Objective: To compare the safety, efficacy, energy efficiency and quality of life (QoL) outcomes of bilateral PSA-DBS vs bilateral VIM-DBS in the treatment of refractory ET.
Background: Deep brain stimulation (DBS) of the ventral intermediate nucleus (VIM) of the thalamus is effective in relieving refractory essential tremor (ET). In recent years, the posterior subthalamic area (PSA) has re-emerged as an alternative target. Differences in outcomes between both targes should be better characterized in clinical practice.
Method: Randomized double-blind crossover clinical trial. Patients with disabling and refractory ET were recruited and received bilateral octopolar electrode implantation in VIM (proximal contacts) and PSA (distal contacts). They were randomly assigned to a VIM→PSA or PSA→VIM sequence of stimulation (3 months on each target). Blinded assessments included Fahn-Tolosa-Marin Tremor Rating Scale (FTM-TRS) total score and Visual Analogue Scale (VAS) for QoL. Adverse events (AE) and energy requirements were also recorded. We present here an interim analysis of the first 6 patients, while trial is ongoing.
Results: Six patients (3M/3F, mean age of 62±9.2 years) were included. Two were assigned to the PSA→VIM group and four to the VIM→PSA group. In the pre-surgical, PSA-DBS and VIM-DBS groups, the average score of the FTM-TRS was 51.3, 7.5 and 9.3 respectively, with no significant differences between both targets (p=0.88). The mean VAS score (higher when better QoL) was 4.3, 9.5 and 8 respectively, with no significant differences between both targets (p=0.41). The average intensities were 1.24 and 1.53 mA in PSA-DBS and VIM-DBS respectively, without significant difference (p=0.21). Three out of 6 patients had some mild AE related to DBS (instability, dysarthria and dystonia), without differences in frequency or type of AE between both targets.
Conclusion: Our preliminary results show no statistical significant differences in outcomes between VIM-DBS vs PSA-DBS for refractory ET. However, a trend towards greater efficacy and efficiency of PSA-DBS was observed.
To cite this abstract in AMA style:
L. Triguero-Cueva, CJ. Madrid Navarro, MJ. Perez Navarro, B. Iáñez Velasco, M. Jouma Katati, JP. Martínez Barbero, A. Mínguez-Castellanos, F. Escamilla Sevilla. Double-blind, randomized, crossover clinical trial to compare VIM vs PSA deep brain stimulation in patients with disabling essential tremor. Preliminary results. [abstract]. Mov Disord. 2023; 38 (suppl 1). https://www.mdsabstracts.org/abstract/double-blind-randomized-crossover-clinical-trial-to-compare-vim-vs-psa-deep-brain-stimulation-in-patients-with-disabling-essential-tremor-preliminary-results/. Accessed May 12, 2025.« Back to 2023 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/double-blind-randomized-crossover-clinical-trial-to-compare-vim-vs-psa-deep-brain-stimulation-in-patients-with-disabling-essential-tremor-preliminary-results/