Bilateral Ventral Intermediate Nucleus Thalamic Deep Brain Stimulation in Orthostatic Tremor

Abstract

Background: Orthostatic tremor (OT) is characterized by high-frequency leg tremor when standing still, resulting in a sense of imbalance, with limited treatment options. Ventral intermediate (Vim) nucleus thalamic deep brain stimulation (DBS) has been reported as beneficial in a few cases. Objective: To report clinical outcomes, lead locations, and stimulation parameters in 2 patients with severe medication-refractory OT treated with Vim DBS. Methods: The patients underwent surface electromyography (EMG) to confirm the OT diagnosis. Outcomes were measured as change in tolerated standing time at the last follow-up. Lead locations were quantified using postoperative MRI. Results: Vim DBS was well tolerated and resulted in improvement in standing time (patient 1: 50 s at baseline to 15 min 16 months after surgery; patient 2: 34 s at baseline to 4.2 min 7 months after surgery). Postoperative surface EMG for patient 1 demonstrated a delayed onset of tremor, lower-amplitude tremor, and periods of quiescence, but an unchanged tremor frequency. Conclusion: These cases provide further support for Vim DBS to improve standing time in severe medication-refractory OT. The location of the effective thalamic target for OT does not differ from the effective target for essential tremor.

Thalamic deep brain stimulation for orthostatic tremor: A multicenter international registry

“…Partial data of 12 cases had previously been published in case reports. [6][7][8][9][10][11][12][13][14] Age at onset ranged from 37 to 73 years, with OT duration between 3 and 30 years at the time of Vim-DBS implantation ( Table 1). Several pharmacological treatments had failed, and 1 case also had undergone spinal cord stimulation (SCS) without benefits (Supplementary Table 1).…”

“…However, the optimal therapeutic target remains unknown. Data gathered from our retrospective experience indicates that only bilateral Vim‐DBS was effective against OT symptoms . Indeed, when the IPG was unilaterally or bilaterally accidentally switched off, there was recrudescence of OT symptoms.…”

Orthostatic Tremor and Orthostatic Myoclonus: Weight-bearing Hyperkinetic Disorders: A Systematic Review, New Insights, and Unresolved Questions

“…Deep brain stimulation (DBS) of bilateral, thalamic ventral intermediate nuclei (VIM) has been reported to benefit a small number of OT patients and requires further study 14,20,82–87…”

Orthostatic Tremor: An Update on a Rare Entity

“… 66 Sixth, cerebellar outflow (dentato-rubro-thalamic) pathways are the target of deep brain stimulation, which may be effective in treating OT. 10 , 78 – 84 Finally, the tremors recorded in each leg have a high coherence. In other words, they have an almost constant phase relationship, which is not typical for most other pathological tremors.…”