# Focused Ultrasound in the Rehabilitation Setting:
## 4 Discussion and Future Directions
### Neurological and Psychiatric Disabilities  
MRgFUS thalamotomy has emerged as a promising therapeutic option for several possible rehabilitation applications (Figure 2). Among the most promising conditions, movement disorders such as ET and PD have raised interest. Studies by [PERSON] et al. [13] and [PERSON] et al. [14] reported substantial tremor reduction rates (56.4-59.4%) in ET patients, with concomitant improvements in QoL. Furthermore, functional imaging by [PERSON] et al. [17] demonstrated increased thalamic-premotor connectivity following thalamotomy, suggesting enhanced motor-sensory integration as a potential mechanism underlying tremor reduction. Functional neurosurgical procedures, including stereotactic lesion surgery, have long demonstrated efficacy in ameliorating the involuntary movements characteristic of PD and ET. MRgFUS offers a less invasive alternative to deep brain stimulation (DBS) by precisely creating localized lesions within deep brain structures without the need for invasive surgical procedures, such as burr holes or electrode implantation [36; 37]. Given the significant impact of movement disorders on QoL [38], effective therapeutic options are crucial, and FUS could represent a crucial alternative for future rehabilitation approaches. Moreover, FUS demonstrated excellent safety profiles with minimal treatment-related side effects. Another area of application for FUS that emerged from our review lies in the treatment of psychiatric conditions such as MDD and OCD, which rank among the most prevalent mental health disorders globally. Notably, approximately one-third of patients with MDD or OCD exhibit treatment resistance, highlighting the critical need for novel therapeutic approaches [39]. Psychiatric surgery, encompassing neurosurgical procedures such as DBS or lesional surgery targeting critical nodes within the limbic circuitry, represents a viable treatment option for these refractory cases [40]. Unlike DBS, which necessitates permanent implantation of a neurostimulator device, lesional procedures such as FUS eliminate the need for continuous device monitoring, programming, and battery replacements, with the potential to revolutionize lesional procedures [41]. Clinical evidence supports the efficacy of lesional procedures in treatment-resistant OCD and MDD. Case series consistently report significant clinical improvement in approximat  
Figure 2: Schematic representation of potential FUS uses in rehabilitation settings. [PERSON] et al. 's [21] findings support this concept, demonstrating significant symptom improvement without cognitive decline in patients with OCD/MDD following MRgFUS anterior capsulotomy. Advancements in the field of neurological conditions following FUS therapy are also supported by [PERSON] et al. [22], who reported a reduction in seizure frequency following anterior thalamic ablation, although transient verbal fluency deficits were observed. In contrast, [PERSON] et al. [24] found no cognitive improvements in patients with Alzheimer's disease despite successful BBB opening using FUS. This discrepancy suggests that achieving therapeutic efficacy in human neurological conditions may require a more nuanced approach, potentially involving adjunctive pharmacotherapies or further refinement of FUS parameters. Moreover, FUS represents an innovative tool for noninvasive neuromodulation with promising applications in motor and cognitive rehabilitation. While rehabilitation of neurological conditions is already a vastly developed field, the ability of FUS to selectively target cortical circuits with minimal side effects positions it as a valuable technique for advancing therapeutic approaches in neurological disorders [43; 44; 45]. Previous studies have demonstrated that transcranial FUS (tFUS) can modulate neuronal activity in animal models with high spatial resolution, targeting specific cortical areas [46; 47; 48].