Distraction by a cognitive task has a higher impact on electrophysiological measures compared with conditioned pain modulation
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±12.0μV to 20.2±9.5μV, cognitive distraction: 30.3±14.2µV to 13.6±5.2μV, 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.
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Posted 02 Nov, 2020
On 26 Oct, 2020
On 25 Oct, 2020
On 25 Oct, 2020
On 25 Oct, 2020
Received 20 Oct, 2020
Received 01 Oct, 2020
On 22 Sep, 2020
Invitations sent on 21 Sep, 2020
On 21 Sep, 2020
On 19 Aug, 2020
On 18 Aug, 2020
On 18 Aug, 2020
On 18 Jul, 2020
Received 03 Jul, 2020
Received 02 Jul, 2020
Received 29 Jun, 2020
On 09 Jun, 2020
On 08 Jun, 2020
On 06 Jun, 2020
Invitations sent on 06 Jun, 2020
On 20 May, 2020
On 19 May, 2020
On 19 May, 2020
Distraction by a cognitive task has a higher impact on electrophysiological measures compared with conditioned pain modulation
Posted 02 Nov, 2020
On 26 Oct, 2020
On 25 Oct, 2020
On 25 Oct, 2020
On 25 Oct, 2020
Received 20 Oct, 2020
Received 01 Oct, 2020
On 22 Sep, 2020
Invitations sent on 21 Sep, 2020
On 21 Sep, 2020
On 19 Aug, 2020
On 18 Aug, 2020
On 18 Aug, 2020
On 18 Jul, 2020
Received 03 Jul, 2020
Received 02 Jul, 2020
Received 29 Jun, 2020
On 09 Jun, 2020
On 08 Jun, 2020
On 06 Jun, 2020
Invitations sent on 06 Jun, 2020
On 20 May, 2020
On 19 May, 2020
On 19 May, 2020
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±12.0μV to 20.2±9.5μV, cognitive distraction: 30.3±14.2µV to 13.6±5.2μV, 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.
Figure 1
Figure 2
Figure 3