Probabilistic Refinement of Focused Ultrasound Thalamotomy Targeting for Parkinson's Disease Tremor

Cletus Cheyuo; Jürgen Germann; Kazuaki Yamamoto; Zion Zibly; Vibhor Krishna; Can Sarica; Yuri Ferreira Felloni Borges; Artur Vetkas; Suneil K Kalia; Mojgan Hodaie; Alfonso Fasano; Michael L Schwartz; W Jeffrey Elias; Andres M Lozano

doi:10.1002/mds.29965

Probabilistic Refinement of Focused Ultrasound Thalamotomy Targeting for Parkinson's Disease Tremor

Mov Disord. 2024 Aug 9. doi: 10.1002/mds.29965. Online ahead of print.

Authors

Cletus Cheyuo^{1

2}, Jürgen Germann², Kazuaki Yamamoto^{2

3

4}, Zion Zibly^{5

6}, Vibhor Krishna⁷, Can Sarica², Yuri Ferreira Felloni Borges^{8

9}, Artur Vetkas², Suneil K Kalia^{2

10}, Mojgan Hodaie^{2

10}, Alfonso Fasano^{8

10}, Michael L Schwartz¹¹, W Jeffrey Elias¹², Andres M Lozano^{2

10}

Affiliations

¹ Department of Neurosurgery, Lahey Hospital and Medical Center, Burlington, Massachusetts, USA.
² Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada.
³ Functional Neurosurgery Center, Shonan Fujisawa Tokushukai Hospital, Fujisawa, Japan.
⁴ Department of Neurosurgery, Osaka Medical and Pharmaceutical University, Takatsuki, Japan.
⁵ Department of Neurosurgery, Sheba Medical Center, Ramat Gan, Israel.
⁶ Center of Neuromodulation, Department of Neurosurgery, Yale School of Medicine, New Haven, Connecticut, USA.
⁷ Department of Neurosurgery, University of North Carolina, Chapel Hill, North Carolina, USA.
⁸ Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, UHN, Toronto, Ontario, Canada.
⁹ Division of Neurology, University of Toronto, Toronto, Ontario, Canada.
¹⁰ Krembil Research Institute, Toronto, Ontario, Canada.
¹¹ Division of Neurosurgery, Sunnybrook Health Sciences, Toronto, Ontario, Canada.
¹² Department of Neurosurgery, University of Virginia Health System, Charlottesville, Virginia, USA.

PMID: 39120112
DOI: 10.1002/mds.29965

Abstract

Background: There remains high variability in clinical outcomes when the same magnetic resonance image-guided focused ultrasound (MRgFUS) thalamotomy target is used for both essential tremor (ET) and tremor-dominant Parkinson's disease (TDPD).

Objective: Our goal is to refine the MRgFUS thalamotomy target for TDPD versus ET.

Methods: We retrospectively performed voxel-wise efficacy and structural connectivity mapping using 3-12-month post-procedure hand tremor scores for a multicenter cohort of 32 TDPD patients and a previously published cohort of 79 ET patients, and 24-hour T1-weighted post-MRgFUS brain images. We validated our findings using Unified Parkinson's Disease Rating Scale part III scores for an independent cohort of nine TDPD patients.

Results: The post-MRgFUS clinical improvements were 45.9% ± 35.9%, 55.5% ± 36%, and 46.1% ± 18.6% for ET, multicenter TDPD and validation TDPD cohorts, respectively. The TDPD and ET efficacy maps differed significantly (p_permute < 0.05), with peak TDPD improvement (87%) at x = -13.5; y = -15.0; z = 1.5, ~3.5 mm anterior and 3 mm dorsal to the ET target. Discriminative connectivity projections were to the motor and premotor regions in TDPD, and to the motor and somatosensory regions in ET. The disorder-specific voxel-wise efficacy map could be used to estimate outcome in TDPD patients with high accuracy (R = 0.8; R² = 0.64; P < 0.0001). The model was validated using the independent cohort of nine TDPD patients (R = 0.73; R² = 0.53; P = 0.025-voxel analysis).

Conclusion: We demonstrated that the most effective MRgFUS thalamotomy target in TDPD is in the ventral intermediate nucleus/ventralis oralis posterior border region. This finding offers new insights into the thalamic regions instrumental in tremor control, with pivotal implications for improving treatment outcomes. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Keywords: essential tremor; focused ultrasound thalamotomy; probabilistic mapping; tremor‐dominant Parkinson's disease.