Attenuation of Sensory and Affective Responses to Heat Pain: Evidence for Contralateral Mechanisms

2005 ◽  
Vol 94 (5) ◽  
pp. 3509-3515 ◽  
Author(s):  
Ariane Gallez ◽  
Marie-Claire Albanese ◽  
Pierre Rainville ◽  
Gary H. Duncan

Attenuation of responses to repeated sensory events has been thoroughly studied in many modalities; however, attenuation of pain perception has not yet benefitted from such extensive investigation. Described here are two psychophysical studies that examined the effects of repeated exposure to thermal stimuli, assessing potential attenuation of the perception of pain and its possible spatial specificity. Twenty-two subjects were presented thermal stimuli to the volar surface of the right and left forearms. Twelve subjects in study 1 received the same stimuli and conditions on each of five daily experimental sessions, whereas 10 subjects in study 2 received thermal stimuli, which were restricted to one side for four daily sessions and then applied to the other side on the fifth session. Ratings of warmth intensity, pain intensity, and pain unpleasantness were recorded while the subjects performed a thermal sensory discrimination task. Results of study 1 demonstrate that repeated stimulation with noxious heat can lead to long-term attenuation of pain perception; results of study 2 extend these findings of attenuation to both pain intensity and unpleasantness and show that this effect is highly specific to the exposed body side for both aspects of the pain experience. We suggest that the functional plasticity underlying this attenuation effect lies in brain areas with a strong contralateral pattern of pain-related activation.

2020 ◽  
Vol 11 ◽  
Author(s):  
Wanghuan Dun ◽  
Tongtong Fan ◽  
Qiming Wang ◽  
Ke Wang ◽  
Jing Yang ◽  
...  

Empathy refers to the ability to understand someone else's emotions and fluctuates with the current state in healthy individuals. However, little is known about the neural network of empathy in clinical populations at different pain states. The current study aimed to examine the effects of long-term pain on empathy-related networks and whether empathy varied at different pain states by studying primary dysmenorrhea (PDM) patients. Multivariate partial least squares was employed in 46 PDM women and 46 healthy controls (HC) during periovulatory, luteal, and menstruation phases. We identified neural networks associated with different aspects of empathy in both groups. Part of the obtained empathy-related network in PDM exhibited a similar activity compared with HC, including the right anterior insula and other regions, whereas others have an opposite activity in PDM, including the inferior frontal gyrus and right inferior parietal lobule. These results indicated an abnormal regulation to empathy in PDM. Furthermore, there was no difference in empathy association patterns in PDM between the pain and pain-free states. This study suggested that long-term pain experience may lead to an abnormal function of the brain network for empathy processing that did not vary with the pain or pain-free state across the menstrual cycle.


2019 ◽  
Vol 122 (2) ◽  
pp. 729-736
Author(s):  
Stuart W. G. Derbyshire ◽  
Victoria Jane En Long ◽  
Christopher L. Asplund

Offset analgesia (OA) is the disproportionate decrease in pain experience following a slight decrease in noxious heat stimulus intensity. We tested whether sequential offsets would allow noxious temperatures to be reached with little or no perception of pain. Forty-eight participants continuously rated their pain experience during trials containing trains of heat stimuli delivered by Peltier thermode. Stimuli were adjusted through either stepwise sequential increases of 2°C and decreases of 1°C or direct step increases of 1°C up to a maximum of 46°C. Step durations (1, 2, 3, or 6 s) varied by trial. Pain ratings generally followed presented temperature, regardless of step condition or duration. For 6-s steps, OA was observed after each decrease, but the overall pain trajectory was unchanged. We found no evidence that sequential offsets could allow for little pain perception during noxious temperature presentation. NEW & NOTEWORTHY Offset analgesia is the disproportionate decrease in pain experience following a slight decrease in noxious heat stimulus intensity. We tested whether sequential offsets would allow noxious temperatures to be reached with little or no perception of pain. We found little evidence of such overall analgesia. In contrast, we observed analgesic effects after each offset with long-duration stimuli, even with relatively low-temperature noxious stimuli.


PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256433
Author(s):  
Roxana Schwab ◽  
Katharina Anić ◽  
Kathrin Stewen ◽  
Mona W. Schmidt ◽  
Stefanie R. Kalb ◽  
...  

Background Endometriosis is a chronic pain condition in premenopausal women. Pain is mainly characterized by pain intensity and may induce disability in all areas of daily life. Nevertheless, pain is influenced by emotional and social factors as well. Social distancing measures or quarantine, as reaction to rapidly rising infections with the COVID-19 virus due to the SARS-CoV-2 pandemic, were implemented across Europe to prevent the spread of the virus and social distancing measures were imposed by the German government by beginning of March 2020 with initiation of the lockdown by the end of March 2020. The objective of this study was to assess, how social distancing measures during the lockdown impacted the various aspects of pain perception in a group of chronic pain patients, such as women suffering from endometriosis. Methods Between 6th to 27th April 2020, an online questionnaire was activated at internet platforms of endometriosis patients support groups. Participants were asked retrospectively at one time point about their visual pain intensity measured by the visual analogue scale (VAS) and pain disability via pain disability index (PDI) prior to initiation of social distancing measures in Germany (VASP, PDIP), as well as the pain intensity and pain disability since implementation of social distancing measures (VASI, PDII). Differences of VAS and PDI previous and after implementation of social distancing measures were displayed as ΔVAS and ΔPDI. Pain experience and social support were assessed by a 5-point Likert scale. Results 285 participants completed at least one question regarding pain intensity, disability, pain experience or social support. Dysmenorrhea, the symptom with the highest level of pain assessed by VAS, decreased significantly during the SARS-CoV-2 pandemic compared to the time period prior to social isolation (45.30% respondents experienced improvemenet vs 40.50% who experienced worsening; p = 0.025). The global physical impairment improved significantly (improvement of pain induced disability in 48.20% vs 40.90% with worsening of pain symptoms; p = 0.032) after the implementation of social distancing measures. Pain experience was negatively affected by social distancing measures, since frequency of pain awareness increased in 43.6% (p<0.001) of participants and 30.0% (p<0.001) more participants experienced pain as a threat. Verbalization of pain experience was reduced in 36.6% (p = 0.001) of participants and 14.6% (p = 0.91), 21.9% (p<0.001) and 31.5% (p<0.001) of participants reported less social support from their partner, family and friends. Conclusions Physical pain and disability on one hand and emotional and social pain experience on the other were differentially affected by the emerged emotional, social and health care constraints related to the SARS-CoV-2 pandemic.


2020 ◽  
Author(s):  
Eleni Frangos ◽  
Marta Ceko ◽  
Binquan Wang ◽  
Emily A. Richards ◽  
John L. Gracely ◽  
...  

ABSTRACTPlacebo analgesia is hypothesized to involve top-down engagement of prefrontal regions that access endogenous pain inhibiting opioid pathways. Fibromyalgia (FM) patients have neuroanatomical and neurochemical alterations in pathways relevant to placebo analgesia. Thus, it remains unclear whether placebo analgesic mechanisms would differ in FM patients compared to healthy controls (HCs). Here, using placebo-analgesia-inducing paradigms that included verbal suggestions and conditioning manipulations, we examined whether behavioral and neural placebo analgesic responses differed between 32 FM patients and 46 age- and sex-matched HCs. Participants underwent a manipulation scan, where noxious high and low heat were paired with the control and placebo cream, respectively, and a placebo experimental scan with equal noxious heat temperatures. Before the experimental scan, each participant received saline or naloxone, an opioid receptor antagonist. Across all participants, the placebo condition decreased pain intensity and unpleasantness ratings, decreased activity within the right insula and bilateral secondary somatosensory cortex, and modulated the Neurologic Pain Signature. There were no differences between HCs and FM patients in pain intensity ratings or neural responses during the placebo condition. Despite the perceptual and neural effects of the placebo manipulation, prefrontal circuitry was not activated during the expectation period and the placebo analgesia was unaltered by naloxone, suggesting placebo effects were driven more by conditioning than expectation. Together, these findings suggest that placebo analgesia can occur in both HCs and chronic pain FM patients, without the involvement of opiodergic prefrontal modulatory networks.


