[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-seo-459846-105":3,"detail-sidebar-cat-0-en-105":80,"doc-detail-459846-en":130},{"code":4,"msg":5,"data":6},0,"ok",{"site_id":7,"language":8,"slug":9,"title":10,"keywords":11,"description":12,"schema_data":13,"social_meta":73,"head_meta":75,"extra_data":77,"updated_unix":79},105,"en","clarifying-order-and-carry-over-considerations-in-dual-target-mrgfus-for-parkinsons-disease-letter-to-the-editor","Clarifying Order and Carry-Over Considerations in Dual-Target MRgFUS for Parkinson's Disease - Letter to the Editor","","Letter to the editor clarifies the rationale behind intraoperative target sequencing and possible post-lesion carry-over in a dual-target MR-guided focused ultrasound strategy for Parkinson’s disease. The authors describe a deliberate first ablation of VIM followed by PTT within the same session, with immediate pre/post evaluations to limit sequence bias. They address transient edema or conduction effects by using VIM scoring timed before effective PTT sonication and confirm lesion confinement by post-op MRI. They argue observed tremor versus rigidity responses support target-specific physiology and outline planned randomized, multi-center validation including a VIM-only control arm.",{"@graph":14,"@context":72},[15,34,55],{"@type":16,"itemListElement":17},"BreadcrumbList",[18,23,27,31],{"item":19,"name":20,"@type":21,"position":22},"https://docshare.wps.com","Home","ListItem",1,{"item":24,"name":25,"@type":21,"position":26},"https://docshare.wps.com/document/","Document",2,{"item":28,"name":29,"@type":21,"position":30},"https://docshare.wps.com/document/healthcare/","Healthcare",3,{"item":32,"name":10,"@type":21,"position":33},"https://docshare.wps.com/document/clarifying-order-and-carry-over-considerations-in-dual-target-mrgfus-for-parkinsons-disease-letter-to-the-editor/459846/",4,{"url":32,"name":10,"@type":35,"image":36,"author":41,"headline":10,"publisher":44,"fileFormat":47,"inLanguage":8,"description":12,"dateModified":48,"datePublished":49,"encodingFormat":47,"isAccessibleForFree":50,"interactionStatistic":51},"DigitalDocument",{"url":37,"@type":38,"width":39,"height":40},"https://docshare.wps.com/thumbnails/clarifying-order-and-carry-over-considerations-in-dual-target-mrgfus-for-parkinsons-disease-letter-to-the-editor/459846.png","ImageObject",300,407,{"name":42,"@type":43},"Cipher","Person",{"url":19,"name":45,"@type":46},"DocShare","Organization","application/pdf","2026-11-08","2026-09-30",true,{"@type":52,"interactionType":53,"userInteractionCount":26},"InteractionCounter",{"@type":54},"ViewAction",{"@type":56,"mainEntity":57},"FAQPage",[58,64,68],{"name":59,"@type":60,"acceptedAnswer":61},"Why did the study perform VIM ablation before PTT in the same MRgFUS session?","Question",{"text":62,"@type":63},"The sequence was chosen based on safety and anatomical hierarchy, with VIM being a validated, relatively superficial target and PTT located deeper near eloquent structures. Performing VIM first aimed to ensure procedural safety, patient tolerance, and adequate acoustic transmission before the deeper lesion.","Answer",{"name":65,"@type":60,"acceptedAnswer":66},"How did the authors reduce the influence of sequence bias and carry-over on assessments?",{"text":67,"@type":63},"Clinical evaluations were conducted immediately before and after each step (VIM then PTT) to enable within-subject comparison. For carry-over, VIM scoring used for analysis was obtained immediately before the first effective PTT sonication, with latency under 10 minutes, and lesion overlap was checked with post-op MRI.",{"name":69,"@type":60,"acceptedAnswer":70},"What do the differential outcomes for tremor versus rigidity suggest?",{"text":71,"@type":63},"Tremor subtypes improved primarily after VIM, while rigidity improved most prominently after PTT. The authors interpret