View clinical trials related to Hyperalgesia.
Filter by:The development of remifentanil-induced hyperalgesia (RIH) is an unpleasant experience for surgical patients. An alternative management, gradual withdrawal of remifentanil was effective in prevention of RIH. The investigators designed a simple modality to assess if under withdrawal of remifentanil and further drip-infusion of remifentanil immediately after extubation affected postoperative pain score, the requirement of rescue analgesics, and adverse effects.
One out of 10 patients undergoing surgery develops persistent post-surgical pain (PPSP). Unfortunately, available therapies for treating this pain have limited success. It is therefore of great importance to find strategies to prevent PPSP. The goal of this project is to find new screening tools that identify patients that are at risk for developing PPSP. Tissue injury and inflammation following surgery increase the excitability of spinal nociceptive neurons ("central sensitisation", CS) with pain hypersensitivity as consequence. It is thought that CS plays an important role in persistent pain. The first objective of this project is to assess in human patients if the propensity to develop CS manifested as secondary hyperalgesia before surgery is predictive for PPSP. In addition, we will test if the frequency content of the resting-state EEG reflecting the initial state of the brain will be related to the propensity for developing CS and to the presence of PPSP at two months after surgery.
Pain is a nociceptive somatosensory process that can arise as a debilitating and chronic symptom in various diseases or following an injury. How pain is experienced can vary widely within and across individuals, and can be shaped by cognitive processes such as learning. Nocebo effects, negative changes in symptom severity attributed to learned outcome-expectations, demonstrate how learning processes can be detrimental for the experience of pain. Research to date has produced inconclusive findings regarding the electrophysiological correlates on nocebo effects. The few studies that have applied electroencephalography (EEG) in this field have pointed towards a potential involvement of alpha-band activity, but the direction of this involvement remains unclear. For example, an EEG study of conditioned nocebo hyperalgesia found a pre to post increase in resting state alpha band power that was correlated with pain catastrophizing scores and not with the magnitude of the nocebo effect. Later, other studies also found pre to post changes in alpha band power, however, these changes were correlated with the magnitude of nocebo effects and not pain catastrophizing. Given the discrepancy in findings, in this study the investigators plan to primarily investigate whether EEG components predict the magnitude of nocebo responses to thermal-pain stimuli. The investigators will also explore electrophysiological correlates during pain anticipation and whether nocebo responses would be significantly related to spectral and temporal EEG biomarkers. This study will utilize a validated model of instructional and associative learning methods (i.e., negative suggestions and classical conditioning, respectively) to experimentally induce nocebo effects on heat-evoked pain. Developing objective, brain-derived markers for nocebo responses, or the detection of individuals most susceptible to nocebo hyperalgesia, will aid in the comprehensive management of pain. This study is conducted at Leiden University.
Nocebo hyperalgesia is characterized by adverse pain outcomes, induced by patients' expectations. In the lab, nocebo effects are commonly studied via classical conditioning, a method that employs pairings of neutral cues/treatments with different pain intensities to install differential pain-related expectations. In such conditioning experiments, participants are typically taught that a (sham) treatment exaggerates their pain, by surreptitiously administering high intensity (e.g. pain) stimuli in combination with this treatment. Verbal suggestions are also often used to inform participants of the supposed adverse effects of such treatments. In nocebo studies, higher pain levels and suggestions that are of more threatening nature may induce fear, thereby adding a crucial element to the experimental manipulation. Since nocebo effects are hypothesized to arise in clinical settings due to a combination of several psychological and cognitive mechanisms, it is important to study the role that factors such as higher pain levels, conditioned pain-related fear, or more threatening verbal suggestions may play in the formation of nocebo hyperalgesia. To date, no studies have focused on the fear-inducing effect that different pain intensities or verbal threat suggestions may have and how this fear, in turn, may strengthen the acquisition of nocebo effects. This study aims to investigate whether higher pain intensity or higher pain-related fear induced via threatening suggestions facilitate the acquisition and hinder subsequent extinction of nocebo hyperalgesia. This study will be conducted at Leiden University.
Prospective, randomized, placebo-controlled, double-blinded, crossover study to investigate the effect of cannabidiol (CBD) on remifentanil-induced hyperalgesia in healthy volunteers in a well-established acute pain model. Participants are randomized according to the order of the two treatments (CBD + Remifentanil or Placebo + Remifentanil).
This study is to investigate the effect of CBD on acute pain in healthy volunteers in a well-established acute pain model.
This study is designed to evaluate the method of assessing the and intensity areas of secondary hyperalgesia induced by High Frequency Stimulation (HFS). Measures of the areas of secondary hyperalgesia will take place on two experimental days separated by a minimum of two weeks. Each experimental day, the areas of secondary hyperalgesia will be assessed three times, starting 30 minutes following HFS. Furthermore, the investigators will assess if anxiety, catastrophization, stress and demographic variables modulate the extend of hyperalgesia.
This study evaluates the treatment of the symptoms of deep endometriosis with a cannabinoid derivate.
Pain is defined as an unpleasant sensory and emotional conscious experience, associated with actual or potential tissue damage. Nociception is the sympathetic response to noxious stimuli during unconsciousness. The appearance of different forms of chronic pain results from sensitization of both peripheral and central neural circuits of pain, which involves inflammatory mechanisms both at a systemic level and specifically in the peripheric and central nervous system, as observed through elevation of specific neuroinflammatory mediators, such as MCP-1, IL-1, IL-1b, and IL-10. Clinically, this sensitization expresses as hyperalgesia and allodynia, which increase postoperative pain and morbidity, but also induce permanent modifications in the nociceptive system. These effects may be ameliorated by adequately adjusting intraoperative analgesia through use of nociception/analgesia balance monitors, of which Nociception Level Index (NOL) shows convenient characteristics and promising results from previous studies. Objectives: The goal of our study is to assess the utility of NOL index monitoring against standard care for Fentanyl-based analgesia by measuring postoperative pain, sensorial thresholds and inflammatory markers related to nociception. Hypothesis: The use of NOL index to guide the intraoperative analgesia will produce less postoperative pain, hyperalgesia, allodynia, and neuroinflammation.
The purpose of this study is to investigate responses of pain and the maintenance of mechanical muscle hypersensitivity following an acute exercise-induced ischemic condition repeated over time in a prolonged NGF-sensitized muscle. Additionally, the influence of the pain modulating system on prolonged NGF muscle hypersensitivity caused by peripheral mechanisms and central mechanisms will also be investigated.