Evaluation of the efficacy and safety of MRI-guided focused ultrasound (MRgFUS) for focal hand dystonia: study protocol for an open-label non-randomised clinical trial

Joel Maamary; James Peters; Kain Kyle; Diane Ruge; Benjamin Jonker; Yael Barnett; Stephen Tisch

doi:10.1136/bmjno-2023-000522

Evaluation of the efficacy and safety of MRI-guided focused ultrasound (MRgFUS) for focal hand dystonia: study protocol for an open-label non-randomised clinical trial

BMJ Neurol Open. 2023 Oct 25;5(2):e000522. doi: 10.1136/bmjno-2023-000522. eCollection 2023.

Authors

Joel Maamary^{1

2}, James Peters^{1

2}, Kain Kyle³, Diane Ruge⁴, Benjamin Jonker⁵, Yael Barnett⁶, Stephen Tisch¹

Affiliations

¹ Department of Neurology, St Vincent's Health Australia Ltd, Sydney, New South Wales, Australia.
² School of Clinical Medicine, University of New South Wales, Sydney, New South Wales, Australia.
³ Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia.
⁴ Laboratoire de Recherche en Neurosciences Cliniques, Montpellier, France.
⁵ Department of Neurosurgery, St Vincent's Health Australia Ltd, Sydney, New South Wales, Australia.
⁶ Department of Radiology, St Vincent's Health Australia Ltd, Sydney, New South Wales, Australia.

Abstract

Introduction: MRI-guided focused ultrasound (MRgFUS) thalamotomy provides an exciting development in the field of minimally invasive stereotactic neurosurgery. Current treatment options for focal hand dystonia are limited, with potentially more effective invasive stereotactic interventions, such as deep brain stimulation or lesional therapies, rarely used. The advent of minimally invasive brain lesioning provides a potentially safe and effective treatment approach with a recent pilot study establishing MRgFUS Vo-complex thalamotomy as an effective treatment option for focal hand dystonia. In this study, we undertake an open-label clinical trial to further establish MRgFUS Vo-complex thalamotomy as an effective treatment for focal hand dystonia with greater attention paid to potential motor costs associated with this treatment. To elucidate pathophysiology of dystonia and treatment mechanisms, neurophysiological and MRI analysis will be performed longitudinally to explore the hypothesis that neuroplastic and structural changes that may underlie this treatment benefit.

Methods and analysis: A total of 10 participants will be recruited into this open-label clinical trial. All participants will undergo clinical, kinemetric, neurophysiological and radiological testing at baseline, followed by repeated measures at predesignated time points post MRgFUS Vo-complex thalamotomy. Further, to identify any underlying structural or neurophysiological abnormalities present in individuals with focal hand dystonia, 10 age and gender matched control participants will be recruited to undergo comparative investigation. These results will be compared with the intervention participants both at baseline and at 12 months to assess for normalisation of these abnormalities, if present.

Ethics and dissemination: This trial was reviewed and approved by the St Vincent's Health Network Sydney Human Research Ethics Committee (2022/ETH00778). Study results will be published in peer-reviewed journals and presented at both national and international conferences.

Trial registration number: CTRN12622000775718.

Keywords: DYSTONIA; MOVEMENT DISORDERS; NEUROSURGERY.