Thalamic Deep Brain Stimulation Salvages Failed Focused Ultrasound Thalamotomy for Essential Tremor: A Case Report

Abstract

Background: A recent randomized controlled trial investigating unilateral MRI-guided focused ultrasound (FUS) for essential tremor demonstrated efficacy. The long-term durability of this thalamotomy, however, is unknown. Furthermore, the feasibility of stimulating a previously lesioned target such as the thalamic nucleus ventralis intermedius (Vim) is poorly understood. We report a case of tremor recurrence, following an initially successful FUS thalamotomy, in which Vim-DBS was subsequently utilized to regain tremor control. Methods: An 81-year-old right-handed female with medically refractory essential tremor (a Clinical Rating Scale for Tremor [CRST] value of 73) underwent left-sided FUS thalamotomy with initial abolition of right-upper extremity tremor. By the 6-month follow-up, there was complete recurrence of tremor (a CRST value of 76). The patient subsequently underwent left-sided Vim-DBS. Results: Vim-DBS provided clinical improvement with a CRST value of 42 at the 3-month follow-up; the patient continues to do clinically well at the 6-month follow-up. This result mirrors previous reported cases of stimulation following radiofrequency and gamma-knife lesioning. Our literature review highlights several reasons for the waning of clinical benefit seen with lesional procedures. Conclusion: This case demonstrates that thalamic DBS can salvage a failed FUS thalamotomy and also the feasibility of stimulating a previously lesioned target.

Diffusion tensor imaging‐based magnetic resonance imaging‐guided focused ultrasound thalamotomy for tremor recurrence after radiofrequency thalamotomy: A case report

“…The best therapeutic option for tremor recurrence has not been elucidated. Three cases of Vim‐DBS for tremor recurrence after MRgFUS Vim thalamotomy have been reported 11‐13 . On the contrary, this is the first report of MRgFUS Vim thalamotomy for tremor recurrence after RF Vim thalamotomy.…”

“…Three cases of Vim-DBS for tremor recurrence after MRgFUS Vim thalamotomy have been reported. [11][12][13] On the contrary, this is the first report of MRgFUS Vim thalamotomy for tremor recurrence after RF Vim thalamotomy. Further studies with a larger number of patients are needed; however, MRgFUS Vim thalamotomy could become one of the therapeutic options for tremor recurrence.…”

Case Report on Deep Brain Stimulation Rescue After Suboptimal MR-Guided Focused Ultrasound Thalamotomy for Essential Tremor: A Tractography-Based Investigation

“…It is noteworthy that despite suboptimal targeting and premature cessation of sonications due to dysarthria, the initial MRgFUS treatment resulted in tremor relief, albeit temporarily. The onset of tremor recurrence within 1 year postoperatively has been reported in numerous cases in the literature, even without lesions complicated by dysarthria (Wang et al, 2018;Halpern et al, 2019). This suggests several plausible explanations for loss of tremor suppression efficacy over time after MRgFUS.…”

“…Tremor relief that is not sustained after MRgFUS treatment is troublesome to patients and presents a significant management challenge. For these patients in whom treatment has failed, it may be appropriate to offer repeat or rescue procedures (Tuleasca et al, 2017;Wang et al, 2018;Weidman et al, 2019). However, in the described case, the scant availability of repeat MRgFUS efficacy, the side effect of dysarthria, and patient preference for bilateral therapy made DBS a favorable alterative, not to mention its ability to be used somewhat reversibly and bilaterally.…”

Microelectrode Recording and Radiofrequency Thalamotomy following Focused Ultrasound Thalamotomy

“…This case illustrates that RF thalamotomy remains a viable salvage therapy for tremor recurrence after ­MRgFUS thalamotomy, although repeated MRgFUS thalamotomy [8] and Vim deep brain stimulation [9] have also successfully been applied in similar cases. However, repeated ablation may carry a higher risk of transient and/or permanent side effects, including hemiparesis, hemihypoesthesia, and hemiataxia.…”