Clinical Pain Assessment Research Articles

Built to Scale: A Corpus-Based Analysis of Adjective Scales in the Mcgill Pain Questionnaire

Modern medical diagnosis relies on precise pain assessment tools in translating clinical information from patient to physician. The McGill Pain Questionnaire (MPQ) is a clinical pain assessment technique that utilizes 78 adjectives of different intensities in 20 categories to quantify a patient’s pain. The questionnaire’s efficacy depends on a predictable pattern of adjective use by patients experiencing pain. In this study, I recreate the MPQ’s adjective intensity orderings using data gathered from patient forums and modern NLP techniques. I extract adjective intensity relationships by searching for key linguistic contexts, and then combine the relationship information to form robust adjective scales. Of 17 adjective relationships predicted by this research, only 4 diverge from the MPQ’s orderings, which is statistically significant at the 0.1 alpha level. The results suggest predictable patterns of adjective use by people experiencing pain, but call into question the MPQ’s categories for grouping adjectives.

Three-Year Results from the Venovo Venous Stent Study for the Treatment of Iliac and Femoral Vein Obstruction

PurposeTo assess safety and patency of the Venovo venous stent for the treatment of iliofemoral vein obstruction.Materials and MethodsTwenty-two international centers enrolled 170 patients in the VERNACULAR study (93 post-thrombotic syndrome; 77 non-thrombotic iliac vein lesions). Primary outcome measures were major adverse events at 30 days and 12-month primary patency (freedom from target vessel revascularization, thrombotic occlusion, or stenosis > 50%). Secondary outcomes included the Venous Clinical Severity Score Pain Assessment and Chronic Venous Quality-of-Life Questionnaire assessments (hypothesis tested). Secondary observations included primary patency, target vessel and lesion revascularization (TVR/TLR), and assessment of stent integrity through 36 months.ResultsFreedom from major adverse events through 30 days was 93.5%, statistically higher than a pre-specified performance goal of 89% (p = 0.032) while primary patency at 12 months was 88.6%, also statistically higher than a performance goal of 74% (p < 0.0001). Mean quality-of-life measures were statistically improved compared to baseline values at 12 months (p < 0.0001). Primary patency at 36 months was 84% (Kaplan–Meier analysis) while freedom from TVR/TLR was 88.1%. There was no stent embolization/migration, and no core laboratory assessed stent fractures reported through 36 months. Six deaths were reported; none adjudicated as device or procedure related.ConclusionThe Venovo venous stent was successfully deployed in obstructive iliofemoral vein lesions and met the pre-specified primary outcome measures through 12 months. At 3 years, primary patency was 84%, reintervention rates were low, standardized quality-of-life and pain measures improved from baseline, and there was no stent migration or fractures.Level of EvidenceLevel 2—prospective, multicenter, controlled clinical study without a concurrent control or randomization. Pre-specified endpoints were hypothesis-tested to performance goals derived from peer-reviewed clinical literature.Registration clinicaltrials.govUnique Identifier NCT02655887.

NGF Expression and Elevation in Hip Osteoarthritis Patients with Pain and Central Sensitization.

Osteoarthritis (OA) is a chronic degenerative musculoskeletal disease that causes articular cartilage degeneration and chronic pain. Research into OA animal models suggests that elevated NGF levels in the synovium contribute to pain and central sensitization (CS). However, it is unclear whether synovial NGF contributes to CS in patients with OA. We investigated the association between synovial NGF expression and clinical assessments of pain and CS in hip OA (hOA) patients. We also aimed to identify which cells in the synovium of hOA patients express NGF. Sixty-six patients who received total hip replacement and a diagnosis of hOA were enrolled. We measured NGF mRNA expression in synovial samples obtained from 50 patients using qPCR and analyzed the correlation of NGF expression with the CS inventory (CSI) score and Japanese Orthopaedic Association (JOA) score, a clinical scoring system for OA. To identify the synovial cells expressing NGF, we analyzed NGF mRNA expression in CD14+ and CD14- cells, which represent macrophage-rich and fibroblast-rich fractions, respectively, extracted from 8 patients. To further identify which macrophage subtypes express NGF, we examined NGF mRNA expression in CD14high and CD14low cells sorted from 8 patients. Synovial NGF mRNA expression was negatively correlated with JOA score but positively correlated with CSI score (JOA pain, r = −0.337, P = 0.017; CSI score, r = 0.358, P = 0.011). Significantly greater levels of NGF were observed in CD14- cells compared to CD14+ cells (P = 0.036) and in CD14high cells compared to CD14low cells (P = 0.008). In conclusion, synovial NGF expression is correlated with the degree of pain and CS in hOA patients. NGF is predominantly expressed in synovial fibroblasts. Further, CD14high synovial macrophages expressed higher levels of NGF. Our results may provide a novel NGF-targeted therapeutic strategy for hOA pain.

