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

TITLE=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

JOURNAL=Frontiers in Neurology

VOLUME=Volume 14 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2023.1129430

DOI=10.3389/fneur.2023.1129430

ISSN=1664-2295

ABSTRACT=Magnetic resonance-guided focussed ultrasound (MRgFUS) is a non-invasive surgical procedure, for treatment of tremor symptoms in movement disorders such as 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. We retrospectively analysed data from 31 subjects with ET, treated with MRgFUS at a single centre. Pre-treatment imaging data was analysed to determine ablation volume overlap with automated thalamic segmentations, and the dentatorubrothalamic tract (DRTT) and compared with percentage change in Clinical Rating Scale for Tremor (CRST) and Hand Tremor Scores (HTS). Tremor symptoms were significantly reduced following treatment. Pre-treatment CRST (mean: 60.7) and HTS (mean: 19.2) improved by an average of 45.5 and 62.6% respectively. Percentage change in CRST was found to be significantly negatively associated with age and SDR standard deviation (SDRSD), and positively associated with ablation overlap with the posterior dentatorubrothalamic tract (DRTT)). Percentage HTS improvement decreased significantly with older age. Our results suggest that increased lesioning of the posterior region of the DRTT could result in improved global tremor suppression, and that the consistency of SDR values across the whole skull may be a more reliable predictor of treatment outcome than the traditionally used mean SDR.