TY - JOUR
T1 - Comparison of low frequency repetitive transcranial magnetic stimulation parameters on motor cortex excitability in normal subjects
AU - Schrader, Lara M.
AU - Sadeghinejad, Sima
AU - Sadeghinejad, Jalleh
AU - Kazanchyan, Movses
AU - Koski, Lisa
AU - Stern, John M.
AU - Wu, Allan D.
AU - Iacoboni, Marco
AU - Nuwer, Marc R.
N1 - Funding Information:
For their generous support, the authors wish to thank the Brain Mapping Medical Center Research Organization, Brain Mapping Support Foundation, Pierson-Lovelace Foundation, The Ahmanson Foundation, Tamkin Foundation, Jennifer Jones-Simon Foundation, Capital Group Companies Charitable Foundation, Robson Family, William M. and Linda R. Dietel Philanthropic Fund at the Northern Piedmont Community Foundation , Northstar Fund , and the National Center for Research Resources grants RR12169 , RR13642 , and RR08655 . This work was also sponsored in part by a UCLA Stein Oppenheimer Award (JMS), the American Academy of Neurology Foundation (LMS), and the National EpiFellow Foundation (LMS). We greatly appreciate the statistical and methodological assistance of Jeffrey Gornbein, PhD, Robert M. Elashoff, PhD, and Weiqing Liu from the UCLA Department of Biomathematics. Also, a special thanks to Sylvia Fong for help with manuscript preparation.
Publisher Copyright:
© 2016 Indian Epilepsy Society.
Copyright:
Copyright 2016 Elsevier B.V., All rights reserved.
PY - 2016/1/1
Y1 - 2016/1/1
N2 - Background/objectives: Optimal low frequency repetitive transcranial magnetic stimulation (LF-rTMS) parameters for treating epilepsy and other brain disorders are unknown. To address this question, a systematic study of the effects of LF-rTMS frequency and intensity on cortical excitability was performed. Methods: Using a four-period crossover design, subjects were scheduled for four LF-rTMS sessions that were at least four weeks apart. LF-rTMS was delivered as 900 pulses directed at primary motor cortex using four protocols: 0.5 Hz at 90% resting motor threshold (RMT), 0.5 Hz at 110% RMT, 1 Hz at 90% RMT, and 1 Hz at 110% RMT. Motor evoked potential (MEP) amplitude, resting motor threshold (RMT), and cortical silent period (CSP) were measured before, immediately after, and 60 min after LF-rTMS. Each of the four protocols was analyzed separately to compare baseline measurements to those after LF-rTMS. Results: None of the four LF-rTMS protocols produced a trend or significant change in MEP amplitude, RMT, or CSP. Conclusion: The lack of significant effect from the four LF-rTMS protocols indicates that none produced evidence for alteration of cortical excitability. The direct comparison of four LF-rTMS protocols is distinct to this investigation, as most similar studies were exploratory and studied only one or two protocols. The negative result relates only to the methods used in this investigation and does not indicate that LF-rTMS does not alter cortical excitability with other parameters. These results may be useful when designing additional investigations into the effect of LF-rTMS on epilepsy, other disorders, and cortical excitability.
AB - Background/objectives: Optimal low frequency repetitive transcranial magnetic stimulation (LF-rTMS) parameters for treating epilepsy and other brain disorders are unknown. To address this question, a systematic study of the effects of LF-rTMS frequency and intensity on cortical excitability was performed. Methods: Using a four-period crossover design, subjects were scheduled for four LF-rTMS sessions that were at least four weeks apart. LF-rTMS was delivered as 900 pulses directed at primary motor cortex using four protocols: 0.5 Hz at 90% resting motor threshold (RMT), 0.5 Hz at 110% RMT, 1 Hz at 90% RMT, and 1 Hz at 110% RMT. Motor evoked potential (MEP) amplitude, resting motor threshold (RMT), and cortical silent period (CSP) were measured before, immediately after, and 60 min after LF-rTMS. Each of the four protocols was analyzed separately to compare baseline measurements to those after LF-rTMS. Results: None of the four LF-rTMS protocols produced a trend or significant change in MEP amplitude, RMT, or CSP. Conclusion: The lack of significant effect from the four LF-rTMS protocols indicates that none produced evidence for alteration of cortical excitability. The direct comparison of four LF-rTMS protocols is distinct to this investigation, as most similar studies were exploratory and studied only one or two protocols. The negative result relates only to the methods used in this investigation and does not indicate that LF-rTMS does not alter cortical excitability with other parameters. These results may be useful when designing additional investigations into the effect of LF-rTMS on epilepsy, other disorders, and cortical excitability.
KW - Brain stimulation
KW - Cortical excitability
KW - Low frequency repetitive transcranial magnetic stimulation
KW - Stimulation parameters
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U2 - 10.1016/j.ijep.2016.02.003
DO - 10.1016/j.ijep.2016.02.003
M3 - Article
AN - SCOPUS:84964645606
VL - 3
SP - 2
EP - 6
JO - International Journal of Epilepsy
JF - International Journal of Epilepsy
SN - 2213-6320
IS - 1
ER -