Patients who are medication-refractory for ET often require a surgical option to relieve symptoms of ET and improve quality of life. To-date, unilateral MRgFUS has been beneficial in providing patients with some of relief from tremor. However, tasks that require two hands remain a challenge for many patients. Historical risks of bilateral treatment have been an impediment to complete tremor relief. The introduction of MRI and current stereotactic methodologies has significantly reduced the probability of non-target tissue injury. In this study, a second MRgFUS thalamotomy will be performed in a cohort of patients who have already successfully undergone unilateral MRgFUS treatment. Tremor severity, speech, balance, gait, and cognition will be assessed during baseline and follow up visits.
This study will be a single-centre, prospective, single-arm, open-label, 12-week pilot trial assessing the safety and preliminary efficacy of a second MR-guided focused ultrasound (MRgFUS) thalamotomy on the naïve brain hemisphere after 48 weeks or more of the first MRgFUS thalamotomy in patients with medication-refractory ET.~This study will be conducted at the Focused Ultrasound Centre of Excellence at Sunnybrook Health Sciences Centre/University of Toronto.