title: Mechanical flutter stimulation induces a lasting response in the sensorimotor cortex as revealed with BOLD fMRI.
abstract: It has been recently shown that 20 min of mechanical flutter stimulation induces lasting motor cortical excitability changes, as assessed by transcranial magnetic stimulation in relaxed hand muscles. The present functional magnetic resonance imaging (fMRI) study aims to examine if such neuromodulatory changes are reflected in the BOLD signal during a motor test. Therefore, two groups were recruited: one group receiving whole-hand flutter stimulation with a frequency of 25 Hz (FSTIM group, n = 22) and a second group receiving no stimulation (NOSTIM group, n = 22). As motor test finger-to-thumb tapping was performed to activate a wide sensorimotor network during the fMRI measurements. Three fMRI measurements were obtained with this test: before stimulation (PRE), after stimulation (POST1), and 1 h after stimulation (POST2). Three regions of interest (ROIs) were defined: primary motor area (M1), primary somatosensory area (S1), and supplementary motor area. In the absence of baseline differences between both groups, the FSTIM group showed increased movement-related brain activations compared with the NOSTIM group, both at POST1 and POST2. ROI analysis revealed increased blood-oxygenation-level-dependent (BOLD) responses within contralateral S1 (+20%) and M1 (+25%) at POST1, which lasted until POST2. These poststimulatory effects within S1 and M1 obviously reflect neuroplastic changes associated with augmented cortical excitability. These findings are of high clinical relevance, for example, to improve the treatment of stroke patients.
authors.affiliation: Department of Physiology, Medical University of Graz, Graz, Austria.
authors.forename: Monica
authors.initials: M
authors.lastname: Christova
authors.forename: Stefan
authors.initials: S
authors.lastname: Golaszewski
authors.forename: Anja
authors.initials: A
authors.lastname: Ischebeck
authors.forename: Alexander
authors.initials: A
authors.lastname: Kunz
authors.forename: Dietmar
authors.initials: D
authors.lastname: Rafolt
authors.forename: Raffaele
authors.initials: R
authors.lastname: Nardone
authors.forename: Eugen
authors.initials: E
authors.lastname: Gallasch
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology; D001931:Brain Mapping; D003463:Cues; D003627:Data Interpretation, Statistical; D005260:Female; D005385:Fingers / Q000502:physiology; D006225:Hand / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology; D010100:Oxygen / Q000097:blood; D010812:Physical Stimulation; D011597:Psychomotor Performance / Q000502:physiology; D013003:Somatosensory Cortex / Q000502:physiology*; D055815:Young Adult
chemical_list: D010100:Oxygen