Skip to main content

Advertisement

Log in

Corticomotor excitability reduction induced by experimental pain remains unaffected by performing a working memory task as compared to staying at rest

  • Research Article
  • Published:
Experimental Brain Research Aims and scope Submit manuscript

Abstract

Experimental pain inhibits primary motor cortex (M1) excitability. Attenuating pain-related inhibition of M1 excitability may be useful during rehabilitation in individuals with pain. One strategy to attenuate M1 excitability is to influence prefrontal and premotor cortex activity. Working memory tasks, e.g. the two-back task (TBT), engage prefrontal and premotor cortices and may influence M1 excitability. We hypothesized that performing the TBT during pain would influence pain-related changes in M1 excitability. Participants (n = 28) received rigorous training in the TBT before baseline testing. Experimental pain was induced by injecting hypertonic saline into the first dorsal interosseous (FDI) muscle. Participants rated pain intensity on a 0–10 numerical rating scale (NRS) every second min until pain-resolved (PR) during the performance of the TBT (n = 14) or during REST (n = 14). In the TBT, letters were presented pseudo-randomly, and accuracy and reaction time to identified letters corresponding to letters shown two times back were recorded. M1 excitability was assessed using transcranial magnetic stimulation. Motor-evoked potentials (MEPs) were recorded at baseline, and at PR, PR + 10, PR + 20, and PR + 30 min. Four minutes after hypertonic saline injection, the pain NRS scores were higher in the TBT group than the REST group (p = 0.009). No time × group interaction was found for MEPs (p = 0.73), but a main effect of time (p < 0.0005) revealed a reduction of MEPs at PR up until PR + 30 (p < 0.008). The TBT accuracy improved at PR + 30 in both groups (p = 0.019). In conclusion, the pain-induced reduction in corticomotor excitability was unaffected by performing a working memory task, despite greater pain in the TBT group.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others

References

Download references

Acknowledgements

Center for Neuroplasticity and Pain (CNAP) is supported by the Danish National Research Foundation (DNRF121). SMS receives salary support from The National Health and Medical Research Council of Australia (#1105040).

Author information

Authors and Affiliations

Authors

Contributions

TG-N, RPH, DS, SS, SAB, and DBL contributed to the conceptual development of the study. Data collection, analysis and the preliminary draft were performed by DBL. All authors interpreted and discussed the results. The manuscript draft was critically revised by RPH, TG-N, and SAB, and edited by all authors. All authors approved the final manuscript.

Corresponding author

Correspondence to Shellie A. Boudreau.

Ethics declarations

Conflict of interest

The authors declare that they have no conflict of interest.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Larsen, D.B., Graven-Nielsen, T., Hirata, R.P. et al. Corticomotor excitability reduction induced by experimental pain remains unaffected by performing a working memory task as compared to staying at rest. Exp Brain Res 237, 2205–2215 (2019). https://doi.org/10.1007/s00221-019-05587-y

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00221-019-05587-y

Keywords

Navigation