Long-Term Outcome and Neuroimaging of Deep Brain Stimulation in Holmes Tremor: A Case Series

Panagiotis Bargiotas; T A Khoa Nguyen; Tobias Bracht; Melina Mürset; Andreas Nowacki; Ines Debove; Julia Muellner; Joan P Michelis; Claudio Pollo; W M Michael Schüpbach; M Lenard Lachenmayer

doi:10.1111/ner.13352

Long-Term Outcome and Neuroimaging of Deep Brain Stimulation in Holmes Tremor: A Case Series

Neuromodulation. 2021 Feb;24(2):392-399. doi: 10.1111/ner.13352. Epub 2021 Jan 3.

Authors

Affiliations

¹ Department of Neurology, University Hospital Bern (Inselspital) and University of Bern, Bern, Switzerland.
² Department of Neurology, Medical School, University of Cyprus, Nicosia, Cyprus.
³ Department of Neurosurgery, University Hospital Bern (Inselspital) and University of Bern, Bern, Switzerland.
⁴ ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland.
⁵ University Hospital of Psychiatry and Psychotherapy, University of Bern; Translational Research Center, University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland.

PMID: 33389771
DOI: 10.1111/ner.13352

Abstract

Background: Different deep brain stimulation (DBS) targets have been suggested as treatment for patients with pharmacologically refractory Holmes tremor (HT). We report the clinical and quality of life (QoL) long-term (up to nine years) outcome in four patients with HT treated with DBS (in thalamic ventral intermediate nucleus-VIM or in dentato-rubro-thalamic tract-DRTT).

Materials and methods: The patients underwent routine clinical evaluations before and after DBS (typically annually). Tremor severity and activities of daily living (ADL) were quantified by the Fahn-Tolosa-Marin Tremor-Rating-Scale (FTMTRS). QoL was assessed using the RAND SF-36-item Health Survey (RAND SF-36). In addition, we computed, in all four patients, the VTA based on the best stimulation settings using heuristic approaches included in the open source toolbox LEAD-DBS.

Results: In all patients, tremor and ADL improved significantly at one-year post-DBS follow-up (34-61% improvement in FTMTRS total score compared to baseline). In three out of four patients, the improvement of tremor was sustained no longer than two to three years and only in one patient was sustained up to nine years. In this patient, the largest intersection between VTA and DBS target has been observed. Scores for ADL deteriorated over the course of time, reaching worse levels compared to baseline already during the three-year post-DBS follow-up, in three out of four patients. Physical and mental health component scores of RAND SF-36 had very different outcome between patients and follow-ups and were not associated with tremor-related outcomes.

Conclusions: The benefits of DBS in HT might not be always long lasting. Although QoL slightly improved, this change seemed to be independent of the motor outcome following DBS. The estimation of DBS target and VTA proximity could be a useful tool for DBS clinicians in order to facilitate the DBS programming process and optimize DBS treatment.

Keywords: Deep brain stimulation; Holmes tremor; Rubral tremor; dentato-rubro-thalamic tract; quality of life; tractography; ventral intermediate nucleus; volume of tissue activated.

Publication types

Case Reports

MeSH terms

Activities of Daily Living
Deep Brain Stimulation*
Essential Tremor* / therapy
Humans
Neuroimaging
Quality of Life
Treatment Outcome
Tremor / diagnostic imaging
Tremor / therapy