Pain
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We previously showed that peripheral noxious input after spinal cord injury (SCI) inhibits beneficial spinal plasticity and impairs recovery of locomotor and bladder functions. These observations suggest that noxious input may similarly affect the development and maintenance of chronic neuropathic pain, an important consequence of SCI. In adult rats with a moderate contusion SCI, we investigated the effect of noxious tail stimulation, administered 1 day after SCI on mechanical withdrawal responses to von Frey stimuli from 1 to 28 days after treatment. ⋯ In addition, immunohistochemical analysis revealed distinct morphological signs of apoptosis in neurons and microglia at 24h after stimulation. Interestingly, expression of the inflammatory mediator NFκB was unaltered by nociceptive stimulation. These results suggest that noxious input caudal to the level of SCI can increase the onset and expression of behavioral responses indicative of pain, potentially involving TNFα signaling.
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Randomized Controlled Trial
Longstanding Complex Regional Pain Syndrome is associated with activating autoantibodies against α-1a adrenoceptors.
Complex regional pain syndrome (CRPS) is a limb-confined posttraumatic pain syndrome with sympathetic features. The cause is unknown, but the results of a randomized crossover trial on low-dose intravenous immunoglobulins (IVIG) treatment point to a possible autoimmune mechanism. We tested purified serum immunoglobulin G (IgG) from patients with longstanding CRPS for evidence of antibodies interacting with autonomic receptors on adult primary cardiomyocytes, comparing with control IgG from healthy and diseased controls, and related the results to the clinical response to treatment with low-dose IVIG. ⋯ To see if there were antibodies to the α-1a receptor, CRPS-IgG was applied to α-1a receptor-transfected rat-1 fibroblast cells. The CRPS serum IgG induced calcium flux, and fluorescence-activated cell sorting showed that there was serum IgG binding to the cells. The results suggest that patients with longstanding CRPS have serum antibodies to α-1a receptors, and that measurement of these antibodies may be useful in the diagnosis and management of the patients.
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The current study aimed to validate the child and parent pain catastrophizing scale in a large chronic pain sample and to identify child pain catastrophizing clinical reference points. Patients and parents (n=697) evaluated at a pediatric pain program completed the Pain Catastrophizing Scale, child (PCS-C) and parent (PCS-P) reports, along with additional measures of psychological functioning. The measure's psychometric properties were examined, as were relations across demographic, pain, and psychological characteristics and pain catastrophizing. ⋯ When comparing PCS-C scores based on child outcomes, significant differences emerged for low, moderate, and high catastrophizing levels. It appears that the influence of parent catastrophizing on outcomes can be explained through its impact on child catastrophizing levels. PCS-C reference points derived from this large sample can aid clinicians in assessment and treatment planning, in turn increasing the utility of the PCS-C for both clinical and research purposes.
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Understanding the molecular mechanisms associated with disease is a central goal of modern medical research. As such, many thousands of experiments have been published that detail individual molecular events that contribute to a disease. Here we use a semi-automated text mining approach to accurately and exhaustively curate the primary literature for chronic pain states. ⋯ We exploit the contextual data associated with our interactions to analyse subnetworks specific to inflammatory and neuropathic pain, and to various anatomical regions. Here, we identify potential targets for further study and several drug-repurposing opportunities. Finally, the network provides a framework for the interpretation of new data within the field of pain.
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Randomized Controlled Trial Multicenter Study
Spinal cord stimulation in patients with painful diabetic neuropathy: a multicentre randomised clinical trial.
Painful diabetic neuropathy (PDN) is a peripheral neuropathic pain condition that is often difficult to relieve. Spinal cord stimulation (SCS) is a proven effective therapy for various types of mixed neuropathic conditions, yet effectiveness of SCS treatment for PDN is not well established. To our knowledge, ours is the first multicentre randomized controlled trial investigating the effectiveness of SCS in patients with PDN. ⋯ After 6 months of treatment, the average VAS score was significantly reduced to 31 in the SCS group (P<.001) and remained 67 (P=.97) in the control group. The SF-MPQ and EuroQoL 5D questionnaires also showed that patients in the SCS group, unlike those in the control group, experienced reduced pain and improved health and quality of life after 6 months of treatment. In patients with refractory painful diabetic neuropathy, spinal cord stimulation therapy significantly reduced pain and improved quality of life.