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Global spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues unabated. Binding of SARS-CoV-2's Spike protein to host angiotensin converting enzyme 2 triggers viral entry, but other proteins may participate, including neuropilin-1 receptor (NRP-1). As both Spike protein and vascular endothelial growth factor-A (VEGF-A) – a pro-nociceptive and angiogenic factor, bind NRP-1, we tested if Spike could block VEGF-A/NRP-1 signaling. VEGF-A-triggered sensory neuronal firing was blocked by Spike protein and NRP-1 inhibitor EG00229. Pro-nociceptive behaviors of VEGF-A were similarly blocked via suppression of spontaneous spinal synaptic activity and reduction of electrogenic currents in sensory neurons. Remarkably, preventing VEGF-A/NRP-1 signaling was antiallodynic in a neuropathic pain model. A 'silencing' of pain via subversion of VEGF-A/NRP-1 signaling may underlie increased disease transmission in asymptomatic individuals.
Learn More >Self-efficacy, fear of movement, and depression may mediate the sequential pathway of how pain leads to disability in nonspecific low back pain. Participants with chronic (>13 weeks) non-specific low back pain were included. They were prospectively monitored for eight consecutive weeks. Each second day, all participants filled in a survey (30 surveys pp). Questionnaires on current back pain intensity (NRS) and disability (PDI) were completed in each survey. One out of three standardized questionnaires on self-efficacy (SES), fear of movement, kinesiophobia (TSK), or depression (PHQ-9) were randomly completed each time. Multilevel mediation analyses on the within-(temporal changes) and between-patients total and indirect (mediated by SES; TSK and PHQ-9) effect of pain on disability were conducted for three temporal associations: No time delay, Simple temporal delay, and Double delay. In total, 280 questionnaires were filled in by 10 participants (m = 4; 34.4 ± 12.2 years). A moderate to strong effect of pain on disability in the no delay-model for the within-patients (0.436), and (all models) in the between-patients (0.595-0.627) models was found. The way how pain affects kinesiophobia was influenced by the time passed. Kinesiophobia itself predicted disability. Further, depression was affected by (within and between) pain intensity (NRS). In the simple delay effects mediation, depression affects disability (within) and is itself affected by the pain (between). No indirect effect of self-efficacy, fear of movement and depression in the pain-disability relationship was found. Understanding underlying mechanisms of how and when pain leads to disability might help to find accurate measures in therapy setting.
Learn More >Neurological disorders account for a large and increasing health burden worldwide, as shown in the Global Burden of Diseases (GBD) Study 2016. Unpacking how this burden varies regionally and nationally is important to inform public health policy and prevention strategies. The population in the EU is older than that of the WHO European region (western, central, and eastern Europe) and even older than the global population, suggesting that it might be particularly vulnerable to an increasing burden of age-related neurological disorders. We aimed to compare the burden of neurological disorders in the EU between 1990 and 2017 with those of the WHO European region and worldwide.
Learn More >Improvements in pain management might be achieved by matching treatment to underlying mechanisms for pain persistence. Many authors argue for a mechanism-based classification of pain, but the field is challenged by the wide variation in the proposed terminology, definitions, and typical characteristics. This study aimed to (1) systematically review mechanism-based classifications of pain experienced in the musculoskeletal system; (2) synthesize and thematically analyze classifications, using the International Association for the Study of Pain categories of nociceptive, neuropathic, and nociplastic as an initial foundation; and (3) identify convergence and divergence between categories, terminology, and descriptions of each mechanism-based pain classification.
Learn More >To test the relationship between the supply of select nonpharmacologic providers (physical therapy (PT) and mental health (MH)) and use of nonpharmacologic services among older adults with a persistent musculoskeletal pain (MSP) episode.
Learn More >Aberrant functional connectivity of brain networks has been demonstrated in migraine sufferers. Functional magnetic resonance imaging (fMRI) may illustrate altered connectivity in patients suffering from migraine without aura (MwoA). Here, we applied a seed-based approach based on limbic regions to investigate disrupted functional connectivity between spontaneous migraine attacks. Resting-state fMRI data were obtained from 28 migraine patients without aura and 23 well-matched healthy controls (HC). The functional connectivity of the limbic system was characterized using a seed-based whole-brain correlation method. The resulting functional connectivity measurements were assessed for correlations with other clinical features. Neuropsychological data revealed significantly increased connectivity between the limbic system (bilateral amygdala and right hippocampus) and left middle occipital gyrus (MOG), and a positive correlation was revealed between disease duration and connective intensity of the left amygdala and the ipsilateral MOG. There was decreased functional connectivity between the right amygdala and contralateral orbitofrontal cortex (OFC). In addition, resting-state fMRI showed that, compared to HC, patients without aura had significant functional connectivity consolidation between the bilateral hippocampus and cerebellum, and a negative correlation was detected between scores on the headache impact test (HIT) and connectivity intensity of the right hippocampus and bilateral cerebellum. There was decreased functional connectivity between the left hippocampus and three brain areas, encompassing the bilateral inferior parietal gyri (IPG) and contralateral supplementary motor area (SMA). There were no structural differences between the two groups. Our data suggest that migraine patients have disrupted limbic functional connectivity to pain-related regions of the modulatory and encoding cortices, which are associated with specific clinical characteristics. Disturbances of resting-state functional connectivity may play a key role in neuropathological features, perception and affection of migraine. The current study provides further insights into the complex scenario of migraine mechanisms. .
