After the revolution in some Parkinson’s treatments, such as deep brain stimulation (DBS), there was a need to pursue more precise treatment with fewer side effects.
The treatment of tremor using MRgFUS technology was the result of the development of neurological medicine, especially in the field of treating essential tremor and Parkinson’s disease, by reaching a modern treatment method without surgery based solely on ultrasound and magnetic resonance imaging. Turkey was one of the first countries to embrace this modern technology and other technologies within hospitals equipped with all the necessary equipment and infrastructure and in cooperation with highly qualified and experienced medical staff.
What is an essential tremor?
Essential tremor, or idiopathic tremor, is a movement disorder that causes uncontrollable tremors in body parts. It usually affects the hands and arms and, to a lesser extent, the head, voice, and other body parts.
In its advanced stages, the disease can disrupt basic tasks such as eating, drinking, and dressing. Many people also experience feelings of embarrassment or anxiety about the symptoms of the condition.
What causes Parkinson’s disease?
Doctors and researchers have yet to find a clear cause for essential tremor, which is why it’s idiopathic. However, there is evidence that changes in certain brain parts cause it. Researchers have found that the disease tends to run in certain families, which is genetic. About half of essential tremor cases are inherited in an autosomal dominant form.
What are the symptoms of essential tremor?
The main symptom of idiopathic tremor is trembling in the hands when you try to use them. This tremor can take different forms and usually occurs under certain circumstances. Shapes and conditions in which tremor are likely to occur include the following:
- Motor tremor: A form of tremor that occurs during actions, such as reaching for something.
- Postural tremor occurs when you hold a part of your body in a particular position, such as with your hand outstretched and at the same height.
Essential tremor are often bilateral but affect one limb more than the other. The tremor itself is not dangerous, but it can cause issues with daily activities. People with prolonged essential tremor may have difficulty eating with spoonfuls, drinking from a cup, dressing, and writing.
Essential tremor improves or worsens under certain conditions described in the following table:
| Factors that increase tremor | Factors that relieve tremor |
| Anxiety, fatigue, or stress | Alcohol in small amounts |
| Some medicines | Comfort |
| Playing sports | Cold compresses |
How is Parkinson’s diagnosed?
A doctor can diagnose essential tremor based on symptoms and a neurological examination in the clinic. There are no tests that can confirm whether a person has necessary tremor or not, so the most critical part of the diagnostic process is to rule out other conditions that may cause similar symptoms:
- Blood tests (help rule out thyroid disease, Wilson’s disease, and toxic exposure to metals such as lead or manganese)
- Computerized tomography (CT) scan
- Genetic tests
- Magnetic Resonance Imaging (MRI)
- Positron Emission Tomography (PET)
What are the stages of tremor treatment with MRgFUS?
The main therapeutic goals of Parkinson’s disease treatment are to reduce motor symptoms and improve quality of life.
The procedure begins with the patient entering the MRI suite and setting up the machine. A transducer helmet allows about a thousand ultrasound beams to be sent out. Each beam has no discernible effect on its own, but when all 1,000 of these beams collide at one point, a tiny and exact burn occurs. This point-to-point burn disables the abnormal synapses that send out the abnormal signals and thus alleviates the symptoms of the disease.
The point targeted during MRI-guided focused ultrasound is smaller than a grain of rice. Because the patient is awake, minor movements may occur, and the radiation in the brain can be moved with a high degree of precision to the left or right. This technique provides real-time imaging, and we can instantly see the results. The procedure takes about 2 to 4 hours, usually in the morning. The patient can go home in the afternoon usually, without incisions or anything implanted inside the body.
What is the mechanism of MRI-guided focused ultrasound?
Magnetic resonance-guided ultrasound combines two imaging techniques to help treat movement disorders and associated symptoms. MRI technology provides doctors with precise images to pinpoint the exact target area, and then highly focused sound waves destroy that area precisely and targeted.
Some magazines describe the technique as magic, brain surgery without having to go to the operating room at all.
Do I have to stay in the hospital after the procedure?
