painDETECT Questionnaire Research Articles

Clinical and emotional/behavioral characteristics of acute and chronic low-back pain

To analyze clinical and emotional/behavioral characteristics of acute and chronic low-back pain that significantly affect quality-of-life. Fifty-three patients with pain syndromes were examined using the painDETECT questionnaire, the Visual Analog Scale for Pain, The McGill Pain Questionnaire and laboratory and instrumental methods of neurological assessment. A 'picture of the patient with acute and chronic pain' was built, a group of patients with neuropathic component of pain was described. The size of herniated discs was not correlated with VAS assessments and the neuropathic component had a mild effect on pain intensity. The significant correlation was found between the severity of pain and coping strategies for pain. The results indicate the importance of effective and safety pain stopping, in particular at the acute stage, to prevent pain chronification. A drug of choice in case of intensive pain and marked nociceptive component are highly effective and safe nonsteroidal anti-inflammatory drugs, in particular etoricoxib (Arcoxia), a selective COX-2 inhibitor.

The Effect of Carpal Tunnel Release on Neuropathic Pain in Carpal Tunnel Syndrome.

Purpose The aim of this study was to determine the risk factors of neuropathic pain (NP) in the patient with carpal tunnel syndrome (CTS) before and after the carpal tunnel release. Materials and Methods One hundred and two CTS patients were enrolled in the study. The pain score was measured by the visual analogue score. NP was determined by the painDETECT (PD) questionnaire. All subjects were divided into 3 groups at 12 weeks after surgery: an Improved, Unchanged, and Worsened group. The risk factors of worsening NP after surgery were evaluated. Results We found that 36% and 18% of patients with CTS had neuropathic pain before and 12 weeks after surgery, respectively, and pain was significantly stronger than in those without NP. The PD score of eight hands worsened after surgery. In the “Improved group,” the average age at the surgery was younger and the pain score was lower than in the “Unchanged group.” Conclusions. The surgery was very effective on NP of CTS; however, the PD in 7% of hands worsened after surgery. Risk factors before surgery that predicted worse NP after surgery were found to be a younger age, weaker pain, and the absence of night pain.

Usefulness of four commonly used neuropathic pain screening questionnaires in patients with chronic low back pain: a cross-sectional study.

BackgroundRecently symptoms-based screening questionnaires have gained attention for screening for a neuropathic pain component (NePC) in various chronic pain conditions. The present study assessed the usefulness of four commonly used NePC screening questionnaires including the Self-completed douleur neuropathique 4 (S-DN4), the ID Pain, the painDETECT questionnaire (PDQ), and the Self-completed Leeds Assessment of neuropathic Symptoms and Signs (S-LANSS) questionnaire in patients with chronic low back pain (CLBP) to assess the presence of NePC.MethodsThis is a single-center cross-sectional study where patients with CLBP, with or without leg pain, were included. Participants were initially screened for NePC presence by a physician according to the regular practice, and later assessed using screening questionnaires. The diagnostic accuracy of these questionnaires was compared assuming the physician-made diagnosis as the gold standard.ResultsA total of 215 patients with CLBP of which 164 (76.3%, 95% CI, 70.2-81.5) had a NePC were included. S-DN4, ID Pain, and PDQ have an area under the curve (AUC) > 0.8 indicating excellent discrimination. However, S-LANSS has an AUC of 0.69 (0.62-0.75), indicating low discrimination. S-DN4 has a significantly higher AUC as compared to ID Pain (d(AUC) = 0.063, P < 0.01) and S-LANSS (d(AUC) = 0.197, P < 0.01). But the AUC of S-DN4 does not significantly differ from that of PDQ (d(AUC) = 0.013, P = 0.62).ConclusionsS-DN4, ID Pain, and PDQ, but not S-LANSS, have good discriminant validity to screen for NePCs in patients with CLBP. Despite using all the tests, 20-30% of patients with an NePC were missed. Thus, these questionnaires can only be used as an initial clue in screening for NePCs, but do not replace clinical judgment.

Prevalence and associations of neuropathic pain in a cohort of multi-ethnic Asian low back pain patients.

