Pain Qualities Research Articles

(342) Measurement of affective, sensory and evaluative dimensions of pain using a Qualities-of-Pain Index (QPI)

Patients express painful experiences using affective and sensory descriptors, not just evaluative terms. Previously, we demonstrated the sensitivity of a qualities-of-pain index comparing the effects of 1 dose of a standard analgesic, hydrocodone 7.5 mg/acetaminophen 325 mg (HC/APAP) to placebo.1 To evaluate changes in these qualitative dimensions of pain over 48 hours, we augmented the design of an analgesic study2 with measurements of these other pain descriptors. After primary unilateral metatarsal bunionectomy, 302 qualifying patients aged ≥18 years with moderate-to-severe pain (on a numerical rating scale, PI-NRS) were randomized to CL-108 (HC/APAP with rapid-release promethazine 12.5mg) or placebo under double-blind conditions, 1 dose every 4–6 hours (up to 6 doses/24 hours). In addition to regularly-scheduled measurements on the PI-NRS, at baseline and 6, 12, 24, and 48 hours after treatment, patients used a separate 0–10 Likert scale in the QPI to rate each quality of pain: affective (annoying, agonizing) sensory (throbbing, heavy, swollen, tight, sharp, hot, pulling, stabbing, pressing, stinging, radiating) and evaluative (aching, hurting). Changes in QPI scores (the sum of all quality-of-pain scales) were compared for all patients regardless of baseline values. QPI scores for CL-108–treated patients were reduced compared with placebo over 24 hours (−45.8% vs −16.2%) and 48 hours (−55.0% vs −35.0%, both p≤0.004), correlating with results on the PI-NRS (both r>0.80, p<0.001). Compared with placebo, CL-108 also reduced the affective (−46.9% vs −14.0%), sensory (−43.4% vs −12.5%), and evaluative (−44.0% vs −17.3%) QPI sub-scores over 24 hours (all p<0.001). We conclude that the QPI is a sensitive indicator of changes in qualities of pain over 6–48 hours and that this instrument can be used to demonstrate the acute analgesic efficacy of opioid medications like CL-108. Funded by Charleston Laboratories, Inc., and Daiichi Sankyo, Inc. (1. Schachtel, J Pain, 2015 2. Richardson, J Pain, 2016)

Comparison of orofacial pain of patients with different stages of precancer and oral cancer

Orofacial pain impairs a patient's speech, swallowing, eating and interpersonal relations. Thirty-seven patients with a premalignant oral lesion, 124 patients with oral squamous cell carcinoma (OSSC), and 21 patients with a recurrence of OSSC were evaluated for their orofacial pain. The University of California San Francisco Oral Cancer Pain Questionnaire was administered to these patients at their initial visit, before they were prescribed analgesics for pain and before any treatment. Significant differences with respect to orofacial pain between the groups could be evaluatedwere observed. Patients with recurrence had the highest facial pain and patients with precancer had the lowest. Patients with OSSC and recurrence of OSSC reported significant levels of orofacial pain and functional restriction because of pain. Moreover, patients with recurrence of OSSC experienced significantly higher function-related pain, rather than pain qualities. These findings suggest that an important predictor for recurrence of OSSC may be the onset of orofacial pain that is exacerbated during function. The present study examined orofacial pain depending on the disease severity of precancer and oral cancer patients. Earlier recognition of symptoms of OSSC may improve early detection of its recurrence.

Assessment of Patient-Reported Outcome Instruments to Assess Chronic Low Back Pain.

