MR-Guided Focused Ultrasound (MRgFUS)

Incisionless Treatment for Tremor Disorders

MR-guided focused ultrasound (MRgFUS) is an advanced, non-invasive treatment used for patients with essential tremor and tremor-dominant Parkinson’s disease.

It combines high-intensity focused ultrasound energy with real-time MRI guidance to precisely target and treat small areas deep within the brain, without the need for surgical incisions, implants, or radiation. This technology represents a shift from conventional neurosurgery toward image-guided, incisionless therapy.

Conditions Treated

MRgFUS is currently used in carefully selected patients with:

  • Essential tremor that is not adequately controlled with medications
  • Parkinson’s disease with significant tremor symptoms
  • Other indications may be considered based on specialist evaluation

Patients are typically referred when symptoms interfere with daily function such as eating, writing, or self-care.

How the Technology Works

MRgFUS works on a fundamental principle of energy convergence.

1. Focused Ultrasound Energy

Multiple ultrasound beams are generated from a transducer helmet placed around the patient’s head.
Each individual beam passes safely through the skull and brain tissue without causing damage.

However, when these beams converge at a single, predefined target, they collectively generate sufficient energy to produce a controlled thermal effect.

2. Precise Thermal Lesioning

At the focal point, the temperature rises (typically 55-60°C), creating a small, controlled lesion in the target area of the brain.

For tremor, this target is usually within the thalamus (VIM nucleus), a region involved in abnormal tremor circuits.

This interruption in neural signaling leads to reduction in tremor symptoms.

3. Real-Time MRI Guidance

MRI plays a critical role in three ways:

  • Targeting: Identifies the exact anatomical location
  • Thermometry: Monitors temperature changes in real time
  • Feedback: Confirms accuracy and safety during treatment

This allows the treating team to make incremental, controlled adjustments, ensuring precision while minimizing risk to surrounding tissue.

4. Intra-Procedural Clinical Testing

Unlike most procedures, MRgFUS is performed with the patient awake.

This allows:

  • Real-time assessment of tremor improvement
  • Immediate feedback from the patient
  • Fine-tuning of treatment before final lesioning

Why this approach is different

Traditional neurosurgical options such as Deep Brain Stimulation (DBS) involve:

  • Surgical implantation of electrodes
  • Hardware placement inside the body
  • Multiple stages (surgery + programming)

In contrast, MRgFUS:

  • Requires no incision or hardware implantation
  • Is performed in a single session
  • Provides immediate clinical feedback

However, unlike DBS, MRgFUS creates a permanent lesion and is not adjustable after treatment, which is an important consideration during patient selection.

What to expect during treatment

Before the Procedure

  • Clinical evaluation by movement disorder specialists
  • MRI and imaging-based planning
  • Assessment of suitability

During the Procedure

  • The patient lies inside an MRI scanner
  • A specialized ultrasound helmet is fitted
  • Low-energy test sonications are performed initially
  • Gradual increase in energy to achieve therapeutic effect
  • Continuous MRI monitoring and clinical assessment

Total duration: approximately 3-4 hours

After the Procedure

  • Observation for a short period
  • Most patients are discharged the same day or next day
  • Follow-up evaluation for clinical outcomes

Benefits

  • Non-invasive (no incision or craniotomy)
  • No implanted devices
  • Reduced risk of infection and surgical complications
  • Short hospital stay
  • Rapid recovery
  • Immediate intra-procedural assessment of effectiveness

Limitations and Considerations

  • Typically performed on one side of the brain (unilateral)
  • Effects are permanent and not adjustable
  • Not all patients are suitable candidates (e.g., skull density factors)
  • Requires careful selection and counseling

Safety

MRgFUS is performed under continuous MRI guidance with real-time thermometry, allowing:

  • Controlled energy delivery
  • Monitoring of adjacent structures
  • Immediate detection of off-target effects

Reported complications are generally low when performed at experienced centers

Care at

Christian Medical College Vellore

Patients are evaluated and managed through a multidisciplinary team, including:

  • Movement disorder neurologists
  • Functional neurosurgeons
  • Neuroradiologists
  • Specialized nursing and rehabilitation teams

The program is integrated within the Department of Neurological Sciences, ensuring comprehensive care from evaluation to follow-up.

Meet the Team

Care is provided by specialists in movement disorders at Christian Medical College Vellore

Movement Disorders Neurology

  • Dr. Shaikh Atif Iqbal Ahmed, D.M (Neurology)

Referral and Appointments

Patients can be referred for evaluation through:

  • Neurology / Movement Disorders Clinic
  • Direct consultation appointments

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