The prevalence of neuropathic low back pain differs in different ethnic populations. The aims of the study are to determine its frequency and associations in a multi-ethnic cohort of Asian low back pain patients. This was a cross-sectional study of low back patients seen at the University of Malaya Medical Centre, Kuala Lumpur, Malaysia. Neuropathic low back pain patients were identified using the painDETECT questionnaire and compared with non-neuropathic (unclear or nociceptive) low back pain patients, in terms of socio-demographic and clinical factors, pain severity (numerical pain rating scale, NPRS), disability (Roland Morris Disability Questionnaire, RMDQ), as well as anxiety and depression (Hospital Anxiety and Depression Scale, HADS). Of 210 patients, 26 (12.4%) have neuropathic low back pain. Neuropathic pain is associated with non-Chinese ethnicity, higher body mass index and pain radiation below the knee. Patients with neuropathic pain have significantly higher NPRS and RMDQ scores, and there are more subjects with anxiety on HADS. However, there are no differences between the groups in age, gender, pain duration or underlying diagnosis of low back pain. The prevalence of neuropathic low back pain in a multi-ethnic Malaysian cohort is lower than previously reported in other populations with possible differences between ethnic groups. It is associated with greater pain severity, disability and anxiety.

Distinguishing between nociceptive and neuropathic components in chronic low back pain using behavioural evaluation and sensory examination

BackgroundDiagnosis of chronic low back pain (CLBP) is traditionally predicated on identifying underlying pathological or anatomical causes, with treatment outcomes modest at best. Alternately, it is suggested that identification of underlying pain mechanisms with treatments targeted towards specific pain phenotypes may yield more success. Differentiation between nociceptive and neuropathic components of CLBP is problematic; evidence suggests that clinicians fail to identify a significant neuropathic component in many CLBP patients. The painDETECT questionnaire (PDQ) was specifically developed to identify occult but significant neuropathic components in individuals thought to have predominantly nociceptive pain. MethodsUsing the PDQ, we classified 50 CLBP patients into two distinct groups; those with predominantly nociceptive pain (Group 1) and those with a significant neuropathic component (Group 2). We characterised these two distinct CLBP sub-groups using a) questionnaire-based behavioural evaluation measuring pain-related function and quality of life, pain intensity and psychological well-being and b) sensory examination, using two-point and tactile threshold discrimination. ObjectiveWe sought to determine if differences in the pain phenotype of each CLBP sub-group would be reflected in sensory and behavioural group profiles. ResultsWe report that Group 1 and Group 2 sub-groups demonstrate unique clinical profiles with significant differences in sensory tactile discrimination thresholds and in a wide range of behavioural domains measuring pain intensity, disability and psychological well-being. ConclusionWe have demonstrated distinct clinical profiles for CLBP patient sub-groups classified by PDQ. Our results give diagnostic confidence in using the PDQ to characterise two distinct pain phenotypes in a heterogeneous CLBP population.

Daily Pain Is Associated with Alterations in Functional Connectivity of the Brain on fMRI in Adults with Sickle Cell Disease

