Subjective Reports Of Pain Research Articles

A Utilization Review of Patients That Respond to Low-Dose Naltrexone (LDN) for Chronic Pain at a Single Institution

Studies have demonstrated the benefits of LDN for various pain indications. This review describes the utilization of and response to LDN in patients with chronic pain within the William S. Middleton Memorial Veterans Hospital (Madison VA). This was a retrospective, single center, chart review of patients that were prescribed LDN for chronic pain. The primary outcome, change in subjective pain report via numeric rating scale (NRS), was analyzed through Wilcoxon Signed Rank Test and descriptive statistics. A total of 136 participants were included. Patients had an average pain score of 7.1 per NRS at baseline. At the initial follow up visit, participants had an average pain of 6.4 (p < 0.001). Additionally, 17.1% of patients had a greater than or equal to 30% pain reduction from baseline. At subsequent follow up, patients reported an average pain of 5.5 (p < 0.0001) per NRS. At the end of the study, 31.6% of patients were maintained on LDN at an average dose of 3.8 mg. This retrospective review demonstrated that LDN may be an effective modality for some chronic pain indications. Reported pain scores were significantly lower at initial follow up compared to baseline for the total population, and for patients with fibromyalgia (FM) specifically.

The effects of neck exercise in comparison to passive or no intervention on quantitative sensory testing measurements in adults with chronic neck pain: A systematic review.

Previous systematic reviews have identified the benefits of exercise for chronic neck pain on subjective reports of pain, but not with objective measures such as quantitative sensory testing (QST). A systematic review was conducted to identify the effects of neck specific exercise on QST measures in adults with chronic neck pain to synthesise existing literature and provide clinical recommendations. The study protocol was registered prospectively with PROSPERO (PROSPERO CRD42021297383). For both randomised and non-randomised trials, the following databases and trial registries were searched: AMED, CINAHL, Embase, Google Scholar, Medline, PEDro, PubMed, Scopus, SPORTDiscus, Science Citation Index and Social Science Citation Index from Web of Science Core Collection, clinicaltrials.gov, GreyOpen, and ISRCTN registry. These searches were conducted from inception to February 2022 and were updated until September 2023. Reference lists of eligible studies were screened. Study selection was performed independently by two reviewers, with data extraction and quality appraisal completed by one reviewer and independently ratified by a second reviewer. Due to high heterogeneity, narrative synthesis was performed with results grouped by exercise type. Three trials were included. Risk of bias was rated as moderate and the certainty of evidence as low or moderate for all studies. All exercise groups demonstrated statistically significant improvement at an intermediate-term follow-up, with progressive resistance training combined with graded physical training demonstrating the highest certainty of evidence. Fixed resistance training demonstrated statistically significant improvement in QST measures at a short-term assessment. Fixed resistance training is effective for short-term changes in pain sensitivity based on low-quality evidence, whilst moderate-quality evidence supports progressive resistance training combined with graded physical training for intermediate-term changes in pain sensitivity.

The Effect of Singular Nonverbal Behaviours of Experimenters on Pain Reports.

Studies suggest facial expressions of caregivers may be important in placebo effects; however, this has not been systematically tested. This experiment investigated the effects of caregivers' singular positive nonverbal behaviours (NBs) on pain reports. Fifty-one males and 53 females (total of 104) participants were randomized to four groups that were displayed positive facial expressions, tone of voice, body movement, or neutral NBs of videotaped experimenters. Subjective reports of pain, stress, arousal, and cardiac activity were obtained in a pre-test, a conditioning phase, and at a post-test. Four minutes of heat pain was induced in each test, and a placebo cream was administered before the conditioning and post-test in all groups. There were no differences between the NB groups in the reduced pain. Males had larger reduction in pain in the post-test, and females had lower arousal than the opposite sex. During the conditioning, females had larger reduction in pain ie, unconditioned pain response (UPR). In females, the UPR predicted the reinforced expectation ie, increase in expectations from conditioning to post-test, and fear of minor pain negatively predicted both the UPR and reinforced expectation. Singular NBs of caregiver were weak to enhance placebo effects. Females had lower pain during conditioning, and the UPR amplitude in females was associated with positive expectations. Moreover, for females, fear of minor pain weakened the UPR and expectations of cream. No NB of caregivers is more effective in reducing pain. Caregivers' NBs are less effective when displayed individually. Males and females may be different in underlying mechanisms of placebo effects.