Changes of Infant- and Family-Centered Care Practices Administered to Extremely Preterm Infants During Implementation of the NIDCAP Program.

Introduction: Many studies have evaluated the Neonatal Individualized Developmental Care and Assessment Program (NIDCAP), but few studies have assessed changes in infant- and family-centered developmental care (IFCDC) practices during its implementation.Objectives: The primary objective of this single center study was to investigate the impact of the implementation of the NIDCAP program on IFCDC practices used for management of extremely preterm infants (EPIs). The secondary objective was to determine during implementation the impact of this program on the short-term medical outcomes of all EPIs hospitalized at our center.Methods: All EPIs (<28 weeks gestational age) who were hospitalized at Strasbourg University Hospital from 2007 to 2014 were initially included. Outborn infants were excluded. The data of EPIs were compared for three time periods: 2007 to 2008 (pre-NIDCAP), 2010 to 2011, and 2013 to 2014 (during-NIDCAP implementation) using appropriate statistical tests. The clinical and caring procedures used during the first 14 days of life were analyzed, with a focus on components of individualized developmental care (NIDCAP observations), infant pain management (number of painful procedures, clinical pain assessment), skin-to-skin contact (SSC; frequency, day of initiation, and duration), and family access and involvement in the care of their children (duration of parental presence, parental participation in care). The short-term mortality and morbidity at discharge were evaluated.Results: We examined 228 EPIs who received care during the three time periods. Over time, painful procedures decreased, but pain evaluations, parental involvement in care, individualized observations, and SSC increased (all p < 0.01). In addition, the first SSC was performed earlier (p = 0.03) and lasted longer (p < 0.01). There were no differences in mortality and morbidity, but there were reductions in the duration of mechanical ventilation (p = 0.02) and the time from birth to first extubation (p = 0.02), and an increase of weight gain at discharge (p = 0.02).Conclusion: NIDCAP implementation was accompanied by progressive, measurable, and significant changes in IFCDC strategies. There were, concomitantly, moderate but statistically significant improvements in multiple important outcome measures of all hospitalized EPI.

Cross-Sectional Associations among Components of Injustice Appraisals and Functioning in Adolescents With Chronic Pain.

Pain-related appraisals, including pain-related injustice, impact the development and maintenance of chronic pain. This cross-sectional study aimed to examine the relationship between the cognitive-emotional components of pain-related injustice-blame/unfairness and severity/irreparability of loss-and functioning in a mixed sample of adolescents with chronic pain. Pediatric patients age 11-18 years (N = 408) completed forms assessing pain-related injustice, pain intensity, and physical and psychosocial functioning as part of their routine assessment in a pediatric chronic pain clinic between January 2014 and January 2019. A series of hierarchical regressions were used to evaluate the relationships among the separate components of pain-related injustice appraisals and functioning. Pain intensity and blame/unfairness appraisals were significantly associated with emotional functioning with blame/unfairness being the stronger association (β = -.27). Blame/unfairness appraisals, severity/irreparability appraisals, and pain intensity were significantly associated with physical functioning with pain intensity being the strongest association (β = .36). Pain intensity, blame/unfairness appraisals, and severity/irreparability appraisals were significantly associated with social functioning with blame/unfairness being the strongest association (β = -.34). Pain intensity and severity/irreparability appraisals were significantly associated with school functioning with severity/irreparability being the stronger association (β = -.19). These results lend further support to incorporating pain-related injustice appraisals in standard clinical pain assessments. Treatment practices should target the specific injustice appraisals and domains of functioning impacted for each pediatric patient with chronic pain.

