Introduction to MRgFUS for the Treatment of Parkinson

Introduction

Parkinson’s disease (PD) is a complex neurological disorder characterized by the early death of dopaminergic neurons in the substantia nigra pars compacta. The resultant dopamine deficiency within the basal ganglia leads to a movement disorder produced by overactivity of the thalamocortical system. The disorder is characterized by classic parkinsonian motor symptoms, such as tremors, rigidity, and hypobradykinesia. In addition to these motor symptoms, PD is also associated with numerous non-motor symptoms, some of which can occur more than a decade before the onset of motor dysfunction. The prevalence of PD for all ages in Europe ranges from 66 to 1500 per 100,000 people, and its incidence varies from 5 to 26 per 100,000 person-years.

For more detailed informations about PD, it's pathophysiology and the MRgFUS technology, read Section two of the Habilitation – thesis «Incisionless transcranial MR-guided focused ultrasound functional neurosurgery», written by Marc Gallay

What is MRgFUS?

Magnetic Resonance-guided Focused Ultrasound (MRgFUS) represents a revolutionary, incisionless treatment option for chronic, therapy-resistant or therapy-intolerant Parkinson’s Disease (PD). By using ultrasound waves to target and thus modulate brain regions associated with motor as well as some non-motor dysfunctions, MRgFUS offers new possibilities for symptom relief in patients who have exhausted other treatment options.

This technique heats and ablates targeted tissue, creating a small lesion that disrupts the abnormal neural activity responsible for PD symptoms. Unlike traditional surgical interventions, MRgFUS does not require an incision or penetrating the brain, making it a safer, more accurate and less invasive alternative to classical functional neurosurgical approaches.

      Source: Insightec Ltd

How It Works

  • Targeting Precision: MRI imaging allows for accurate visualization of brain structures, enabling precise focus on areas like the pallidothalamic tract, a key neural pathway implicated in PD.
  • Controlled Energy Delivery: Ultrasound energy is applied in a controlled manner to achieve therapeutic effects without damaging surrounding tissues.
  • Real-time Monitoring: MR thermometry monitors temperature changes during the procedure to ensure safety and efficacy.

Advantages

  1. No incision and no penetration: Eliminates risks of infection and significantly reduces the bleeding risk (e.g., 0 > 650 targets performed in the clinic SoniModul).
  2. No implanted material
  3. Accuracy in targeting (0.5–1 mm) thanks to the absence of brain penetration (no shift).
  4. Intraoperative targeting and monitoring options via MRI.
  5. No general anesthesia required.
  6. No ionizing radiation used.

MRgFUS can be suitable for patients with advanced, therapy-resistant PD who are either ineligible or reluctant to undergo DBS.

 

Key Findings from our experience

  • Tremor Control: Tremor reductions exceeding 80% have been reported in treated patients, with immediate effects following the procedure.
  • Improved Rigidity and Bradykinesia: Rigidity and bradykinesia, two hallmark symptoms of PD, showed reductions of 70% and 73%, respectively, in single-center studies.
  • Pain and Sleep Disorders: Up to 89% of patients experienced pain relief, and significant improvements in sleep quality were observed.
  • Dyskinesia: Nearly 100% symptom control on the treated body side.

Long-term Benefits

MRgFUS offers durable symptom relief, with studies showing sustained improvements over one year of follow-up. Unlike pharmacological treatments, which may lose effectiveness over time, MRgFUS addresses the underlying neural dysfunctions, providing a more consistent therapeutic outcome. Our retrospective experience with this technique now stretches back more than 10 years.

The Psychoemotional Dimension

Parkinson’s Disease not only affects physical mobility but also has profound psychological and emotional impacts. This emotional dimension must be taken into account in assessments and treated accordingly. For some patients, psychotherapy may be required before MRgFUS can be performed.

 Switzerland’s Leadership and the International Context

Switzerland has emerged as a global leader in the development and implementation of MRgFUS, particularly through the pioneering efforts of the SoniModul Center for Ultrasound Functional Neurosurgery. This leadership is rooted in a combination of innovative research and patient care.

 Candidacy and Next Steps

MRgFUS is suitable for patients with:

  • Advanced PD unresponsive to medication or experiencing side effects.
  • Severe tremor, rigidity, or bradykinesia significantly impacting daily life.
  • No major cognitive impairments or contraindications for MRI.

How to Proceed

You can contact us either through your treating physician or by sending us a request at This email address is being protected from spambots. You need JavaScript enabled to view it..

 

Further reading: Section two of the Habilitation – thesis «Incisionless transcranial MR-guided focused ultrasound functional neurosurgery», written by PD Dr. med. Marc Gallay 

 

Peer-reviewed articles about how we treat Parkinson with the MRgFUS technology:

1. Magara A, Bühler R, Moser D, Kowalski M, Pourtehrani P, Jeanmonod D. First experience with MR-guided focused ultrasound in the treatment of Parkinson’s disease. J Ther Ultrasound. 2014;2:11.

2. Gallay MN, Moser D, Rossi F, et al. MRgFUS Pallidothalamic Tractotomy for Chronic Therapy-Resistant Parkinson’s Disease in 51 Consecutive Patients: Single Center Experience. Front Surg. 2020;6.

3. Gallay MN, Moser D, Federau C, Jeanmonod D. Anatomical and technical reappraisal of the pallidothalamic tractotomy with the incisionless transcranial MR-guided focused ultrasound. A technical note. Front Surg. 2019;6.

4. Gallay M, Moser D, Federau C, Jeanmonod D. Radiological and thermal dose correlations in pallidothalamic tractotomy with MRgFUS. Front Surg. Published online April 30, 2019.

5. Gallay MN, Moser D, Magara AE, Haufler F, Jeanmonod D. Bilateral MR-guided focused ultrasound pallidothalamic tractotomy for Parkinson’s disease with one year follow-up. Front Neurol. 2021;12. Accessed January 6, 2021

6. Gallay MN, Moser D, Jeanmonod D. Safety and accuracy of incisionless transcranial MR-guided focused ultrasound functional neurosurgery: single-center experience with 253 targets in 180 treatments. J Neurosurg. 2019;130(4):1234-1243. doi:10.3171/2017.12.JNS172054

7. Gallay MN, Jeanmonod D, Liu J, Morel A. Human pallidothalamic and cerebellothalamic tracts: anatomical basis for functional stereotactic neurosurgery. Brain Struct Funct. 2008;212(6):443-463.