Management of Superficial and Deep Peroneal Nerve Neuromas with Targeted Muscle Reinnervation in Nonamputees: Operative Technique and Early Outcomes.

Targeted muscle reinnervation (TMR), a surgical technique developed by the senior authors that coapts proximal ends of nerves to distal motor nerves of adjacent muscles, has demonstrated efficacy in the treatment and prevention of neuroma pain. The objective of this study is to describe the surgical technique for TMR of the superficial peroneal nerve (SPN) and deep peroneal nerve (DPN) in nonamputee patients and provide data on postoperative functional outcomes. A single-institution retrospective chart review was performed between March 2018 and April 2021. Patients were de-identified and included if they were nonamputees receiving TMR for pain in the peroneal nerve distribution. Data extracted included demographic information, symptoms before operation, relevant nerve coaptation, peri-, and postoperative complications, and long-term functional outcomes. Of the 19 patients reviewed, 11 patients underwent TMR of the SPN alone: eight had complete resolution of their symptoms; two indicated partial improvement in pain; and one patient had no improvement. Four patients underwent TMR of the DPN alone: two patients had complete resolution of their pain, and two patients had partial improvement with pain. Four patients underwent TMR of both the SPN/DPN: two patients had complete resolution of their symptoms, and two patients were noted to have significant improvement but had persistent pain from prior foot operations. Average follow-up time was 260 days. TMR is a successful technique in the management of SPN and DPN neuroma pain. Our technique revealed excellent clinical outcomes, no procedure-specific complications, and improved subjective pain reports.

Pain severity scale: A methodology for classifying postoperative pain severity by surgical procedure

BackgroundAcute postoperative pain is common following many types of surgery, and a significant subset of patients experience severe pain, which can be difficult to manage and result in postoperative complications. Opioid agonists are commonly used to treat severe postoperative pain, but their use has been associated with adverse outcomes. This retrospective study uses data from the Veterans Administration Surgical Quality Improvement Project (VASQIP) database to develop a postoperative Pain Severity Scale (PSS) based on subjective pain reports and postoperative opioid requirements. MethodsPostoperative pain scores and opioid prescription data were extracted from the VASQIP database for surgeries occurring between 2010 and 2020. Procedures were grouped by surgical Common Procedural Terminology (CPT) codes, and a total of 165,321 surgical procedures were examined, representing 1141 distinct CPT codes. K-means clustering analysis was used to group the surgeries based on 24-h maximum pain, 72-h average pain, and postoperative opioid prescriptions. ResultsK-means clustering analysis showed two optimal grouping strategies; one with 3 and the other with 5 groups. Both clustering strategies produced a PSS that categorized surgical procedures with generally increasing pain scores and opioid requirements. The 5-group PSS accurately captured typical postoperative pain experience across a range of procedures. ConclusionsK-means clustering produced a Pain Severity Scale that can distinguish typical postoperative pain for a large variety of surgical procedures based on subjective and objective clinical data. The PSS will facilitate research into the optimal postoperative pain management and could be used in the development of clinical decision support tools.

Does past/current pain change pain experience? Comparing self-reports and pupillary responses.

