Enhancement of Neuromodulation with Novel Pulse Shapes Generated by Controllable Pulse Parameter Transcranial Magnetic Stimulation.




Curated By TMS Solutions on Sep 8, 2016 1:01:00 PM
Curated By TMS Solutions
Title:
Enhancement of Neuromodulation with Novel Pulse Shapes Generated bControllable Pulse Parameter Transcranial Magnetic Stimulation.
Authors:
Goetz SM; Luber B; Lisanby SH; Murphy DL; Kozyrkov IC; Grill WM; Peterchev AV. Institution Goetz,Stefan M. Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC 27710, USA.
Luber,Bruce. Department of Psychiatry and Behavioral Sciences, Duke
University, Durham, NC 27710, USA; Department of Psychology and
Neuroscience, Duke University, Durham, NC 27710, USA. Lisanby,Sarah H. Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC 27710, USA; Department of Psychology and Neuroscience, Duke University, Durham, NC 27710, USA. Murphy,David L K. Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC 27710, USA. Kozyrkov,I Cassie. Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC 27710, USA.
Grill,Warren M. Department of Biomedical Engineering, Duke University,
Durham, NC 27710, USA; Department of Neurobiology, Duke University,
Durham, NC 27710, USA; Department of Surgery, Duke University, 
Durham, NC 27710, USA; Department of Electrical and Computer Engineering, DukUniversity, Durham, NC 27710, USA. Peterchev,Angel V. Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC 27710, USA; Department of Biomedical Engineering, Duke University, Durham, NC 27710, USA; Department of Electrical and Computer Engineering, Duke University, Durham, NC 27710, USA.
Electronic address: angel.peterchev@duke.edu.
 
Title:
Enhancement of Neuromodulation with Novel Pulse Shapes Generated bControllable Pulse Parameter Transcranial Magnetic Stimulation.
 
Source:
Brain Stimulation. 9(1):39-47, 2016 Jan-Feb.
 
Abstract:
BACKGROUND: Standard repetitive transcranial magnetic stimulation (rTMS) devices generate bidirectional biphasic sinusoidal pulses that are energy efficient, but may be less effective than monophasic pulses that induce a more unidirectional electric field. To enable pulse shape optim
ization, we developed a controllable pulse parameter TMS (cTMS) device.
 
OBJECTIVE:
We quantified changes in cortical excitability produced by conventional sinusoidal bidirectional pulses and by three rectangular-shaped cTMS pulses, one bidirectional and two unidirectional (in opposite directions), and compared their efficacy in modulating motor evoked potentials (MEPs) produced by stimulation of motor cortex.
 
METHODS:
Thirteen healthy subjects completed four sessions of 1 Hz rTMS of
the left motor cortex. In each session, the rTMS electric field pulse had
 one of the four shapes. Excitability changes due to rTMS were measured by applying probe TMS pulses before and after rTMS, and comparing resultant MEP amplitudes. Separately, we measured the latency of the MEPs evoked by each of the four pulses.
 
RESULTS:
While the three cTMS pulses generated significant mean in hibitory effects in the subject group, the conventional biphasic cosine pulses did not. The strongest inhibition resulted from a rectangular un
idirectional pulse with dominant induced current in the posterior-anterior direction. The MEP latency depended significantly on the pulse shape.
 
CONCLUSIONS:
The pulse shape is an important factor in rTMS induced 
neuromodulation. The standard cosine biphasic pulse showed the smallest effect on cortical excitability, while the greatest inhibition was
observed for an asymmetric, unidirectional, rectangular pulse. 
Differences in MEP latency across the various rTMS pulse shapes suggest activation of distinct subsets of cortical microcircuitry.
 
Copyright:  2015 Elsevier Inc. All rights reserved. 
 
Publication Type:
Journal Article. Research Support, N.I.H., Extramural. Research Support,Non-U.S. Gov't.

Topic of this Article:

Topics: Transcranial Magnetic Stimulation, Novel Pulse Shapes


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