (n = 51) and healthy comparisons (HC; n = 51). Participants underwent an inspiratory breath-holding challenge as a probe of respiratory interoception and a cold pressor challenge as a probe of pain processing. We expected both clinical groups to report greater stress and fear in response to respiratory and nociceptive perturbation than HCs, in the absence of differential physiological and behavioral responses. During breath-holding, both the ED and MA groups reported significantly more stress, feelings of suffocation, and suffocation fear than HC, with the ED group reporting the most severe symptoms. Moreover, anxiety sensitivity was related to suffocation fear only in the ED group. The heightened affective responses in the current study occurred in the absence of group differences in behavioral (breath hold duration, cold pressor duration) and physiological (end-tidal carbon dioxide, end-tidal oxygen, heart rate, skin conductance) responses. Against our expectations, there were no group differences in the response to cold pain stimulation. A matched-subgroup analysis focusing on individuals with anorexia nervosa (n = 30) produced similar results. These findings underscore the presence of abnormal respiratory interoception in MA and suggest that hyperreactivity to respiratory signals may be a potentially overlooked clinical feature of ED.

Unilateral Lateral Epicondylalgia Shows a Pro-nociceptive Pain Profile: A Case-control Observational Study.

OBJECTIVE: Lateral epicondylalgia (LE, tennis elbow) is characterized by both local tissue pathology and features indicative of secondary hyperalgesia. The aim of this study was to evaluate endogenous pain modulation characteristics in people with chronic LE, and to investigate the relationship between endogenous pain modulation and clinical characteristics. MATERIALS AND METHODS: This case-control observational study included 25 participants with LE of at least 6 weeks' duration and 15 age-matched (±5 y) healthy control participants, who were each evaluated in a single session. Pain and disability were assessed using the patient-rated tennis elbow evaluation and pain-free grip strength. Endogenous pain modulation was assessed using pressure pain threshold, cold pain threshold, conditioned pain modulation (CPM), and temporal summation (TS). RESULTS: The LE group exhibited significantly lower pain-free grip and pressure pain threshold bilaterally compared with the control group. Cold pain threshold was significantly reduced on the affected side compared with the matched control side. There was no significant difference between groups for CPM; however, the LE group exhibited significantly increased facilitation as measured by TS (between-group difference in change score of 9.6 mm on a 0 to 100 mm pain visual analogue scale; 95% confidence intervals, 3.4-15.8 mm). There was no significant correlation between pain modulation and clinical measures of pain and disability. DISCUSSION: LE is characterized by locally increased facilitation of pain, as measured by TS, but this is not associated with severity of pain or disability.

High Prevalence of Neuropathic Pain Component in Patients with Low Back Pain: Evidence from Meta-Analysis.

BACKGROUND: Low back pain (LBP) is a complex syndrome which includes a nociceptive (NcP) component, a neuropathic (NeP) component, or a mixture of components (mixed pain). The NeP component (NePC) in LBP is defined as the presence of NeP with or without an NcP. OBJECTIVE: This meta-analysis aimed at assessing the pooled prevalence of NePC in patients with LBP and at identifying the factors causing significant heterogeneity in reported prevalence. STUDY DESIGN: Meta-analysis. METHODS: A systematic literature search was carried out, with inclusion of all epidemiological studies describing the NeP prevalence levels in LBP patients while using standard diagnostic methods. The "pooled prevalence rate (PPR)" of NePC, either on its own or in combination with NcP, was calculated. A pre-specified subgroup analysis was carried out, considering LBP duration, presence of leg pain, diagnostic method(s), and questionnaire(s) used. RESULTS: The meta-analysis included 20 studies relating to a total of 14,269 LBP patients, of whom 7,969 patients (55.8%) were identified as presenting with NePC. The pooled PR (95% CI) of NePC in patients with LBP was 0.47 (0.40 - 0.54), while the pooled PR of NcP was 0.56 (0.48 - 0.63). Higher NePC pooled PR values were identified in LBP with leg pain as compared to uncomplicated LBP (respectively: 0.60; 0.47 - 0.73 vs 0.27; 0.23 - 0.31; Pinteraction < 0.01). LIMITATIONS: The quality of the included studies was assessed using ad-hoc criteria. Due to the limited number of available studies, one may need to be cautious in reaching conclusions about the impact of disease duration on NePC prevalence values. We pooled studies which used a range of different diagnostic methods, with putatively different sensitivity/specificity diagnosing levels. CONCLUSIONS: Overall, high NePC prevalence levels were here identified in LBP patients. As the pain is a subjective phenomenon and there is no gold standard for the diagnosis of NePC, there is the possibility that the pooled effect estimate may alter depending upon the diagnostic method used. KEY WORDS: Neuropathic pain, nociceptive pain, low back pain, symptom-based questionnaire, chronicity.

High prevalence of neuropathic pain in the hand of patients with traumatic brachial plexus injury: a cross-sectional study.

OBJECTIVE: To describe the pain profile of patients with traumatic brachial plexus injury. METHODS: We enrolled 65 patients with traumatic brachial plexus injury. The Douleur Neuropathique 4 questionnaire was used to classify pain and the SF-36 was used to evaluate quality of life. RESULTS: The patients with traumatic brachial plexus injury were predominantly young male victims of motorcycle accidents. Pain was present in 75.4% of the individuals and 79% presented with neuropathic pain, mostly located in the hands (30.41%). The use of auxiliary devices (p = 0.05) and marital status (p = 0.03) were both independent predictors of pain. Pain also impacted negatively on the quality of life (p = 0.001). CONCLUSIONS: Pain is frequent in patients with traumatic brachial plexus injury. Despite the peripheral nervous system injury, nociceptive pain is not unusual. Pain evaluation, including validated instruments, is essential to guide optimal clinical management of patients with the condition.