For decades, a substantial body of research has confirmed the subjective nature of pain. Subjectivity seems to be integrated into the concept of pain but is often confined to self-reported pain. Although it seems likely that past and current pain experiences would interact and influence subjective pain reports, the influence of these factors has not been investigated in the context of physiological pain. The current study focused on exploring the influence of past/current pain on self-reporting and pupillary responses to pain. Overall, 47 participants were divided into two groups, a 4°C-10°C group (experiencing major pain first) and a 10°C-4°C group (experiencing minor pain first), and performed cold pressor tasks (CPT) twice for 30 s each. During the two rounds of CPT, participants reported their pain intensity, and their pupillary responses were measured. Subsequently, they reappraised their pain ratings in the first CPT session. Self-reported pain showed a significant difference (4°C-10°C: p = 0.045; 10°C-4°C: p < 0.001) in the rating of cold pain stimuli in both groups, and this gap was higher in the 10°C-4°C group than in the 4°C-10°C group. In terms of pupillary response, the 4°C-10°C group exhibited a significant difference in pupil diameter, whereas this was marginally significant in the 10°C-4°C group (4°C-10°C: p < 0.001; 10°C-4°C: p = 0.062). There were no significant changes in self-reported pain after reappraisal in either group. The findings of the current study confirmed that subjective and physiological responses to pain can be altered by previous experiences of pain.

Sex-Based Differences in Adult ACL Reconstruction Outcomes.

In the setting of ever improving outcomes following anterior cruciate ligament (ACL) reconstruction, both objectively and subjectively, there remains continued interest in better understanding the differences in outcomes between male and female patients. The current review investigates the recent literature surrounding the roles of biological sex in adult ACL reconstruction outcomes. Within the past five years, the most prominent and recurrent difference between male and female patient cohorts is the subjective report of pain and function. Female patients have been consistently shown to have worse self-reported outcomes following ACL reconstruction. Specific and quantifiable subjective outcomes that are highlighted include the International Knee Documentation Committee (IKDC) subjective score, the Knee injury and Osteoarthritis Outcome Score (KOOS), and patient-acceptable symptom state (PASS). Current research on the topic of biological sex-based differences in ACL reconstruction outcomes can be divided into four main categories: patient-reported subjective outcomes; physical assessment and gait analysis; kinematics; and rates of reinjury, revision, and contralateral reconstruction. This chapter provides a summary of recent literature focused on these four main areas of interest related to ACL reconstruction outcomes in males and females.

Use of Scheduled Nonopioid Analgesia to Decrease Inpatient Opioid Consumption After Scheduled Cesarean Birth

ObjectiveTo compare opioid use and pain scores in women who had scheduled cesarean birth before and after implementing a scheduled nonopioid analgesia practice guideline. DesignQuality improvement project with a comparison of pre-/postintervention. Setting/Local ProblemA 170-bed community hospital where the administration of postcesarean pain medications was unstandardized. ParticipantsConvenience sample of 175 individuals who were scheduled for cesarean birth (106 in preintervention group and 69 in postimplementation group). Intervention/MeasurementsAll participants had received a dose of 150 mcg of intrathecal morphine intraoperatively. Care of participants in the postimplementation group included a new practice guideline using preoperative oral acetaminophen 1 g and postoperative intravenous ketorolac 30 mg that transitioned to ibuprofen 600 mg orally every 6 hours until discharge. Acetaminophen 1 g every 6 hours also continued until discharge. For breakthrough pain, oxycodone 5 mg to 10 mg was available. ResultsResults were analyzed using the chi-square and t test. There was a statistical difference in the mean milligram morphine equivalent consumed after scheduled cesarean birth (preintervention = 21.15 vs. postintervention = 3.91, p < .001). Postimplementation, 84.1% of participants did not consume any opioids beyond the intrathecal dose compared to 47.2% of participants preintervention. Mean pain scores decreased from 2.49 to 1.62 (p < .001), and there was an observed decrease of the highest reported pain score from 5.39 to 4.03 (p < .001). ConclusionThe results of this project support the current literature indicating that the administration of a scheduled nonopioid multimodal analgesia regimen to individuals with scheduled cesarean birth is an effective postoperative pain management strategy. This approach to managing surgical birth pain can decrease subjective reports of pain and overall opioid consumption during the hospital stay.

