Ricerc@Sapienza

Few minutes of focal vibration (FV) on limb muscles can improve motor control in neurological (stroke, Parkinson) patients for unknown underlying neurophysiological mechanisms. Previous results showed that FV increased excitability in the primary sensorimotor cortex (S1-M1) during an isometric contraction of the stimulated muscle (Lopez et al., 2017). Here, we will use the same archive data used in the reference study to evaluate whether FV is also able to modulate the cortical functional connectivity among S1-M1 and other brain regions in healthy subjects. To this aim, electroencephalographic (EEG) data recorded in 20 healthy young volunteers will be used. The design included an initial control condition with no FV stimulation (Baseline) as well as three short experimental sessions of FV and a Sham (fake) session in a pseudo-random order. In the Baseline condition and immediately after those sessions, EEG activity was recorded during a mild isometric muscle contraction of the right arm. We predict that, compared to the Baseline (no FV) or Sham stimulation, the first two FV sessions may show a cumulative modulation of functional connectivity between contralateral S1-M1 and the other cortical regions. These results would suggest a specific effect of vibration on the excitability and functional connectivity of contralateral S1-M1 generating EEG ``mu¿ rhythms. The expected outcome may help to explain the clinical effects of vibratory rehabilitation in neurological patients with motor deficits.