Frontiers in Neurology (Apr 2023)

Tremor suppression following treatment with MRgFUS: skull density ratio consistency and degree of posterior dentatorubrothalamic tract lesioning predicts long-term clinical outcomes in essential tremor

  • Kain Kyle,
  • Kain Kyle,
  • Jerome Maller,
  • Yael Barnett,
  • Yael Barnett,
  • Benjamin Jonker,
  • Benjamin Jonker,
  • Michael Barnett,
  • Michael Barnett,
  • Michael Barnett,
  • Arkiev D’Souza,
  • Fernando Calamante,
  • Fernando Calamante,
  • Fernando Calamante,
  • Joel Maamary,
  • Joel Maamary,
  • James Peters,
  • Chenyu Wang,
  • Chenyu Wang,
  • Stephen Tisch,
  • Stephen Tisch

DOI
https://doi.org/10.3389/fneur.2023.1129430
Journal volume & issue
Vol. 14

Abstract

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ObjectivesMagnetic resonance-guided focussed ultrasound (MRgFUS) is an incisionless ablative procedure, widely used for treatment of Parkinsonian and Essential Tremor (ET). Enhanced understanding of the patient- and treatment-specific factors that influence sustained long-term tremor suppression could help clinicians achieve superior outcomes via improved patient screening and treatment strategy.MethodsWe retrospectively analysed data from 31 subjects with ET, treated with MRgFUS at a single centre. Tremor severity was assessed with parts A, B and C of the Clinical Rating Scale for Tremor (CRST) as well as the combined CRST. Tremor in the dominant and non-dominant hand was assessed with Hand Tremor Scores (HTS), derived from the CRST. Pre- and post-treatment imaging data were analysed to determine ablation volume overlap with automated thalamic segmentations, and the dentatorubrothalamic tract (DRTT) and compared with percentage change in CRST and HTS following treatment.ResultsTremor symptoms were significantly reduced following treatment. Combined pre-treatment CRST (mean: 60.7 ± 17.3) and HTS (mean: 19.2 ± 5.7) improved by an average of 45.5 and 62.6%, respectively. Percentage change in CRST was found to be significantly negatively associated with age (β = −0.375, p = 0.015), and SDR standard deviation (SDRSD; β = −0.324, p = 0.006), and positively associated with ablation overlap with the posterior DRTT (β = 0.535, p < 0.001). Percentage HTS improvement in the dominant hand decreased significantly with older age (β = −0.576, p < 0.01).ConclusionOur results suggest that increased lesioning of the posterior region of the DRTT could result in greater improvements in combined CRST and non-dominant hand HTS, and that subjects with lower SDR standard deviation tended to experience greater improvement in combined CRST.

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