In most cases, there is no reason for the patient to stay in the hospital after the procedure. Still, some surgeons consider factors that may change their decision to discharge the patient after MRI-guided focused ultrasound, such as the Time spent under sedation, the area resected by ultrasound, the patient’s pain level after the procedure, and the patient’s comorbidities.
Who are the people who cannot be treated with MRgFUS?
The doctor decides who cannot undergo treatment with this technique;,. Usually, people who cannot undergo MRI cannot undergo treatment, such as patients with metal implants, artificial valves, artificial joints, artificial pacemakers, patients with claustrophobia, patients who are allergic to contrast material (a dye used during MRI), patients who weigh more than 140 kilograms, and patients under the age of 22.
Diseases that can be treated with MRI-guided ultrasound
This treatment is not limited to Parkinson’s disease but can be applied to various neurological diseases. It is based on what is known as “neuromodulation,” where ultrasound is used to stimulate or inhibit neural activity in specific areas of the brain. The following are some of the diseases whose symptoms can be treated or ameliorated by ultrasound:
- Drug-refractory Parkinson’s disease
- Essential Tremor (ET)
- Depression
- addiction by targeting the nucleus accumbens, the brain’s “pleasure center” that plays a significant role in addiction
- Clinical studies have also begun for use in the treatment of PTSD and Alzheimer’s disease
What can a Parkinson’s patient expect after MRgFUS treatment?
This technique is a new and advanced treatment with many advantages that make it the preferred method for most patients with Parkinson’s disease, including:
- Immediate and permanent recovery from Parkinson’s in 90% of patients
- There is no need for incisions and stitches after the procedure
- There is no need to implant a foreign object inside the skull
- The short time this procedure takes
- Only minor pain during the procedure
- Ability to stabilize the hand and do chores better
Risks of treating tremor with MRI-guided focused ultrasound
Healthy tissue near the treatment area is unlikely to be damaged, and careful control of where the radiation is delivered and the duration of treatment minimizes this potential damage.
Side effects that occur during treatment mainly include the following:
- Headaches and dizziness, which usually go away by the end of treatment
- After treatment, some patients may experience a sense of imbalance when walking, disturbance in hand coordination, and disturbance in the sense of taste.
For most patients, these side effects disappear after a month of treatment; in very few cases, some symptoms may persist for longer.
The future of MRI-guided ultrasound technology
Focused ultrasound can offer a less invasive and less painful alternative to traditional biopsies. At the same time, it, can provide more accurate and faster information and results.
John Lewis, professor of oncology at the University of Alberta, Canada, explained: “A core biopsy is a very invasive procedure, especially from the bones where prostate cancer metastases are found, but using high-energy focused ultrasound to release specific extracellular agents is a completely non-invasive way to capture the same information from the biopsy.
Doctors are currently working with bioscience and medical engineering experts to develop a new MRI-guided ultrasound technique called microfractionation, which involves liquefying small volumes of tissue to release specific cancer markers present in cancer cells and absent in blood cells to be released by ultrasound.
Doctors assert that the future of this technology is to detect even single cancer cells found in several milliliters of blood.
As with any new technology, there will be significant challenges before it becomes the cornerstone of cancer diagnosis instead of traditional biopsies. In 2022, about 100,000 patients were treated with MR-guided focused ultrasound. That number could grow significantly as costs come down and more hospitals and medical centers start offering it for a broader range of conditions.
Comparison of Deep Brain Stimulation and MRgFUS for Parkinson’s Disease
Deep brain stimulation (DBS) was clinically applied decades before MRI-guided focused ultrasound. DBS is usually recommended to alleviate motor fluctuations (changes in the ability to move between times when a medication works well and when it doesn’t), dyskinesia, and drug-resistant tremors. Still, after a detailed study of MRI-guided focused ultrasound, doctors have confirmed that it is also effective for the above conditions.
The main difference is that guided ultrasound is a permanent and irreversible treatment if successful, while DBS is reversible if stopped. Another difference is that MRI-guided focused ultrasound is an incision-free technique, and no devices are placed in the body.
MRI-guided focused ultrasound has many other potential uses in the brain. Treating essential tremor is just one of many that will be developed. Future applications may include conditions such as tumors, epilepsy, and dementia, as these areas will be ripe for research and development in the coming years.
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