Hypersensitivity relief of MIH-affected molars using two sealing techniques: a 12-week follow-up

ObjectivesThe aim of this study was to compare the efficacy in reducing hypersensitivity in molar incisor hypomineralization (MIH)-affected molars immediately and over 12 weeks after sealing using two different materials (composite and glass ionomer). Furthermore, the retention rates of both materials were analyzed.MethodsThirty-nine children with two MIH-affected molars showing hypersensitivity and non-occlusal breakdowns were included. Hypersensitivity was assessed with an evaporative (air) stimulus. Both teeth were sealed by two calibrated operators using a split-mouth design with either Clinpro Sealant in combination with Scotchbond Universal (C) or Ketac Universal (K), respectively. Clinical pain assessments (Schiff Score Air Sensitivity Scale [SCASS], Visual Analog Scale [VAS]) were made at baseline (“pre”), immediately after treatment (“post”), and after 1, 4, 8, and 12 weeks. Paired t tests were calculated in each group between baseline and all other time points.ResultsThirty-eight children with 76 molars completed all stages of the study. Regardless of the material used, the application of the sealant decreased hypersensitivity significantly immediately as well as throughout the 12-week recalls (all p values < 0.001). We found no statistically significant difference among both materials chosen in any of the time points evaluated. Furthermore, retention of both materials was comparable in both groups.ConclusionsBoth sealant materials were able to reduce hypersensitivity successfully immediately and throughout the 12-week follow-up. Furthermore, their performance was similar in terms of retention.Clinical relevanceHypersensitivity can be a major complaint in patients with MIH. This is the first study evaluating hypersensitivity relief of MIH-affected molars using two sealing techniques.

Level of patient comfort and measurement reproducibility of three different probes: A cross-sectional study.

To determine the comfort level and reproducibility assessment of the probing pocket depth obtained with three different probes. A cross-sectional clinical study was conducted in accordance with the STROBE standards. Three different types of periodontal probes were selected: (1) University of North Carolina (UNC) probe, (2) World health organization (WHO) probe and (3) UNC12 COLORVUE probe. Three experienced and calibrated periodontists performed periodontal clinical assessments (probing depth) and pain assessment with the visual analogue scale (VAS). The clinical evaluations were carried out in 13 volunteers who attended the dental clinic of the Universidad Científica del Sur (Lima, Peru). A total of 2106 periodontal clinical measurements were obtained (702 measurements per examiner). Each examiner evaluated 234 sites for each type of probe. When patient comfort values during the periodontal evaluation performed with the 3 types of probes were compared, the patients evaluated with the UNC12 COLORVUE probe perceived less pain with a mean value of 0.61, followed by the WHO probe and the UNC probe. When evaluating the clinical measurements, the UNC probe was observed to obtain the greatest mean depth on probing 1.4+0.5mm, while with the UNC12 Colorvue probe, the values obtained were 1.1+0.3mm, and with the WHO probe, 1.2+0.4mm. Based on the periodontal probe used, experience of the examiner and the patient, we can conclude that the UNC12 Colorvue probe was the instrument that promoted the greatest comfort or the slightest response to pain, followed by the WHO probe. However, the use of the WHO probe resulted in obtaining the lowest reproducibility among depths on probing. The UNC probe produced the highest response to pain in the patients.

How and Why Patient Concerns Influence Pain Reporting: A Qualitative Analysis of Personal Accounts and Perceptions of Others' Use of Numerical Pain Scales.

