MR-Guided Focused Ultrasound (MRgFUS) for Parkinson’s Disease

3Welcome to Precision Brain Spine and Pain, where we provide innovative solutions for managing Parkinson’s Disease (PD). This brochure aims to provide you with relevant information about MR-guided focused ultrasound (MRgFUS) as a treatment option for PD, including scientific details regarding risks, clinical outcomes, and specific statistics related to the procedure.

Understanding Parkinson’s Disease:

Parkinson’s disease is a progressive neurological disorder that affects movement control. It occurs when the brain cells responsible for producing dopamine, a chemical that helps regulate muscle movement, become impaired or die. This results in a range of motor symptoms, including tremors, rigidity, slowness of movement, and postural instability.

What is MR-Guided Focused Ultrasound (MRgFUS)?

MR-guided focused ultrasound (MRgFUS) is an innovative non-invasive procedure that utilises focused ultrasound waves to target and treat specific areas of the brain associated with Parkinson’s disease. This technique combines the precision of magnetic resonance imaging (MRI) with ultrasound technology to deliver focused energy without the need for surgery or incisions.

How Does MRgFUS Work?

Planning: Before the procedure, your healthcare team performs a comprehensive evaluation and employs MRI scans to create a personalised treatment plan. This plan precisely identifies the brain region requiring intervention.

Treatment: During the MRgFUS procedure, you are comfortably positioned inside an MRI scanner. High-intensity ultrasound waves are then precisely focused on the targeted brain tissue, creating small lesions. These lesions help modulate neural circuits responsible for Parkinson’s symptoms.

Monitoring: Throughout the procedure, the MRI scanner continuously monitors the process, allowing real-time adjustments to ensure accuracy and safety.

Advantages of MRgFUS for Parkinson’s Disease:

Non-invasive: MRgFUS eliminates the need for surgery or incisions, reducing the risks associated with traditional surgical treatments.

Precise Targeting: The technology allows for precise targeting of affected brain regions while preserving healthy tissue.

Rapid Recovery: Most patients can return to their regular activities within days to a week after the procedure.

No Radiation: MRgFUS relies on MRI for guidance, avoiding exposure to ionising radiation.

Advances in MRgFUS: Pallidothalamic Tractotomy (PTT)

Building upon a long history of ablative neurosurgery for Parkinson’s Disease, recent advances have refined the approach to target specific brain regions responsible for motor symptoms such as tremors, rigidity, and bradykinesia. This procedure, known as Pallidothalamic Tractotomy (PTT), is conducted using MR-Guided Focused Ultrasound (MRgFUS).

Recent developments in this field include a re-evaluation of the histology of the pallidothalamic tract, combined with an optimisation of lesioning strategy using thermal dose control.

Clinical Outcomes: MRgFUS PTT for Chronic Therapy-Resistant PD

A consecutive case series by Gallay et al. demonstrated the effectiveness of MRgFUS PTT in chronic therapy-resistant Parkinson’s Disease.

The Unified Parkinson’s Disease Rating Scale (UPDRS) off-medication postoperative score showed significant reductions: 84% for tremor, 70% for rigidity, and 73% for distal bradykinesia (all values for the treated side).

PTT achieved 100% suppression of on-medication dyskinesias as well as reduced pain, dystonia, and REM sleep disorders.

Patients reported an 88% mean tremor relief and 82% mean global symptom relief on the operated side. Additionally, there was a 69% mean global symptom improvement for the whole body.

Cognitive functions remained stable with no significant changes.

A significant reduction (55%) in the mean L-Dopa intake was observed.

Tremor-Dominant Parkinson’s Disease

Tremor-dominant Parkinson’s Disease is a subtype of Parkinson’s Disease primarily characterised by pronounced tremors and relatively mild rigidity and bradykinesia. Managing tremor symptoms in these patients can be challenging and often requires targeted interventions.

