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1) To assess the feasibility of research methods to test a self-management intervention aimed at preventing acute to chronic pain transition in patients with major lower extremity trauma (iPACT-E-Trauma) and 2) to evaluate its potential effects at three and six months postinjury. Design. A pilot randomized controlled trial (RCT) with two parallel groups.
Learn More >To estimate the prevalence of co-occurring pain sites among older adults with persistent back pain and associations of multisite pain with longitudinal outcomes.
Learn More >The most debilitating symptoms during oxaliplatin-based chemotherapy in patients with colorectal cancer (CRC) are neuropathy and fatigue. Inflammation has been suggested to contribute to these symptoms, and the anti-inflammatory agent minocycline is safe and readily available.
Learn More >Migraine is a condition frequently associated with gastrointestinal disorders. Previous reports have shown the relationship between irritable bowel syndrome and migraine, but no data are yet available in patients with functional dyspepsia. We therefore evaluated whether alteration of gastric sensorimotor activity may be related to migraine.
Learn More >Factors contributing to development of Complex Regional Pain Syndrome (CRPS) are not fully understood. This study examined possible epigenetic mechanisms that may contribute to CRPS following traumatic injury. DNA methylation profiles were compared between individuals developing CRPS (n=9) and those developing non-CRPS neuropathic pain (n=38) after undergoing amputation following military trauma. Linear Models for Microarray (LIMMA) analyses revealed 48 differentially methylated cytosine-phosphate-guanine dinucleotide (CpG) sites between groups (unadjusted p's<.005), with the top gene COL11A1 meeting Bonferroni-adjusted p<0.05. The second largest differential methylation was observed for the HLA-DRB6 gene, an immune-related gene linked previously to CRPS in a small gene expression study. For all but seven of the significant CpG sites, the CRPS group was hypomethylated. Numerous functional Gene Ontology-Biological Process categories were significantly enriched [FDR (q value)<.15], including multiple immune-related categories (e.g., activation of immune response, immune system development, regulation of immune system processes, antigen processing and presentation). Differentially methylated genes were more highly connected in human protein-protein networks than expected by chance (p<.05), supporting the biological relevance of the findings. Results were validated in an independent sample linking a DNA biobank with electronic health records (n=126 CRPS phenotype, n=19,768 non-CRPS chronic pain phenotype). Analyses using PrediXcan methodology indicated differences in the genetically-determined component of gene expression in 7 of 48 genes identified in methylation analyses (p's<.02). Results suggest immune- and inflammatory-related factors might confer risk for developing CRPS following traumatic injury. Validation findings demonstrate the potential of using electronic health records linked to DNA for genomic studies of CRPS.
Learn More >Routine assessment of photophobia in the clinical setting may underestimate the presence and severity of this condition. We aimed to develop and validate a questionnaire to improve evaluation of the impact of photophobia on activities of daily living, and to determine the relationship of this questionnaire to psychophysical assessment of light sensitivity thresholds.
Learn More >The clinical characteristics of cluster headache (CH) are based mainly on retrospective attack descriptions of "usual" attacks, but whether these reports are reliable is uncertain. We aimed to compare retrospective and prospective attack descriptions and describe the within- and between patient variability of attacks.
Learn More >Chronic pain is a potentially stigmatizing condition. However, stigma has received limited empirical investigation in people with chronic pain. Therefore, we examined the psychometric properties of a self-report questionnaire of stigma in people with chronic pain attending interdisciplinary treatment. Secondarily, we undertook an exploratory examination of the magnitude of change in stigma associated with interdisciplinary treatment in a prospective observational cohort. Participants attending interdisciplinary treatment based on Acceptance and Commitment Therapy completed the Stigma Scale for Chronic Illness eight-item version (SSCI-8; previously developed and validated in neurological samples), and measures of perceived injustice, pain acceptance, and standard pain outcomes before (n=300) and after treatment (n=247). A unidimensional factor structure and good internal consistency were found for the SSCI-8. Total SSCI-8 scores were correlated with pain intensity, indices of functioning, and depression in bivariate analyses. Stigma scores were uniquely associated with functioning and depression in multiple regression analyses controlling for demographic factors, pain intensity, pain acceptance, and perceived injustice at baseline. SSCI-8 total scores did not significantly improve following treatment, although an exploratory subscale analysis showed a small improvement on internalized stigma. In contrast, scores on perceived injustice, pain acceptance, and pain outcomes improved significantly. Taken together, these data support the reliability and validity of the SSCI-8 for use in samples with chronic pain. Further research is needed optimise interventions to target stigma at both the individual and societal levels. Perspective: This study supports the use of the SSCI-8 to measure stigma in chronic pain. Stigma is uniquely associated with worse depression and pain-related disability. Research is needed to identify how to best target pain-related stigma from individual and societal perspectives.
Learn More >We utilized diffusion tensor imaging (DTI) to evaluate the cerebral white matter changes that are associated with phantom limb pain in patients with unilateral arm amputation. It was anticipated that this would complement previous research in which we had shown that changes in cerebral blood volume were associated with the cerebral pain network.
Learn More >Background and Purpose- Central poststroke pain (CPSP) is a disabling condition in stroke patients, and evidence suggests that altered corticospinal and motor intracortical excitability occurs in neuropathic pain. The objective of this study was to investigate changes in motor cortex excitability and sensorimotor interaction and their correlates with clinical manifestations and alterations in somatosensory systems in CPSP patients. Methods- Fourteen patients with CPSP but no motor weakness were compared with age- and sex-matched healthy controls for motor cortex excitability and sensorimotor interaction assessed by transcranial magnetic stimulation to measure resting motor thresholds, short-interval intracortical inhibition, intracortical facilitation, and afferent inhibitions. The sensory pathway was evaluated by quantitative sensory testing, contact heat evoked potential, and somatosensory evoked potentials. Clinical pain and quality of life were assessed with validated tools. Results- The duration of CPSP was 3.3±3.0 years (ranging 0.5-10 years), and pain significantly impaired quality of life. Compared with the unaffected hemisphere, the stroke hemisphere had higher thermal thresholds, lower contact heat evoked potential amplitudes, and prolonged cortical somatosensory evoked potential latencies. There was no difference in resting motor thresholds between the stroke and unaffected hemisphere or between patients and controls. CPSP patients had a reduction in short-interval intracortical inhibition in the stroke hemisphere compared with that in the unaffected hemispheres of patients and controls. No changes were noted in afferent inhibitions between the stroke and unaffected hemispheres. The short-interval intracortical inhibition of the stroke hemisphere was negatively correlated with self-rated health on a visual analog scale and positively correlated with cortical somatosensory evoked potential latencies. Conclusions- CPSP patients with intact corticospinal tracts showed reduced motor intracortical inhibition in the stroke hemisphere, suggesting defective gamma-aminobutyric acid-ergic inhibition. This disinhibition was associated with impaired quality of life and was related to dorsal column-medial lemniscus pathway dysfunction.
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