The effect of phasic versus combined neuromuscular electrical stimulation using the StimaWELL 120MTRS system on multifidus muscle morphology and function in patients with chronic low back pain: a randomized controlled trial protocol

BackgroundNeuromuscular electrical stimulation (NMES) is used to improve muscle strength clinically when rehabilitating various musculoskeletal disorders. However, the effects of NMES on muscle morphology and function in individuals with non-specific chronic low back pain (CLBP) have scarcely been investigated. Although research links deficits in the paraspinal musculature with subjective reports of pain and disability, it is unknown if treatment with NMES can help reverse these deficits. Therefore, the primary aim of this study is to compare the effects of two muscle therapy protocols with a medium-frequency electrotherapy device (the StimaWELL 120MTRS system) on multifidus muscle morphology and function in CLBP patients. The secondary aims are to determine the effects of these protocols subjective reports of pain intensity, pain interference, disability, and catastrophizing.MethodsA total of 30 participants with non-specific CLBP, aged 18–60, will be recruited from local orthopedic clinics and databases. Participants will be randomized (1:1) to either the phasic or combined (phasic + tonic) muscle therapy protocols on the StimaWELL 120MTRS system. Participants will undergo 20 supervised electrotherapy treatments over a 10-week period. The primary outcomes will be multifidus morphology (e.g. cross-sectional area (CSA), fat infiltration) and function (e.g., contraction measured via %thickness change from a rested to contracted state, and stiffness at rest and during contraction). Secondary outcomes will include pain intensity, interference, disability, and catastrophizing. Both primary and secondary outcomes will be obtained at baseline and at 11-weeks; secondary outcomes measured via questionnaires will also be obtained at 6-weeks, while LBP intensity will be measured before and after each treatment. Paired t-tests will be used to assess within-group changes for all primary outcome measures. A two-way repeated-measures analysis of variance will be used to assess changes in secondary outcomes over time.DiscussionThe results of this trial will help clarify the role of medium-frequency NMES on lumbar multifidus morphology and function.Trial RegistrationNCT04891692, registered retrospectively on May 18, 2021.

Hip Pain in Nonambulatory Children with Type-I or II Spinal Muscular Atrophy

Background:The purpose of the present study was to define the prevalence of hip pain in nonambulatory children with spinal muscular atrophy (SMA) (type I or II) treated with aggressive medical management, prior to widespread use of disease-modifying therapies (DMTs).Methods:A retrospective chart review (1993 to 2017) was performed on children diagnosed with SMA to identify subjective reports of hip pain and associated interventions, while radiographs were evaluated to assess hip instability and spinal deformity.Results:Seventy-two patients (33 with type I and 39 with type II) met the inclusion criteria. Hip pain was more frequent in type-II SMA (49% versus 12%; p = 0.001). Seventeen percent of the patients with 2 copies of the SMN2 (survival motor neuron 2) gene, 53% of patients with 3 copies, and 1 of the 2 patients with 4 copies reported hip pain. Nearly all patients had abnormal findings on hip radiographs made at the onset of pain or at the latest follow-up; however, no patient with type-I and 18% of those with type-II SMA had pain that was severe enough to undergo invasive intervention (p = 0.01). The intervention reduced the pain in most of those patients but completely eliminated it in only 1 patient. No significant differences were found with respect to the mean age at the onset of scoliosis, the mean age at the time of scoliosis surgery, or whether insertion of growing rods or posterior spine fusion was performed between those with and without hip pain requiring invasive treatment.Conclusions:This study is, to our knowledge, the largest investigation to date to assess hip pain among nonambulatory children with type-I or type-II SMA and suggests that symptoms rather than radiographs be utilized to direct care. These data will be crucial in assessing any effects that the new DMTs have on the natural history of hip pathology and pain in nonambulatory patients with SMA.Level of Evidence:Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Reliabilities of mean and variability of ambulatory pain among community dwelling older adults

