Enhancing Balance Control in Aging Through Cerebellar Theta-Burst Stimulation.

The cerebellum undergoes significant age-related changes linked to poor balance in older adults. Although multi-session cerebellar iTBS combined with rehabilitation has been used in some clinical populations, its isolated effects in community-dwelling healthy older adults remain unknown, particularly in context of balance control and underlying cerebellar-motor cortex (M1) interactions. We tested whether a single-session, sham-controlled, cerebellar iTBS-only intervention could modulate balance and cerebellar-motor cortex (M1) interactions in community-dwelling older adults without neurological disease. The effects of cerebellar intermittent theta-burst stimulation (iTBS) on balance control and underlying cerebellar-motor cortex (M1) interactions in this population remain unclear. We investigated whether cerebellar iTBS led to [1] improved standing balance, and [2] changes in cerebellar-M1interactions measured using cerebellar brain inhibition (CBI) in older adults. Forty older adults were randomized to receive Active (n = 20) or Sham (n = 20) iTBS to the right lateral cerebellum. We measured postural sway (95% ellipse area of the center of pressure) during standing and CBI before iTBS and at multiple time points up to 30 min post-stimulation. Compared to sham, a single session of active iTBS reduced postural sway, with balance improvements sustained for at least 30 min post-stimulation. Cerebellar iTBS did not significantly alter CBI. Our results support the neuroplastic potential of the cerebellum as a viable target for therapeutic interventions aimed at improving balance in aging, potentially influencing circuits beyond direct cerebellar-M1 motor pathways.