The modulation of rolandic oscillation induced by digital nerve stimulation and self-paced movement of the finger: A MEG study

Abstract Background The rolandic cortex exhibits spontaneous rhythmic activity. This oscillation can be modulated by somatosensory stimulation and voluntary movement. The purpose of this study is to elucidate the influence of sensory input on the rolandic oscillation in comparison with movement-related oscillation. Methods Magnetic brain rhythms were recorded in nine healthy subjects in two sessions: electrical stimulation (STIM) of the digital nerve and self-paced movement (SPM) of the right index finger. Thereafter, 10 and 20 Hz oscillatory activities were compared between the two sessions with temporal spectral evolution analysis. Results Sensory input altered the rolandic oscillations even under no movement conditions. As for 10 Hz ERD in the STIM session, three subjects showed a contralateral dominant pattern, whereas the remaining subjects showed a bilateral pattern. In spite of this individual variability, ERD showed comparable amplitude in both sessions. However, ERSs in the SPM session were larger than that in the STIM session. These findings might reflect the activation of neural networks common to sensory and motor systems followed by the inhibition of the other surrounding cortical areas. Conclusions Our results suggest that rolandic oscillations may reflect the coordination of sensory and motor systems in the neural networks including both sensory and motor systems.