2001 ◽  
Vol 86 (3) ◽  
pp. 1499-1503 ◽  
Author(s):  
Lars Timmermann ◽  
Markus Ploner ◽  
Katrin Haucke ◽  
Frank Schmitz ◽  
Rüdiger Baltissen ◽  
...  

The primary (SI) and secondary (SII) somatosensory cortices have been shown to participate in human pain processing. However, in humans it is unclear how SI and SII contribute to the encoding of nociceptive stimulus intensity. Using magnetoencephalography (MEG) we recorded responses in SI and SII in eight healthy humans to four different intensities of selectively nociceptive laser stimuli delivered to the dorsum of the right hand. Subjects' pain ratings correlated highly with the applied stimulus intensity. Activation of contralateral SI and bilateral SII showed a significant positive correlation with stimulus intensity. However, the type of dependence on stimulus intensity was different for SI and SII. The relation between SI activity and stimulus intensity resembled an exponential function and matched closely the subjects' pain ratings. In contrast, SII activity showed an S-shaped function with a sharp increase in amplitude only at a stimulus intensity well above pain threshold. The activation pattern of SI suggests participation of SI in the discriminative perception of pain intensity. In contrast, the all-or-none–like activation pattern of SII points against a significant contribution of SII to the sensory-discriminative aspects of pain perception. Instead, SII may subserve recognition of the noxious nature and attention toward painful stimuli.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Mira A. Preis ◽  
Elisabeth Vögtle ◽  
Nele Dreyer ◽  
Stefanie Seel ◽  
Ruth Wagner ◽  
...  

Chronic pain has high prevalence rates and is one of the top causes of years lived with disability. The aim of the present study was to evaluate the long-term effects of a multimodal day-clinic treatment for chronic pain. The sample included 183 chronic pain patients (114 females and 69 males; 53.3 ± 9.8 years) who participated in a four-week multimodal day-clinic treatment for chronic pain. The patients’ average current pain intensity (NRS), sensory and affective pain (Pain Perception Scale), and depression and anxiety (HADS) were assessed at pre- and posttreatment, as well as at three follow-ups (one month, six months, and twelve months after completion of the treatment). Multilevel models for discontinuous change were performed to evaluate the change of the outcome variables. Improvements from pretreatment to posttreatment and from pretreatment to all follow-ups emerged for pain intensity (NRS; 0.54 ≤ d ≤ 0.74), affective pain (Pain Perception Scale; 0.24 ≤ d ≤ 0.47), depression (HADS; 0.38 ≤ d ≤ 0.53), and anxiety (HADS; 0.26 ≤ d ≤ 0.43) (all p<0.05). Sensory pain as assessed with the Pain Perception Scale did not show any significant change. Patients suffering from chronic pain benefited from the multimodal pain treatment up to twelve months after completion of the treatment.


2002 ◽  
Vol 88 (1) ◽  
pp. 464-474 ◽  
Author(s):  
Jen-I Chen ◽  
Brian Ha ◽  
M. Catherine Bushnell ◽  
Bruce Pike ◽  
Gary H. Duncan

The role of the somatosensory cortices (SI and SII) in pain perception has long been in dispute. Human imaging studies demonstrate activation of SI and SII associated with painful stimuli, but results have been variable, and the functional relevance of any such activation is uncertain. The present study addresses this issue by testing whether the time course of somatosensory activation, evoked by painful heat and nonpainful tactile stimuli, is sufficient to discriminate temporal differences that characterize the perception of these stimulus modalities. Four normal subjects each participated in three functional magnetic resonance imaging (fMRI) sessions, in which painful (noxious heat 45–46°C) and nonpainful test stimuli (brushing at 2 Hz) were applied repeatedly (9-s stimulus duration) to the left leg in separate experiments. Activation maps were generated comparing painful to neutral heat (35°C) and nonpainful brushing to rest. Directed searches were performed in SI and SII for sites reliably activated by noxious heat and brush stimuli, and stimulus-dependent regions of interest (ROI) were then constructed for each subject. The time course, per stimulus cycle, was extracted from these ROIs and compared across subjects, stimulus modalities, and cortical regions. Both innocuous brushing and noxious heat produced significant activation within contralateral SI and SII. The time course of brush-evoked responses revealed a consistent single peak of activity, approximately 10 s after the onset of the stimulus, which rapidly diminished upon stimulus withdrawal. In contrast, the response to heat pain in both SI and SII was characterized by a double-peaked time course in which the maximum response (the 2nd peak) was consistently observed ∼17 s after the onset of the stimulus (8 s following termination of the stimulus). This prolonged period of activation paralleled the perception of increasing pain intensity that persists even after stimulus offset. On the other hand, the temporal profile of the initial minor peak in pain-related activation closely matched that of the brush-evoked activity, suggesting a possible relationship to tactile components of the thermal stimulation procedure. These data indicate that both SI and SII cortices are involved in the processing of nociceptive information and are consistent with a role for these structures in the perception of temporal aspects of pain intensity.