Background:One-third of adults with sickle cell disease (SCD) have daily, chronic pain. Despite the high prevalence of chronic pain in adults with SCD, the mechanism of is not well defined. In other chronic pain disorders, functional MRI (fMRI) demonstrates a re-organization of the brain's connectivity, which may be maladaptive and contribute to the development of a chronic pain syndrome. We performed fMRI in adults with SCD as well as age-matched controls in order to test two hypotheses: 1) functional connectivity is different between adults with SCD and controls, and 2) differences in functional connectivity among adults with SCD are associated with a more severe pain phenotype.Methods:We performed resting-state fMRI in adults with SCD and age-matched controls. Functional connectivity was calculated using two approaches: 1) a seed-voxel approach with the seed being periaqueductal gray (PAG), an area of the brain known to inhibit pain sensation, and 2) an inter-network functional connectivity strength (FCS) analysis, in which seven brain functional networks were selected based on previous brain modularity analysis findings. To calculate the inter-network FCS between networks A and B, the summation of all functional connectivities between two networks are used. Thereafter, the networks that were significantly different in FCS between SCD and controls were used to determine the association between altered functional connectivity and pain phenotype within SCD subjects. Pain phenotype measurements in SCD subjects included a day-of-study pain score, a 15-day diary to document daily pain and opioid use, McGill pain and Pain DETECT questionnaires, and quantitative sensory testing in response to mechanical, cold, and heat stimuli. Statistical analyses were performed using FSL and Matlab software.Results: A total of 27 adults were examined, including 13 with SCD (9 HbSS, 4 HbSC) and 14 age-matched controls. Seed-based functional connectivity analyses revealed significantly decreased connectivity in SCD as compared to controls between PAG and the regions involved in pain, sensation, salience, emotion, learning, and memory (temporal gyrus, anterior/posterior insula, parahippocampal gyrus, fusiform gyrus, precunes, posterior cingulate gyrus, anterior cingulate, subcallosal gyrus, paracentral gyrus, inferior/superior parietal lobe, inferior frontal gyrus and superior temporal gyrus) (P<0.001, t-test with AlphaSim correction). Furthermore, inter-network analyses show significantly decreased FCS in SCD as compared to controls among networks involved in salience, emotion, learning, and memory (between the salience network and the striatum network, between the salience network and the temporal network, and within both the salience network and the hippocampus network) (P<0.001, t-test). When these inter-network differences in FCS between SCD subjects and controls were examined within SCD subjects to determine the association with clinical phenotype, significant associations were found with age (rs=0.63, P<0.024, Spearman correlation analysis), SCD genotype (SS vs SC) (r2=0.43, P<0.016, linear regression analysis), and number of diary days with pain score >5 (r2=0.5, P<0.011, linear regression analysis).Conclusions: In adults with SCD compared to controls, there were differences in inter-network FCS, including the salience, striatum, temporal, and hippocampus networks, which are crucial networks for salience, emotion, learning, and memory. When these inter-network FCS differences were examined within adults with SCD, significant associations were found with age, SCD genotype and number of pain days. Taken together, these data suggest that altered connectivity in the brain of adults with SCD contributes to the development of a chronic pain syndrome. These changes in functional connectivity on fMRI could be used as a biomarker to determine the efficacy of interventions targeted to decrease chronic pain. DisclosuresField:NKT Therapeutics: Research Funding; Astellas Pharmaceuticals: Research Funding.

Neuropathic pain may be common in chronic lower limb tendinopathy: a prospective cohort study.

To identify the prevalence of neuropathic pain, through the use of the painDETECT questionnaire, in a cohort of patients with chronic lower limb tendinopathy conditions. Patients with chronic lower limb tendinopathy conditions treated within a Sport and Exercise Medicine hospital clinic were identified from clinical records. At the time of the clinical consultation, pain and painDETECT scores were recorded. In total, 282 suitable patients with chronic lower limb tendinopathy conditions were identified who had completed a painDETECT questionnaire. There was a median age of 51.9 years, 35% of patients were male and a median duration of symptoms of 24.0 months. There was a median score of 7.0/10 for self-reported 'average' pain and 8.0/10 for self-reported 'worst' pain. There was a median painDETECT score of 14.0, 28% of respondents scored 19 or higher with painDETECT (neuropathic component to pain may be likely), 29% scored 13-18 (equivocal result) and 43% of respondents scored 12 or less (neuropathic pain component was unlikely). This study suggests that neuropathic pain as identified by the painDETECT questionnaire may be common in patients with chronic lower limb tendinopathy conditions. It is unclear if patients with tendinopathy who have neuropathic pain may have poorer outcomes from initial treatments, contributing to the high proportion seen in secondary care. These are results from a single hospital clinic, and comparison with a control group is currently lacking. However, on the results to date, neuropathic pain should be considered in management strategies in patients with chronic tendinopathy.

Neuropathic pain in patients with rotator cuff tears.

BackgroundRecent 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.MethodsData 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.ResultsPatients 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.ConclusionsUsing 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.

Insufficient treatment of severe depression in neuromyelitis optica spectrum disorder.

Objective:To investigate depression frequency, severity, current treatment, and interactions with somatic symptoms among patients with neuromyelitis optica spectrum disorder (NMOSD).Methods:In this dual-center observational study, we included 71 patients diagnosed with NMOSD according to the International Panel for NMO Diagnosis 2015 criteria. The Beck Depression Inventory (BDI) was classified into severe, moderate, or minimal/no depressive state category. We used the Fatigue Severity Scale to evaluate fatigue. Scores from the Brief Pain Inventory and the PainDETECT Questionnaire were normalized to estimate neuropathic pain. Psychotropic, pain, and immunosuppressant medications were tabulated by established classes.Results:Twenty-eight percent of patients with NMOSD (n = 20) had BDI scores indicative of moderate or severe depression; 48% of patients (n = 34) endorsed significant levels of neuropathic pain. Severity of depression was moderately associated with neuropathic pain (r = 0.341, p < 0.004) but this relationship was confounded by levels of fatigue. Furthermore, only 40% of patients with moderate or severe depressive symptoms received antidepressant medical treatment. Fifty percent of those treated reported persistent moderate to severe depressive symptoms under treatment.Conclusions:Moderate and severe depression in patients with NMOSD is associated with neuropathic pain and fatigue and is insufficiently treated. These results are consistent across 2 research centers and continents. Future research needs to address how depression can be effectively managed and treated in NMOSD.

Intra-articular onabotulinumtoxinA in osteoarthritis knee pain: effect on human mechanistic pain biomarkers and clinical pain

Objectives: OnabotulinumtoxinA (onabotA) attenuates peripheral nociceptive transduction and consequently neuronal firing. The aim of this mechanistic study was to evaluate the effect of intra-articular (IA) onabotA in patients with painful knee osteoarthritis (OA).Method: We conducted a double-blind, randomized, placebo-controlled, 12-week trial using a single ultrasound-guided IA injection of onabotA (200 U). Patients (N = 121) were randomized to receive onabotA (n = 61) or placebo (n = 60). Mechanistic pain biomarkers and clinical outcomes were used for profiling the effect. The biomarkers were pressure pain thresholds (PPTs) from the knee joint (localized sensitization) and extra-articular sites (widespread sensitization), and wind-up pain (central sensitization). Clinical assessments included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), average daily pain (ADP), patient global impression of change (GIC), and rescue medication. The painDETECT questionnaire (PD-Q) was used for subgrouping patients (nociceptive, neuropathic, and mixed/uncertain).Results: The nociceptive and non-nociceptive groups were identical with respect to all baseline data. No significant differences in clinical efficacy parameters were found between onabotA and placebo in the entire population. The nociceptive group showed significant improvement after IA onabotA at week 8 for all WOMAC outcomes, ADP at weeks 9 and 10, and patient GIC at week 12, and significant reduction in rescue medication counts within each 14-day period at weeks 9 and 10. After 4, 8, and 12 weeks, significant correlations were obtained in the onabotA group between ADP (both the entire group and the nociceptive group) and various sensitization parameters. The nociceptive group showed pronounced effects on widespread sensitization.Conclusions: Intra-articular onabotA given to patients with nociceptive knee OA reduced pain sensitization together with improvement in pain and function.

Chronic persistent post-surgical pain following staging laparotomy for carcinoma of ovary and its relationship to signal transduction genes.

BackgroundThe present study was undertaken to evaluate the incidence of chronic persistent post-surgical pain (CPPP) and the role of signal transduction genes in patients undergoing staging laparotomy for carcinoma ovary.MethodsThe present observational study was undertaken following institutional ethical committee approval and informed consent from all the participants. A total 21 patients of ASA grade I to III with age 20−70 years, scheduled for elective staging laparotomy for carcinoma ovary were included. Patients were excluded if had other causes of pain, cognitive dysfunction or chronic neurological disorders. Statistical analysis of pool data was done using SPSS version-17. For various scales like GPE, PDQ, NPSI, the visual analogue scale (VAS), global perceived effect (GPE), the pain DETECT questionnaire (PDQ), and neuropathic pain symptoms inventory (NPSI), one factor repaeted measure ANOVA applied with simple contrast with baseline as on post-operative day 1 (considered as reference and compared with subsequent time-interval), and the P values were adjusted according to "Bonferroni adjustments". In patients with CPPP, the Δct values of mRNA expressions of genes at the end of postoperative day 90 were compared with the baseline control values by one factor repeated ANOVA. P value < 0.005 significant.ResultsThe present study demonstrates 38.1% (8 out of 21 patients) incidence of CPPP. The functional status and quality of life as were observed to be significantly diminished in all patients with chronic pain. An up-regulation in the mRNA expression of signal transduction and a positive correlation was noted between the mRNA expression of signal transduction genes and VAS score in all patients with CPPP at the end of postoperative day 90.ConclusionsThe reported incidence of CPPP in patients with carcinoma ovary was 38.1%. An up-regulation and positive correlation between mRNA expression of signal transduction genes and VAS score depicts its potential role in the pathogenesis of CPPP.