Individual’s pain experiences vary substantially over time periods, and the variability in pain may be an important metric to predict health consequences. However, research on its reliability is lacking among older adults. We aimed to examine the reliabilities of both intra-individual mean (IIM) and intra-individual variability (IIV) of subjective pain reports assessed using ecological momentary assessments (EMA) among racially diverse, community dwelling older adults. Participants were from the Einstein Aging Study (N=311, age=70-91) and completed a 14-day EMA protocol which included self-reports of pain intensity 6 times a day. Pain IIV was quantified using intraindividual standard deviation (iSD). We followed Wang and Grimm(2012)’s approach to calculate the reliability of IIM and IIV. Over a 2-week period, we found excellent reliabilities for both pain IIM (.99) and pain IIV (.91), showing that these measures are reliable and can be used to link with various health outcomes among community dwelling older adults. We also estimated the average number of assessments that produce acceptable levels of reliability. The average of 2 assessments for pain IIM and 23 assessments for pain IIV produced values that exceeded reliability score of .80, suggesting that a briefer study design may be used to reduce participants’ burden with reliable pain metrics. Future studies need to examine whether pain IIV is associated with cognitive, emotional, and physical health among older adults and whether intervention studies that target to reduce pain IIV improve health consequences.

Relationship Between Pitch Volume and Subjective Report of Injury in High School Female Fast-Pitch Softball Pitchers.

The relationship between pitch volume and injury is well-represented within baseball literature. However, the impact of softball pitch volume on injury epidemiology is limited. The purpose was to determine if increased pitch volumes in high school-aged softball pitchers are related to increased rates of subjectively reported pain/injury. We hypothesized that pitchers with increased volumes would have higher pain/injury rates. Cross-sectional study. Level 4. A total of 28 female softball pitchers (aged 14-18 years) completed an online survey of questions pertaining to pitching history, pitch volume, and subjective report of pain or injury in the back, shoulder, and elbow. An independent-samples t test was used to (1) compare pitch volumes in those who reported pain in individual body regions (shoulder, elbow, back) compared with those who did not; (2) compare pitch volumes in those who reported pain in 0 or 1 of the regions of interest compared with 2 or 3 regions; and (3) compare the reported percentage of the past year that players reported playing through pain in players who averaged >85 compared with <85 pitches per game. Chi-square analysis was used to compare those who pitched either >85 or <85 pitches per game with regard to frequency of shoulder pain, elbow pain, back pain, seeking of medical attention, and actual injury diagnosis. Type I error was set at α = 0.05. Weekly and yearly pitch counts were higher in those reporting pain or injury (YES) than those who did not (NO) in the shoulder (pitches per week: NO = 219 ± 35; YES = 429 ± 101; P = 0.027) (pitches per year: NO = 8876 ± 946; YES = 19,195 ± 4944; P = 0.022) and back (pitches per week: NO = 188 ± 16; YES = 426 ± 90; P = 0.014) (pitches per year: NO = 8334 ± 793; YES = 18,252 ± 4340; P = 0.027). Similar results were observed for those with pain or injury reported in 2 or 3 regions compared with 0 or 1 regions (pitches per week: NO = 220 ± 38; YES = 414 ± 95; P = 0.039) (pitches per year: NO = 8765 ± 1010; YES = 18,661 ± 4623; P = 0.028). Those reporting shoulder pain or injury also reported higher pitch counts per game (NO = 71.4 ± 5.2; YES = 83 ± 4; P = 0.049), and those reporting back pain also reported playing more games per week (NO = 2.7 ± 0.2; YES = 5.2 ± 1.1; P = 0.034). Those with pitch counts of >85/game were more than twice as likely to see a physician regarding pain/injury (P = 0.027) and reported playing through pain a higher percentage of the year (>85, 49.3% ± 10%; <85, 25.2% ± 6%; P < 0.05). High pitching volumes commonly prevalent in high school-aged softball pitchers may be associated with increased pain/injury and appear related to cumulative volume. This study provides recommendations for cumulative pitch volume guidelines in softball pitchers.

