Outcomes of Focused Ultrasound Thalamotomy in Tremor Syndromes

Abstract

BackgroundThe current literature comparing outcomes after a unilateral magnetic resonance image–guided focused ultrasound (MRgFUS) thalamotomy between tremor syndromes is limited and remains a possible preoperative factor that could help predict the long‐term outcomes.ObjectiveThe aim was to report on the outcomes between different tremor syndromes after a unilateral MRgFUS thalamotomy.MethodsA total of 66 patients underwent a unilateral MRgFUS thalamotomy for tremor between November 2018 and May 2020 at St Vincent's Hospital Sydney. Each patient's tremor syndrome was classified prior to treatment. Clinical assessments, including the hand tremor score (HTS) and Quality of Life in Essential Tremor Questionnaire (QUEST), were performed at baseline and predefined intervals to 36 months.ResultsA total of 63 patients, comprising 30 essential tremor (ET), 24 dystonic tremor (DT), and 9 Parkinson's disease tremor (PDT) patients, returned for at least one follow‐up. In the ET patients, at 24 months there was a 61% improvement in HTS and 50% improvement in QUEST compared to baseline. This is in comparison to PDT patients, where an initial benefit in HTS and QUEST was observed, which waned at each follow‐up, remaining significant only up until 12 months. In the DT patients, similar results were observed to the ET patients: at 24 months there was a 61% improvement in HTS and 43% improvement in QUEST compared to baseline.ConclusionThese results support the use of unilateral MRgFUS thalamotomy for the treatment of DT, which appears to have a similar expected outcome to patients diagnosed with ET. Patients with PDT should be warned that there is a risk of treatment failure. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Focused ultrasound therapy in movement disorders: management roadmap toward optimal pathway organization

“…Among interventional approaches, magnetic resonance-guided focused ultrasound (MRgFUS) ablation therapy is a non-invasive modality requiring neither craniotomy nor skin incision for the treatment of ET, unilateral tremor in PD or dystonia and neuropathic pain ( 4 ). It immediately appeared necessary and indispensable to structure a pathway for patients with movement disorders eligible for interventional therapies to offer them the best personalized option based on international guidelines and expert consensus and on the availability of healthcare institute in terms of expertise, facilities, technology, staff available.…”

The evolution of ventral intermediate nucleus targeting in MRI-guided focused ultrasound thalamotomy for essential tremor: an international multi-center evaluation

“…Over the past decade, the efficacy of FUS VIM ablation has been proven in multiple international studies ( 1 – 3 ) and recent systematic reviews, which demonstrated pooled tremor suppression of 56.7%, 62.4%, and 61.5%, respectively ( 4 – 7 ). Although other tremor-specific targets such as the cerebellothalamic tract ( 8 ) or even a combination of targets such as the VIM with the posterior subthalamic area (PSA) ( 9 , 10 ) have been explored, the VIM alone remains the most frequently used target in FUS treatment for ET ( 11 , 12 ). Several alternative targets have been considered in Parkinson's disease (PD) ( 13 – 16 ), but the VIM remains the target of choice for FUS treatment of tremor-dominant PD ( 17 ).…”

Which Focused Ultrasound Thalamotomy Lesion Is Optimal for Dystonic Tremor?

“…In the literature, previous studies indicate enhanced efficacy of PSA or VOA lesions in dystonic conditions, warranting a detailed subgroup analysis to understand the differential therapeutic impacts of these lesion types. [1][2][3] The study's methodology, involving the creation of additional lesions in response to residual tremor, was identified as a potential limitation in the article discussion. 1 However, a detailed quantitative analysis comparing outcomes before and after this modification in the treatment strategy is absent.…”

“…[1][2][3] The study's methodology, involving the creation of additional lesions in response to residual tremor, was identified as a potential limitation in the article discussion. 1 However, a detailed quantitative analysis comparing outcomes before and after this modification in the treatment strategy is absent. Such an analysis is crucial to understand the full impact of this approach on tremor control.…”