Effects of disturbed sleep on gastrointestinal and somatic pain symptoms in irritable bowel syndrome.

BACKGROUND: Sleep disturbances are common, and perhaps are even more prevalent in irritable bowel syndrome (IBS). AIMS: To determine the effect of measured sleep on IBS symptoms the following day, IBS-specific quality of life (IBS-QOL) and non-GI pain symptoms. METHODS: IBS patients' sleep patterns were compared to healthy individuals via wrist-mounted actigraphy over 7 days. Daily bowel pain logs (severity, distress; 10-point Likert) stool pattern (Bristol scale) and supporting symptoms (e.g. bloating, urgency; 5-point Likert) were kept. Validated measures, including the GI Symptom Rating Scale-IBS, Visceral Sensitivity Index, Pittsburgh Sleep Quality Index and the IBS-Quality of Life were collected. Mediation analysis explored the relationship between sleep, mood and bowel symptoms. RESULTS: Fifty subjects (38.6 ± 1.0 years old, 44 female; 24 IBS and 26 healthy controls) completed sleep monitoring. IBS patients slept more hours per day (7.7 ± 0.2 vs. 7.1 ± 0.1, P = 0.008), but felt less well-rested. IBS patients demonstrated more waking episodes during sleep (waking episodes; 12.1 vs. 9.3, P < 0.001). Waking episodes predicted worse abdominal pain (P ≤ 0.01) and GI distress (P < 0.001), but not bowel pattern or accessory IBS symptoms (P > 0.3 for each). Waking episodes negatively correlated with general- and IBS-specific QOL in IBS (r = -0.58 and -0.52, P < 0.001 for each). Disturbed sleep effects on abdominal pain were partially explained by mood as an intermediate. CONCLUSIONS: Sleep disturbances are more common in irritable bowel syndrome, and correlate with IBS-related pain, distress and poorer irritable bowel syndrome-related quality of life. Disturbed sleep effects extend beyond the bowel, leading to worse mood and greater somatic pain in patients with the irritable bowel syndrome.

Diagnosis of Neuropathic Components in Patients with Back Pain Before and After Surgery.

Background: The perception of back pain subjective is hard for physicians to measure. For this reason, questionnaires are an important instrument to evaluate the pain 1. The main point of this study was to verify differentiation of pain symptoms in patients with different pain mechanisms. The most important parameter was the PainDetect questionnaire, which can differentiate between nociceptive and neuropathic pain. Additional parameters were measured before and after surgery to characterise pain symptoms in detail. Material and Methods: We selected patients with diagnosed vertebral compression fracture, herniated disc or with spinal cord compression. To characterise the preoperative condition on admittance, we collected the data from the physical examination, as well as clinical data, including X-ray, CT and MRI. To characterise the pain, we used the painDetect questionnaire, the Oswestry Index questionnaire (ODI) and the visual analogue scale (VAS). Depending on the diagnosis, patients were treated by surgery (radiofrequency kyphoplasty, nucleotomy, spondylodesis). At 2 to 3 days and 6 months after surgery, we repeated the questionnaire and compared the results with those before the operation. Data on patient satisfaction and adverse events were also collected. Results: This study included 62 patients with vertebral compression fracture (group 1: VBF, 89 % female, mean age 71 years) and 77 patients with herniated disc or spinal cord compression (group 2: non-VBF, 55 % female, mean age 53 years). There was no difference between both groups in preoperative pain intensity (acute, maximum, average): median ordinal scale 0 to 10; group 1: 6, 8, 7; group 2: 6, 9, 7. The total score in the painDetect questionnaire differed significantly between the two groups (median group 1 = 9, group 2 = 17; effect size r = 0.5; p = 0.000). The existence of neuropathic pain was presumed (> 90 %) in 3 % of the patients in group 1 and in 13 % of patients it was not excluded. In contrast, in group 2 it was presumed (> 90 %) in 43 % of patients and in 30 % of patients it could not be excluded. Patients with vertebral compression fracture had greater pain intensity (VAS 71) than patients from group 2 (VAS 53). There was no difference in the total score of the Oswestry questionnaire between the two groups (56 % vs. 58 %). Pain intensity was significantly reduced in both groups after the operations. Six months postoperatively, pain intensity (median ordinal scale 0 to 10; acute, maximum, average) was 2, 5, 3 in group 1 and 2, 4, 2 in group 2. Moreover, the final scores of the painDetect questionnaires were significantly lower in both groups after the operations (4 in both groups). The median score of the ODI was reduced in both groups, with an effect size of 0.6. 98 % of the patients in group 1 and 94 % in group 2 were satisfied with the outcome of the operation. Conclusion: The preoperative pain characteristics of patients with vertebral compression fracture is different from those of patients with herniated disc or with spinal cord compression. 43 % of patients in group 2 exhibited a neuropathic pain component and in 30 % this could not be excluded. In contrast, in group 1 only 3 % of the patients exhibited a neuropathic pain component. Postoperatively, pain symptoms were significant reduced in both groups, so that the risk of chronic pain was considerably less.