Key result
Longer stimulus duration (500 µs vs 200 µs) significantly increased N1P1-amplitudes (p=0.046) and evoked pain intensity (p<0.001), while using 3 electrodes instead of 1 reduced pain (p=0.008).
Why the study?
Due to the lack of a standard stimulation protocol for pain-related evoked potentials, it was unclear whether results across studies using different protocols were comparable.
Do different stimulation protocols for pain-related evoked potentials affect N1P1-amplitudes, N1-latencies, and evoked pain intensity in healthy volunteers?
RCT (n=31)
Randomized cross-over
No
Do different stimulation protocols for pain-related evoked potentials affect N1P1-amplitudes, N1-latencies, and evoked pain intensity in healthy volunteers?
p-value: p=0.046
Different stimulation protocols for pain-related evoked potentials yield significantly different amplitudes and pain intensities, highlighting the need for standardized protocols to allow comparison across studies.
Protocol variations alter amplitudes and pain; supports standardization but leaves optimal parameters open for validation.
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.
No takes yet. Share an insight, caveat, or question.
Brech et al. (2021) conducted an RCT in Healthy volunteers (n=31). Different stimulation protocols for PREP (stimulus duration 200 µs vs 500 µs, 1 vs 3 electrodes) vs. Alternative stimulation protocols (cross-over) was evaluated on N1P1-amplitudes and evoked pain intensity (p=0.046). Longer stimulus duration (500 µs vs 200 µs) significantly increased N1P1-amplitudes (p=0.046) and evoked pain intensity (p<0.001), while using 3 electrodes instead of 1 reduced pain (p=0.008).
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: