F Maeda1, J P Keenan, J M Tormos, H Topka, A Pascual-Leone. 1. Laboratory for Magnetic Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Ave. KS452, Boston, USA.
Abstract
OBJECTIVE: Repetitive transcranial magnetic stimulation (rTMS) is able to modulate the corticospinal excitability and the effects appear to last beyond the duration of the rTMS itself. Different studies, employing different rTMS parameters, report different modulation of corticospinal excitability ranging from inhibition to facilitation. Intraindividual variability of these effects and their reproducibility are unclear. METHODS: We examined the modulatory effects of rTMS to the motor cortex at various frequencies (1, 10, 20 Hz) and at different time-points in twenty healthy volunteers. RESULTS: We observed significant inhibition of MEPs following 1 Hz rTMS and significant facilitation of MEPs following 20 Hz rTMS for both day1 and day 2. Interestingly, at 1 Hz and 20 Hz rTMS, the modulatory effect produced by rTMS was greater on day 2. However, there was no significant change in corticospinal excitability following 10 Hz rTMS neither on day 1 nor day 2. CONCLUSION: Our findings raise questions as to how stimulation parameters should be determined when conducting studies applying rTMS on multiple days, and in particular, studies exploring rTMS as a treatment modality in neuropsychiatric disorders.
OBJECTIVE: Repetitive transcranial magnetic stimulation (rTMS) is able to modulate the corticospinal excitability and the effects appear to last beyond the duration of the rTMS itself. Different studies, employing different rTMS parameters, report different modulation of corticospinal excitability ranging from inhibition to facilitation. Intraindividual variability of these effects and their reproducibility are unclear. METHODS: We examined the modulatory effects of rTMS to the motor cortex at various frequencies (1, 10, 20 Hz) and at different time-points in twenty healthy volunteers. RESULTS: We observed significant inhibition of MEPs following 1 Hz rTMS and significant facilitation of MEPs following 20 Hz rTMS for both day1 and day 2. Interestingly, at 1 Hz and 20 Hz rTMS, the modulatory effect produced by rTMS was greater on day 2. However, there was no significant change in corticospinal excitability following 10 Hz rTMS neither on day 1 nor day 2. CONCLUSION: Our findings raise questions as to how stimulation parameters should be determined when conducting studies applying rTMS on multiple days, and in particular, studies exploring rTMS as a treatment modality in neuropsychiatric disorders.
Authors: Antonio Oliviero; Lucy H A Strens; Vincenzo Di Lazzaro; Pietro A Tonali; Peter Brown Journal: Exp Brain Res Date: 2002-12-18 Impact factor: 1.972
Authors: Arnaud Fumal; Valentin Bohotin; Michel Vandenheede; Laurence Seidel; Victor de Pasqua; Alain Maertens de Noordhout; Jean Schoenen Journal: Exp Brain Res Date: 2003-04-16 Impact factor: 1.972
Authors: Margaret A Naeser; Paula I Martin; Ethan Treglia; Michael Ho; Elina Kaplan; Shahid Bashir; Roy Hamilton; H Branch Coslett; Alvaro Pascual-Leone Journal: Restor Neurol Neurosci Date: 2010 Impact factor: 2.406