scholarly journals Standardized Stimulation Protocols Are Needed for Comparable Analysis of Pain-related Evoked Potentials (PREP)

Author(s):  
Katharina Brech ◽  
Elena K. Enax-Krumova ◽  
Lynn Eitner ◽  
Jan Vollert ◽  
Christoph Maier ◽  
...  

Abstract Objective: Pain-related evoked potentials (PREP) are increasingly used to investigate nociception and small-fibre function. Due to lack of a standard stimulation protocol, it is unclear whether results from studies using different protocols are comparable. Aim of the study was to assess the influence of different stimulation parameters on N1P1-amplitudes, N1-latencies and PREP-induced pain intensity. Methods: In a cross-over design we examined 31 healthy volunteers using four different stimulation protocols (number of stimulation electrodes 1 vs. 3, stimulus durations 200 µs vs. 500 µs) in a randomized order. Statistics: paired t-test, ANOVA, correlation analyses. Results: Longer stimulus duration induced higher N1P1-amplitudes (p<0.05) and higher pain intensity (p<0.001). Stimulation with 3 electrodes lead to a lower pain intensity (p<0.01), whereas the N1P1-amplitude and stimulus intensity at twofold of individual pain remained unaffected by the number of electrodes. Also, there was no relation between stimulus intensities and N1P1-amplitudes (one electrode: r=0.079; p=0.646, three electrodes: r=-0.10, p=0.70) was observed. N1-latencies remained comparable between the four protocols.Conclusions and Significance: The use of different stimulation protocols for PREP is limited by relevant differences in the N1P1-amplitudes and evoked pain intensities. Standard consented stimulation protocols are needed to allow data comparison between different labs and studies.

Author(s):  
Melissa A Day ◽  
Rhonda M Williams ◽  
Aaron P Turner ◽  
Dawn M Ehde ◽  
Mark P Jensen

Abstract Background Chronic pain in Veterans is a major problem compounded by comorbid posttraumatic stress disorder (PTSD) and depression. Adopting a transdiagnostic framework to understanding “shared territory” among these diagnoses has the potential to inform our understanding of the underlying cognitive processes and mechanisms that transverse diagnostic boundaries. Purpose To examine the associations between pain-related cognitive processes (diversion, distancing, absorption, and openness), pain intensity, PTSD and depressive symptoms, and the extent to which Veterans with chronic pain with and without comorbid PTSD and depression engage in different/similar pain-related cognitive processes. Methods Secondary analysis of pretreatment data with a subsample (n = 147) of Veterans with chronic pain from a larger clinical trial. Pretreatment PCL-5 and PROMIS Depression scales were used to categorize participants into three groups: (a) Pain-only; (b) Pain-PTSD; and (c) Pain-PTSD-DEP. Results Compared to the Pain-only group, the Pain-PTSD and Pain-PTSD-DEP groups reported significantly greater pain intensity, PTSD and depressive symptoms, and ruminative pain absorption. The Pain-PTSD-DEP group had significantly lower pain diversion and pain openness scores. When diversion and openness were used within the Pain-PTSD-DEP group, however, they were both associated with lower pain intensity and openness was additionally associated with lower PTSD scores. However, in the Pain-PTSD group, pain openness was associated with higher depression scores. Conclusions Across increasing complexity of comorbidity profiles (i.e., one vs. two comorbid conditions), ruminative absorption with pain emerged as a cognitive process that transverses diagnoses and contributes to worse outcomes. Nonjudgmental acceptance may not be universally beneficial, potentially depending upon the nature of comorbidity profiles.


Author(s):  
Zachary L. Mannes ◽  
Erin G. Ferguson ◽  
Nicole Ennis ◽  
Deborah S. Hasin ◽  
Linda B. Cottler

Over 80% of National Football League (NFL) retirees experience daily pain. Pain acceptance is an important psychological construct implicated in the intensity of chronic pain, though these findings have not been extended to NFL retirees. Therefore, the current study examined the association between pain acceptance and pain intensity among former NFL athletes. NFL retirees (N = 90) recruited from 2018 to 2019 completed questionnaires that assessed pain, substance use, and NFL career information. Multiple linear regression examined the association between current pain acceptance and pain intensity while adjusting for other risk factors of pain. NFL retirees reported average scores of 33.31 (SD = 10.00), and 2.18 (SD = 2.40) on measures of pain acceptance and pain intensity, respectively. After covariate adjustment, greater pain acceptance (β = −0.538, p < .001) was associated with lower pain intensity. These findings can further inform the behavioral and mental health care of retired NFL athletes.


2017 ◽  
Vol 11 (1) ◽  
pp. 1-11
Author(s):  
Jacob Miguel Vigil ◽  
Patrick Coulombe ◽  
Lauren Nikki Rowell ◽  
Chance Strenth ◽  
Eric Kruger ◽  
...  