Medical‐Surgical Patients’ and Registered Nurses’ Satisfaction and Comprehensiveness of Patient Assessment Using the Clinically Aligned Pain Assessment Tool

BackgroundThe pain experience is complex, and nurses are challenged to objectively assess and document patients’ subjective reports of pain. There is a clear need for an assessment tool that is easy to use and provides meaningful, actionable information for patients and nurses. AimsThis study explored nurses’ and patients’ satisfaction with the Clinically Aligned Pain Assessment (CAPA) as well as nurses’ charting. Setting and ParticipantsA convenience sample of adult patients and nurses on four medical-surgical units in one community hospital. MethodsA quantitative, two-group comparison design between patients and nurses using questionnaires to determine satisfaction and a retrospective chart review to determine comprehensiveness of nurse charting. ResultsNo significant differences existed between patients’ and nurses’ responses to seven of eight satisfaction questions The median score for seven of eight questions was 5 (using a 6-point Likert scale with 1 = strongly disagree and 6 = strongly agree), which demonstrated more than 80% agreement (somewhat agree, agree, strongly agree) among both groups that CAPA was superior to the NRS, based on individual responses. The one significant difference (p = 0.03) revealed patients were more likely to respond “agree or strongly agree” compared to nurses regarding the nurse thoroughly addressing patients’ needs using CAPA. Inter-rater reliability using CAPA was determined to be 89.5%, and a panel of clinical experts determined CAPA had strong content validity of 88.33%. In addition, 70.41% of nurses charted comprehensively using CAPA. ConclusionAs a result, CAPA was determined to be convenient, accurate, and valuable in guiding intervention decisions.

Effects of Exercise-induced Hypoalgesia and Its Neural Mechanisms.

Exercise-induced hypoalgesia is frequently documented in the literature. However, the underlying neural mechanism of this phenomenon remains unclear. Here, we explored the effects of different intensities of isometric exercise on pain perception with a randomized controlled design and investigated its neural mechanisms through tracing the dynamic changes of heat-evoked brain responses. Forty-eight participants were randomly assigned to one of the three groups with different exercise intensities (i.e., high, low, and control). Their subjective pain reports and brain responses elicited by heat stimuli before and after exercise were assessed. We observed 1) the increased pressure pain thresholds and heat pain thresholds on the dorsal surface of the hand and the biceps brachii muscle of the exercised limb (closed to the contracting muscle), and the decreased pressure pain ratings at the indexed finger of the unexercised limb; 2) more reduction of pain sensitivity on both the biceps brachii muscle and the dorsal surface of the hand induced by the high-intensity isometric exercise than the low-intensity isometric exercise; and 3) both the high-intensity and the low-intensity isometric exercise induced the reduction of N2 amplitudes and N2-P2 peak-to-peak amplitudes, as well as the reduction of event-related potential magnitudes elicited by the heat stimuli on the exercised limb. The hypoalgesic effects induced by the isometric exercise were not only localized to the moving part of the body but also can be extended to the distal part of the body. The exercise intensities play a vital role in modulating these effects. Exercise-induced hypoalgesia could be related to the modulation of nociceptive information transmission via a spinal gating mechanism and also rely on a top-down descending pain inhibitory mechanism.

Tooth movement, orofacial pain, and leptin, interleukin-1β, and tumor necrosis factor-α levels in obese adolescents.

