Analysis of Clinical Outcomes in Patients Undergoing Magnetic Resonance-Guided Focused Ultrasound for Medication-Refractory Tremor

A Prospective, Long-term Analysis of Clinical Outcomes in Patients Undergoing Magnetic Resonance-Guided Focused Ultrasound for Medication-Refractory Tremor

The goal of this observational study is to evaluate the long-term efficacy and safety of MR-guided focused ultrasound (MRgFUS) thalamotomy in patients with medication-refractory essential tremor.

The main questions it aims to answer are:

1. Does MRgFUS thalamotomy provide sustained reduction in tremor severity over 3 years?
2. What are the long-term neurological and quality-of-life outcomes associated with this procedure?

Participants will:

• Undergo MRgFUS thalamotomy as part of standard of care at Sunnybrook Health Sciences Centre.

• Be followed prospectively for a minimum of 3 years with scheduled assessments including:

  1. Clinical Rating Scale for Tremor (CRST)
  2. Neurological exams and adverse event monitoring
  3. Quality of Life in Essential Tremor (QUEST) questionnaire
  4. Scale for the Assessment and Rating of Ataxia (SARA)
  5. MRI imaging and neuropsychological testing

This single-centre, prospective observational cohort study will evaluate long-term outcomes of MR-guided focused ultrasound (MRgFUS) thalamotomy for medication-refractory essential tremor at Sunnybrook Health Sciences Centre. It is anticipated that about 240 people will be recruited into this study over the next 6 years. It is expected that this study will take 6 years to complete and that results will be known in 6-7 years.

Inclusion Criteria:

1. Aged 22 years or older
2. Able and willing to give consent and to attend all visits
3. Diagnosed with essential tremor that is refractory to at least two first-line tremor medications
4. Confirmed to have moderate-to-severe hand tremor by the MRI guided Focused Ultrasound (MRgFUS) neurology team
5. Deemed suitable surgical candidates (decision-to-treat) by the MRgFUS neurosurgical team

Exclusion Criteria:

1. Patients with standard contraindications to MRI such as non-MRI compatible implants or devices
2. Patients deemed clinically unfit to undergo MRgFUS thalamotomy due to health status including (but not limited to) pregnancy, advanced kidney disease, unstable cardiac status, severe hypertension, cerebrovascular disease, brain tumour, pulmonary disorders
3. Receiving anti-coagulants or drugs known to increase risk of hemorrhage within 2 weeks of MRgFUS procedure