If you’ve been diagnosed with essential tremor or Parkinson’s disease and medication is not doing enough to control your involuntary shaking, rigidity, and/or slow movement (also known as bradykinesia), high-intensity focused ultrasound (HIFU) may be an option. This FDA-approved treatment requires no incisions and can significantly reduce these symptoms. Here, Duke HIFU experts share how HIFU works and what you can expect from this treatment.
How HIFU Works
High-intensity focused ultrasound, or HIFU, uses precisely targeted sound waves to reach a small, carefully selected area deep within the brain that is known to drive tremors and Parkinson’s symptoms, said Lynne Todd, PA-C, a Duke physician assistant who specializes in movement disorder treatment. Guided by advanced MRI imaging, experts identify this target beforehand and then perform the procedure while you are inside an MRI scanner, allowing real-time image monitoring during treatment. Focused energy creates a tiny area of damage called a lesion -- typically just a few millimeters in size -- that disrupts abnormal signals. This often leads to immediate symptom improvement.
Why Choose HIFU
HIFU targets the same area of the brain as other procedures like deep brain stimulation (DBS) and traditional thalamotomy surgery. However, HIFU requires no incisions, implanted probes, ionizing radiation, or general anesthesia. The risk of infection and serious side effects are also lower with HIFU.
“There are people who are aware of deep brain stimulation but think, ‘My tremor is not so bad that I want to have a brain surgery or wires and a pacemaker implanted inside my body,’” said Duke neurosurgeon Nandan Lad, MD. HIFU is a much less invasive procedure that doesn’t require a hospital stay. “Basically, you could come in with severe tremors and see a significant improvement the same day, and that is something more and more people are interested in."
What to Expect During HIFU
Because ultrasound beams don’t penetrate through hair very well, your head will be shaved before the procedure. Then your doctor will numb four spots on your scalp where a custom frame will be fitted. The frame keeps your head perfectly still during the procedure.
Next, you’ll lie on an MRI bed wearing a helmet-like device secured to the metal frame. The bed will move in and out of the MRI scanner as it maps your unique tremor brain circuit.
Once doctors have identified a target area in your brain, they will apply a low dose of focused ultrasound energy. This is like a test run, allowing doctors to fine-tune the target. Doctors may ask you to provide feedback, like whether you feel any tingling in your fingers.
When your doctors have identified the final target area, they will apply the full dose of focused ultrasound treatment. It usually only takes about 20 to 30 seconds to create a lesion. Then, your doctor will test the success of the treatment by asking you to complete a simple task, such as draw a spiral, write your name, or hold a cup. Your doctor may apply a second treatment to solidify your results.
Afterward, doctors, remove your head frame, observe you for about an hour, and make sure you’re comfortable before you go home. Many people experience some instability or what feels like “sea legs” for the first couple of weeks after treatment. “That's usually from the swelling around the focused ultrasound lesion. It expands over the first several days, and then it contracts back to normal,” Dr. Lad said. Other side effects like numbness, tingling, and headaches typically resolve within two or three months.
Is HIFU Right for Me?
If you are an adult with refractory essential tremor or Parkinson’s disease (meaning medications aren’t working well enough), HIFU might be right for you.
“HIFU is one of several exciting, effective options we now have for treating tremor and Parkinson’s disease,” said Duke neurosurgeon Stephen C. Harward, MD. “Choosing the right approach depends on your specific symptoms, goals, and overall health. The most important step is a thoughtful evaluation with your doctors about whether HIFU or another therapy is the best fit for you.”