To evaluate tooth movement, orofacial pain, and leptin, interleukin (IL)-1β, and tumor necrosis factor (TNF)-α cytokine levels in the gingival crevicular fluid (GCF) during orthodontic treatment in obese adolescents. Participants included adolescent patients aged 12-18 years: group 1, obese (n = 30), and group 2, nonobese controls (n = 30). They were evaluated before (T0) and after 1 hour (T1), 24 hours (T2), and 1 week (T3) of fixed appliance bonding. Periodontal examination (T0), collection of GCF (T1, T2, T3), and evaluation of Little's irregularity index (T0, T3) were performed, and a visual analog scale was used to measure pain (T1, T2, T3). Evaluation of IL-1β, TNF-α, and leptin cytokines was performed using a Luminex assay. Mann-Whitney and t-tests were used for intergroup comparisons, and a generalized estimating equation and cluster analyses were used for comparisons among observation times (P < .05). The obese group had a higher prevalence of probing depth of ≥4 mm and bleeding on probing. Orthodontic tooth movement was similar in both groups. Peak of pain was at T2 in both groups and was higher in the obese patients. TNF-α showed a slight increase at T1, followed by a gradual decrease at T2 and T3 in both groups. The obese group had a higher concentration of IL-1β before and during orthodontic treatment. There was no difference in tooth movement between obese and control patients during the first week of orthodontic treatment. Obese adolescents had a greater subjective report of orofacial pain after 24 hours of orthodontic treatment and higher concentrations of IL-1β proinflammatory cytokine before and during tooth movement as compared with nonobese control adolescents.

Buprenorphine blood concentrations: A biomarker for analgesia.

Opioids, the frontline drugs for postsurgical analgesia, have been linked to diversion and abuse with lethal consequences. The search for safe analgesics with less harm potential has been decades long. However, clinical trials for safe opioid and nonopioid analgesics have relied on subjective pain reports, which are biased by placebo effects that increase the complexity of trials to develop new therapies to manage pain. Research in opioid naïve animals and humans demonstrates that blood concentrations of opioids that effectively saturate the morphine opioid receptor are tightly linked with patient reports and quantitative sensory tests for analgesia. Opioid drug concentrations can predict clinical responses. This report reviews preclinical and clinical evidence correlating buprenorphine pharmacokinetics with analgesia. More than 30 years of data confirm buprenorphine blood concentrations can be an objective biomarker of analgesia for moderate to severe acute postoperative pain.

Words matter: Labelling, bias and stigma in nursing

Words matter: Labelling, bias and stigma in nursing

Whiplash injuries associated with experienced pain and disability can be visualized with [11C]-D-deprenyl positron emission tomography and computed tomography.

Knowledge of etiological mechanisms underlying whiplash-associated disorders is incomplete. Localisation and quantification of peripheral musculoskeletal injury and inflammation in whiplash-associated disorders would facilitate diagnosis, strengthen patients' subjective pain reports, and aid clinical decisions, all of which could lead to improved treatment. In this longitudinal observational study, we evaluated combined [11C]-D-deprenyl positron emission tomography and computed tomography after acute whiplash injury and at 6-month follow-up. Sixteen adult patients (mean age 33 years) with whiplash injury grade II were recruited at the emergency department. [11C]-D-deprenyl positron emission tomography and computed tomography, subjective pain levels, self-rated neck disability, and active cervical range of motion were recorded within 7 days after injury and again at 6-month follow-up. Imaging results showed possible tissue injuries after acute whiplash with an altered [11C]-D-deprenyl uptake in the cervical bone structures and facet joints, associated with subjective pain locale and levels, as well as self-rated disability. At follow-up, some patients had recovered and some showed persistent symptoms and reductions in [11C]-D-deprenyl uptake correlated to reductions in pain levels. These findings help identify affected peripheral structures in whiplash injury and strengthen the idea that positron emission tomography and computed tomography detectable organic lesions in peripheral tissue are relevant for the development of persistent pain and disability in whiplash injury.

