Relative and absolute reliability of somatosensory evoked potentials in response to non-noxious electrical stimulation of the paraspinal muscles in healthy participants at an interval of 3-months

Abstract

Background

Somatosensory evoked potentials (SEPs) are used extensively to quantify cortical activity in response to noxious and/or non-noxious sensory stimuli. However, data demonstrating the reliability of SEP measures in response to non-noxious stimulation over time are scarce.

Aim

We investigated the relative and absolute reliability, and the smallest detectable change at 95% confidence (SDC₉₅) for SEPs evoked by non-noxious electrical stimulation of the paraspinal muscles in thirty-nine healthy participants at a 3-month interval.

Methods

SEPs were evoked at an intensity three-times that of each participant's perceptual threshold and recorded from a single electrode placed over the primary somatosensory cortex (S1).

Results

Our analyses reveal that i) latency, as a measure of activity onset, has poor relative reliability but good absolute reliability; ii) area, as a measure of cortical activity, has good relative and absolute reliability (except for the N₁₅₀ component) and iii) perceptual threshold and stimulation intensity was not reliable over time.

Conclusion

These findings suggest that the area of the N₈₀ and P₂₆₀ SEP components, and the area of the N₈₀-N₁₅₀-P₂₆₀ SEP complex, can be utilised in future studies as reliable markers of cortical activity.

Keywords:

• Somatosensory evoked potentials
• relative reliability
• absolute reliability
• healthy
• cortical activity

Ethical approval and consent to participate

All participants provided written informed consent to participate in the study. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee Western Sydney University Human Research Ethics Committee (H10465) and from Neuroscience Research Australia (SSA: 16/002) and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Disclosure statement

The authors declare that they have no conflict of interests.

Author contributions

SMS acquired funding to undertake this research. LJ and W-JC acquired the original data for this research. CC performed the data analysis for this research. CC and SMS drafted the research paper. All authors contributed to revisions and approved the final version of the manuscript.

Additional information

Funding

This work was supported by Grant 1059116 from the National Health and Medical Research Council (NHMRC) of Australia. SMS receives salary support from The National Health and Medical Research Council of Australia (1105040).