title: Cortico-cortical modulation induced by 1-Hz repetitive transcranial magnetic stimulation of the temporal cortex.
abstract: OBJECTIVE
  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).
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Neurology, Ewha Womans University School of Medicine, Seoul, Korea.
authors.forename: Mina
authors.initials: M
authors.lastname: Lee
authors.forename: Song E
authors.initials: SE
authors.lastname: Kim
authors.forename: Won Sup
authors.initials: WS
authors.lastname: Kim
authors.forename: Jooman
authors.initials: J
authors.lastname: Han
authors.forename: Hee-Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Bom Sahn
authors.initials: BS
authors.lastname: Kim
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Kim
authors.forename: Seung Bong
authors.initials: SB
authors.lastname: Hong
authors.forename: Byung Gon
authors.initials: BG
authors.lastname: Kim
authors.forename: Hyang Woon
authors.initials: HW
authors.lastname: Lee
keywords: cortical excitability; cortico-cortical modulation; fluorodeoxyglucose positron emission tomography (FDG-PET); repetitive transcranial magnetic stimulation (rTMS)