Intraclass Correlation in Paired Associative Stimulation and Metaplasticity
Giuditta Schapira,
Justin Chang,
Yeun Kim,
Jacqueline P. Ngo,
Choi Deblieck,
Valentina Bianco,
Dylan J. Edwards,
Bruce H. Dobkin,
Allan D. Wu,
Marco Iacoboni
Affiliations
Giuditta Schapira
Ahmanson-Lovelace Brain Mapping Center, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
Justin Chang
Ahmanson-Lovelace Brain Mapping Center, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
Yeun Kim
Ahmanson-Lovelace Brain Mapping Center, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
Jacqueline P. Ngo
Ahmanson-Lovelace Brain Mapping Center, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
Choi Deblieck
Antwerp Management School, University of Antwerp, 2000 Antwerpen, Belgium
Valentina Bianco
Department of Movement, Human and Health Sciences, University of Rome “Foro Italico”, 00185 Rome, Italy
Dylan J. Edwards
Moss Rehabilitation Research Institute, Elkins Park, PA 19027, USA
Bruce H. Dobkin
Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
Allan D. Wu
Department of Neurology, Feinberg School of Medicine, Northwestern University, Evanston, IL 60208, USA
Marco Iacoboni
Ahmanson-Lovelace Brain Mapping Center, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
Paired associative stimulation (PAS) is a widely used noninvasive brain stimulation protocol to assess neural plasticity. Its reproducibility, however, has been rarely tested and with mixed results. With two consecutive studies, we aimed to provide further tests and a more systematic assessment of PAS reproducibility. We measured intraclass correlation coefficients (ICCs)—a widely used tool to assess whether groups of measurements resemble each other—in two PAS studies on healthy volunteers. The first study included five PAS sessions recording 10 MEPS every 10 min for an hour post-PAS. The second study included two PAS sessions recording 50 MEPS at 20 and 50 min post-PAS, based on analyses from the first study. In both studies PAS sessions were spaced one week apart. Within sessions ICC was fair to excellent for both studies, yet between sessions ICC was poor for both studies. We suggest that long term meta-plasticity effects (longer than one week) may interfere with between sessions reproducibility.
