Essential Tremor, Tremor
Conditions
Keywords
Tremor, Essential Tremor, Medication-refractory Essential Tremor
Brief summary
A feasibility Study to Evaluate Safety and Initial Effectiveness of ExAblate Transcranial MR Guided Focused Ultrasound for Unilateral Thalamotomy in the Treatment of Tremor
Detailed description
The non-invasive high-intensity focused ultrasound has been coupled with high resolution MRI to provide precise, consistent treatments that can be monitored in real-time. The development of phased array transducers allows for tightly focused treatment volumes and for the ability to compensate for distortions by tissue inhomogeneities. The landmark advance in MRgFUS for neurosurgeons occurred as the ability to sonicate through the intact cranium was achieved with phased array transducers and acoustic modeling using CT reconstructions of the skull. By coupling HIFU with MRI, detailed treatment plans can be generated and intra-procedure real-time monitoring is available. Standard MR sequences have been shown to reliably predict tissue damage during thermal lesioning with ultrasound. The precision of the technology has already been demonstrated in animal models and is currently being investigated in humans with brain tumors and neuropathic pain syndromes. Unlike stereotactic radiosurgery, the treatment can be monitored continuously in real time with MRI and MR-thermography. We anticipate that a MRgFUS non-invasive thermal lesioning is similarly as safe as DBS (or other current procedure and will provide several years of benefit through reduction of contralateral motor symptoms and potential medication side effects in ET, while still permitting subsequent treatment with DBS should that become clinically desirable.
Interventions
MR Guided Focused Ultrasound
Sponsors
InSightec
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
1. Men and women, between 18 and 80 years, inclusive 2. Patients who are able and willing to give consent and able to attend all study visits 3. A diagnosis of ET as confirmed from clinical history and examination by a movement disorder neurologist 4. Tremor refractory to adequate trials of at least two medications, one of which should be either propranolol or primidone. An adequate medication trial is defined as a therapeutic dose of each medication or the development of side effects as the medication dose is titrated. 5. Vim nucleus of thalamus can be target by the ExAblate device. The Vim region of the thalamus must be apparent on MRI such that targeting can be performed with either direct visualization or by measurement from a line connecting the anterior and posterior commissures of the brain. 6. Able to communicate sensations during the ExAblate MRgFUS treatment 7. Postural or intention tremor severity score of greater than or equal to 2 in the dominant hand/arm as measured by the CRST rating scale. 8. Stable doses of all medications for 30 days prior to study entry and for the duration of the study. 9. May have bilateral appendicular tremor 10. Significant disability due to essential tremor despite medical treatment (CRST score of 2 or above in any one of the items 16-23 from the Disability subsection of the CRST: \[speaking, feeding other than liquids, bringing liquids to mouth, hygiene, dressing, writing, working, and social activities\]) 11. Inclusion and
Exclusion criteria
have been agreed upon by two members of the medical team.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Accuracy of Thalamotomy lesion | 1 day | Comparison of the stereotactic coordinates of the atlas to the lesion created in the brain. |
Countries
Canada
Outcome results
None listed