OBJECTIVE: To optimize the clinical uses of repetitive transcranial magnetic stimulation (rTMS), we compared the effects of rTMS on somatosensory-evoked potentials (SEPs) and regional cerebral blood flow (rCBF) using different phases (monophasic vs. biphasic) or frequencies (0.2Hz vs. 0.8Hz) of stimulation. METHODS: In the first experiment, different phases were compared (0.2Hz monophasic vs. 0.2Hz biphasic). Biphasic 1Hz or sham condition served as controls. The second experiment was to explore the effect of frequencies (0.2Hz vs. 0.8Hz) using the monophasic stimulation. Substhreshold TMS was applied 250 times over the left premotor cortex. Single photon emission computed tomography (SPECT) was performed before and after monophasic 0.2Hz or biphasic 1Hz rTMS. RESULTS: Monophasic rTMS of both 0.2 and 0.8Hz significantly increased the ratio of N30 amplitudes as compared with sham rTMS, whereas biphasic stimulation showed no significant effects. SPECT showed increased rCBF in motor cortices after monophasic 0.2Hz rTMS, but not after biphasic 1Hz stimulation. CONCLUSIONS: Monophasic rTMS exerted more profound effects on SEPs and rCBF than biphasic rTMS over the premotor cortex. SIGNIFICANCE: Monophasic rTMS over the premotor cortex could be clinically more useful than biphasic rTMS.
OBJECTIVE: To optimize the clinical uses of repetitive transcranial magnetic stimulation (rTMS), we compared the effects of rTMS on somatosensory-evoked potentials (SEPs) and regional cerebral blood flow (rCBF) using different phases (monophasic vs. biphasic) or frequencies (0.2Hz vs. 0.8Hz) of stimulation. METHODS: In the first experiment, different phases were compared (0.2Hz monophasic vs. 0.2Hz biphasic). Biphasic 1Hz or sham condition served as controls. The second experiment was to explore the effect of frequencies (0.2Hz vs. 0.8Hz) using the monophasic stimulation. Substhreshold TMS was applied 250 times over the left premotor cortex. Single photon emission computed tomography (SPECT) was performed before and after monophasic 0.2Hz or biphasic 1Hz rTMS. RESULTS: Monophasic rTMS of both 0.2 and 0.8Hz significantly increased the ratio of N30 amplitudes as compared with sham rTMS, whereas biphasic stimulation showed no significant effects. SPECT showed increased rCBF in motor cortices after monophasic 0.2Hz rTMS, but not after biphasic 1Hz stimulation. CONCLUSIONS: Monophasic rTMS exerted more profound effects on SEPs and rCBF than biphasic rTMS over the premotor cortex. SIGNIFICANCE: Monophasic rTMS over the premotor cortex could be clinically more useful than biphasic rTMS.
Authors: Stefan M Goetz; Bruce Luber; Sarah H Lisanby; David L K Murphy; I Cassie Kozyrkov; Warren M Grill; Angel V Peterchev Journal: Brain Stimul Date: 2015-09-01 Impact factor: 8.955
Authors: Simone Rossi; Andrea Antal; Sven Bestmann; Marom Bikson; Carmen Brewer; Jürgen Brockmöller; Linda L Carpenter; Massimo Cincotta; Robert Chen; Jeff D Daskalakis; Vincenzo Di Lazzaro; Michael D Fox; Mark S George; Donald Gilbert; Vasilios K Kimiskidis; Giacomo Koch; Risto J Ilmoniemi; Jean Pascal Lefaucheur; Letizia Leocani; Sarah H Lisanby; Carlo Miniussi; Frank Padberg; Alvaro Pascual-Leone; Walter Paulus; Angel V Peterchev; Angelo Quartarone; Alexander Rotenberg; John Rothwell; Paolo M Rossini; Emiliano Santarnecchi; Mouhsin M Shafi; Hartwig R Siebner; Yoshikatzu Ugawa; Eric M Wassermann; Abraham Zangen; Ulf Ziemann; Mark Hallett Journal: Clin Neurophysiol Date: 2020-10-24 Impact factor: 4.861