Deep brain stimulation and magnetic resonance-guided focused ultrasound in Parkinsonism and related disorders: State-of-the-Art and future prospects.

Deep brain stimulation (DBS) has been a cornerstone treatment for pharmacologically refractory Parkinson's disease, essential tremor, and dystonia for over three decades. While it offers substantial symptom relief and medication reduction, its invasive nature introduces risks such as surgical complications and hardware-related issues. Magnetic resonance-guided focused ultrasound (MRgFUS) has recently emerged as a non-invasive neuromodulation alternative, providing incisionless lesioning for selected cases, particularly tremor-dominant phenotypes. However, the two modalities differ significantly in terms of mechanism, adaptability, safety profile, and long-term efficacy. This review synthesizes recent developments in DBS and MRgFUS for Parkinsonism and related movement disorders, focusing on clinical efficacy, safety outcomes, and technological innovations. We evaluated the following key areas: adaptive and closed-loop DBS systems, advances in MRgFUS targeting and imaging, long-term outcomes, and the integration of machine learning in DBS personalization. These findings underscore the complementary roles of DBS and MRgFUS, supporting individualized, data-driven treatment approaches and highlighting the need for future large-scale, controlled trials to further optimize therapeutic strategies.