Complex factors influence how people report and interpret numerical pain ratings. Such variability can introduce noise and systematic bias into clinical pain assessment. Identification of factors that influence self-rated pain and its interpretation by others may bolster utility of these scales. In this qualitative study, 338 participants described motivations for modulating their own pain reports relative to a numerical pain scale (0–10), as well as perceptions of others’ pain reporting modulation. Responses indicated that people over-report pain to enhance provider belief/responsiveness or the likelihood of pain relief, and out of fear of future pain or potential illness. Concerns of how one’s pain affects and is perceived by others, and financial concerns motivated pain under-reporting. Unprompted, many participants reported never modulating their pain ratings, citing trust in providers and personal ethics. Similar reasons were assumed to motivate others’ pain ratings. However, participants often attributed others’ over-reporting to internal causes, and their own to external. This bias may underlie common assumptions that patients over-report pain for nefarious reasons, distort interpretation of pain reports, and contribute to pain invalidation. Recognition of patient concerns and one’s own personal biases toward others’ pain reporting may improve patient-provider trust and support precision of numerical pain ratings.

Non – Clinical Pain Assessment System – A Pilot Study

The term ‘Pain’ refers to the sensory response of the body when the reflex tolerance level of the person exceeds the threshold value. Though most of the pain senses are tolerable, it still disturbs the normal anatomical actions of the body, classifying it as tolerable and intolerable pain. Various techniques have evolved in the past few years to quantify pain; however, they are successful only in subjective determination thus leading to inaccuracy in prediction. The proposed paper discusses a few objective methods to quantify non – clinical pain. FLIR spectroscopic images can recognize inflammation and high-temperature points in a given region. Upon using various mechanical algorithms, accurate pain values can be determined. Similarly, by solving the pain-causing equation, we can derive the pain peak values. These methods can replace the conventional scales and help in subsidiary pain assessment.

Opioid Use Predicts Self-Reported Mobility in Older Adults with Chronic Lower Back Pain

Chronic low back pain (cLBP) prevalence increases with advancing age and is a leading contributor to mobility disability among older adults. Opioids are commonly prescribed treatments to reduce pain related symptoms. The rise in opioid use and misuse can enhance a variety of issues in the adult population; such as, lack of mobility and decrease in overall health and wellbeing. Few studies have examined the impact of opioid use on mobility in older adults with cLBP. Therefore, we sought to examine the relationship between self-reported opioid use and self-reported mobility. cLBP participants (n = 140) completed a series of questionnaires regarding pain intensity, interference, and disability including demographics, clinical pain assessment, and the Brief Pain Inventory-Short form. Pearson's chi-square tests, and regression-based analyses were conducted using SPSS version 26.0. Among cLBP participants, those who self-reported opioid use were more likely to have greater self-reported difficulty climbing stairs (χ2 = 16.6, p

Predictors for Pain Severity, Interference, and the Use of Tertiary Providers among Community Dwelling, Southern Adults

Chronic low back pain (cLBP) is a leading cause of morbidity and health care utilization in the US. Ample evidence suggests sociodemographic variables (i.e., gender, age, income, and race) influence pain. However, a framework informing associations of multiple sociodemographic factors with provider and intervention utilization, specifically in cLBP, has yet to be established. The purpose was to examine whether sociodemographic variables was associated with the type of provider seen (primary care only, tertiary, or none). cLBP patients completed a series of questionnaires including a clinical pain assessment, provider attendance, medication and treatment use, demographics, and the Brief Pain Inventory-Short form. The SPSS version 26.0 statistical package was used for analysis. cLBP patients (n=140), 56% were female, 57% were Non-Hispanic Black (NHB), 42% were Non-Hispanic White (NHW). Of the cLBP participants, 27% did not seek care from a provider, 46% sought primary care only, and 27% sought some form of tertiary care. In a regression-based model, results suggest that age (p = .001) and pain interference (p = .024) increases use of a provider for cLBP, but sociodemographic variables did not predict which type of care used. Use of physical therapy was increased by pain interference (p=.026), having insurance (p=.037), age (p=.034), and being NHW (p=.004). Sociodemographic variables predict the use of a provider in cLBP. Findings from this study expand on the existing literature as it relates to disparities in access to healthcare providers, associations between pain severity and interference, and sociodemographic factors. Future research should seek to understand the influence of sociodemographic factors extends to other types of chronic pain. This work was supported by Examining Racial And SocioEconomic Disparities in cLBP; ERASED; R01MD010441.