To identify patient-reported outcome (PRO) instruments that assess chronic low back pain (cLBP) symptoms (specifically pain qualities) and/or impacts for potential use in cLBP clinical trials to demonstrate treatment benefit and support labeling claims. Literature review of existing PRO measures. Publications detailing existing PRO measures for cLBP were identified, reviewed, and summarized. As recommended by the US Food & Drug Administration (FDA) PRO development guidance, standard measurement characteristics were reviewed, including development history, psychometric properties (validity and reliability), ability to detect change, and interpretation of observed changes. Thirteen instruments were selected and reviewed: Low Back Pain Bothersomeness Scale, Neuropathic Pain Symptom Inventory, PainDETECT, Pain Quality Assessment Scale Revised, Revised Short Form McGill Pain Questionnaire, Low Back Pain Impact Questionnaire, Oswestry Disability Index, Pain Disability Index, Roland-Morris Disability Questionnaire, Brief Pain Inventory and Brief Pain Inventory Short Form, Musculoskeletal Outcomes Data Evaluation and Management System Spine Module, Orebro Musculoskeletal Pain Questionnaire, and the West Haven-Yale Multidimensional Pain Inventory Interference Scale. The instruments varied in the aspects of pain and/or impacts that they assessed, and none of the instruments fulfilled all criteria for use in clinical trials to support labeling claims based on recommendations outlined in the FDA PRO guidance. There is an unmet need for a validated PRO instrument to evaluate cLBP-related symptoms and impacts for use in clinical trials.

Measurement properties of painDETECT: Rasch analysis of responses from community-dwelling adults with neuropathic pain

BackgroundpainDETECT (PD-Q) is a self-reported assessment of pain qualities developed as a screening tool for pain of neuropathic origin. Rasch analysis is a strategy for examining the measurement characteristics of a scale using a form of item response theory. We conducted a Rasch analysis to consider if the scoring and measurement properties of PD-Q would support its use as an outcome measure.MethodsRasch analysis was conducted on PD-Q scores drawn from a cross-sectional study of the burden and costs of NeP. The analysis followed an iterative process based on recommendations in the literature, including examination of sequential scoring categories, unidimensionality, reliability and differential item function. Data from 624 persons with a diagnosis of painful diabetic polyneuropathy, small fibre neuropathy, and neuropathic pain associated with chronic low back pain, spinal cord injury, HIV-related pain, or chronic post-surgical pain was used for this analysis.ResultsPD-Q demonstrated fit to the Rasch model after adjustments of scoring categories for four items, and omission of the time course and radiating questions. The resulting seven-item scale of pain qualities demonstrated good reliability with a person-separation index of 0.79. No scoring bias (differential item functioning) was found for this version.ConclusionsRasch modelling suggests the seven pain-qualities items from PD-Q may be used as an outcome measure. Further research is required to confirm validity and responsiveness in a clinical setting.

Age-Related Patterns in Cancer Pain and Its Psychosocial Impact: Investigating the Role of Variability in Physical and Mental Health Quality of Life.

Age-related patterns in cancer pain remain equivocal. Most studies ignore heterogeneity across multiple domains of well-being, and the potential role of physical (PH) and mental health (MH) quality of life (QOL) in these age-related patterns is unknown. We investigated the relationships between age and cancer pain intensity, qualities, and interference, and physical and psychosocial adaptation and the interaction between age and PH and MH QOL on pain and adaptation to cancer pain. In this cross-sectional study, 244 patients with advanced cancer and pain completed measures of pain, QOL, physical function, and psychosocial well-being. Pearson's correlations and ANOVAs assessed relationships between age and demographic and clinical factors, pain, and physical and psychosocial measures. Regression models tested the role of age and its interaction with PH and MH QOL on pain and physical and psychosocial adaptation. Older age was associated with a lower likelihood of receiving an opioid prescription, greater likelihood of having comorbidities, and worse functional status. When we did not account for these factors, age was not associated with pain and most adaptation indices. When we did account for these factors and PH QOL, older age was associated with lower non-neuropathic and neuropathic pain and several indices of psychosocial adaptation. Most interestingly, older age was associated with lower non-neuropathic pain among those with high, but not low, MH QOL. This study addresses knowledge gaps about factors underlying age-related patterns in cancer pain. Impaired MH QOL may be a proxy for age-related patterns in cancer pain. This study investigated age-related patterns in the experience of cancer pain and the role of quality of life in resilience and vulnerability to pain and adaptation to pain. Older age is associated with lower non-neuropathic pain among those with high, but not low, mental health quality of life, suggesting that impaired mental health quality of life is an important indicator of vulnerability to multidimensional pain outcomes.

Reward, motivation, and emotion of pain and its relief.

