Frequently Asked Questions About Focused Ultrasound
Here are answers to some of the most frequently asked questions about the MR-guided focused ultrasound procedure, which is offered at our Rush Oak Brook location.
What are the benefits of having MR-guided focused ultrasound treatment?
Studies show an immediate and significant reduction in hand tremor, improving your ability to do activities such as eating, drinking, writing, grooming (shaving, brushing teeth, etc.) and getting dressed.
It's important to note that MR-guided focused ultrasound does not treat the underlying disease or prevent the exacerbation or progression of the disease.
Should I try medication first?
To have the MR-guided focused ultrasound treatment, you must have a confirmed diagnosis of essential tremor or parkinsonian tremor that does not respond to medication (such as propranolol or primidone). It's estimated that 30 to 50 percent of patients do not get acceptable tremor relief from medication or the medication has undesirable side effects.
If your doctor verifies that you have not responded to at least two medications or have experienced severe side effects from the medication, MR-guided focused ultrasound may be an option for you.
How do I know if I am eligible for MR-guided focused ultrasound?
This procedure is FDA approved for unilateral (one side of the body) treatment of tremor only. To be eligible, you must meet the following criteria:
- Be at least 22 years old (for essential tremor) or at least 30 years old (for parkinsonian tremor)
- Have not responded to at least one medication, or experience severe side effects from medication
You will need to have a CT scan to determine if you are a suitable candidate.
In general, people who cannot go into an MRI scanner will not be able to go through the treatment. You may not be a suitable candidate if any of the following is true:
- You have any kind of metallic implants, such as pacemakers, neurostimulators, spine or bone fixation devices, total joints, metal clips, screws, etc. Any metallic implants must be non-magnetic to prevent injury to the patient from the MRI's strong magnetic field. If you have a pacemaker, we can help you determine whether your device is MRI-compatible.
- You are allergic to the contrast agent (the dye used during the procedure).
- You are not generally healthy enough to withstand the treatment and lie still in the same position for approximately two hours.
- You have had a recent heart attack or have congestive heart failure, unstable angina pectoris (chest pain) or spinal conditions. You should discuss these issues with your doctor.
- You have extensive scarring on the scalp.
- Your skull is too thick. A percentage of patients (10 to 15 percent) may not be candidates for this procedure due to the thickness of their skull, which is calculated using a head CT scan. If your skull is too thick, ultrasound energy may not be able to properly pass through the skull to reach the thalamus.
- You cannot physically fit into the MRI scanner. Since the procedure is done in the bore (opening) of the MRI scanner, there is a physical weight limit, which is generally in the range of 300 pounds.
What happens before, during and after treatment?
Here's what you can expect:
- Preparation: Your scalp will be shaved and cleaned. You will be given a local numbing medication, and an immobilizing frame will be secured to your head. Your heart rate, blood pressure and blood oxygen levels will be monitored throughout the procedure. You will then lie on the treatment bed, which will move in and out of the MRI scanner. You may be given additional medication to keep you comfortable. You will be conscious, communicating with the physician and nurses throughout the treatment.
- Planning: First, a series of MRI images will be taken for the purpose of planning the treatment. The physician will mark the area to be treated on the system's software, and light doses of ultrasound energy will be administered to evaluate the temporary tremor improvement and identify any potential side effects. Cool water will circulate in the helmet around the top of your head, and you will be kept warm in case you get chilled. You will also be given a "stop sonication" button to indicate to the physician that you want to stop the procedure for any reason.
- Treatment: High energy sound waves will be delivered to create a small lesion. After each application of energy, the physician will ask you questions and have you perform tasks to confirm the tremor improvement. Tasks may include touching your nose with your finger and/or drawing circles on a board. The treatment will last approximately one hour from when you get on the treatment table until you get off.
- Post-Treatment: After treatment, you will move to the recovery room for observation. The frame will be removed from your head. At some point, you will have a final 20-minute MRI scan for post-treatment assessment. You will be able to go home the same day. Your physician will let you know when you will need to return for your first follow-up visit (you will have multiple follow-up visits).
If the thalamus is in the center of the brain, why doesn't this treatment affect the rest of the brain?
The ultrasound beams pass harmlessly through the rest of your brain. Only where they come together in the thalamus does the temperature rise, creating a lesion that helps disrupt what is causing your tremor.
Is there a possibility of missing the target?
The possibility is very rare because MR imaging allows the treating physician to continuously see the treatment area and monitor the temperatures. The physician also does testing with low temperatures to identify the target before making the lesion.
Why do I have to be awake during the treatment?
You will be asked to do tasks such as drawing spirals, so the treating physician can evaluate the improvement of your tremor and identify any potential side effects that you may be experiencing during the treatment.
What are the risks and side effects of MR-guided focused ultrasound?
In general, the side effects of this treatment are minimal, but as with any medical procedure there are potential risks:
- For short periods of time during the treatment, you may experience nausea, pain or other sensations.
- There is a small risk that you could develop temporary or permanent muscle weakness, imbalance and/or gait disturbances, and/or sensory effects (tingling, numbness) in your fingers or elsewhere in your body.
Be sure to talk to your physician about all of the risks involved with MR-guided focused ultrasound treatment.
Will my tremor return after MR-guided focused ultrasound treatment?
The FDA approval is based on clinical data that showed tremor improvement at one year. There is the possibility that your tremor may return months or even years after the treatment, or that the tremor may not improve at all.
Is this effective with head or vocal tremors?
There is no data on effectiveness for head or vocal tremors. The treatment provides relief for hand tremor.
If you have tremor in both hands, do you need treatments for each hand?
The treatment is only FDA approved at this point for unilateral treatment — treating only one side (usually your dominant hand).
Is the procedure reversible?
It is not a reversible procedure, but having it does not necessarily mean you cannot have another procedure like deep brain stimulation (DBS) in the future.
If I am a suitable candidate, how soon can I have the treatment?
This will depend on availability. Your doctor can discuss timing with you once they determine that you are eligible.
Does insurance cover MR-guided focused ultrasound?
MR-guided focused ultrasound treatment for medication-refractory essential tremor is covered under Medicare Part B in the state of Illinois.
- Per Medicare rules and regulations, Medicare beneficiaries traveling outside of their home state for treatment at a facility providing MR-guided focused ultrasound would be subject to the Medicare contractor coverage decision based on where the treatment is performed. We recommend confirming with your local Medicare contractor prior to treatment.
Under the Blue Card Network, patients traveling outside of their home state for treatment at a facility providing MR-guided focused ultrasound would be subject to their home plan coverage decision. We recommend confirming coverage determination with your health plan prior to treatment.
MR-guided focused ultrasound treatment for medication-refractory tremor-dominant Parkinson's disease is currently not a Medicare-covered benefit in the state of Illinois.