HIFU, short for High-Intensity Focused Ultrasound, is a non-invasive and radiation-free procedure to treat Parkinson’s disease tremor. HIFU creates an irreversible brain lesion to destroy tremor-causing neurons. While it doesn’t stop the disease from progressing, patients report a 60-90% tremor reduction 1. Some patients are also able to reduce their levodopa medication for some time 2, 3.
The thought of purposely getting a lesion in the brain is scary. To monitor the lesion at all times, doctors use magnetic resonance imaging during the procedure, also known as MRgFUS (magnetic resonance-guided focused ultrasound). They also check the effects of the lesion in real time on the patient—who is awake during the procedure—by asking specific questions.
HIFU is also used to treat other diseases. It has been used to destroy cancer tissue in the prostate 4, to shrink uterine fibroids 5, and to tighten and lift skin in cosmetic procedures 6. In this post, we break down everything you need to know about HIFU for Parkinson’s disease, from how it works to how long the relief lasts.
Quick Summary:
- HIFU (High Intensity Focused Ultrasound) is a non-invasive treatment that creates a targeted, irreversible lesion in the brain to reduce Parkinson’s disease tremor.
- The tremor relief provided by HIFU varies between patients, with some experiencing a sustained benefit 5 years after the procedure.
- If the tremor comes back, it is possible to retreat with HIFU or opt for Deep Brain Stimulation (DBS).
How Does HIFU Treat Parkinson’s Disease Tremor?
During HIFU, ultrasound beams converge on a specific, small brain area, generating heat that irreversibly destroys the neurons responsible for Parkinson’s tremor.
HIFU is usually done on only one side of the brain, left or right. The most studied treated brain areas are: the globus pallidus internus (GPi), the subthalamic nucleus (STN), and the ventral intermediate nucleus (VIM) of the thalamus 7. Both the GPi and the STN are located in the basal ganglia in the brain; the VIM is located in the thalamus. During Parkinson’s, these brain areas become dysregulated due to dopamine loss.
The brain area treated depends on the patient’s specific needs.
- The STN is an emerging target to treat bradykinesia, rigidity, and tremor, allowing some patients to reduce their levodopa medication. HIFU targeting the STN /subthalamic nucleus is known as subthalamotomy.
- The GPi is favored for patients with severe levodopa-induced involuntary movements (dyskinesias), rigidity, and tremor. HIFU targeting the GPi/globus pallidus internus is known as pallidotomy.
- The VIM is favored for patients with tremor-dominant Parkinson’s disease. HIFU targeting the VIM/ventral intermediate nucleus is known as thalamotomy.
Here is a quick step-by-step of how HIFU for Parkinson’s is performed:
What Happens Before HIFU Treatment
Patients undergo a computed tomography (CT) scan of the brain to evaluate the skull thickness and how effectively ultrasound beams can penetrate it. Doctors also inform the patients of the sensations they may feel, such as heat or pressure. Then, patients have their heads shaved and fixed into a head frame.
What Happens During HIFU Treatment
Patients are fully awake during HIFU treatment to assess its effects in real time. If they feel discomfort or nausea, medication is given intravenously.
HIFU begins with reversible temperatures of 40–45 °C applied to the target brain area, monitored with MRI. Doctors test patients for tremor relief using finger-to-nose or drawing tasks. They also check for adverse effects like slurred speech, numbness, or vision changes. If any of these occur, the target area is adjusted before HIFU creates permanent damage.
Once the target area is confirmed safe and effective, the ultrasound energy is increased to 54–60 °C to create an irreversible lesion.
What Happens After HIFU Treatment
The effect of HIFU on tremors is immediate. Patients undergo a high-resolution MRI to confirm the location and size of the lesion and to check for any rare complications. Usually, they leave the hospital within 24 hours and can resume daily activities immediately. Follow-ups are often scheduled at 1 month, 4 months, and 1 year.
How Does HIFU Affect Parkinson’s Motor Symptoms and Levodopa?
In Parkinson’s disease, HIFU is mainly used to reduce tremor, but it can also improve slowness of movement (bradykinesia), involuntary movements (dyskinesia), and rigidity 7.
A reduction in levodopa medication may be possible for some people after HIFU. According to a clinical study published in the New England Journal of Medicine, people who had STN-targeted HIFU were able to decrease their levodopa medication 4 months after the procedure 2. However, this reduction is not permanent. In a 3-year follow-up study, these patients went back to taking their original levodopa dose, in spite of sustained motor benefits 3. Some had to increase their dose due to the natural progression of the disease 3.
What Are the Risks of MRgFUS?
The risks of HIFU are often temporary and vary depending on the brain area treated.
General risks during the procedure include:
- Head pain
- Nausea
- Dizziness
Risks associated with the brain area include:
STN:
- Slurred speech
- Imbalance
- Motor and face weakness
GPi:
- Loss of taste
- Visual disturbances
- Face weakness
VIM:
- Numbness or tingling
- Loss of coordination and imbalance
- Slurred speech
- Weakness
Procedure-related risks usually resolve quickly, while the brain-specific risks may take some time. In one study, 15 patients of 27 (56%) developed speech disturbances immediately after the procedure. This effect persisted in 3 patients by 4 months, and in 1 by one year 2.
Can The Tremor Come Back After HIFU?
Yes, tremor associated with Parkinson’s disease can come back after HIFU, although many patients experience long-term relief.