this parameter-specific dissociation as evidence against a non-specific additive or order-driven effect and as support for target-specific physiological effects.","https://schema.org",{"og:url":32,"og:type":74,"og:title":10,"og:site_name":45,"og:description":12},"article",{"robots":76,"canonical":32},"index,follow",{"doc_id":78,"site_id":7},459846,1790757086,{"code":4,"msg":81,"data":82},"success",[83,87,91,95,100,105,109,114,119,122,126],{"id":22,"doc_module":4,"doc_module_name":25,"category_name":84,"show_sort_weight":85,"slug":86},"Story & Novel",90,"story-novel",{"id":26,"doc_module":4,"doc_module_name":25,"category_name":88,"show_sort_weight":89,"slug":90},"Literature",80,"literature",{"id":33,"doc_module":4,"doc_module_name":25,"category_name":92,"show_sort_weight":93,"slug":94},"Exam",70,"exam",{"id":96,"doc_module":4,"doc_module_name":25,"category_name":97,"show_sort_weight":98,"slug":99},5,"Comic",60,"comic",{"id":101,"doc_module":4,"doc_module_name":25,"category_name":102,"show_sort_weight":103,"slug":104},6,"Technology",50,"technology",{"id":106,"doc_module":4,"doc_module_name":25,"category_name":29,"show_sort_weight":107,"slug":108},7,40,"healthcare",{"id":110,"doc_module":4,"doc_module_name":25,"category_name":111,"show_sort_weight":112,"slug":113},8,"Research & Report",30,"research-report",{"id":115,"doc_module":4,"doc_module_name":25,"category_name":116,"show_sort_weight":117,"slug":118},9,"Religion & Spirituality",20,"religion-spirituality",{"id":117,"doc_module":4,"doc_module_name":25,"category_name":120,"show_sort_weight":117,"slug":121},"World Cup","world-cup",{"id":123,"doc_module":4,"doc_module_name":25,"category_name":124,"show_sort_weight":123,"slug":125},10,"Lifestyle","lifestyle",{"id":127,"doc_module":4,"doc_module_name":25,"category_name":128,"show_sort_weight":96,"slug":129},19,"General","general",{"code":4,"msg":81,"data":131},{"doc_id":78,"user_id":132,"nickname":42,"user_avatar":133,"doc_module":4,"category_id":106,"category_name":29,"doc_title":10,"doc_description":12,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":26,"is_deleted":4,"is_public":22,"is_downloadable":22,"audit_status":22,"page_count":26,"language":139,"language_code":8,"site_id":7,"html_lang":8,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":12,"update_tm":79,"read_time":96,"preview_page_count":4},687208528416,"https://ap-avatar.wpscdn.com/davatar_9964176cb1d06d4a9deccf72a44ae3dc","European Journal of Neurology  \nLETTER TO THE EDITOR  OPEN ACCESS   \nClarifying Order and Carry-Over Considerations in Dual-Target MRgFUS for Parkinson's Disease  \nJui-Cheng Chen  | Ming-Kuei Lu | Chon-Haw Tsai   \nDivision of Parkinson's Disease and Movement Disorders, China Medical University Hospital, Taichung, Taiwan Correspondence: Jui-Cheng Chen ([013132@tool.caaumed.org.tw](013132@tool.caaumed.org.tw))  \nReceived: 14 November 2025 | Revised: 14 November 2025 | Accepted: 27 November 2025  \nTo the Editor,  \nWe appreciate the thoughtful comments regarding our recent article, “Immediate Motor Control Enhancement via Pallidothalamic Tract (PTT) Circuit Ablation: A Dual-Target MR-Guided Focused Ultrasound Approach for TremorDominant Parkinson's Disease” [1] . We welcome this opportunity to address concerns regarding the possible influence of order effects and carry-over phenomena in our intraoperative design.  \n1 | Order Effect  \nAll participants underwent ventral intermediate nucleus (VIM) ablation first, followed by PTT ablation within the same MRgFUS session. This sequence was deliberately selected based on safety and anatomical hierarchy. The VIM is a well-validated and relatively superficial target for tremor control, whereas the PTT lies deeper, adjacent to eloquent structures such asthe Mammillothalamic tract (MTT) and subthalamic nucleus (STN) . Performing VIM first ensured procedural safety, patient tolerance, and adequate acoustic transmission before proceeding to the deeper lesion.  \nTo mitigate potential sequence bias, clinical evaluations were performed immediately before and after each step (VIM evaluation → PTT evaluation), allowing within-subject comparison. Distinct temporal and domain-specific effects were observed: all tremor subtypes improved primarily after VIM, while rigidity improved most prominently after PTT. These differential response patterns argue against a non-specific additive or orderdriven gain.  \n2 | Carry-Over and Microlesional Effects  \nWe concur that transient edema or temperature-dependent conduction block may transiently influence immediate post-lesion testing. To minimize such effects, the VIM score used for analysis was obtained immediately before the first effective PTT sonication, with a latency of less than 10 min. Lesion overlap was also evaluated by post-op MRI, confirming confinement to the intended PTT zone.  \nWhile our study design cannot fully exclude microlesional carry-over, the parameter-specific dissociation (rigidity versus tremor) and the consistency across subjects support targetspecific physiological effects rather than generalized intraoperative augmentation.  \n3 | Future Directions  \nWe fully agree that randomized or counterbalanced target order, standardized lesion metrics, and objective blinded kinematic assessments are essential to confirm causality. These refinementshave already been incorporated into our upcoming multi-center trial, which will include a VIM-only intraoperative control arm to rigorously evaluate the incremental contribution of PTTlesioning.  \n4 | Conclusion  \nOur present study was intended as a physiological feasibility investigation, not as a definitive randomized comparison. In  \nThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.  \n© 2026 The Author(s). European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.  \nEuropean Journal of Neurology, 2026; 33:e70467 1 of 2  \n[https://doi.org/10.1111/ene.70467](https://doi.org/10.1111/ene.70467)  \nclinical practice, patients with Parkinson's disease frequently present with a mixed motor phenotype in which disabling tremor coexists with varying degrees of rigidity and bradykinesia. For such individuals, our standard treatment algorithm prioritizes VIM ab","cbCaibDD6Sncgm3r","https://ap.wps.com/l/cbCaibDD6Sncgm3r","pdf",133450,"English","# Order Effect\n## Carry-Over and Microlesional Effects\n# Future Directions\n# Conclusion","[{\"question\":\"Why did the study perform VIM ablation before PTT in the same MRgFUS session?\",\"answer\":\"The sequence was chosen based on safety and anatomical hierarchy, with VIM being a validated, relatively superficial target and PTT located deeper near eloquent structures. Performing VIM first aimed to ensure procedural safety, patient tolerance, and adequate acoustic transmission before the deeper lesion.\"},{\"question\":\"How did the authors reduce the influence of sequence bias and carry-over on assessments?\",\"answer\":\"Clinical evaluations were conducted immediately before and after each step (VIM then PTT) to enable within-subject comparison. For carry-over, VIM scoring used for analysis was obtained immediately before the first effective PTT sonication, with latency under 10 minutes, and lesion overlap was checked with post-op MRI.\"},{\"question\":\"What do the differential outcomes for tremor versus rigidity suggest?\",\"answer\":\"Tremor subtypes improved primarily after VIM, while rigidity improved most prominently after PTT. The authors interpret this parameter-specific dissociation as evidence against a non-specific additive or order-driven effect and as support for target-specific physiological effects.\"}]","Clarifying Order and Carry-Over Considerations in Dual-Target MRgFUS for Parkinson's Disease - Letter to the Editor | PDF"]