2015 ◽  
Vol 43 (01) ◽  
pp. 44-38
Author(s):  
C.-C. Lin ◽  
K.-S. Chen ◽  
Y.-L. Lin ◽  
J. P.-W. Chan

SummaryA 5-month-old, 13.5 kg, female Corriedale sheep was referred to the Veterinary Medicine Teaching Hospital, with a history of traumatic injury of the cervical spine followed by non-ambulatoric tetraparesis that occurred 2 weeks before being admitted to the hospital. At admission, malalignment of the cervical spine with the cranial part of the neck deviating to the right was noted. Neurological examinations identified the absence of postural reactions in both forelimbs, mildly decreased spinal reflexes, and normal reaction to pain perception tests. Radiography revealed malalignment of the cervical vertebrae with subluxations at C1–C2 and C2–C3, and a comminuted fracture of the caudal aspect of C2. The sheep was euthanized due to a presumed poor prognosis. Necropsy and histopathological findings confirmed injuries of the cervical spine from C1 to C3, which were consistent with the clinical finding of tetraparesis in this case. This paper presents a rare case of multiple subluxations of the cervical spine caused by blunt force trauma in a young sheep. These results highlight the importance of an astute clinical diagnosis for such an acute cervical spine trauma and the need for prompt surgical correction for similar cases in the future.


2020 ◽  
Vol 133 (3) ◽  
pp. 727-735
Author(s):  
Peter Shih-Ping Hung ◽  
Sarasa Tohyama ◽  
Jia Y. Zhang ◽  
Mojgan Hodaie

OBJECTIVEGamma Knife radiosurgery (GKRS) is a noninvasive surgical treatment option for patients with medically refractive classic trigeminal neuralgia (TN). The long-term microstructural consequences of radiosurgery and their association with pain relief remain unclear. To better understand this topic, the authors used diffusion tensor imaging (DTI) to characterize the effects of GKRS on trigeminal nerve microstructure over multiple posttreatment time points.METHODSNinety-two sets of 3-T anatomical and diffusion-weighted MR images from 55 patients with TN treated by GKRS were divided within 6-, 12-, and 24-month posttreatment time points into responder and nonresponder subgroups (≥ 75% and < 75% reduction in posttreatment pain intensity, respectively). Within each subgroup, posttreatment pain intensity was then assessed against pretreatment levels and followed by DTI metric analyses, contrasting treated and contralateral control nerves to identify specific biomarkers of successful pain relief.RESULTSGKRS resulted in successful pain relief that was accompanied by asynchronous reductions in fractional anisotropy (FA), which maximized 24 months after treatment. While GKRS responders demonstrated significantly reduced FA within the radiosurgery target 12 and 24 months posttreatment (p < 0.05 and p < 0.01, respectively), nonresponders had statistically indistinguishable DTI metrics between nerve types at each time point.CONCLUSIONSUltimately, this study serves as the first step toward an improved understanding of the long-term microstructural effect of radiosurgery on TN. Given that FA reductions remained specific to responders and were absent in nonresponders up to 24 months posttreatment, FA changes have the potential of serving as temporally consistent biomarkers of optimal pain relief following radiosurgical treatment for classic TN.


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