Assessment of neuropathic pain after spinal cord injury using quantitative pain drawings

Study designClinimetric cross-sectional cohort study in adults with paraplegic spinal cord injury (SCI) and neuropathic pain (NP).ObjectiveTo assess the reliability of standardized quantitative pain drawings in patients with NP following SCI.SettingHospital-based research facility at the Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland.MethodsTwenty individuals with chronic thoracic spinal cord injury and neuropathic pain were recruited from a national and local SCI registry. A thorough clinical examination and pain assessments were performed. Pain drawings were acquired at subsequent timepoints, 13 days (IQR 7.8–14.8) apart, in order to assess test-retest reliability.ResultsThe average extent [%] and intensity [NRS 0–10] of spontaneous NP were 11.3% (IQR 4.9–35.8) and 5 (IQR 3–7), respectively. Pain extent showed excellent inter-session reliability (intraclass correlation coefficient 0.96). Sensory loss quantified by light touch and pinprick sensation was associated with larger pain extent (rpinprick = −0.47, p = 0.04; rlight touch = −0.64, p < 0.01).ConclusionAssessing pain extent using quantitative pain drawings is readily feasible and reliable in human SCI. Relating information of sensory deficits to the presence of pain may provide distinct insights into the interaction of sensory deafferentation and the development of neuropathic pain after SCI.

Understanding peripheral neuropathic pain in primary care: diagnosis and management.

To describe an approach that allows for a dedicated clinical assessment and accurate recognition of peripheral neuropathic pain in primary care and to provide an update on the available pharmacologic therapies MATERIALS AND METHODS: Medline was searched using the key word "neuropathic pain". Searches were refined for each pathophysiological mechanism, diagnosis and treatment by adding appropriate key words. The distinction between neuropathic and nociceptive pain is essential for an adequate treatment because these forms of pain differ in their underlying mechanisms and therefore in their response to different drugs. Chronic pain with neuropathic characteristics presents a significant challenge as it is often unresponsive to conventional analgesics. The correct diagnosis and early management of peripheral neuropathic pain not only improve health-related outcomes, but also yield significant cost benefit to society.

Turnover Flap of External Rectus Sheath as Autologous Graft for Correction of Scrotal Hernia in Rams

The aim of this study was to evaluate the outcomes of external rectus sheath (ERF) turnover flap with and without platelet-rich plasma (PRP) for reconstruction of large scrotal hernia in ram. Thirteen baladi rams suffered from large sized unilateral voluminous scrotal swelling were used in this study. All rams were randomly divided into two groups according to the type of surgical interference; group ERF (n=6) were subjected to surgical correction by external rectus sheath turnover flap and group ERF-PRP (n=7) were subjected to surgical correction by ERF with PRP. The scrotal hernia was successfully reduced, and the graft turnover procedure was easily carried out in all rams in both groups. Clinical assessment of pain and heat in ERF-PRP depicted the lowest score at all time points compared to ERF group. Hematological analyses showed significant changes in white blood cells (WBCs), neutrophil, lymphocytes, eosinophils, basophils count, serum amyloid A (SAA) , haptoglobin (Hp), tumor necrosis factor-α (TNF-α) and interlukin-1β (IL-1β) in ERF-PRP group (lower) when compared to ERF group at days 3 and 7. Ultrasonographic examination of all rams in the ERF and ERF-PRP groups showed that the graft was secure and correctly positioned. Ultrasound color doppler recorded higher vascularity in ERF-PRP in the form of a high-color signal at lateral margin of turnover flap at days 7, 21 and 35-days post-operative. Conclusively, autologous grafting with external rectus sheath flap with PRP, is a simple procedure, with low cost, fewer adhesion and no short-term complications.