The experience of pain depends on interpretation of context and past experience that guide the choice of an immediate behavioral response and influence future decisions of actions to avoid harm. The aversive qualities of pain underlie its physiological role in learning and motivation. In this review, we highlight findings from human and animal investigations that suggest that both pain, and the relief of pain, are complex emotions that are comprised of feelings and their motivational consequences. Relief of aversive states, including pain, is rewarding. How relief of pain aversiveness occurs is not well understood. Termination of aversive states can directly provide relief as well as reinforce behaviors that result in avoidance of pain. Emerging preclinical data also suggests that relief may elicit a positive hedonic value that results from activation of neural cortical and mesolimbic brain circuits that may also motivate behavior. Brain circuits mediating the reward of pain relief, as well as relief-induced motivation are significantly impacted as pain becomes chronic. In chronic pain states, the negative motivational value of nociception may be increased while the value of the reward of pain relief may decrease. As a consequence, the impact of pain on these ancient, and conserved brain limbic circuits suggest a path forward for discovery of new pain therapies.

Nociceptive and Neuropathic Pain Qualities in Men and Women with Acute Coronary Syndromes: A Complex Pain Presentation

Background: Cardiac pain arising from acute coronary syndrome (ACS) is a multi-factorial phenomenon. Historically, episodes of cardiac pain have been captured using a one-dimensional numeric pain rating scale. Lacking in clinical practice are acute pain assessments that employ a comprehensive evaluation of an emergent ACS episode. Aim: To examine the sensory-discriminative, motivational-affective and cognitive-evaluative dimensions of ACS-related pain. Methods: A descriptive-correlational, repeated-measure design was used to collect data on 121 ACS patients of their cardiac pain intensity. The (numeric rating scale-NRS 0-10 scale) measured chest pain “Now” and “Worst pain in the previous 2 hours over 8 hours” and the McGill Pain Questionnaire Short-Form (MPQ-SF) measured pain at 4 hours. Results: Mean age was 67.6 ± 13, 50% were male, 60% had unstable angina and 40% had Non-ST-elevation myocardial infarction. Cardiac pain intensity scores remained in the mild range from 1.1 ± 2.2 to 2.4 ± 2.7. MPQ-SF: 66% described pain as distressing and 26% reported pain was horrible or excruciating. Participants described ACS pain quality as acute injury (nociceptive pain: heavy, cramping, stabbing), as nerve damage (neuropathic: gnawing, hot-burning, shooting) and as a mixture of acute and chronic pain qualities (aching, tender and throbbing). Conclusions: Patients reported both nociceptive and neuropathic cardiac pain. It is unclear if pain perceptions are due to: i) pathophysiology of clot formation, ii) occurrence of a first or repeated ACS episode, or iii) complex co-morbidities. Pain arising from ACS requires an understanding of the interplay of ischemic, metabolic and neuropathophysiological mechanisms that contribute to complex cardiac pain experiences.

Central Pain in Patients with Multiple sclerosis

Central pain (CP) is little recognized and diagnosed type of pain in multiple sclerosis. Objective: This second part of our work related to pain in multiple sclerosis is concentrated on occurrence of CP and defined its characteristics. Methods: Questionnaires on pain were sent to 307 patients with definitive multiple sclerosis diagnose. Patients admitting to CP were examined with aim to diagnose CP. The dates were statistically processed. Results: Out of 220 responders 92% reported pain during the course of their multiple sclerosis. CP was found in 57.72%, including 40.91% with central neuropathic extremity and trunk pain (CNEP), 5.91% with trigeminal neuralgia (TN), and 33.18% with Lhermitte‘s sign (LS). In 28.8% of all patients, CP was an initial multiple sclerosis symptom. The prevalence of CP does not increase with age, disease duration, or the Expanded Disability Status Scale (EDSS). Lower extremities were the commonest location of CNEP (74.5%) and burning was the commonest painful sensation. Three and more concurrent unpleasant painful sensations experienced 68.9% of patients, which were in 46.7% located in the lower extremities. Three and more concurrent CP locations (including TN and LS) were reported by 89% of patients. Number of locations in CP increases significantly with age and EDSS, in contrast to group with nociceptive and peripheral neuropathic pain (n=113), where does not increase with age, EDSS and multiple sclerosis duration. The group with nociceptive and peripheral neuropathic pain featured significantly less patients with only one pain location (p=0.0269) and only one pain quality. In contrast to the other group, In CP increases significantly the number of patients with increase the number of concurrent pain qualities (p<0.0001). Conclusion: CP is not only a frequent complaint among persons with multiple sclerosis, but is a distinctive type of pain requiring special attention and their identification remains still the major challenge.

