Investigating the intra-session reliability of short and long latency afferent inhibition

• Published in: Clinical neurophysiology practice Vol. 8; pp. 16 - 23
• Main Authors: Rehsi, Ravjot S., Ramdeo, Karishma R., Foglia, Stevie D., Turco, Claudia V., Adams, Faith C., Toepp, Stephen L., Nelson, Aimee J.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.01.2023; Elsevier
• Subjects: Afferent inhibition; LAI; Reliability; Research Paper; SAI; Transcranial Magnetic Stimulation; Transcranial Magnetic Stimulation; Afferent inhibition; SAI; Reliability; LAI
• ISSN: 2467-981X; 2467-981X
• DOI: 10.1016/j.cnp.2022.12.001

•As few as 20 trials of data lead to high intrasession relative reliability for afferent inhibition.•Afferent inhibition is a good indicator of group level, but not individual change in a within-session model.•Whenever possible, studies should attempt to include assessments of reliability to verify their findings. To establish the intrasession relative and absolute reliability of Short (SAI) and Long-Latency Afferent Inhibition (LAI). These findings will allow us to guide future explorations of changes to these measures. 31 healthy individuals (21.06 ± 2.85 years) had SAI and LAI obtained thrice at 30-minute intervals in one session. To identify the minimum number of trials required to reliably elicit SAI and LAI, relative reliability was assessed at running intervals of 5 trials. SAI had moderate–high, and LAI had high-excellent relative reliability. Both SAI and LAI had high amounts of measurement error. LAI had high relative reliability when only 5 frames of data were included, whereas SAI required ∼20–30 frames of data for the same. For both SAI and LAI, individual smallest detectable change was large but was reduced at the group level. SAI and LAI can be used for both diagnostic purposes and to assess group level change but have limited utility in assessing within-individual changes. These results can be used to inform future work regarding the utility of SAI and LAI, particularly in terms of their ability to identify particularly high or low values of afferent inhibition.