A study by Chua et al. in 2023 assessed the clinical outcomes of 48 patients with medically refractory TdPD who underwent MRgFUS thalamotomy. The results showed significant tremor control that persisted at all follow-up intervals.

Side effects observed in the study by Chua et al. were generally mild and manageable. At 3 months, these included:

  1. Gait imbalance (38%)
  2. Sensory deficits (26%)
  3. Motor weakness (18%)
  4. Dysgeusia (altered taste) (6%)
  5. Dysarthria (altered speech) (6%)

Whilst some of these side effects persisted at 1 year, all side effects were categorised as mild.

Alternative Treatments: Deep Brain Stimulation (DBS) vs. MRgFUS

Deep Brain Stimulation (DBS) is a well-established alternative for managing symptoms of Parkinson’s Disease. This procedure involves the surgical implantation of electrodes into specific brain regions, such as the thalamus or subthalamic nucleus. DBS functions by delivering continuous electrical stimulation to modulate abnormal neural activity.

Clinical Trials of MRgFUS Targets in PD

In recent years, MR-Guided Focused Ultrasound (MRgFUS) has emerged as a safe and effective treatment for movement disorders, including Parkinson’s Disease.

Several potential targets for MRgFUS in PD treatment have been explored, such as the Vim, STN, GPi, and pallidothalamic tract (PTT). However, determining the optimal target for individual patients remains a subject of ongoing research.

Choosing the Right Clinic:

When considering MRgFUS thalamotomy for Parkinson’s Disease, it is crucial to receive advice and treatment from an experienced clinic with a strong track record in both deep brain stimulation and MRgFUS. Expertise Matters, and is required across a broad range of specialties:

  1. Fellowship-Trained Functional and Stereotactic Neurosurgeons: An experienced team of fellowship-trained functional and stereotactic neurosurgeons specialising in MRgFUS ensures precise targeting and safe procedures.
  2. Neurologists: Expert neurologists can provide comprehensive pre- and post-operative care, optimising treatment outcomes.
  3. Neuroradiologists: These specialists play a vital role in guiding the procedure with real-time imaging, enhancing accuracy.
  4. MR Technicians: Well-trained and skilled MR technicians are essential for obtaining high-quality imaging during MRgFUS. This contributes to the procedure’s safety and effectiveness.
  5. Nursing Team: Nurses are a crucial part of the care team, providing attentive and compassionate care throughout your treatment journey.

Benefits of Choosing an Experienced Clinic:

Safety: A clinic with years of experience in both MRgFUS and Deep Brain Stimulation should be better equipped to minimise risks and manage potential complications.

Precision: Expertise ensures accurate targeting of the thalamus, maximising the effectiveness of the treatment.

Personalised Care: Experienced teams tailor treatment plans to each patient’s unique needs, enhancing the overall patient experience.

MRgFUS at Precision Brain Spine and Pain:

At Precision Brain Spine and Pain, we pride ourselves on our extensive experience and expertise in MRgFUS and deep brain stimulation. Our multidisciplinary team includes expert fellowship-trained functional and stereotactic neurosurgeons, neurologists, neuroradiologists, highly skilled MR technicians, and a dedicated nursing team. We are committed to providing the highest level of care for patients with Parkinson’s Disease.

References:

Gallay, M. N., Moser, D., Rossi, F., et al. (2019). MRgFUS Pallidothalamic Tractotomy for Chronic Therapy-Resistant Parkinson’s Disease in 51 Consecutive Patients: Single-Center Experience. Frontiers in Surgery, 6, 76.

Chua, M. M. J., Blitz, S. E., Ng, P. R., et al. (2023). Focused Ultrasound Thalamotomy for Tremor in Parkinson’s Disease: Outcomes in a Large, Prospective Cohort. Movement Disorders, 38(10), 1962-1967. DOI: 10.1002/mds.29569

Please remember that this page provides general information and does not replace personalised advice from your healthcare provider. Always consult with your healthcare team to make informed decisions about your treatment options.