Pain extent and function in youth with physical disabilities

BackgroundThe aim of this study was to increase our understanding of the role that spatial qualities of pain (location and extent) play in functioning, among youths with disabilities and chronic pain.MethodsOne-hundred and fifteen youths (mean age 14.4 years; SD ±3.3 years) with physical disabilities and chronic pain were interviewed and were asked to provide information about pain locations and their average pain intensity in the past week, and to complete measures of pain interference, psychological function and disability. Most of the participants in this sample were males (56%), Caucasian (68%), and had a cerebral palsy (34%) or muscular dystrophy (25%) problem. Most participants did not report high levels of disability ( , SD ±9.5, range 0–60) or global pain intensity ( , SD ±2.4, range 0–10).ResultsPain at more than one body site was experienced by 91% of participants. There were positive associations between pain extent with pain interference (r = 0.30) and disability (r = 0.30), and a negative association with psychological function (r = –0.38), over and above average pain intensity. Additionally, pain intensity in the back (as opposed to other locations) was associated with more pain interference (r = 0.29), whereas pain intensity in the shoulders was associated with less psychological function (r = –0.18), and pain intensity in the bottom or hips was associated with more disability (r = 0.29).ConclusionThe findings support the need to take into account pain extent in the assessment and treatment of youths with physical disabilities and chronic pain, call our attention about the need to identify potential risk factors of pain extent, and develop and evaluate the benefits of treatments that could reduce pain extent and target pain at specific sites.

Impaired psychomotor ability and attention in patients with persistent pain: a cross-sectional comparative study.

Background and aimsPatients with pain have shown cognitive impairment across various domains. Although the pain qualities vary among patients, research has overlooked how cognitive performance is affected by the duration and persistence of pain. The current study sought to fill this gap by examining how qualitatively different pain states relate to the following cognitive functions: sustained attention, cognitive control, and psychomotor ability.Patients and methodsPatients with musculoskeletal pain in primary care were divided into three pain groups: acute pain (duration <3 months), regularly recurrent pain (duration >3 months), and persistent pain (duration >3 months). These groups were then compared with healthy controls. The MapCog Spectra Test, the Color Word Test, and the Grooved Pegboard Test were used to measure sustained attention, cognitive control, and psychomotor ability, respectively.ResultsPatients with persistent pain showed significantly worse sustained attention and psychomotor ability compared with healthy controls. The acute pain group showed a significant decrease in psychomotor ability, and the regularly recurrent pain group showed a significant decrease in sustained attention. These results remained unchanged when age, education, and medication were taken into account.ConclusionPersistent musculoskeletal pain seems to impair performance on a wider range of cognitive tasks than acute or regularly recurrent pain, using pain-free individuals as a benchmark. However, there is some evidence of impairment in psychomotor ability among patients with acute pain and some impairment in sustained attention among patients with regularly recurrent pain.ImplicationsCaregivers may need to adjust communication methods when delivering information to cognitively impaired patients.

Assessment of Somatosensory Function in Patients With Idiopathic Dry Eye Symptoms