The current study examines how subjective pain reporting is influenced by the concordant and discordant nature of the ethnic identities of pain expressers (participants) and pain assessors (experimenters). Three discomfort conditions that varied in stimuli intensity (Study 1: mild pain; Study 2: severe pain), and distraction components (Study 3) were used to assess whether pain intensity and tolerance reporting differ with the ethnic identification of the participant and the experimenter. Specifically, 87 Hispanic and 74 Non-Hispanic White (NHW) women (18–51 yrs., Mage = 20.0, SD = 4.3) underwent a cold pressor pain task (CPT) after engaging in minimal procedural interactions with one of the 22 research experimenters (47% Hispanic, 42% females). The procedural interactions with the experimenters included only consenting and instructions, with no interaction between experimenter and participant during the actual CPT. Random-effects models showed that between the 0% and 18% of the variance in pain sensitivity (intensity and tolerance scores) was attributable to characteristics of the experimenters. Controlling for self-esteem, baseline pain levels, and the gender of the experimenter, Hispanic subjects showed higher pain sensitivity (as marked by lower pain tolerance and higher pain intensity scores) following interactions with an NHW rather than a Hispanic experimenter in response to the most severe pain intensity stimuli. These results question the validity of common findings of ethnic differences in pain sensitivity from studies that have not accounted for the ethnic identity of the pain assessor (and the general communicative nature of pain reporting).


2020 ◽  
Vol 21 (1) ◽  
Author(s):  
A. T. L. Do ◽  
E. K. Enax-Krumova ◽  
Ö. Özgül ◽  
L. B. Eitner ◽  
S. Heba ◽  
...  

Abstract Background Conditioned pain modulation (CPM) evaluates the effect of a painful conditioning stimulus (CS) on a painful test stimulus (TS). Using painful cutaneous electrical stimulation (PCES) as TS and painful cold water as CS, the pain relief was paralleled by a decrease in evoked potentials (PCES-EPs). We now aimed to compare the effect of CPM with cognitive distraction on PCES-induced pain and PCES-EP amplitudes. Methods PCES was performed using surface electrodes inducing a painful sensation of 60 (NRS 0–100) on one hand. In a crossover design healthy subjects (included: n = 38, analyzed: n = 23) immersed the contralateral hand into 10 °C cold water (CS) for CPM evaluation and performed the 1-back task for cognitive distraction. Before and during the CS and 1-back task, respectively, subjects rated the pain intensity of PCES and simultaneously cortical evoked potentials were recorded. Results Both CPM and cognitive distraction significantly reduced PCES-EP amplitudes (CPM: 27.6 ± 12.0 μV to 20.2 ± 9.5 μV, cognitive distraction: 30.3 ± 14.2 µV to 13.6 ± 5.2 μV, p < 0.001) and PCES-induced pain (on a 0–100 numerical rating scale: CPM: 58 ± 4 to 41.1 ± 12.3, cognitive distraction: 58.3 ± 4.4 to 38.0 ± 13.0, p < 0.001), though the changes in pain intensity and PCES-amplitude did not correlate. The changes of the PCES-EP amplitudes during cognitive distraction were more pronounced than during CPM (p = 0.001). Conclusions CPM and cognitive distraction reduced the PCES-induced pain to a similar extent. The more pronounced decrease of PCES-EP amplitudes after distraction by a cognitive task implies that both conditions might not represent the general pain modulatory capacity of individuals, but may underlie different neuronal mechanisms with the final common pathway of perceived pain reduction.


2017 ◽  
Vol 128 (12) ◽  
pp. e420
Author(s):  
F. Ranieri ◽  
G. Coppola ◽  
G. Musumeci ◽  
F. Capone ◽  
G. Di Pino ◽  
...  

2004 ◽  
Vol 36 (05) ◽  
pp. 181-186 ◽  
Author(s):  
T. Gunnarsson ◽  
C. Mahoney ◽  
J. Shlik ◽  
J. Bradwejn ◽  
V. Knott

2012 ◽  
Vol 3 (3) ◽  
pp. 187-187
Author(s):  
C.S. Madsen ◽  
B. Johnsen ◽  
A. Fuglsang-Frederiksen ◽  
T.S. Jensen ◽  
N.B. Finnerup

Abstract Background/aims Brief noxious heat stimuli activate Aδ and C fibers, and contact heat evoked potentials (CHEPs) can be recorded from the scalp. Under standard conditions, late responses related to AS fibers can be recorded. This study examines C-fiber responses to contact heat stimuli. Methods A preferential A-fiber blockade by compression to the superficial radial nerve was applied in 22 healthy subjects. Quality and intensity of heat evoked pain (NRS, 0–10), and CHEPs were examined at baseline, during nerve compression, and during further nerve compression with topical capsaicin (5%). Results During the A-fiber blockade, 3 subjects had CHEPs with latencies below 400 ms, 8 subjects within 400–800 ms and 6 subjects later than 800 ms. Pain intensity to contact heat stimuli was reduced and fewer subjects reported the heat stimuli as stinging. Following acute capsaicin application, ultralate CHEPs with latencies >800 ms could be recorded in 13 subjects, pain intensity to the contact heat stimuli was increased (p <0.01) and more subjects reported the heat stimuli as being more warm/hot-burning. Conclusion The results indicate that following a compression to the superficial radial nerve, CHEPs compatible within complete A fibers or C fibers were recorded. Following sensitization with capsaicin, C-fiber responses were recorded in 62% of subjects.


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