Intra and inter-session reliability of rapid Transcranial Magnetic Stimulation stimulus-response curves of tibialis anterior muscle in healthy older adults

Intra and inter-session reliability of rapid Transcranial Magnetic Stimulation stimulus-response curves of tibialis anterior muscle in healthy older adults

Peri, Elisabetta (Politecnico di Milano)
Ambrosini, E. (Politecnico di Milano; Istituti Clinici Scientifici Maugeri)
Colombo, Vera Maria (Politecnico di Milano)
van de Ruit, M.L. (TU Delft Biomechatronics & Human-Machine Control)
Grey, Michael J. (University of East Anglia)
Monticone, Marco (University of Cagliari; Istituti Clinici Scientifici Maugeri)
Ferriero, Giorgio (Istituti Clinici Scientifici Maugeri)
Pedrocchi, Alessandra (Politecnico di Milano)
Ferrigno, Giancarlo (Politecnico di Milano)
Ferrante, Simona (Politecnico di Milano)

2017

Objective: The clinical use of Transcranial Magnetic Stimulation (TMS) as a technique to assess corticospinal excitability is limited by the time for data acquisition and the measurement variability. This study aimed at evaluating the reliability of Stimulus-Response (SR) curves acquired with a recently proposed rapid protocol on tibialis anterior muscle of healthy older adults. Methods: Twenty-four neurologically-intact adults (age:55–75 years) were recruited for this test-retest study. During each session, six SR curves, 3 at rest and 3 during isometric muscle contractions at 5% of maximum voluntary contraction (MVC), were acquired. Motor Evoked Potentials (MEPs) were normalized to the maximum peripherally evoked response; the coil position and orientation were monitored with an optical tracking system. Intra- and inter-session reliability of motor threshold (MT), area under the curve (AURC), MEP_max, stimulation intensity at which the MEP is mid-way between MEP_max and MEP_min (I50), slope in I50, MEP latency, and silent period (SP) were assessed in terms of Standard Error of Measurement (SEM), relative SEM, Minimum Detectable Change (MDC), and Intraclass Correlation Coefficient (ICC). Results: The relative SEM was ≤10% for MT, I50, latency and SP both at rest and 5%MVC, while it ranged between 11% and 37% for AURC, MEP_max, and slope. MDC values were overall quite large; e.g., MT required a change of 12%MSO at rest and 10%MSO at 5%MVC to be considered a real change. Inter-sessions ICC were >0.6 for all measures but slope at rest and MEP_max and latency at 5%MVC. Conclusions: Measures derived from SR curves acquired in <4 minutes are affected by similar measurement errors to those found with long-lasting protocols, suggesting that the rapid method is at least as reliable as the traditional methods. As specifically designed to include older adults, this study provides normative data for future studies involving older neurological patients (e.g. stroke survivors).

http://resolver.tudelft.nl/uuid:ddee56d1-9aca-4550-93bc-204d2ff1bd79

https://doi.org/10.1371/journal.pone.0184828

1932-6203

PLoS ONE, 12 (9)

Institutional Repository

journal article

© 2017 Elisabetta Peri, E. Ambrosini, Vera Maria Colombo, M.L. van de Ruit, Michael J. Grey, Marco Monticone, Giorgio Ferriero, Alessandra Pedrocchi, Giancarlo Ferrigno, Simona Ferrante