Cortical beta modulation during active movement is highly reproducible in healthy adults

The rolandic beta (13-30 Hz) rhythm recorded over the sensorimotor cortices is known to be modified by movement execution and observation. Beta modulation has been considered as a biomarker of motor function in various neurological diseases, and active natural-like movements might offer a clinically feasible method to assess them. Although the stability of movement-related beta modulation has been addressed during passive and highly controlled active movements, the test-retest reliability of natural-like movements has not been established. We used magnetoencephalography (MEG) to evaluate the reproducibility of movement-related sensorimotor beta modulation longitudinally over 3 mo in a group of healthy adults (n = 22). We focused on the changes in beta activity both during active grasping movement (beta suppression) and after movement termination (beta rebound). The strengths of beta suppression and rebound were similar between the baseline and follow-up measurements; intraclass correlation coefficient values (0.76-0.96) demonstrated high reproducibility. Our results indicate that the beta modulation in response to an active hand-squeezing task has excellent test-retest reliability: the natural-like active movement paradigm is suitable for evaluating the functional state of the sensorimotor cortex and can be used as a biomarker in clinical follow-up studies.NEW & NOTEWORTHY This research demonstrates that the beta rhythm modulation related to active hand-squeezing task has an excellent test-retest reproducibility in healthy adults over a three-month follow-up period. This natural-like active movement is thus suitable for evaluating beta modulation to assess the functional state of the sensorimotor cortex and can be utilized as a biomarker, for example, in clinical longitudinal follow-up studies.