1. Evaluating functional connectivity differences between DBS ON/OFF states in essential tremor.
- Author
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Fenoy AJ, Chu ZD, Ritter RJ 3rd, Conner CR, and Kralik SF
- Subjects
- Humans, Female, Male, Middle Aged, Aged, Ventral Thalamic Nuclei diagnostic imaging, Neural Pathways physiopathology, Neural Pathways diagnostic imaging, Brain physiopathology, Brain diagnostic imaging, Essential Tremor therapy, Essential Tremor physiopathology, Essential Tremor diagnostic imaging, Deep Brain Stimulation methods, Magnetic Resonance Imaging methods
- Abstract
Deep brain stimulation (DBS) targeting the ventral intermediate (Vim) nucleus of the thalamus is an effective treatment for essential tremor (ET). We studied 15 ET patients undergoing DBS to a major input/output tract of the Vim, the dentato-rubro-thalamic tract (DRTt), using resting state functional MRI (rsfMRI) to evaluate connectivity differences between DBS ON and OFF and elucidate significant regions most influential in impacting tremor control and/or concomitant gait ataxia. Anatomical/functional 1.5T MRIs were acquired and replicated for each DBS state. Tremor severity and gait ataxia severity were scored with DBS ON at optimal stimulation parameters and immediately upon DBS OFF. Whole brain analysis was performed using dual regression analysis followed by randomized permutation testing for multiple correction comparison. Regions of interest (ROI) analysis was also performed. All 15 patients had tremor improvement between DBS ON/OFF (p < 0.001). Whole brain analysis revealed significant connectivity changes between states in the left pre-central gyrus and left supplemental motor area. Group analysis of ROIs revealed that, with threshold p < 0.05, in DBS ON vs. OFF both tremor duration and tremor improvement were significantly correlated to changes in connectivity. A sub-group analysis of patients with greater ataxia had significantly decreased functional connectivity between multiple ROIs in the cortex and cerebellum when DBS was ON compared to OFF. Stimulation of the DRTt and concordant improvement of tremor resulted in connectivity changes seen in multiple regions outside the motor network; when combined with both structural and electrophysiologic connectivity, this may help to serve as a biomarker to improve DBS targeting and possibly predict outcome., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Albert Fenoy reports financial support was provided by National Institute of Neurological Disorders and Stroke. Stephen Kralik reports financial support was provided by National Institute of Neurological Disorders and Stroke. Zili Chu reports financial support was provided by National Institute of Neurological Disorders and Stroke. Albert Fenoy reports a relationship with Medtronic Inc that includes: consulting or advisory. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
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