Comparing deep brain stimulation in the ventral intermediate nucleus versus the posterior subthalamic area in essential tremor patients

Abstract

Background:The ventral intermediate nucleus (VIM) is the most commonly used target for deep brain stimulation (DBS) in patients with essential tremor (ET). Recent evidence suggests that the posterior subthalamic area (PSA) might be a better target for tremor reduction. We compared the outcome of VIM DBS with PSA DBS in our cohort of patients.Methods:Overall, 19 ET patients with bilateral DBS were included in this retrospective study, with a total of 38 electrodes (12 located in the VIM, 12 in the PSA, and 14 in an intermediate area). The outcome was measured using the essential tremor rating scale (ETRS), the glass scale and the quality of life in essential tremor questionnaire (QUEST).Results:Unilateral tremor-scores with items 5–6 (tremor of the upper extremity), 8–9 (tremor of the lower extremity), and 11-14 (hand function) from the ETRS showed a 63% tremor reduction in the VIM group, 47% tremor reduction in the PSA group, and 67% tremor reduction in the intermediate group after a mean follow-up of 1.6 years. After a mean follow-up of 5.8 years, there was a tremor reduction of 50%, 34%, and 45%, respectively. In our series, side effects such as dysarthria (75%), ataxia and disequilibrium (40%), and paraesthesia (15%) were assessed.Conclusions:All aforementioned anatomical target areas are effective in reducing tremor, although no superior reduction was found with PSA stimulation. Because of intraindividual differences between left and right hemisphere regarding the stimulated anatomical target, no conclusions can be drawn regarding differences in side effects.

Ventral intermediate nucleus of the thalamus, dentatorubrothalamic tract, and caudal zona incerta: stimulation of which structure provides ongoing tremor control in patients with essential tremor?

“…Small, medium, and high differences between the means of the pair distributions are color coded in yellow, light red, and dark red, respectively. software 44,59 or classic stereotactic atlases; 19,50 thus our analysis based on validated MNI atlases may be considered more advanced. On the other hand, the distance from the active contact might seem to be a surrogate marker of target structure stimulation if it is compared with the surface covered by stimulation volume.…”

Posterior subthalamic area deep brain stimulation for recurrent tremor after ventral intermediate nucleus thalamotomy: a case report

“…Blomstedt et al [16] also reported that the total score of the tremor was reduced to 60% from baseline to 1-year follow-up; in particular, 95% improvement was seen in the tremor of the upper extremity, accompanied by 66% improvement in activities of daily living. When comparing VIM and PSA as optimal targets for tremor, previous studies have shown that they are not superior in reducing tremor [17]. However, a randomized, double-blind, crossover trial by Barbe et al [18] identified that PSA DBS is equally effective and more efficient than VIM DBS after 1-year-use.…”

Technical Issues of Vim–PSA Double-Target DBS for Essential Tremor

“…Since 2012, several studies have proposed that PSA/cZi is a better target than Vim for tremor alleviation [ 10 , 11 , 12 , 13 ]. However, in 2018, two observational studies suggested that Vim-DBS might be more efficient in reducing tremors, and might provide better long-term outcomes than PSA/cZi-DBS [ 14 , 15 ]. Importantly, a randomized double-blind crossover trial performed by Barbe et al suggested that PSA–DBS is equally as effective as Vim-DBS [ 16 ].…”