Somatosensory dysfunction likely underlies dry eye (DE) symptoms in many individuals yet remains an understudied component of the disease. Its presence has important diagnostic and therapeutic implications. To assess the integrity of nociceptive system processes in persons with DE and ocular pain using quantitative sensory testing (QST) techniques applied at a site remote from the eye. A cross-sectional study conducted at Miami Veterans Affairs Hospital included 118 individuals with a wide variety of DE symptoms and signs. The study was conducted from October 31, 2013, to January 28, 2016. Individuals completed questionnaires regarding ocular symptoms (5-Item Dry Eye Questionnaire [DEQ5], Ocular Surface Disease Index [OSDI], and Neuropathic Pain Symptom Inventory modified for the eye [NPSI-E]), psychological status, and medication use and underwent an ocular surface examination. The QST metrics included measures of vibratory and thermal thresholds and cold and hot pain temporal summation (surrogate measures of central sensitization) on the forearm. Correlations among DE and ocular pain symptom severity with QST metrics measured on the forearm. The OSDI score ranges from 0 to 100, with 100 indicating the most severe DE symptoms. The DEQ5 score ranges from 0 to 22, with the highest score indicating the most severe symptoms, and the NPSI-E score ranges from 0 to 100, with the highest score indicating the most severe symptoms. Psychological state was measured with the 9-item Patient Health Questionnaire, the PTSD Checklist-Military Version for PTSD, and the Symptom Checklist-90 for anxiety. Of the 118 patients who participated in the study, 105 (88.9%) were men (mean [SD] age, 60 [10] years), and a mean of 41% had PTSD, 10% depression, and 0.93% anxiety. Using stepwise linear regression analyses, significant associations were identified between overall DE symptom severity and posttraumatic stress disorder scores and tear breakup time (DEQ5 model: R = 0.54; OSDI model: R = 0.61, P < .001). All other variables (ie, demographics, comorbidities, medications, tear film factors, and QST metrics) dropped out of these models. When specifically considering neuropathic-like qualities of DE pain, however, anxiety and hot pain temporal summation at the forearm explained 17% of the variability in ocular burning (R = 0.41; P < .001), and PTSD score, tear breakup time, and hot pain temporal summation at the forearm explained 25% of the variability in sensitivity to wind (R = 0.50; P < .001) and 30% of the variability in total NPSI-E scores (R = 0.55; P < .001). Our findings demonstrate that neuropathic-like DE pain symptom severity correlates with quantitative measures of pain sensitivity at a site remote from the eye. This result provides additional evidence that DE symptoms are not only manifestations of a local disorder but also involve somatosensory dysfunction beyond the trigeminal system.

Pain quality descriptors in community-dwelling older adults with nonmalignant pain.

This study aimed to characterize the prevalence of various pain qualities in older adults with chronic nonmalignant pain and determine the association of pain quality to other pain characteristics namely: severity, interference, distribution, and pain-associated conditions. In the population-based MOBILIZE Boston Study, 560 participants aged ≥70 years reported chronic pain in the baseline assessment, which included a home interview and clinic exam. Pain quality was assessed using a modified version of the McGill Pain Questionnaire (MPQ) consisting of 20 descriptors from which 3 categories were derived: cognitive/affective, sensory, and neuropathic. Presence of ≥2 pain-associated conditions was significantly associated with 18 of the 20 pain quality descriptors. Sensory descriptors were endorsed by nearly all older adults with chronic pain (93%), followed by cognitive/affective (83.4%) and neuropathic descriptors (68.6%). Neuropathic descriptors were associated with the greatest number of pain-associated conditions including osteoarthritis of the hand and knee. More than half of participants (59%) endorsed descriptors in all 3 categories and had more severe pain and interference, and multisite or widespread pain than those endorsing 1 or 2 categories. Strong associations were observed between pain quality and measures of pain severity, interference, and distribution (P < 0.0001). Findings from this study indicate that older adults have multiple pain-associated conditions that likely reflect multiple physiological mechanisms for pain. Linking pain qualities with other associated pain characteristics serve to develop a multidimensional approach to geriatric pain assessment. Future research is needed to investigate the physiological mechanisms responsible for the variability in pain qualities endorsed by older adults.

Assessment of Chronic Pain: Domains, Methods, and Mechanisms.

Accurate classification of chronic pain conditions requires reliable and valid pain assessment. Moreover, pain assessment serves several additional functions, including documenting the severity of the pain condition, tracking the longitudinal course of pain, and providing mechanistic information. Thorough pain assessment must address multiple domains of pain, including the sensory and affective qualities of pain, temporal dimensions of pain, and the location and bodily distribution of pain. Where possible, pain assessment should also incorporate methods to identify pathophysiological mechanisms underlying the pain. This article discusses assessment of chronic pain, including approaches available for assessing multiple pain domains and for addressing pathophysiological mechanisms. We conclude with recommendations for optimal pain assessment. Pain assessment is a critical prerequisite for accurate pain classification. This article describes important features of pain that should be assessed, and discusses methods that can be used to assess the features and identify pathophysiological mechanisms contributing to pain.

Intravenous immunoglobulin therapy for small fiber neuropathy: study protocol for a randomized controlled trial.

