Large-scale analysis of interindividual variability in single and paired-pulse TMS data. Issue 10 (October 2021)

• Record Type: Journal Article
• Authors: Corp, Daniel T.; Bereznicki, Hannah G.K.; Clark, Gillian M.; Youssef, George J.; Fried, Peter J.; Jannati, Ali; Davies, Charlotte B.; Gomes-Osman, Joyce; Kirkovski, Melissa; Albein-Urios, Natalia; Fitzgerald, Paul B.; Koch, Giacomo; Di Lazzaro, Vincenzo; Pascual-Leone, Alvaro; Enticott, Peter G.
• Is Part Of: Clinical neurophysiology. Volume 132:Issue 10(2021)
• Page Start: 2639
• Page End: 2653
• Publication Date: 2021-10
• Subjects: Single-pulse TMS -- Paired-pulse TMS -- Motor threshold -- Big data -- Variability; TMS Transcranial magnetic stimulation -- MEP motor evoked potential -- pp paired-pulse -- SICI short-interval intracortical inhibition -- ICF intracortical facilitation -- IV independent variable -- DV dependent variable -- Normalised MEP DV for SICI and ICF analyses (conditioned MEP amplitude expressed as a percentage of the baseline MEP amplitude) -- CS conditioning stimulus (initial pulse for paired-pulse TMS protocols) -- TS test stimulus (second pulse for pp TMS protocols, or unconditioned / baseline MEPs for pp protoocol) -- ISI interstimulus interval -- RMT resting motor threshold -- AMT active motor threshold -- Pulse waveform monophasic or biphasic pulse waveforms; Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2021.06.014
• Languages: English
• ISSNs: 1388-2457

Abstract

Highlights: 687 healthy participant's TMS data were pooled across 35 studies. Significant relationships between age and resting motor threshold. Significant relationships between baseline MEP amplitude and SICI/ICF. Abstract: Objective: This study brought together over 60 transcranial magnetic stimulation (TMS) researchers to create the largest known sample of individual participant single and paired-pulse TMS data to date, enabling a more comprehensive evaluation of factors driving response variability. Methods: Authors of previously published studies were contacted and asked to share deidentified individual TMS data. Mixed-effects regression investigated a range of individual and study level variables for their contribution to variability in response to single and paired-pulse TMS data. Results: 687 healthy participant's data were pooled across 35 studies. Target muscle, pulse waveform, neuronavigation use, and TMS machine significantly predicted an individual's single-pulse TMS amplitude. Baseline motor evoked potential amplitude, motor cortex hemisphere, and motor threshold (MT) significantly predicted short-interval intracortical inhibition response. Baseline motor evoked potential amplitude, test stimulus intensity, interstimulus interval, and MT significantly predicted intracortical facilitation response. Age, hemisphere, and TMS machine significantly predicted MT. Conclusions: This large-scale analysis has identified a number of factors influencing participants' responses to single and paired-pulse TMS. We provide specific recommendations to minimise interindividual variability in single and paired-pulse TMS data. Significance: This study has used large-scale analyses to give clarity to factors driving variance in TMS data. We hope that this ongoing collaborative approach will increase standardisation of methods and thus the utility of single and paired-pulse TMS.