Neuropsychological assessment protocol in an ongoing randomized controlled trial on posterior subthalamic area vs. ventral intermediate nucleus deep brain stimulation for essential tremor

Front Neurol. 2023 Oct 30:14:1222592. doi: 10.3389/fneur.2023.1222592. eCollection 2023.

Abstract

Objective: Patients with essential tremor (ET) may experience cognitive-affective impairment. Deep brain stimulation (DBS) of different targets, such as the ventral intermediate nucleus (VIM) of the thalamus or the posterior subthalamic area (PSA), has been shown to be beneficial for refractory ET. However, there is little evidence regarding the possible neuropsychological effects of PSA-DBS on patients with ET, and there are few studies comparing it with VIM-DBS in this population.In this study, we aim to present the evaluation protocol and neuropsychological battery as used in an ongoing trial of DBS for ET comparing the already mentioned targets.

Methods: As part of a randomized, double-blind, crossover clinical trial comparing the effectiveness and safety of PSA-DBS vs. VIM-DBS, 11 patients with refractory ET will undergo a multi-domain neuropsychological battery assessment. This will include a pre-/post-implantation assessment (3 months after the stimulation of each target and 6 months after an open stage of DBS on the most optimal target).

Conclusion: Evidence on the neuropsychological effects of DBS in patients with refractory ET is very scarce, particularly in lesser-explored targets such as PSA. This study could contribute significantly in this field, particularly on pre-procedure safety analysis for tailored patient/technique selection, and to complete the safety analysis of the procedure. Moreover, if proven useful, this proposed neuropsychological assessment protocol could be extensible to other surgical therapies for ET.

Keywords: cognitive-affective impairment; deep brain stimulation; essential tremor; neuropsychological assessment; posterior subthalamic area; surgical therapies; ventral intermediate nucleus.

Grants and funding

This study was part of the study protocol “Randomized crossover double blind clinical trial: deep brain stimulation on the posterior subthalamic area vs. on the ventral intermediate nucleus of the thalamus in essential tremor,” protocol version 1.1 (07/10/19). This clinical trial has been approved and funded by the Instituto de Salud Carlos III, co-financed by the European Regional Development Fund (PI19/01571). This funding organism plays no role in the study design or the data collection, analysis, and interpretation. The present study was part of the doctoral thesis “Artificial intelligence in clinical evaluation and selection of the best target in patients with refractory essential tremor undergoing bilateral deep brain stimulation (ventral intermediate nucleus of the thalamus versus posterior subthalamic area),” by the LT-C, within the Doctorate Program in Biomedicine at the University of Granada.