title: Test-retest assessment of cortical activation induced by repetitive transcranial magnetic stimulation with brain atlas-guided optical topography.
abstract: Repetitive transcranial magnetic stimulation (rTMS) is a technology that stimulates neurons with rapidly changing magnetic pulses with demonstrated therapeutic applications for various neuropsychiatric disorders. Functional near-infrared spectroscopy (fNIRS) is a suitable tool to assess rTMS-evoked brain responses without interference from the magnetic or electric fields generated by the TMS coil. We have previously reported a channel-wise study of combined rTMS/fNIRS on the motor and prefrontal cortices, showing a robust decrease of oxygenated hemoglobin concentration (Δ[HbO2]) at the sites of 1-Hz rTMS and the contralateral brain regions. However, the reliability of this putative clinical tool is unknown. In this study, we develop a rapid optical topography approach to spatially characterize the rTMS-evoked hemodynamic responses on a standard brain atlas. A hemispherical approximation of the brain is employed to convert the three-dimensional topography on the complex brain surface to a two-dimensional topography in the spherical coordinate system. The test-retest reliability of the combined rTMS/fNIRS is assessed using repeated measurements performed two to three days apart. The results demonstrate that the Δ[HbO2] amplitudes have moderate-to-high reliability at the group level; and the spatial patterns of the topographic images have high reproducibility in size and a moderate degree of overlap at the individual level.
authors.affiliation: University of Texas at Arlington, Department of Bioengineering, 500 UTA Building, Arlington, Texas, USA.
authors.forename: Fenghua
authors.initials: F
authors.lastname: Tian
authors.forename: F Andrew
authors.initials: FA
authors.lastname: Kozel
authors.forename: Amarnath
authors.initials: A
authors.lastname: Yennu
authors.forename: Paul E
authors.initials: PE
authors.lastname: Croarkin
authors.forename: Shawn M
authors.initials: SM
authors.lastname: McClintock
authors.forename: Kimberly S
authors.initials: KS
authors.lastname: Mapes
authors.forename: Mustafa M
authors.initials: MM
authors.lastname: Husain
authors.forename: Hanli
authors.initials: H
authors.lastname: Liu
mesh_terms: D000328:Adult; D001931:Brain Mapping; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000033:anatomy & histology / Q000098:blood supply / Q000502:physiology*; D061848:Optical Imaging / Q000295:instrumentation / Q000379:methods*; D055620:Optical Phenomena; D010108:Oxyhemoglobins / Q000378:metabolism; D017397:Prefrontal Cortex / Q000033:anatomy & histology / Q000098:blood supply / Q000502:physiology*; D015203:Reproducibility of Results; D019265:Spectroscopy, Near-Infrared / Q000295:instrumentation; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult
chemical_list: D010108:Oxyhemoglobins