Learn More >Chronic pelvic pain (CPP) affects a significant number of women worldwide. Internationally, people with endometriosis report significant negative impact across many areas of their life. We aimed to use an online survey using the EndoCost tool to determine if there was any difference in the impact of CPP in those with vs. those without a confirmed diagnosis of endometriosis, and if there was any change in diagnostic delay since the introduction of clinical guidelines in 2005. 409 responses were received; 340 with a diagnosis of endometriosis and 69 with no diagnosis. People with CPP, regardless of diagnosis, reported moderate to severe dysmenorrhea and non-cyclical pelvic pain. Dyspareunia was also common. Significant negative impact was reported for social, academic, and sexual/romantic relationships in both cohorts. In the endometriosis cohort there was a mean diagnostic delay of eight years, however there was a reduction in both the diagnostic delay (p < 0.001) and number of doctors seen before diagnosis (p < 0.001) in those presenting more recently. Both endometriosis and CPP have significant negative impact. Whilst there is a decrease in the time to diagnosis, there is an urgent need for improved treatment options and support for women with the disease once the diagnosis is made.
Learn More >Avoiding any harm, such as painful experiences, is an important ability for our physical and mental health. This avoidance behavior might be overactive under chronic pain, and the cortical and subcortical brain volumetry, which also often changes in chronic pain states, might be a significant correlate of this behavior. In the present study, we thus investigated the association between volumetric brain differences using 3 T structural magnetic resonance imaging and pain- versus pleasure-related approach-avoidance behavior using an Approach Avoidance Task in the laboratory in chronic back pain (N = 42; mean age: 51.34 years; 23 female) and healthy individuals (N = 43; mean age: 45.21 years; 15 female). We found significant differences in hippocampal, amygdala and accumbens volumes in patients compared to controls. The patients` hippocampal volume was significantly positively related to pain avoidance, the amygdala volume to positive approach, and the accumbens volume negatively to a bias to pain avoidance over positive approach. These associations were significantly moderated by pain symptom duration. Cortical structure may thus contribute to an overacting pain avoidance system in chronic back pain, and could, together with a reduction in approaching positive stimuli, be related to maladaptive choice and decision-making processes in chronic pain.
Learn More >Chronic pain is a leading cause of disability in low- and middle-income countries; however, pain assessment tools have generally been developed and validated in high-income countries. This study examines the psychometric properties of a set of translated pain (and distress) questionnaires in Mongolia and documents the characteristics of people seeking treatment for chronic pain in Mongolia, compared with those in New Zealand, which is representative of high-income countries.
Learn More >Traumatic brain injury (TBI) occurs in 1.7 million people annually and many patients go on to develop persistent disorders including post-traumatic headache (PTH). PTH is considered chronic if it continues past 3 months. In this study we aimed to identify changes in cerebral grey matter volume (GMV) associated with PTH in mild TBI patients. 50 mTBI patients (31 Non-PTH; 19 PTH) underwent MRI scans: within 10 days post-injury, 1 month, 6 months and 18 months. PTH was assessed at visit 4 by a post-TBI headache questionnaire. Healthy controls (n = 21) were scanned twice 6 months apart. Compared to non-PTH, PTH patients had decreased GMV across two large clusters described as the right anterior-parietal (p = 0.012) and left temporal-opercular (p = 0.027). Compared to healthy controls non-PTH patients had decreased GMV in the left thalamus (p = 0.047); PTH patients had decreased GMV in several extensive clusters: left temporal-opercular (p = 0.003), temporal-parietal (p = 0.041), superior frontal gyrus (p = 0.008) and right middle frontal/superior frontal gyrus (0.004) and anterior-parietal (p = 0.003). Differences between PTH and non-PTH patients were most striking at early time points. These early changes may be associated with an increased risk of PTH. Patients with these changes should be monitored for chronic PTH.
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