Neuropathic pain screening for diabetes mellitus: a conceptual analysis

ABSTRACT BACKGROUND AND OBJECTIVES: The assessment and early diagnosis of neuropathic pain associated to Peripheral Diabetic Neuropathy has been a challenge in clinical practice, requiring the systematization of risk tracking through the identification of specific instruments to guide treatment. The objective of this study was to identify specific instruments for tracking neuropathic pain and Peripheral Diabetic Neuropathy in order to build a protocol. CONTENTS: Integrative review using the indexed databases Scielo, Cochrane and Pubmed between 2007 and 2020, identifying the most used validated instruments in high predictive value for tracking Peripheral Diabetic Neuropathy and neuropathic pain, building a specific protocol directing clinical treatment. 44 selected articles pointed out 14 different instruments for screening of Peripheral Diabetic Neuropathy and neuropathic pain, most prevalent being: the Screening Instrument for Assessment of Peripheral Diabetic Neuropathy (MNSI), Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) and Douleur Neuropathique (DN4) for clinical assessment of neuropathic pain and Brief Pain Inventory (BPI) for numerical pain assessment, highlighted by their predictive values above 80%. CONCLUSION: Such instruments enable the development of a neuropathic pain screening protocol that will assist in the early diagnosis of this complication in Diabetes, directing clinical and physiotherapeutic treatment.

Clinical Pain Assessment Scoring Systems and Practice Essentials in Acute and Chronic Pain

Clinical Pain Assessment Scoring Systems and Practice Essentials in Acute and Chronic Pain

Differences and similarities among questionnaires to assess pain status in chronic widespread pain population: a quantitative analysis.

In clinical practice, multiple questionnaires are often used as part of the diagnosis of chronic widespread pain. Body Surface Area (BSA), Visual Analogue Scale (VAS), Fibromyalgia Diagnostic Criteria (FDC) and Central Sensitization Inventory (CSI) have all been used as screening tools to assess pain status in individuals with widespread pain. However, substantial overlap can be observed among these commonly employed questionnaires. This study aimed to quantitatively determine the most independent and dependent clinical characteristics obtained through these questionnaires and to examine potential redundancies. Seventy-nine participants with widespread pain, 61 females and 18 males, from a chronic pain outpatient clinic were recruited. The FDC, BSA, VAS and the CSI were measured for all participants. A principal component analysis (PCA) using a varimax rotation was used to determine which clinical measures represented separate constructs of widespread pain. This was followed by a regression analysis to assess redundancy between the constructs and related pain characteristics. The identified three-component PCA solution was characterized by (1) the FDC and CSI score, (2) the VAS score and (3) the BSA score. This indicates that the BSA and the VAS scores capture independent patient information. From the regression analysis, the FDC and CSI scores shared approximately 80% of the variance, indicative of substantial overlap between scores. Our findings demonstrated that BSA and VAS scores were independent clinical measures of widespread chronic pain, while the FDC and CSI scores were not independent, were highly correlated and provided redundant information. Clinicians should continue using both the BSA and VAS; however, either only FDC or CSI will be beneficial during clinical assessment of widespread chronic pain.

Pressure Algometry for the Detection of Mechanical Nociceptive Thresholds in Horses.

