Active clinical trials for "Hyperalgesia"

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.

The purpose of this study is to investigate pain evoked responses and facilitation of NGF-induced mechanical muscle hyperalgesia over time following an acute exercised-induced ischemic condition in a NGF-sensitized muscle.

The purpose of this prospective study is to investigate how close Heat Pain Detection Threshold is associated with the area of secondary hyperalgesia, elicited by the clinical pain model Brief Thermal Sensitization. Furthermore we wish to investigate how close the clinical pain model: Pain during 1 min. heating of the skin (45 degrees celsius), and the psychological tests, Pain Catastrophizing Scale and Hospital Anxiety and Depression Scale are associated with the area of secondary hyperalgesia, elicited by the clinical pain model Brief Thermal Sensitization.

The purpose of this study is to compare pain threshold, pain tolerance, and wind up, as measured by QST, before and after a single dose of ketamine infusion under two clinical conditions: chronic pain patients on opioid therapy and chronic pain patients without opioid therapy.

The purpose of this prospective study is to investigate the degree of association between the volume of important pain-relevant structures in the brain and the size of the areas of secondary hyperalgesia.

Recent studies have focused on the role of endogenous opioids on central sensitization. Central sensitization is known to be impaired or altered in chronic pain conditions, as fibromyalgia or chronic tension headache. Animal studies have shown reinstatement of mechanical hypersensitivity following naloxone administration after resolution of an injury. This suggests latent sensitization. In the present study, investigators hypothesize that naloxone (2 mg/kg) can reinstate secondary hyperalgesia 168 hours after a first-degree burn-injury. Investigators aim therefore to show that latent sensitization is present in humans and is modulated by endogenous opioids.

The purpose of this study is to investigate the sensory-motor cortical excitability response to delayed onset muscle soreness (DOMS) on Extensor Carpi Radialis (ECR) muscle during muscle hyperalgesia provoked by nerve growth factor (NGF).

Cutaneous allodynia is an increased skin sensitivity experienced during a headache. It has been noted in several studies that in patients with migraine, seventy nine percent of the patients experienced allodynia on the facial skin on the same side as the headache. Understanding more about the occurrence of phonophobia (increased sensitivity to sound) and allodynia may help us understand how the pain system works in migraine. It is hoped that the knowledge gained from this trial may enable us to more effectively treat patients with migraine headache.

In this prospective trial we aim to investigate the intra-individual and inter-individual variance in secondary hyperalgesia following pain elicited by the experimental pain model: Brief Thermal Sensitization. Furthermore we wish to investigate how precise the psychological tests, Pain Catastrophizing Scale and Hospital Anxiety and Depression Scale predict the size of the area of secondary hyperalgesia.

Assessments of mechanical skin sensitivity include psychophysical responses to stimulation with calibrated polyamide monofilaments. One of the applications of polyamide monofilaments are the assessments of magnitude of secondary hyperalgesia areas (SHAs), i.e. areas in normal skin near an injury with increased mechanical sensitivity. The objective of the study is to investigate the hypothesis, based on previous studies, that a light tactile stimulus delineates a larger SHA than stimulation with a more rigid monofilament. Twenty-three healthy participants were included in this randomized, two-observer, test-retest study. A highly significant positive correlation between the bending force of the polyamide filaments and the magnitude of SHA was demonstrated. The "weighted-pin" instrument showed significantly and consistently larger areas than the polyamide monofilaments. The hypothesis was rejected: a light tactile stimulus did not delineate a larger secondary hyperalgesia area than stimulation with a more rigid monofilament. The "weighted-pin" instrument seems an alternative to the conventional polyamide monofilaments.