Pre-operative diffusion metrics associated with long-term tremor outcome following MR-Guided Focused Ultrasound Thalamotomy

Motivation: Fibre tract integrity may play a role in treatment-resistant Essential Tremor. Goal(s): To determine if pre-operative DTI measurements of ET-related neuronal pathways had any association with long-term tremor improvement following MRgFUS-thalamotomy. Approach: Pre-operative DTI metrics (FA & MD) of both DRTT were compared with clinical tremor outcomes 12-months following MRgFUS left thalomotomy in right-handed patients. Results: Higher measures of pre-operative mean diffusivity in the DRTT contralateral to the surgically-targeted DRTT/Vim (particularly in cerebellar regions) showed greater reductions in tremor 12 months post-MRgFUS thalamotomy. Impact: The DRTT contralateral to the surgical target plays an undetermined role in the long-term effectiveness of MRgFUS thalamotomy for Essential Tremor, particularly in cerebellar regions. Future research into tremor understanding and treatment should consider anatomy outside of direct pathways.