scholarly journals Capsaicin-Induced Changes in Electrical Pain Perception Threshold Can Be Used to Assess the Magnitude of Secondary Hyperalgesia in Humans

Pain Medicine ◽  
2020 ◽  
Vol 21 (11) ◽  
pp. 2830-2838
Author(s):  
Sam W Hughes ◽  
Meirvaan Basra ◽  
Calvin Chan ◽  
Callum Parr ◽  
Felyx Wong ◽  
...  
Keyword(s):  
Pain Perception ◽  
Rapid Assessment ◽  
Central Zone ◽  
Mechanical Hyperalgesia ◽  
Electrocutaneous Stimulation ◽  
Secondary Hyperalgesia ◽  
Individual Subject ◽  
Perception Threshold ◽  
Pain Thresholds ◽  
Secondary Zone

Abstract Objectives Areas of secondary hyperalgesia can be assessed using quantitative sensory testing (QST). Delivering noxious electrocutaneous stimulation could provide added benefit by allowing multiple measurements of the magnitude of hyperalgesia. We aimed to characterize the use of electrical pain perception (EPP) thresholds alongside QST as a means by which to measure changes in pain thresholds within an area of secondary mechanical hyperalgesia. Methods EPP and heat pain thresholds (HPTs) were measured at five distinct points at baseline and following 1% capsaicin cream application, one within a central zone and four within a secondary zone. Areas of secondary mechanical hyperalgesia were mapped using QST. In a further 14 participants, capsaicin-induced reduction in EPP thresholds was mapped using a radial lines approach across 24 points. Results There was a reduction in EPP threshold measured at the four points within the secondary zone, which was within the mapped area of mechanical secondary hyperalgesia. The magnitude of secondary hyperalgesia could be split into a mild (∼4% reduction) and severe (∼21% reduction) area within an individual subject. There was no reduction in HPT within the secondary zone, but there was a reduction in both HPT and EPP threshold within the primary zone. EPP mapping revealed differences in the magnitude and spread of hyperalgesia across all subjects. Conclusions Measuring capsaicin-induced reduction in EPP thresholds can be used to map hyperalgesic areas in humans. This semi-automated approach allows rapid assessment of the magnitude of hyperalgesia, both within an individual subject and across a study population.

Arthroscopic Knee Surgery Does Not Modify Hyperalgesic Responses to Heat Injury

2003 ◽  
Vol 99 (5) ◽  
pp. 1152-1157 ◽  
Author(s):  
Mads U. Werner ◽  
Preben Duun ◽  
Otto Kraemer ◽  
Birgit Lassen ◽  
Henrik Kehlet
Keyword(s):  
Pain Perception ◽  
Burn Injury ◽  
Knee Surgery ◽  
Secondary Hyperalgesia ◽  
Arthroscopic Knee Surgery ◽  
Pain Thresholds ◽  
Heat Injury ◽  
Thermal Pain ◽  
Nociceptive Responses ◽  
Arthroscopic Knee

Background Experimental studies suggest that surgical injury may up- or down-regulate nociceptive function. Therefore, the aim of this clinical study was to evaluate the effect of elective arthroscopically assisted knee surgery on nociceptive responses to a heat injury. Methods Seventeen patients scheduled to undergo repair of the anterior cruciate ligament and 16 healthy controls were studied. The first burn injury was induced 6 days before surgery, and the second burn was induced 1 day after surgery with a contact thermode (12.5 cm2, 47 degrees C for 7 min) placed on the medial aspect of the calf contralateral to the surgical side. Ibuprofen and acetaminophen were given for 2 days before the first burn injury and again from the time of surgery. In the controls, the two burn injuries were separated by 7 days. Sensory variables included cumulated pain score during induction of the burn (visual analog scale), secondary hyperalgesia area, and mechanical and thermal pain perception and pain thresholds assessed before and 1 h after the burn injury. Results The heat injuries induced significant increases in pain perception (P < 0.001) and decreases in pain thresholds (P < 0.02). Baseline heat pain thresholds were higher during the second burn injury in patients (P < 0.001) and controls (P < 0.01). However, there were no significant differences in pain to heat injury (P > 0.8), secondary hyperalgesia areas (P > 0.1), mechanical and thermal pain perception (P > 0.1), or mechanical and thermal pain thresholds (P > 0.08) in the burn area before surgery compared to after surgery. Conclusion Arthroscopic knee surgery did not modify nociceptive responses to a contralaterally applied experimental burn injury.

scholarly journals Comparison of antinociceptive effect of the antiepileptic drug gabapentin to that of various dosage combinations of gabapentin with lamotrigine and topiramate in mice and rats

2011 ◽  
Vol 02 (02) ◽  
pp. 130-136 ◽  
Author(s):  
Keshab Raj Paudel ◽  
SK Bhattacharya ◽  
GP Rauniar ◽  
BP Das
Keyword(s):  
Pain Perception ◽  
Late Phase ◽  
Antinociceptive Effect ◽  
Experimental Pain ◽  
Mechanical Hyperalgesia ◽  
Tail Flick ◽  
Hot Plate ◽  
Analgesic Effects ◽  
Pain Models ◽  
Antinociceptive Effects

