A tremor is an involuntary, rhythmic movement caused by alternating muscle contractions that can affect one or more parts of the body. It is the most common movement disorder. Tremor most often affects the hands, but can also occur in the arms, head, vocal cords, torso, and legs. A tremor can be caused by several different neurological conditions. Determining the cause of the tremor is important to guarantee appropriate treatment.
High-Intensity Focused Ultrasound (HiFU)/MRI-guided Focused Ultrasound (MRIgFUS)/Focused Ultrasound (FUS) is an incisionless treatment that uses sound waves to target deep structures in the brain that are responsible for tremor. The ultrasound waves are focused on a small location typically of the thalamus of the brain. The temperature at the target rises high enough to create a small ablation or burn that can be monitored in real-time. The MRI acts as the “eyes” of the treatment. It also acts like a thermometer by providing continuous temperature monitoring to make sure that only the targeted tissue is affected.
The clinical benefit is immediate and long-lasting. To date, effects have been studied up to five years after treatment. Adverse effects are minimal and your HIFU provider will go over with you.
The University of Colorado Advanced Therapies for Movement Disorders (CU ATMD) program is the most comprehensive in the region. Patients are treated by a team of experts who work together to provide the best care for patients. The team has distinguished experience in surgical planning using cutting-edge technology. Patients approved for HIFU are evaluated throughout the procedure by a movement disorders neurologist and go home the same day.
For Patients
Am I a candidate?
The treatment is for individuals with a confirmed diagnosis of essential tremor or tremor-predominant Parkinson’s disease that is not adequately controlled with medication. As part of the evaluation process, your diagnosis will be confirmed and the severity of your tremor and overall health will be evaluated. You will need to undergo a CT scan to determine if you are a candidate for the HIFU treatment.
Benefits of Focused Ultrasound
Benefits of this treatment can include:
- Lasting tremor improvement seen immediately.
- Incisionless, noninvasive treatment
- Quick recovery
- Return home the same day
What will happen before, during, and after the treatment?
Preparation
The HIFU treatment requires that a patient have a cleanly shaven head. This is to ensure no interference of the sound waves. A local numbing medication will be applied and a head frame will be attached to ensure no movement during the treatment.
Planning
A series of MRI images will be taken to plan the treatment according to your specific anatomy. Your physician will first apply low doses of ultrasound energy to verify the focal point of the ultrasound waves aligns with the treatment plan. These low doses will cause temporary improvement in tremor and will allow the physician to see potential side effects.
After each application of energy, you will be asked to perform specific tasks, such as holding your arm in specific positions, touching your nose with your finger, and writing to evaluate your tremor improvement.
Treatment
After verifying the ideal location by seeing an improvement in tremor with no adverse effects, your physician will further increase the energy to create a permanent lesion. You will notice immediate improvement during the treatment itself. The treatment lasts, on average, 1.5-2 hours.
After Treatment
After the treatment, you will move to the recovery room where the frame will be removed. Another brief MRI is performed to verify and ensure an adequate lesion was created. You will be monitored for one to two hours and then return home. The following day, you will see your physician to discuss any questions and ensure optimal results. You should be able to return to normal activities within days.
For Providers
Who should be referred for treatment?
Patients who have been diagnosed with essential tremor or tremor-predominant Parkinson’s disease and who do not receive adequate tremor relief from medications may benefit from a focused ultrasound consultation. For essential tremor, patients should have been tried on first-line medications including propranolol and primidone. For tremor-predominant Parkinson’s disease, patients should be on an adequate dosage of carbidopa/levodopa.
Focused ultrasound for tremor has been approved in Colorado for staged unilateral treatment, treating both sides of the brain with a minimum of 9 months between treatments.
- Patients who have tried and failed to respond to primidone and propanolol
- Patients under 300 lbs who are able to go into an MRI and have no metallic implants that are not MRI-compatible
- Patients who are otherwise healthy and can lie still in the same position for 1.5 to 3 hours
Other things should be kept in mind when referring a patient:
- Patients must undergo a complete head shave before the procedure
- Certain underlying health conditions may exclude a patient from being a candidate
- This treatment is an outpatient procedure resulting in immediate tremor relief
How do I refer a patient?
p. 720-848-2080
f. 720-848-0015