Neurosurgeon Dr. Devin Binder discusses MR-guided focused Ultrasound (MRgFUS) and Deep Brain Stimulation (DBS).
Dr. Binder Describes Differences & Similarities between Parkinson's Disease and Essential Tremor
Tremor, as a symptom, is not yet understood as well as many hopes it may one day be, even though approximately 60,000 people are diagnosed with Parkinson’s Disease every year. Essential Tremor affects between 6-7 million people in the U.S. currently.
Although many associate tremors with Parkinson’s disease, they are also the primary symptoms of essential tremors. In people with Parkinson's disease, the tremor is often experienced at rest and may also be accompanied by other motor symptoms, such as rigidity, slowness of movement, and difficulty walking.
However, in those with ET, tremor tends to be the primary symptom and becomes apparent when the hand is in motion, sometimes referred to as an ‘action’ tremor.
Both Essential Tremor and Parkinson’s Disease are considered progressive diagnoses, meaning symptoms will increase over time. For many, their condition can progress to the point that they will constantly experience tremors, whether their hands are in action or at rest.
While tremor can occur exclusively in the arms, for others, it can manifest as midline tremor involving the head, jaw, and even the voice.
“Essential Tremor used to be called benign essential tremor,” says Dr. Binder, neurosurgeon & Medical Director of the MemorialCare Neuroscience Institute at Orange Coast Medical Center, “the thing is, at some point it becomes severe enough that it interferes with daily living. To me, that is not benign.”
Dr. Binder Discusses Treatment Options for Essential Tremor and Parkinson’s Disease:
According to Dr. Binder, the best option to treat tremors would be “as safe as possible,” minimizing potential side effects or recovery time, and “most importantly, improving the person's quality of life.”
Many medications have been developed to treat essential tremor, and “30 to 50% of patients, particularly those with mild to moderate tremor, will receive great benefit,” says Dr. Binder.
“However, when tremor gets quite severe, these drugs’ ability to help can be blunted, and possibly result in significant side effects,” such as dizziness, impacted sexual function, and depression.
“We know that the circuit for tremor goes through the VIM, or Ventral Intermediate nucleus” says Dr. Binder, referring to a green-pea sized brain region situated on either side of the thalamus. “That's what we're after.”
In Deep Brain Stimulation (DBS), the tremor signal is interrupted, and the circuit is synchronized by applying individualized and adjustable electrical stimulation to the VIM.
In MR-guided Focused Ultrasound (MRgFUS), the circuit is blocked by targeted ultrasound beams that create an ablation, or “focal damage,” to that same area.
For both procedures, the target and goal are the same, “we’re going through that structure and interrupting or disconnecting the circuit to help get rid of the tremor.”
“Orange Coast Medical Center was the first in Orange County to make an investment in MR-guided Focused Ultrasound technology back in 2020 - talk about doing something positive over the pandemic,” says Dr. Binder, “- and it's been FDA approved now to treat both essential tremor and tremor-dominant Parkinson's disease.”
MRgFUS is achieved without incisions or implants and performed in a specially outfitted MRI rather than an operating room.
The MRI shows the patient’s skull anatomy in real-time and at three-hundred and sixty degrees, allowing the neurosurgeon to assess, plan, and deliver an individualized level of treatment via “sonication,” in which thousands of ultrasound beams intersect at the target, creating a confined thermal lesion and leaving all surrounding tissue unaffected.
“The idea there, again,” says Dr. Binder, “is that you're cutting the tremor circuit, which then accomplishes greater than 70% reduction in the tremor.”
MR-guided Focused Ultrasound is a unilateral procedure, meaning it's done on just one side of the brain at a time. Patients with bilateral tremors, or tremors in both hands, must wait at least 9 months after their first MRgFUS procedure to schedule the second, whereas Deep Brain Stimulation can be done on both sides a single week apart.
Deep Brain Stimulation (DBS), which consists of an electrode, extension wire, and battery programmed to maximize symptom relief, has been performed at Orange Coast Medical Center since 2011. Studies going further back demonstrate its high effectiveness “in the range of 75 - 90% elimination of the tremor,” says Dr. Binder.
Just as the VIM nucleus is associated with and therefore targeted to treat tremors resulting from Essential Tremors or Parkinson’s Disease, other areas of the brain, such as the subthalamic nucleus (STN) and globus pallidus internus (GPi) can be targeted using DBS to treat other non-tremor motor symptoms of PD, such as gait instability, rigidity, or dyskinesias as a side effect of Parkinson’s medication.
For patients who experience symptoms bi-laterally, “we can do both sides separated by a week, enabling us to control and adjust both sides of the brain independently.”
As the patient’s condition progresses, adjustments can be made to the DBS implant’s programming during routine visits to the patient’s neurologist, much like adjustments can be made to a pacemaker for the heart,
“The benefits persist,” says Dr. Binder, and so too does the improvement to the patient’s quality of life.
Lloyd Dalton, who underwent MRgFUS at MemorialCare Orange Coast Medical Center with Dr. Binder, shared his inspiring story of obtaining relief from the tremor he’s experienced since he was 15 years old.
“It was getting ridiculous,” he says, now in his eighties, “growing worse as I got older and especially this last year.”
“I had MRgFUS here, and it provided the relief that I needed from this," Lloyd says, “It’s just amazing.”
The MemorialCare Orange Coast Medical Center Neuroscience Institute and Movement Disorders Program continues a rich history of comprehensive and compassionate treatment and investment in groundbreaking research and technological innovation, making results like Lloyd’s and countless others possible.
“Orange Coast Medical Center is the only one in this county offering both of these therapies,” says Dr. Binder, “We are unique in being able to offer what everyone with tremor deserves: a customized, individualized consultation to determine the best treatment to improve their quality of life.”