ABSTRACT Introduction: Newer anticonvulsants have a neuromodulatory effect on pain perception mechanisms in a hyperexcitable and damaged nervous system. Aim: This study was designed to study the analgesic effects of gabapentin alone and in combination with lamotrigine and topiramate in experimental pain models. Materials and Methods: Adult albino mice (n = 490) weighing 20–30 g and rats (n = 130) weighing 100–200 g were injected intraperitoneally with gabapentin, lamotrigine, and topiramate alone and in different dose combinations. The hot-plate method, tail-flick method, capsaicin-induced mechanical hyperalgesia, and formalin assay were used to assess the antinociceptive effects. Results: Of the three antiepileptic drugs, when given separately, gabapentin was more efficacious than either topiramate or lamotrigine in all the pain models. Combination of 25 mg/kg gabapentin with 25 mg/kg topiramate was more efficacious (P <.05) than 50 mg/kg gabapentin alone in the capsaicin-induced mechanical hyperalgesia test. Similarly, 50 mg/kg gabapentin with 50 mg/kg topiramate or 5 mg/kg lamotrigine was more efficacious (P <.05) than 50 or 100 mg/kg gabapentin alone in late-phase formalin-induced behaviors. Conclusions: Combination of gabapentin with either lamotrigine or topiramate produced better results than gabapentin alone in capsaicin-induced mechanical hyperalgesia test and in late-phase formalin-induced behaviors.

scholarly journals The Combination Neuroprotective Abilities of Resveratrol and Naringenin in Attenuation of Sleep Deprivation Complications in Rats

2021 ◽  
Vol 10 ◽  
pp. e2315
Author(s):  
Zahra Abbasy ◽  
Hesam Adin Atashi ◽  
Felicia Agatha ◽  
Fatemeh Mirparsa ◽  
Hamid Zaferani Arani ◽  
...  
Keyword(s):  
Sleep Deprivation ◽  
Pain Perception ◽  
Male Rats ◽  
Ordinary People ◽  
Neuroprotective Effects ◽  
Perception Threshold ◽  
Sd Rats ◽  
Important Health ◽  
Control Sham ◽  
Drug Vehicle

Background: Sleep loss is one of the most important health problems in the world, and about 30 to 40 percent of ordinary people suffer from it. This study aimed to investigate the neuroprotective effects of the combination of resveratrol and naringenin in attenuation of sleep deprivation (SD) complications in rats. Materials and Methods: In this experimental study, 72 Wistar male rats were randomly divided into three main groups, including control, sham, and 7-days SD group. Each of its main groups consisted of three subgroups, including without drug, vehicle, and combination therapy groups (naringenin [100 mg/kg], resveratrol [100 mg/kg]). The day after the latest injection, the fear conditioning memory tests, locomotor activity test, hot plate, and forced swimming tests (FST) were carried out on all rats, and then sham and SD groups were induced 48 hours of non-REM SD (device off and on, respectively) and these behavioral tests were repeated for all rats again. Finally, the brains of all rats were removed and histopathologically examined, and stained with nissl and TUNNEL. Results: To assess fear condition memory, the rate of latency to first freezing in the visual and auditory phase increased in sham and SD rats that received vehicle or no drug (P<0.001), which indicates memory corruption. Injection of the combination of naringenin and resveratrol reduced the latency to first freezing (P<0.001), which means improved memory. In the FST test, injection of naringenin and resveratrol reduced the rate of immobility (P<0.001), which means improved depressive behavior. The naringenin and resveratrol reduced the pain perception threshold. Also, the naringenin and resveratrol reduced apoptosis compared to the control and vehicle groups (P<0.001). Conclusions: The combination of naringenin and resveratrol compared to other groups could improve memory and mood as well as reduce apoptosis, depression, and pain perception threshold. [GMJ.2021;10:e2315]

scholarly journals Lack of Analgesia by Oral Standardized Cannabis Extract on Acute Inflammatory Pain and Hyperalgesia in Volunteers

2008 ◽  
Vol 109 (1) ◽  
pp. 101-110 ◽  
Author(s):  
Birgit Kraft ◽  
Nathalie A. Frickey ◽  
Rainer M. Kaufmann ◽  
Marcus Reif ◽  
Richard Frey ◽  
...  
Keyword(s):  
Inflammatory Pain ◽  
Animal Studies ◽  
Analgesic Efficacy ◽  
Spontaneous Pain ◽  
Heat Pain ◽  
Secondary Hyperalgesia ◽  
Double Blind ◽  
Pain Thresholds ◽  
Healthy Female ◽  
Cannabis Extract