Classifying patients with lumbar spinal stenosis using painDETECT: a cross-sectional study

BackgroundThe pathological mechanisms of lumbar spinal stenosis are unclear. Family doctors in the primary care setting may perform medical examinations of patients with lumbar spinal stenosis. Our aim was to use the painDETECT questionnaire to quantify the pathological mechanisms of low back pain and/or leg pain caused by lumbar spinal stenosis.MethodsWe enrolled 102 patients (37 men, 65 women) who had been newly diagnosed with lumbar spinal stenosis at 2 facilities. The patients’ conditions were evaluated using the painDETECT questionnaire, Numerical Rating Scale, Roland-Morris Disability Questionnaire, Japanese Orthopaedic Association Back Pain Evaluation Questionnaire, and 36-Item Short-Form Health Survey. The pathological mechanisms of low back pain and/or leg pain caused by lumbar spinal stenosis were classified based on results of the painDETECT questionnaire as nociceptive pain, neuropathic pain, or unclear type of pain (mixed pain). Statistical analyses were performed using the Kruskal–Wallis test. A value of p < 0.05 was considered to indicate statistical significance.ResultsThe mean age of all patients in this study was 70.3 ± 2 years. The male:female distribution was 37:65 (36.3:63.7 %). In all, 72 (70.6 %) patients had chronic pain (duration of ≥3 months), and 30 (29.4 %) had subacute or acute pain (duration of <3 months). The pain was classified as nociceptive in 59 patients (57.9 %), neuropathic in 18 (17.6 %), and unclear in 25 (24.5 %). The neuropathic pain group had a significantly lower quality of life (p < 0.05) than did the other groups.ConclusionsPatients with neuropathic back and/or leg pain caused by lumbar spinal stenosis may have lower physical and/or psychological quality of life than patients with such pain caused by other mechanisms.

Korean Version of the painDETECT Questionnaire: A Study for Cultural Adaptation and Validation.

The purpose of this study was to adapt the painDETECT Questionnaire (PD-Q) into a Korean version (KPD-Q) and validate it. A single-center prospective observational study was performed. During the first phase of the study, linguistic adaptation was carried out to develop the KPD-Q. During the second phase of the study, feasibility, internal consistency, discriminant validity, and concurrent validity were assessed for psychometric validation of the KPD-Q. A total of 232 patients participated. Among them, 82 patients (35%) were classified in the neuropathic pain (NeP) group, 80 (34%) in the nociceptive pain group, and 70 (30%) in the mixed pain group. Regarding the reliability of the KPD-Q, internal consistency for the whole scale was 0.804, as evaluated by Cronbach's alpha. Pearson's correlation between the Leeds Assessment of Neuropathic Symptoms and Signs scale and the KPD-Q scores was positive and statistically significant (r = 0.74, P < 0.001). Similar to the result obtained by the original developers, a value of ≥ 19 points suggested a clear diagnosis of the presence of an NeP component with 95.4% sensitivity, 73.8% specificity, and 0.737 Youden index. We used ≤ 13 (as opposed to ≤ 12, as suggested previously) as an alternative cutoff value, which showed a sensitivity of 95.4%, specificity of 73.8%, and the Youden index of 0.691. The KPD-Q showed good psychometric and discriminant features for assessing the neuropathic component in chronic pain patients. We hope that this newly validated KPD-Q will be recognized in Korea as a credible tool for detection of NeP and thus may be used in further international clinical research.