Steady-State Cognitive Function and Pain Severity in Youth with Sickle Cell Disease

▪Introduction : In youth with sickle cell disease (SCD), vaso-occlusive crises are a major cause of morbidity and episodes of acute pain are among the most common manifestations of the disease. Previous studies in other chronic pain populations suggest that pain, as well as treatment for pain, impairs cognitive and neuropsychological functioning. In SCD, there have been studies examining the role of disease-related factors and disease severity, psychosocial and demographic factors, coping strategies and personality factors, and environmental factors on pain severity, but we are not aware of research investigating whether pain in SCD is related to baseline cognitive function. The goal of this study is to examine whether steady-state intellectual function, attention, and/or executive function differs in youth with SCD based on pain severity.Methods : Adolescents and young adults with SCD (N = 47) aged 17-24 years (M = 15.9, SD = 2.4); 57% male; 64% HbSS disease, completed a brief neuropsychological evaluation as part of their participation in one of several research studies, which included measures of intellectual function (WASI-II), attention (CPT-II), and executive function (D-KEFS Trail Making Test, Color Word Interference Test, Tower; WISC-IV Processing Speed Index and Working Memory Index). Those measures were collected at steady-state, when subjects were not experiencing pain or fever and were not taking medication for pain. Medical chart review was used to collect information about genotype and steady-state hemoglobin, as well as self-reported pain at each outpatient clinic visit (coded 1-5 at each) and number and length of hospitalizations for pain in the year prior to and the year following neuropsychological evaluation.Results :Chi square and linear correlation analyses found no significant relationships between number of admissions or mean pain report and age, gender, genotype, or mother's education. Two pain variables with 4 levels each were also constructed for analysis: Admissions for pain (ADM) and subjective Pain Report. Analysis of Variance (ANOVA) with each of 9 neuropsychological (NP) variables as outcomes found significant associations of ADM with cognitive inhibition (DKEFS Color Word Interference: Inhibition; p = .015) and PR with sustained attention/vigilance (CPT-II Hit RT Standard Error; p = .031). Linear correlations of actual number of admissions and mean pain score over all reports showed a significant negative correlation between admissions and cognitive inhibition. (r = -.428, p = .007).Conclusion :Results of this study suggest that poorer attention and executive functioning (inhibition) at baseline are associated with pain report or health utilization for pain in youth with SCD. There was no association with general intellectual function and these relationships were not accounted for by disease severity or demographic factors. These findings support the possibility that neuropsychological weaknesses unrelated to disease severity may place youth with SCD at risk for more severe subjective pain or for increased hospitalizations. This could be related to coping styles. Further study of neuropsychological risk factors associated with pain experience and health utilization in youth with SCD is warranted. DisclosuresNo relevant conflicts of interest to declare.

The Prediction of Acute Postoperative Pain Based on Neural Oscillations Measured before the Surgery.

Even with an improved understanding of pain mechanisms and advances in perioperative pain management, inadequately controlled postoperative pain remains. Predicting acute postoperative pain based on presurgery physiological measures could provide valuable insights into individualized, effective analgesic strategies, thus helping improve the analgesic efficacy. Considering the strong correlation between pain perception and neural oscillations, we hypothesize that acute postoperative pain could be predicted by neural oscillations measured shortly before the surgery. Here, we explored the relationship between neural oscillations 2 hours before the thoracoscopic surgery and the subjective intensity of acute postoperative pain. The spectral power density of resting-state beta and gamma band oscillations at the frontocentral region was significantly different between patients with different levels of acute postoperative pain (i.e., low pain vs. moderate/high pain). A positive correlation was also observed between the spectral power density of resting-state beta and gamma band oscillations and subjective reports of postoperative pain. Then, we predicted the level of acute postoperative pain based on features of neural oscillations using machine learning techniques, which achieved a prediction accuracy of 92.54% and a correlation coefficient between the real pain intensities and the predicted pain intensities of 0.84. Altogether, the prediction of acute postoperative pain based on neural oscillations measured before the surgery is feasible and could meet the clinical needs in the future for better control of postoperative pain and other unwanted negative effects. The study was registered on the Clinical Trial Registry (https://clinicaltrials.gov/ct2/show/NCT03761576?term=NCT03761576&draw=2&rank=1) with the registration number NCT03761576.