Cortico-Cortical Modulation Induced by 1-Hz Repetitive Transcranial Magnetic Stimulation of the Temporal Cortex

Department of Neurology, Ewha Womans University School of Medicine, Seoul, Korea.
Journal of Clinical Neurology (Impact Factor: 1.7). 04/2013; 9(2):75-82. DOI: 10.3988/jcn.2013.9.2.75
Source: PubMed


Repetitive transcranial magnetic stimulation (rTMS) has potential as a noninvasive neuromodulation treatment method for various neuropsychiatric disorders, and repeated sessions of rTMS are more likely to enhance the therapeutic efficacy. This study investigated neurophysiologic and spatiodynamic changes induced by repeated 1-Hz rTMS of the temporal cortex using transcranial magnetic stimulation (TMS) indices and fluorodeoxyglucose positron emission tomography (FDG-PET).
Twenty-seven healthy subjects underwent daily 1-Hz active or sham rTMS of the right temporal cortex for 5 consecutive days. TMS indices of motor cortical excitability were measured in both hemispheres daily before and after each rTMS session, and 2 weeks after the last stimulation. FDG-PET was performed at baseline and after the 5 days of rTMS sessions.
All subjects tolerated all of the sessions well, with only three of them (11.1%) reporting mild transient side effects (i.e., headache, tinnitus, or local irritation). One-Hz rTMS decreased motor evoked potential amplitudes and delayed cortical silent periods in the stimulated hemisphere. Statistical parametric mapping of FDG-PET data revealed a focal reduction of glucose metabolism in the stimulated temporal area and an increase in the bilateral precentral, ipsilateral superior and middle frontal, prefrontal and cingulate gyri.
Repeated rTMS sessions for 5 consecutive days were tolerated in all subjects, with only occasional minor side effects. Focal 1-Hz rTMS of the temporal cortex induces cortico-cortical modulation with widespread functional changes in brain neural networks via long-range neural connections.

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Available from: Hee-Jin Kim, May 07, 2014
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    • "It has been shown, that rTMS over the temporal cortex can induce changes in motor cortex excitability. In a sham-controlled study 27 healthy subjects showed decreased motor evoked potential amplitudes and delayed cortical silent period (CSP) after five days of 1Hz rTMS of the right temporal cortex [14]. Furthermore, these changes were accompanied by a decrease in glucose metabolism in the stimulated temporal cortex and an increase in cingulate and frontal areas but also in motor cortex. "
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