Prevalence of neuropathic pain in early multiple sclerosis

Background: Pain is considered a frequent symptom in multiple sclerosis. Neuropathic pain is the type of pain most closely related to the pathology of multiple sclerosis and its prevalence estimates vary largely. Objective: We prospectively assessed the prevalence of neuropathic pain in patients with early multiple sclerosis and investigated the association of neuropathic pain with other clinical parameters. Methods: A total of 377 outpatients with multiple sclerosis at an early disease stage were included in this prospective study. Mean disease duration was 4.2 years, mean Expanded Disability Status Scale (EDSS) score was 1.6, 96.8% of patients were classified as having relapsing–remitting multiple sclerosis. Neuropathic pain was assessed using the PainDETECT questionnaire (PDQ). Depression, fatigue and cognition were assessed using the Beck Depression Inventory (BDI), the Fatigue Scale for Motor and Cognitive Functions (FSMC) and the Paced Auditory Serial Addition Test. Results: PDQ scores indicative of neuropathic pain were found in 4.2% of patients. Regression analysis revealed EDSS, BDI and FMSC scores as strongest predictors of PDQ scores. Conclusions: Neuropathic pain appears to be less frequent in early multiple sclerosis than expected and is significantly associated with disability, depression and fatigue. The assessment and therapy of pain in multiple sclerosis should thus take into account neuropsychiatric symptoms already at early disease stages.

Pain Drawings Improve Subgrouping of Low Back Pain Patients.

Subgrouping of low back pain (LBP) patients may be improved when pain drawings are combined with the painDETECT (PD-Q) questionnaire. We hypothesized that (1) different LBP subgroups determined by their pain radiation show different clinical patterns and (2) the occurrence of neuropathic symptoms depends on pain radiation. A total of 19,263 acute (< 6 weeks' duration), subacute (6 to 12 weeks), and chronic (> 3 months) LBP patients were allocated prospectively into 4 groups based on the location of pain drawings on a manikin and compared regarding neuropathic pain components, functionality, depression, pain intensity, and surgical interventions. All items were investigated at baseline and follow-up visits. Group I was composed of patients with axial LBP without radiating pain; group II, LBP with radiation into the thigh; group III, LBP with radiation into the shank; and group IV, LBP with radiation into the feet. Side-dependent pain radiation was assessed additionally. Depression, functionality, and pain intensity showed no clinically relevant differences, whereas PD-Q scores and the probability to rate positive for neuropathic pain increased with more distally radiating pain. Surgery and medication intake were most frequent in group IV. Follow-up analyses showed that only axial LBP became more neuropathic, whereas pain intensity decreased over time. Radicular patterns of pain drawings in LBP patients indicate severe pain conditions with the most neuropathic components, while axial LBP has the fewest. For the categorization of LBP, pain drawings help explain the underlying mechanism of pain, which might further improve mechanism-based treatment when used in clinical routines and research.

Symptom profiles in the painDETECT Questionnaire in patients with peripheral neuropathic pain stratified according to sensory loss in quantitative sensory testing.

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. An exploratory analysis in the Innovative Medicines Initiative Europain and Neuropain database was performed. Data records of 336 patients identified with NP were grouped into sensory profiles characterized by (1) no loss of sensation, (2) loss of thermal sensation, (3) loss of mechanical sensation, and (4) loss of thermal and mechanical sensation. painDETECT Questionnaire profiles were analyzed in a 2-factor analysis of variance. 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.

Poor efficacy of the phosphorylated high-molecular-weight neurofilament heavy subunit serum level, a biomarker of axonal damage, as a marker of chemotherapy-induced peripheral neuropathy.

The phosphorylated form of the high-molecular-weight neurofilament heavy subunit (pNF-H) is a major structural protein in axons. The pNF-H level is elevated in the serum of certain patients with central nervous disorders, including chemotherapy-induced cognitive impairment. The present study was conducted to elucidate the potential role of pNF-H as a marker of chemotherapy-induced peripheral neuropathy (CIPN). A total of 71 patients with early breast cancer in various stages of treatment (following 1, 3 or 7 cycles of chemotherapy, or a previous history of breast cancer chemotherapy) were assessed with a self-administered PainDETECT questionnaire [pain location, pain intensity on an 11-point numeric rating scale (NRS), and various pain qualities] and a single serum pNF-H measurement. Patients were divided into two groups based on the presence or absence of bilateral symmetric pain in the distal portions of the extremities [CIPN(+) or CIPN(-)]. The χ2 and Mann-Whitney tests were used for statistical analyses. Among the participants, only 8 patients complained of CIPN. Their pain intensity was 3.5±1.9 (mean ± standard deviation) compared with 1.5±1.8 in the CIPN(-) group (P<0.01). The NRS of numbness in the CIPN(+) group was significantly higher (2.4±1.4) than that of the CIPN(-) group (1.0±1.0). Increased pNF-H levels were observed in 37.5% of the CIPN(+) patients and in 23.8% of CIPN(-) patients (P=0.40). In conclusion, CIPN is observed in the most distal portions of the peripheral nerves that are composed of dendrites but not axons. Although serum pNF-H is a biomarker of axonal damage, it is not useful as a marker of CIPN.

