MRgFUS of the nucleus ventralis intermedius in essential tremor modulates functional connectivity within the classical tremor network and beyond

Christine Kindler; Neeraj Upadhyay; Veronika Purrer; Frederic Carsten Schmeel; Valeri Borger; Lukas Scheef; Ullrich Wüllner; Henning Boecker

doi:10.1016/j.parkreldis.2023.105845

MRgFUS of the nucleus ventralis intermedius in essential tremor modulates functional connectivity within the classical tremor network and beyond

Parkinsonism Relat Disord. 2023 Oct:115:105845. doi: 10.1016/j.parkreldis.2023.105845. Epub 2023 Sep 12.

Authors

Christine Kindler¹, Neeraj Upadhyay², Veronika Purrer³, Frederic Carsten Schmeel⁴, Valeri Borger⁵, Lukas Scheef⁶, Ullrich Wüllner³, Henning Boecker²

Affiliations

¹ Department of Neurology, University Hospital Bonn, Bonn, Germany; German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany. Electronic address: christine.kindler@ukbonn.de.
² German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany; Division 'Clinical Functional Imaging', Department of Diagnostic and Interventional Radiology, University Hospital Bonn, Bonn, Germany.
³ Department of Neurology, University Hospital Bonn, Bonn, Germany; German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.
⁴ Department of Neuroradiology, University Hospital Bonn, Bonn, Germany.
⁵ Department of Neurosurgery, University Hospital Bonn, Bonn, Germany.
⁶ Division 'Clinical Functional Imaging', Department of Diagnostic and Interventional Radiology, University Hospital Bonn, Bonn, Germany.

PMID: 37717502
DOI: 10.1016/j.parkreldis.2023.105845

Abstract

Background: Magnetic resonance-guided focused ultrasound (MRgFUS) of the thalamic ventral intermediate nucleus is an incisionless lesional treatment for essential tremor.

Objective: To examine relationships between tremor severity and functional connectivity in patients with essential tremor and to assess long-term changes in the tremor network after sonication of the ventral intermediate nucleus.

Methods: Twenty-one patients with essential tremor (70.33 ± 11.32 years) were included in the final analysis and underwent resting state functional magnetic resonance imaging at 3 T before and 6 months after treatment. Tremor severity (Fahn-Tolosa-Marin Clinical Rating Scale) was evaluated and functional connectivity was investigated using independent component analysis.

Results: MRgFUS of the thalamic ventral intermediate nucleus reduced contralateral tremor effectively. Multiple regression analysis revealed exclusively negative correlations between FC and tremor severity, notably in the right cerebellar lobe VI and the left cerebellar lobe VIIIa (cerebellar network), in the left occipital fusiform gyrus (lateral visual network), the anterior division of the left superior temporal gyrus (fronto-parieto-temporal network), and in the posterior division of the left parahippocampal gyrus and the bilateral lingual gyri (default mode network). Six months after treatment, increased functional connectivity was observed in almost all tremor-associated clusters, except the cluster localized in the left cerebellum.

Conclusions: Our findings suggest that tremor-related activity in essential tremor extends beyond the classical cerebellar network, additionally involving areas related to visual processing. Functional restoration of network activity after sonication of the ventral intermediate nucleus is observed within the classical tremor network (cerebellum) and notably also in visual processing areas.

Keywords: Essential tremor; Functional brain networks; Independent component analysis; MR-Guided focused ultrasound.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Essential Tremor*
Humans
Magnetic Resonance Imaging / methods
Thalamic Nuclei
Tremor / diagnostic imaging
Ventral Thalamic Nuclei* / diagnostic imaging