2024

Pauls, K. Amande M. .; Nurmi, Pietari; Ala-Salomäki, Heidi; Renvall, Hanna; Kujala, Jan; Liljeström, Mia

Objective Diseases affecting sensorimotor function impair physical independence. Reliable functional clinical biomarkers allowing early diagnosis or targeting treatment and rehabilitation could reduce this burden. Magnetoencephalography (MEG) non-invasively measures brain rhythms such as the somatomotor ‘rolandic’ rhythm which shows intermittent high-amplitude beta (14-30Hz) ‘events’ that predict behavior across tasks and species and are altered by sensorimotor neurological diseases. Methods We assessed test-retest stability, a prerequisite for biomarkers, of spontaneous sensorimotor aperiodic (1/f) signal and beta events in 50 healthy human controls across two MEG sessions using the intraclass correlation coefficient (ICC). Beta events were determined using an amplitude-thresholding approach on a narrow-band filtered amplitude envelope obtained using Morlet wavelet decomposition. Results Resting sensorimotor characteristics showed good to excellent test-retest stability. Aperiodic component (ICC 0.77-0.88) and beta event amplitude (ICC 0.74-0.82) were very stable, whereas beta event duration was more variable (ICC 0.55-0.7). 2-3 minute recordings were sufficient to obtain stable results. Analysis automatization was successful in 86%. Conclusions Sensorimotor beta phenotype is a stable feature of an individual’s resting brain activity even for short recordings easily measured in patients. Significance Spontaneous sensorimotor beta phenotype has potential as a clinical biomarker of sensorimotor system integrity.