Background Cannabinoid-induced analgesia was shown in animal studies of acute inflammatory and neuropathic pain. In humans, controlled clinical trials with Delta-tetrahydrocannabinol or other cannabinoids demonstrated analgesic efficacy in chronic pain syndromes, whereas the data in acute pain were less conclusive. Therefore, the aim of this study was to investigate the effects of oral cannabis extract in two different human models of acute inflammatory pain and hyperalgesia. Methods The authors conducted a double-blind, crossover study in 18 healthy female volunteers. Capsules containing Delta-tetrahydrocannabinol-standardized cannabis extract or active placebo were orally administered. A circular sunburn spot was induced at one upper leg. Heat and electrical pain thresholds were determined at the erythema, the area of secondary hyperalgesia, and the contralateral leg. Intradermal capsaicin-evoked pain and areas of flare and secondary hyperalgesia were measured. Primary outcome parameters were heat pain thresholds in the sunburn erythema and the capsaicin-evoked area of secondary hyperalgesia. Secondary measures were electrical pain thresholds, sunburn-induced secondary hyperalgesia, and capsaicin-induced pain. Results Cannabis extract did not affect heat pain thresholds in the sunburn model. Electrical thresholds (250 Hz) were significantly lower compared with baseline and placebo. In the capsaicin model, the area of secondary hyperalgesia, flare, and spontaneous pain were not altered. Conclusion To conclude, no analgesic or antihyperalgesic activity of cannabis extract was found in the experiments. Moreover, the results even point to the development of a hyperalgesic state under cannabinoids. Together with previous data, the current results suggest that cannabinoids are not effective analgesics for the treatment of acute nociceptive pain in humans.

Pain Pressure Threshold in Cluster Headache Patients

Cephalalgia ◽  
1996 ◽  
Vol 16 (1) ◽  
pp. 62-66 ◽  
Author(s):  
G Bono ◽  
F Antonaci ◽  
G Sandrini ◽  
E Pucci ◽  
G Nappi ◽  
...  
Keyword(s):  
Cluster Headache ◽  
Pain Perception ◽  
Perception Threshold ◽  
Temporal Muscle ◽  
Mean Values ◽  
Pressure Threshold ◽  
Pain Pressure Threshold ◽  
Pressure Algometer ◽  
Symmetrical Points ◽  
Symptomatic Side

Pain perception threshold (PFT) in the head was assessed with a pressure algometer in 58 cluster headache (CH) patients (52M, 6F; 41 episodic and 17 chronic). Fourteen patients in cluster period were retested in remission. Thresholds were assessed at 10 symmetrical points on each side of the head and at the deltoid. Compared with controls ( n = 80), CH patients had lower PPT in the head and in the deltoid. PPT was lower on the symptomatic side than on the non-symptomatic side in patients with episodic CH during a cluster period ( p<0.001) and in patients with chronic CH ( p<0.05). This pattern was more evident during a cluster period than during remission ( p<0.05). A reduced PPT did not correlate with illness duration and pain side. The lowest PPT mean values were found at the anterior and intermediate levels of the temporal muscle on the symptomatic side. These results imply a central mechanism underlying the pathogenesis of CH.

Effect of Oral Ketamine on Secondary Hyperalgesia, Thermal and Mechanical Pain Thresholds, and Sedation in Humans

2000 ◽  
Vol 25 (5) ◽  
pp. 452-458 ◽  
Author(s):  
Søren Mikkelsen ◽  
Henrik Jørgensen ◽  
Pia S. Larsen ◽  
Jannick Brennum ◽  
Jørgen B. Dahl
Keyword(s):  
Secondary Hyperalgesia ◽  
Pain Thresholds ◽  
Oral Ketamine ◽  
Mechanical Pain Thresholds

scholarly journals Effect of Progressive Muscle Relaxation on Pain Threshold and Effectiveness of Footballers’ Training

2015 ◽  
Vol 16 (4) ◽  
Author(s):  
Lilianna Jaworska ◽  
Arletta Hawrylak ◽  
Bartosz Burzyński ◽  
Joanna Szczepańska-Gieracha
Keyword(s):  
Pain Threshold ◽  
Pain Perception ◽  
Muscle Relaxation ◽  
Pressure Pain Threshold ◽  
Progressive Muscle Relaxation ◽  
Relaxation Techniques ◽  
Training Methods ◽  
Lumbar Region ◽  
Perception Threshold ◽  
Pressure Therapy

AbstractPurpose. Relaxing in the athlete’s training process is underutilized. Relaxation techniques, however, should be taught from the very beginning of the footballer’s training career. The main aim of this study was to present the effect of progressive muscle relaxation on pressure pain threshold levels and the effectiveness of the footballer’s training. Methods. A sample of 32 football players participated in the therapeutic program consisting of 8 PMR sessions. Before and after applying a pressure therapy, the pain threshold in the lumbar region was measured by a dolorimeter and the Cooper test was carried out to determine the footballers’ level of endurance. Results. PMR training did not increase significantly the pain threshold level in the experimental group (p > 0.05), but it increased significantly the distance covered in the Cooper test (p = 0.04). Analysis of the Spearman rank correlation was also carried out (p = 0.81). Conclusions. PMR does not lower pain perception threshold. PMR therapy increases the distance measured by the Cooper test. In order to determine the role of PMR in injury prevention, further research is necessary.

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