Results from a 2023 clinical trial showed that 37 of 53 participants (70%)—who received GPI-targeted HIFU— still benefited from the treatment 12 months after the procedure, though 20% reported no response 8.
In follow-up studies from an STN-targeted HIFU trial, participants experienced a sustained motor benefits: their motor scores (MDS-UPDRS part III) during OFF time remained 50% lower than at baseline 5 years after HIFU 9.
Parkinson’s is a progressive disease. As a result, motor symptoms may worsen beyond the initial HIFU treatment.
Can You Have HIFU Again if The Tremor Returns?
People with Parkinson’s disease whose initial HIFU benefit wanes over time can be retreated with HIFU or DBS.
- Bilateral HIFU: a second HIFU procedure can be performed on the untreated side of the brain 3. This is because Parkinson’s progresses to affect both sides of the body.
- Deep Brain Stimulation (DBS): electrodes can be implanted in the exact brain areas previously treated by HIFU 8, 10.
Final Thoughts: Is HIFU a Durable Treatment Option for Parkinson’s Tremor?
HIFU offers a meaningful, non-invasive option for people living with Parkinson’s tremor, especially for those who want to avoid surgery or are resistant to levodopa. While results vary and the disease continues to progress, many patients experience significant and lasting tremor relief. And if symptoms return, retreatment options are available.
If you or a loved one are exploring tremor or mobility treatments, speak with a movement disorder specialist to find out whether HIFU is an option for you.
Frequently Asked Questions (FAQs)
HIFU, or High Intensity Focused Ultrasound, is a non-invasive tremor treatment in which ultrasound beams are focused in a targeted brain area to destroy tremor-causing brain cells.
HIFU is generally considered a safe and effective option for those who do not want an invasive treatment like DBS. Because HIFU is incisionless, it doesn’t carry the same risks associated with electrode implantation, like brain bleeding or infection.
The effect of HIFU on tremor varies between people. Some experience relief for up to 5 years; others may see it wear off within the first year.
HIFU is recommended for people with tremor-dominant Parkinson’s disease, for those whose symptoms do not respond to medication, or for those who do not want DBS. Age and underlying health conditions are also taken into account, as some people may not be good candidates for invasive surgery.
Yes, HIFU for Parkinson’s disease is available in many countries across Europe, including Spain, Germany, Italy, Switzerland, and England.
References
- Armengou-Garcia L, Sanchez-Catasus CA, Aviles-Olmos I, et al. Unilateral Magnetic Resonance-Guided Focused Ultrasound Lesion of the Subthalamic Nucleus in Parkinson’s Disease: A Prospective Study. Mov Disord. 2024;39(12):2230-2241. doi:10.1002/mds.30020
- Martínez-Fernández R, Máñez-Miró JU, Rodríguez-Rojas R, et al. Randomized Trial of Focused Ultrasound Subthalamotomy for Parkinson’s Disease. N Engl J Med. 2020;383(26):2501-2513. doi:10.1056/NEJMoa2016311
- Martínez-Fernández R, Natera-Villalba E, Máñez Miró JU, et al. Prospective Long-term Follow-up of Focused Ultrasound Unilateral Subthalamotomy for Parkinson Disease. Neurology. 2023;100(13):e1395-e1405. doi:10.1212/WNL.0000000000206771
- Abufaraj M, Siyam A, Ali MR, et al. Functional Outcomes after Local Salvage Therapies for Radiation-Recurrent Prostate Cancer Patients: A Systematic Review. Cancers (Basel). 2021;13(2):244. Published 2021 Jan 11. doi:10.3390/cancers13020244
- Tonguc T, Recker F, Ganslmeier J, et al. Improvement of fibroid-associated symptoms and quality of life after US-guided high-intensity focused ultrasound (HIFU) of uterine fibroids. Sci Rep. 2022;12(1):21155. Published 2022 Dec 7. doi:10.1038/s41598-022-24994-w
- Juhász M, Korta D, Mesinkovska NA. A Review of the Use of Ultrasound for Skin Tightening, Body Contouring, and Cellulite Reduction in Dermatology. Dermatol Surg. 2018;44(7):949-963. doi:10.1097/DSS.0000000000001551
- Meng Y, Hynynen K, Lipsman N. Applications of focused ultrasound in the brain: from thermoablation to drug delivery. Nat Rev Neurol. 2021;17(1):7-22. doi:10.1038/s41582-020-00418-z
- Krishna V, Fishman PS, Eisenberg HM, et al. Trial of Globus Pallidus Focused Ultrasound Ablation in Parkinson’s Disease. N Engl J Med. 2023;388(8):683-693. doi:10.1056/NEJMoa2202721
- Natera-Villalba E, Martínez-Fernández R, Jiménez-Castellanos T, et al. Five-Year Follow-Up of Unilateral Focused Ultrasound Subthalamotomy for Parkinson’s Disease. Mov Disord. Published online April 15, 2026. doi:10.1002/mds.70307
- Saluja S, Barbosa DAN, Parker JJ, et al. Case Report on Deep Brain Stimulation Rescue After Suboptimal MR-Guided Focused Ultrasound Thalamotomy for Essential Tremor: A Tractography-Based Investigation. Front Hum Neurosci. 2020;14:191. Published 2020 Jun 26. doi:10.3389/fnhum.2020.00191