Effect of rhythmic auditory stimulation (RAS)® with and without melody on Parkinson's disease (PD) patients with deep brain stimulation (DBS): A study protocol.

Parkinson's Disease (PD) is characterized by motor impairments, including gait abnormalities that contribute to instability and an increased risk of falls as the disease progresses. While deep brain stimulation (DBS) of the subthalamic nucleus (STN) or the globus pallidus internus (GPi) can be highly effective for managing tremor, rigidity and limb bradykinesia, its impact on gait remains limited, highlighting the need for dedicated gait therapies. Rhythmic auditory stimulation (RAS)® has been used to improve PD gait parameters, such as cadence, velocity and stride length. This exploratory pilot study aims to investigate behavioral and neurophysiological response to two RASTM approaches: pure rhythmic RAS, which uses metronome-generated beats, and melodic RAS, which incorporates composed music along with rhythmic beats. We will record local field potentials (LFP) from the DBS devices already implanted in individuals with PD as part of their routine care, along with gait parameters, to assess neurophysiological and behavioral responses to RAS. By recording neural signals from the STN and GPi with assessment of gait parameters, this innovative approach will provide insights into how pure and melodic RAS paradigms modulate neural activity in the basal ganglia, informing the design of future multi-session or powered efficacy trials.