If you have essential tremor, an innovative treatment known as focused ultrasound may help.
Focused ultrasound is an incisionless, nonsurgical treatment option for essential tremor. It combines ultrasound and magnetic resonance imaging (MRI) technology. High-intensity, precisely targeted ultrasound waves create a lesion in the brain area that is causing the patient’s tremors.
Although focused ultrasound can’t cure tremors permanently, it can reduce them significantly.
“We never say that we can improve 100%, but what we see is a great improvement that’s probably higher than 80% tremor reduction,” says Jorge González-Martínez, MD, neurosurgeon and director, Epilepsy and Movement Disorders Division, UPMC Department of Neurosurgery.
Learn more about focused ultrasound, how it works, and who’s a candidate for it.
Who Is a Candidate for Focused Ultrasound?
People with essential tremor are potential candidates for focused ultrasound if multiple medications haven’t resolved their tremors.
“That’s the first line for every surgical intervention: We try to control (the condition) with medication,” Dr. González-Martínez says. “They need to have a very fair try of medications before we indicate the focused ultrasound treatment.”
Deep brain stimulation (DBS) is another option for these patients. DBS is a more versatile procedure and doesn’t create a permanent lesion. Because of this, it’s often preferable, Dr. González-Martínez says. However, not every patient can undergo DBS; those people may get better results from focused ultrasound.
“Some patients cannot undergo DBS because they cannot go through general anesthesia or they take blood thinners that can prevent them from an open procedure,” he says. “Those are the patients who are also optimal candidates for the focused ultrasound.”
Focused ultrasound requires MRI technology, so patients with metal in their bodies or who meet other MRI exclusion criteria can’t undergo the procedure. Patients with poor bone density are also poor candidates.
Patients go through thorough testing to determine if they’re candidates. This testing includes a full neurology exam, MRI imaging, and a bone density test.
How Does Focused Ultrasound Work?
Focused ultrasound treats one side of the body at a time. On the day of the procedure, a member of your care team will completely shave your head. Hair can interfere with the ultrasound beams.
Your team will give you local anesthesia before attaching a specialized crown-like device to your scalp. This device contains ultrasound transmitters and also allows the neurosurgeon to see the coordinates of the area responsible for the tremors inside your brain.
You’ll then move to the treatment area where you’ll lie on a table that slides in and out of an MRI machine. Your neurosurgeon will stay in another room, seated at a computer. There, they can see the MRI images of your brain and control the ultrasound beams.
When the procedure begins, the table will slide into the machine. The ultrasound waves converge on the area of your brain responsible for your tremors. They raise the temperature in that area high enough to create a lesion.
The area of your brain targeted is 2 millimeters, or about the size of a standard pencil lead.
After creating the lesion, your care team will test you to see if your tremor has improved. They’ll have you write your name, draw a spiral, or perform another simple task.
“If the tremor is not improved or is only partially improved, we can repeat the procedure as many times as we judge necessary,” Dr. González-Martínez says. “In general, we repeat the procedure twice. Very rarely, we repeat it three times.”
Patients’ tremors often improve during the procedure itself.
“It’s a light bulb switch: on and off,” Dr. González-Martínez says. “That’s the beauty of this treatment because they improve right away. They go home better.”
The procedure lasts one to two hours, and patients can go home the same day. They can return a month or more later to have the procedure create a lesion on the other side of their brain.
Because the target area is tiny, the procedure won’t harm any surrounding brain tissue.
Is Focused Ultrasound Safe?
Focused ultrasound creates a permanent lesion in your brain. If it creates the lesion in the wrong brain area, it can affect other brain and motor functions. That’s why surgical teams take great care and use advanced imaging to ensure they’re in the right place.
“The smaller the lesion, the more precise you need to be,” Dr. González-Martínez says.
As an added safety measure, your neurosurgeon will create a “test lesion” before creating the permanent lesion. They’ll use the ultrasound beams to raise the temperature in the target area high enough for the neurons to stop working but not high enough to create a lesion. Then they’ll test the tremor.
If they see an improvement in the tremor, that means they’re in the right place. If not, they can recalibrate the machine to target the correct area.
Other side effects of the procedure are generally mild. They include:
- Balance issues.
- Changes in tasting ability.
- Dizziness.
- Headache.
- Nausea.
- Numbness or tingling in the lips, mouth, or tongue.
- Pain.
- Scalp irritation.
- Slurred speech.
These side effects typically go away within a couple of weeks after the procedure.
Dr. González-Martínez says it’s important for patients to get focused ultrasound done at an experienced center.
“Like any other surgical procedure, it needs to be performed with very careful hands and minds,” he says.
Is Focused Ultrasound Effective?
Focused ultrasound isn’t a cure — patients often need to redo the procedure several years later. However, it can improve tremors by 80% or more in the meantime.
That can make a major difference for people living with essential tremor, Dr. González-Martínez says. These people are living with constant tremors in their hands, arms, head, or other areas of their bodies. It can make eating, drinking, writing, and even talking difficult.
“These people cannot do things (like) being able to eat their meals or being able to drink a cup of coffee without spilling all the coffee on their clothes because they are shaking, or even signing or writing,” Dr. González-Martínez says. “Some people have speech problems, and they cannot talk normally because they have a tremor in their speech. These people cannot walk normally because they have tremor in their legs.”
Focused ultrasound can improve their tremor, leading to a better quality of life, Dr. González-Martínez says.
“If you reduce the tremor by 50%, they’ll be very, very happy because no medication can provide that,” he says. “But when they see the tremors improve 80%, it’s kind of a dream for them.”
To learn more about focused ultrasound at UPMC, visit our website.