BackgroundSmall fiber neuropathy is the most common cause of neuropathic pain in peripheral neuropathies, with a minimum prevalence of 53/100,000. Patients experience excruciating pain, and currently available anti-neuropathic and other pain drugs do not relieve the pain substantially. Several open-label studies have suggested an immunological basis in small fiber neuropathy and have reported efficacy of treatment with intravenous immunoglobulin. Therefore, immunological mechanisms conceivably may play a role in small fiber neuropathy. To date, no randomized controlled study with intravenous immunoglobulin in patients with small fiber neuropathy has been performed.Methods/designThis study is a randomized, double-blind, placebo-controlled, clinical trial in patients with idiopathic small fiber neuropathy. The primary objective is to investigate the efficacy of intravenous immunoglobulin versus placebo on pain alleviation. A 1-point change in the PI-NRS compared to baseline is considered the minimum clinically important difference. In the IVIg-treated group, we assume a response rate of approximately 60 % based on the criteria composed by the IMMPACT group for measurement of pain. Based on this, a sample size of 60 patients is needed. Eligible patients fulfilling the inclusion/exclusion criteria will be randomized to receive either intravenous immunoglobulin or placebo (0.9 % saline). The treatment regimen will start with a loading dose of 2 g/kg body weight over 2–4 consecutive days, followed by a maintenance dose of 1 g/kg body weight over 1–2 consecutive days given three times at a 3-week interval. The primary endpoint is the comparison of the percentage of responder subjects between the two treatment groups from the first randomization during the 12 weeks of treatment. A responder is defined as ≥ 1-point Pain Intensity Numerical Rating Scale improvement on the mean weekly peak pain relative to baseline. The secondary outcomes are pain intensity, pain qualities, other small fiber neuropathy-related complaints, daily and social functioning, as well as quality of life. In addition, safety assessments will be performed for adverse events, vital signs, and laboratory values outside the normal range. Responders during the 12-week treatment period will be followed during a 3-month extension phase.DiscussionThis is the first randomized, double-blind, placebo-controlled clinical trial with intravenous immunoglobulin in patients with idiopathic small fiber neuropathy. Positive findings will result in a new treatment option for small fiber neuropathy and support an immunological role in this condition.Trial registrationClinicalTrials.gov, NCT02637700. Registered on 16 December 2015.Electronic supplementary materialThe online version of this article (doi:10.1186/s13063-016-1450-x) contains supplementary material, which is available to authorized users.

Creating a better picture of chronic pain: improving pain pictogram designs through systematic evaluation of user responses.

This article discusses the challenges of visually representing pain qualities in pictogram design. An existing set of 12 pictograms designed for people with literacy problems was evaluated to understand more about misunderstandings of pictogram interpretation. Two sets of university students from different disciplines were asked to interpret the pictograms, and a novel classification system was developed to categorise answer types, as 'location', 'affective', temporal' or 'literal'. Several design recommendations are made as a result that will help improve the design of pain pictograms as a whole as well as guide designers of related pictogram work. We demonstrate how, through the robust classification of incorrect responses, it is possible to extract useful comprehension error patterns to inform future design.

Three subgroups of pain profiles identified in 227 women with arthritis: a latent class analysis.

The objectives were to identify subgroups of women with arthritis based upon the multi-dimensional nature of their pain experience and to compare health and socio-demographic variables between subgroups. A latent class analysis of 227 women with self-reported arthritis was used to identify clusters of women based upon the sensory, affective, and cognitive dimensions of the pain experience. Multivariate multinomial logistic regression analysis was used to determine the relationship between cluster membership and health and sociodemographic characteristics. A three-class cluster model was most parsimonious. 39.5% of women had a unidimensional pain profile; 38.6% of women had moderate multidimensional pain profile that included additional pain symptomatology such as sensory qualities and pain catastrophizing; and 21.9% of women had severe multidimensional pain profile that included prominent pain symptomatology such as sensory and affective qualities of pain, pain catastrophizing, and neuropathic pain. Women with severe multidimensional pain profile have a 30.5% higher risk of poorer quality of life and a 7.3% higher risk of suffering depression, and women with moderate multidimensional pain profile have a 6.4% higher risk of poorer quality of life when compared to women with unidimensional pain. This study identified three distinct subgroups of pain profiles in older women with arthritis. Women had very different experiences of pain, and cluster membership impacted significantly on health-related quality of life. These preliminary findings provide a stronger understanding of profiles of pain and may contribute to the development of tailored treatment options in arthritis.

