Functional Neuroimaging During Asleep DBS Surgery: A Proof of Concept Study.

Francesco Sammartino,Vibhor Krishna,Paul Taylor,Richard C Reynolds,Daniel Glen,Gang Chen

doi:10.3389/fneur.2021.659002

Abstract

Object: A real-time functional magnetic resonance imaging (fMRI) feedback during ventral intermediate nucleus (VIM) deep brain stimulation (DBS) under general anesthesia (or “asleep” DBS) does not exist. We hypothesized that it was feasible to acquire a reliable and responsive fMRI during asleep VIM DBS surgery.Methods: We prospectively enrolled 10 consecutive patients who underwent asleep DBS for the treatment of medication-refractory essential tremor. Under general anesthesia, we acquired resting-state functional MRI immediately before and after the cannula insertion. Reliability was determined by a temporal signal-to-noise-ratio >100. Responsiveness was determined based on the fMRI signal change upon insertion of the cannula to the VIM.Results: It was feasible to acquire reliable fMRI during asleep DBS surgery. The fMRI signal was responsive to the brain cannula insertion, revealing a reduction in the tremor network's functional connectivity, which did not reach statistical significance in the group analysis.Conclusions: It is feasible to acquire a reliable and responsive fMRI signal during asleep DBS. The acquisition steps and the preprocessing pipeline developed in these experiments will be useful for future investigations to develop fMRI-based feedback for asleep DBS surgery.

Highlights

Magnetic resonance imaging (MRI) during surgery augments the real-time visualization of the brain anatomy
In parallel to the technological advancements, asleep deep brain stimulation (DBS) motivated neuroimaging research to enhance the visualization of therapeutic targets [5]
While structural imaging proved adequate for some therapeutic targets, tractography has emerged as the primary technique for improved localization of the ventral intermediate nucleus (VIM) for DBS surgery [6, 7]

Summary

Introduction

Magnetic resonance imaging (MRI) during surgery augments the real-time visualization of the brain anatomy. Intraoperative MRI was deployed to improve the accuracy of neurosurgical procedures since the 1990’s [1]. The seamless integration of MRI into the surgical workflow has enabled performing deep brain stimulation (DBS) under general anesthesia (or asleep DBS) [2]. The electrode placement was shown to be highly accurate, and patient outcomes in experienced centers were comparable with the conventional “awake” DBS [3, 4]. In parallel to the technological advancements, asleep DBS motivated neuroimaging research to enhance the visualization of therapeutic targets [5]. While structural imaging proved adequate for some therapeutic targets, tractography has emerged as the primary technique for improved localization of the ventral intermediate nucleus (VIM) for DBS surgery [6, 7]

Methods

Results

Discussion

Conclusion