title: Brain topological correlates of motor performance changes after repetitive transcranial magnetic stimulation.
abstract: Repetitive transcranial magnetic stimulation (rTMS) influences the brain temporally beyond the stimulation period and spatially beyond the stimulation site. Application of rTMS over the primary motor cortex (M1) has been shown to lead to plastic changes in interregional connectivity over the motor system as well as alterations in motor performance. With a sequential combination of rTMS over the M1 and functional magnetic resonance imaging (fMRI), we sought changes in the topology of brain networks and specifically the association of brain topological changes with motor performance changes. In a sham-controlled parallel group experimental design, real or sham rTMS was administered to each of the 15 healthy subjects without prior motor-related dysfunctions, over the right M1 at a high frequency of 10 Hz. Before and after the intervention, fMRI data were acquired during a sequential finger motor task using the left, nondominant hand. Changes in the topology of brain networks were assessed in terms of global and local efficiency, which measures the efficiency in transporting information at global and local scales, respectively, provided by graph-theoretical analysis. Greater motor performance changes toward improvements after real rTMS were shown in individuals who exhibited more increases in global efficiency and more decreases in local efficiency. The enhancement of motor performance after rTMS is supposed to be associated with brain topological changes, such that global information exchange is facilitated, while local information exchange is restricted.
authors.affiliation: 1 Department of Physical and Rehabilitation Medicine, Sungkyunkwan University School of Medicine , Seoul, Korea.
authors.forename: Chang-hyun
authors.initials: CH
authors.lastname: Park
authors.forename: Won Hyuk
authors.initials: WH
authors.lastname: Chang
authors.forename: Woo-Kyoung
authors.initials: WK
authors.lastname: Yoo
authors.forename: Yong-Il
authors.initials: YI
authors.lastname: Shin
authors.forename: Sung Tae
authors.initials: ST
authors.lastname: Kim
authors.forename: Yun-Hee
authors.initials: YH
authors.lastname: Kim
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods; D005260:Female; D005385:Fingers / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D050781:Transcranial Magnetic Stimulation / Q000379:methods; D055815:Young Adult
keywords: functional magnetic resonance imaging; graph-theoretical analysis; motor performance; repetitive transcranial magnetic stimulation