Pain mechanisms and ultrasonic inflammatory activity as prognostic factors in patients with psoriatic arthritis: protocol for a prospective, exploratory cohort study

IntroductionPersistent pain is a major concern for patients with psoriatic arthritis (PsA). Pain may be due to inflammatory activity or augmented central pain processing. Unawareness of the origin and mechanisms...

Evidence for a central mode of action for etoricoxib (COX-2 inhibitor) in patients with painful knee osteoarthritis.

The COX-2 inhibitor etoricoxib modulates the peripheral and central nociceptive mechanisms in animals. This interaction has not been studied in patients with pain. This randomized, double-blind, placebo-controlled, 2-way crossover, 4-week treatment study investigated the pain mechanisms modulated by etoricoxib in patients with painful knee osteoarthritis. Patients were randomized to group A (60 mg/d etoricoxib followed by placebo) or B (placebo followed by 60 mg/d etoricoxib). The quantitative, mechanistic pain biomarkers were pressure pain thresholds, temporal summation (TS), and conditioning pain modulation. Clinical readouts were Brief Pain Inventory, WOMAC, painDETECT questionnaire (PD-Q), and time and pain intensity during walking and stair climbing. Etoricoxib as compared with placebo significantly modulated the pressure pain thresholds (P = 0.012, localized sensitization) at the knee and leg (control site) (P = 0.025, spreading sensitization) and TS assessed from the knee (P = 0.038) and leg (P = 0.045). Conditioning pain modulation was not modulated. The Brief Pain Inventory (pain scores), PD-Q, WOMAC, and walking and stair climbing tests were all significantly improved by etoricoxib. Based on a minimum of 30% or 50% pain alleviation (day 0-day 28), responders and nonresponders were defined. The nonresponders showed a significant association between increased facilitation of TS and increased pain alleviation. None of the other parameters predicted the degree of pain alleviation. Generally, a responder to etoricoxib has the most facilitated TS. In conclusion, etoricoxib (1) modulated central pain modulatory mechanisms and (2) improved pain and function in painful osteoarthritis. Stronger facilitation of TS may indicate a better response to etoricoxib, supporting the central mode-of-action of the drug.

Non-nociceptive pain in rheumatoid arthritis is frequent and affects disease activity estimation: cross-sectional data from the FRAME study

Background: The painDETECT questionnaire (PDQ) is a mechanism-based pain classification tool assigning patients to one of three categories depending on the quality of the experienced pain. Patients with non-nociceptive pain score high on the PDQ. The objective was to assess the proportions of the three PDQ classification groups in patients with rheumatoid arthritis (RA) and to explore differences in clinical characteristics.Method: RA patients initiating or escalating their RA therapy were included prospectively and underwent a thorough examination programme. Low (PDQ score < 13), medium (PDQ score 13–18), and high (PDQ score > 18) scores indicate nociceptive, unclear/possible neuropathic, or neuropathic pain mechanisms, respectively.Results: The 102 included patients were classified into the following PDQ classification groups: low = 65%, medium = 23%, and high = 12%. Patients in the medium and high PDQ groups scored worse on indicators of anxiety, depression, disability, mental health-related quality of life, pain, and fatigue. They also had more tender points and an RA disease activity score based on 28 joints (DAS28) where a higher fraction of the composite score pertained to non-inflammatory factors compared to patients in the low PDQ classification group. There were no differences in objective inflammatory indices across groups. Multiple regression analysis demonstrated that the tender joint count (TJC) and the 36-item Short Form Health Survey (SF36) mental component summary (MCS) score were independently associated with the PDQ score.Conclusions: In patients initiating or intensifying medical treatment for their RA, non-nociceptive pain (PDQ score ≥ 13) is common. In these patients, the pain mechanisms result in increased disease activity scores on a non-inflammatory basis.