Characterising the Analgesic Effect of Different Targets for Deep Brain Stimulation in Trigeminal Anaesthesia Dolorosa

Background: Several deep brain stimulation (DBS) targets have been explored for the alleviation of trigeminal anaesthesia dolorosa. We aimed to characterise the analgesia produced from the periaqueductal grey (PAG) and centromedian-parafascicular (CmPf) nucleus using a within-subject design. Method: We report a case series of 3 subjects implanted with PAG and CmPf DBS systems for the treatment of anaesthesia dolorosa. At follow-up, testing of onset and offset times, magnitude, and thermal and mechanical sensitivity was performed. Results: The mean pain score of the cohort was acutely reduced by 56% (p < 0.05) with PAG and 67% (p < 0.01) with CmPf stimulation at mean time intervals of 38 and 16 min, respectively. The onset time was 12.5 min (p < 0.05) for PAG stimulation and 2.5 min (p < 0.01) for CmPf. The offset time was 2.5 min (p < 0.05) for PAG and 12.5 min (p < 0.01) for CmPf. The two targets were effective at different stimulation frequencies and were not antagonistic in effect. Conclusion: The mechanisms by which stimulation at these two targets produces analgesia are likely to be different. Certain pain qualities may respond more favourably to specific targets. Knowledge of onset and offset times for the targets can guide optimisation of stimulation settings. The use of more than one stimulation target may be beneficial and should be considered in anaesthesia dolorosa patients.

Comprehension of pictograms for pain quality and pain affect in adults with Down syndrome

ABSTRACTBackground Adults with Down syndrome (DS) are at risk for age-related painful physical conditions, but also for under-reporting pain. Pictograms may facilitate self-report of pain, because they seem suitable for the global visual processing in DS and for iconic representation of abstract concepts.Method Participants (N = 39, M age = 41.2) assigned pain qualities to pictograms, rated pain affect levels in facial scales (pictograms vs. drawn faces), and performed cognitive tests.Results Recognition of all intended pain qualities was above chance level. Pain affect levels of both facial scales were ordered equally well. Both facial scales were preferred equally well. Comprehension of the 3 scales was positively associated with mental age, receptive language ability, and verbal memory. Most participants (74%) had pictograms in their direct environment, mainly to communicate activities or objects.Conclusion Using pictograms may optimise communication about pain for a subgroup of cognitively higher functioning adults with DS.

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.

Who will benefit from surgical repair for painful varicocele: a meta-analysis.

To determine the efficacy of different surgical approaches and techniques for resolving varicocele-related pain and factors that predict surgical outcomes. The PubMed and Embase databases were searched with the terms "varicocele", "varicocelectomy" and "pain". Manual searches by reviewing the references of included studies were performed. Studies were included when they focused on the influence of varicocele grade, pain quality, different surgical approaches or techniques on pain resolution. A meta-analysis was conducted with RevMan5.3 software. Twelve studies were identified in the analysis. No significant correlation was found between varicocele grade and pain resolution (P>0.05). The resolution rate for dull pain was significantly higher than sharp pain [RR=1.11, 95% CI (1.02, 1.22), P=0.02], and there were no other significant differences between the qualities of pain and pain resolution. The pain resolution rate was significantly higher after subinguinal varicocelectomy than after high or inguinal varicocelectomy [RR=0.83, 95% CI (0.76, 0.90), P<0.00001 and RR=0.92, 95% CI (0.86, 0.99), P=0.02]. The pain resolution rate was significantly higher after microsurgery than after laparoscopic varicocelectomy [RR=0.77, 95% CI (0.60, 0.99), P=0.04]. Subinguinal varicocelectomy and microsurgical varicocelectomy are efficacious for resolving varicocele-related pain compared to other approaches and techniques. Pain quality is a factor that predicts surgical outcomes while varicocele grade is not. Additional controlled studies are warranted to clearly define this clinical problem.