Magnetic Resonance Guided Focused Ultrasound (MRgFUS)
Magnetic resonance guided focused ultrasound (MRgFUS) – often just referred to as focused ultrasound – is a treatment for essential tremor patients who haven’t responded to medication.
The treatment is FDA approved to treat hand tremor. If you experience hand tremor, focused ultrasound could be a beneficial treatment that doesn’t require incisions, radiation, anesthesia or ongoing maintenance. Your head tremor may see some improvement, but the therapy is primarily designed to treat hand tremor.
Focused ultrasound is used with MRI to precisely guide ultrasound beams to treat and ablate a small area deep within the brain. The procedure doesn’t require any incisions.
The ultrasound waves pass through the brain and converge in an area called the thalamus, heating and creating a lesion that disrupts the cause of the tremor.
Focused ultrasound is approved for staged unilateral treatment, able to treat both sides of the brain. If you have tremor in both hands, you must wait a minimum of 9 months between treatments to see if you experience any significant side effects from the first treatment.
Focused ultrasound does require you to meet certain criteria:
- You must have an official diagnosis of essential tremor or Parkinson’s Disease.
- You must be at least 22 years old.
- You must be under 300 pounds and able to go into an MRI machine without experiencing significant claustrophobia.
- You must be able to lie in the same position for 3 hours.
- You must have tried and failed to respond adequately to both primidone and propranolol.
- You must undergo a complete head shave before the procedure and have no extensive scarring on your scalp.
Please note that not all metal implants, including certain kinds of pacemakers, exclude patients from this procedure.
Focused ultrasound is a safe process for tremor treatment with few side effects:
- It doesn’t require incisions, implants or ongoing, long-term maintenance, so there is no risk of infection.
- The procedure precisely targets the area of the brain responsible for your tremor, allowing the physician a continuous view of the treatment area and the ability to monitor the temperature.
- Typically, you can receive the treatment and go home the same day.
- Focused ultrasound is expected to improve your hand tremors, providing you with a better quality of life.
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. And while the treatment may improve your tremor, it’s important to understand that it doesn’t treat the underlying disease nor prevent its progression.
You should have a detailed conversation with your physician regarding possible complications and side effects that you may experience.
Common side effects experienced after treatment include:
- Headache/head pain
- Imbalance/gait disturbance
- Numbness/tingling
Most of these events were classified as mild or moderate.
Complications that persisted at 5 years were all mild or moderate and included:
- Dysgeusia, experiencing unpleasant taste or smells
- Dysmetria, a lack of movement coordination
- Gait disturbance
- Limb weakness
- Numbness/tingling
- Unsteadiness
The most common adverse events experienced during and after treatment of the second side are:
- Ataxia, poor muscle control
- Dysarthria, slurred or slow speech
- Dysgeusia, experiencing unpleasant taste or smells
- Dysmetria, a lack of movement coordination
- Dysphagia, difficulty swallowing
- Gait disturbance
- Fatigue
- Hypogeusia, reduced sense of taste
- Imbalance
- Numbness/Tingling
- Unsteadiness
Frequently Asked Questions
Focused ultrasound is a safe process for tremor treatment with few side effects:
- It doesn’t require incisions, implants or ongoing, long-term maintenance, so there is no risk of infection.
- The procedure precisely targets the area of the brain responsible for your tremor, allowing the physician a continuous view of the treatment area and the ability to monitor the temperature.
- Typically, you can receive the treatment and go home the same day.
- Focused ultrasound may potentially improve your hand tremors, providing you with a better quality of life.
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. And while the treatment may improve your tremor, it’s important to understand that it doesn’t treat the underlying disease nor prevent its progression.
The treatment time lasts approximately 2.5 hours on average. It’s usually performed on an outpatient basis, which means that typically you’ll be able to go home the same day.
However, your treating physician will evaluate you and ultimately decide when you can return home.
Prior to getting a focused ultrasound treatment, you need to complete the following:
- Undergo an evaluation with the treating physician to see if you’re a candidate
- Get a specialized CTA scan and potentially an MRI scan
- Shave your head
Everyone’s skull is different. A CT scan determines if the shape and thickness of your skull are suitable for focused ultrasound. Certain skull shapes and thickness might make it impossible for ultrasound waves to reach the temperature at the target required for treatment.
Your CT scan can be done closer to where you live; you aren’t required to get it at the same place where you’ll receive focused ultrasound treatment.
Yes, it is necessary to shave your head. Ultrasound waves don’t travel well through the air.
Air bubbles could get trapped in the hair, blocking the ultrasound waves and absorbing energy, which could potentially lead to skin burns.
- Right before treatment, a water-based gel is applied to your scalp as a conductive medium. Then, you wear a silicone cap to help the ultrasound transducer work properly.
- A standard stereotactic frame is placed on your head to ensure that it doesn’t move during treatment.
- You lay on the treatment bed and are placed inside the MRI scanner from the mid-torso up.
- You need to be awake during the entire procedure, which takes around 2.5 hours on average.
- After each application of energy, the bed moves out of the scanner and you’re asked to complete different neurological tasks, like drawing a spiral. These tasks help the treating physician evaluate your tremor’s improvement and address potential side effects.
No. You’ll need to arrange for a ride home following the procedure, and you won’t be able to drive for at least two weeks afterward.
As of July 12, 2020, the MR-guided focused ultrasound treatment for medication-refractory essential tremor is a Medicare-covered benefit in all 50 states, covered under Medicare Part B.
Other private health insurance plans cover focused ultrasound, but it’s always best to check with your provider and see if it is covered under your health plan.