Simple SummaryIt is difficult to measure pain in horses. As animals are not able to verbalize what they feel, we are left with trying to interpret the different signs that they display when they are in pain. Many of these signs are vague (e.g., not eating their food), but some are more readily identified if the animal moves away or lifts their leg when pressure is applied to a sensitive area. Pressure algometry is a tool used to detect responses to applied mechanical stimuli within painful and nonpainful tissues. Pressure algometry has been used in many different studies, but there is no consensus on how to synthesize this information to better diagnose and treat pain in horses. The purpose of this study was to summarize the results of these studies. Based on that review, we conclude that there is good evidence that pressure algometry is a reliable and objective method to measure pain responses. This information will help to improve the diagnosis and treatment of pain in horses.The clinical assessment of pain is subjective; therefore, variations exist between practitioners in their ability to identify and localize pain. Due to differing interpretations of the signs or severity of pain equine practitioners may assign varying levels of clinical significance and treatment options. There is a critical need to develop better tools to qualify and quantify pain in horses. Palpation is the most common method to detect local tenderness or sensitivity. To quantify this applied pressure, pressure algometry has been used to gradually apply pressure over specified landmarks until an avoidance response is noted, which is defined as the mechanical nociceptive threshold (MNT). Numerous studies have used pressure algometry in different applications to measure MNTs in horses. There is an acute need to establish normative values within different body regions and to develop standardized methods of testing MNTs to better guide practitioners in the diagnosis and treatment of pain. The aim of this systematic review was to summarize the evidence for the use of pressure algometry in horses. There is good evidence that pressure algometry is a repeatable, semi-objective method that can be used in a wide array of clinical and research applications to assess MNTs in horses.

Enforcing Multilabel Consistency for Automatic Spatio-Temporal Assessment of Shoulder Pain Intensity.

The standard clinical assessment of pain is limited primarily to self-reported pain or clinician impression. While the self-reported measurement of pain is useful, in some circumstances it cannot be obtained. Automatic facial expression analysis has emerged as a potential solution for an objective, reliable, and valid measurement of pain. In this study, we propose a video based approach for the automatic measurement of self-reported pain and the observer pain intensity, respectively. To this end, we explore the added value of three self-reported pain scales, i.e., the Visual Analog Scale (VAS), the Sensory Scale (SEN), and the Affective Motivational Scale (AFF), as well as the Observer Pain Intensity (OPI) rating for a reliable assessment of pain intensity from facial expression. Using a spatio-temporal Convolutional Neural Network - Recurrent Neural Network (CNN-RNN) architecture, we propose to jointly minimize the mean absolute error of pain scores estimation for each of these scales while maximizing the consistency between them. The reliability of the proposed method is evaluated on the benchmark database for pain measurement from videos, namely, the UNBC-McMaster Pain Archive. Our results show that enforcing the consistency between different self-reported pain intensity scores collected using different pain scales enhances the quality of predictions and improve the state of the art in automatic self-reported pain estimation. The obtained results suggest that automatic assessment of self-reported pain intensity from videos is feasible, and could be used as a complementary instrument to unburden caregivers, specially for vulnerable populations that need constant monitoring.

Pancreatic QST Differentiates Chronic Pancreatitis Patients into Distinct Pain Phenotypes Independent of Psychiatric Comorbidities

Quantitative sensory testing (QST) has been previously used to study pain in chronic pancreatitis (CP) but included methods that are not suitable for clinical purposes. The aims of this study were to determine if pancreatic QST (P-QST) can differentiate patients into distinct pain phenotypes and to determine the association of these with their clinical pain and psychiatric comorbidities. A multicenter cross-sectional study was conducted where patients completed validated questionnaires assessing quality of life (QoL), depression and anxiety scores as well as clinical pain symptoms followed by P-QST which included a cold pressor test, repetitive pinprick stimuli and pressure stimulation of the upper abdominal (T10) and control dermatomes. P-QST categorized patients into pain phenotypes based on a previously established nomogram. QoL, clinical pain and psychiatric assessment scores were compared across these groups. A total of 179 patients were enrolled with a mean age of 54.1±13.6 years among whom 59% were males and 42% had an alcoholic etiology. P-QST showed no hyperalgesia in 91 (51%), segmental hyperalgesia in 50 (28%) and widespread hyperalgesia in 38 (21%) patients. Patients with widespread hyperalgesia had significantly higher pain intensity scores (P= .03) and rates of constant pain (P= .002) as well as decreased QoL (P < .001) and physical functioning (P=.03) in comparison with the other two pain phenotypes. In contrast, psychiatric comorbidities were similar across all groups. P-QST may serve as a novel unbiased pain assessment tool in CP as it categorizes patients into distinct pain phenotypes independent of their psychiatric comorbidities.